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MG MGF Technical Tyre Worn on inside on left side (FAO Roger) BBS discussion at MG-Cars.net
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MG MGF Technical - Tyre Worn on inside on left side (FAO Roger)
| Roger, My front tyre on the Left is worn on the inside. This wories me a little as it suggests that something is wrong on one side only, could this be that the unadjustable camber is out on that side? The mechanic said the steering is not centering properly from the left, could this be something to do with the problem? I address this to Roger as he usually seems to know what he is talking about :-) |
| Tony |
| Yes it could be that one thing or perhaps a combination of a couple of minor imbalances. The obvious next check would be a full geometry check to evaluate exactly what is what. I would not be surprised for you to find a couple of out of scale readings. Another area that can cause problem is one of suspension bush wear, be that normal wear and tear or perhaps aggravated wear due to transmitted impact shocks from uneven road surfaces. I know that one of the problem areas for cars as they age will be the lower inner wishbone bushes as they can be on Rover Metro, especially the GTi. These degrade and can collapse which allows the arm to move away from the longnitudinal centre line of the car. This adds camber to the wheel that could increase inner tyre wear. Uprated bushes have been available for the Mtero for some time and they can show a marked improvement over the original bushes. Now I have not checked with anyone, but I suspect that these uprated polyeurothane bushes for the Metro will be the same as the MGF. Certainly the one absolutely horrible mounting inside the subframe is exactly the same as the Mtero and of the two cars I have had hands on with changing these four of the bushes had to be burned out with gas welding equipment. For general consumption... A pertinent point here is that if the car ever has a heavier 'kerb kissing' excercise then the chances are that the inner captive nut on the inside of the subframe will break away and make it almost impossible to remove. Rover would quote you for a replacement subframe and the associated heavy labour costs. If anyone suffers from such a problem I do have an alternative cure that does involve cutting and welding, but negates the removal of the subframe. It is a little long to explain but if the demand arises I will do so. Rog |
| Roger Parker Tamworth roger.parker@virgin.net |
| Cheers Roger, I think I want to start getting this checked myself at a decent tyre place. I'm also going to look at decent bushes. I don't think the car has ever hit a curb hard so it should be ok (unless it was done in the first 1000km, I got the one I test drove, so I only had to wait two weeks). I think I can get something going with my new dealer where we can go through a learning process together. I want him to keep information about my car for future use. I'm an MG customer not a Rover customer, it should be like doctor and patient :-) |
| Tony |
| Let us know what the results are. Rog |
| Roger Parker Tamworth roger.parker@virgin.net |
| Hi, I'm back, Here are the figures from 4 wheel alignment from a tyre center (Looks a little odd to me)... I had 2 Pirelli P7000 fitted on the front before the alignment, it is still not right as the vibration through the steering (and of the whole car) from 100 kph upwards is very high. Going to get this checked / fixed again at my dealers specialist. In case you don't already know the height of my car is 365mm. Yes Dieter, I sent you the figures by email :-) Settings Before Camber LF = -0 53' RF = -0 27' LR = -1 57' RR = -1 39' Caster LF = 3 01' RF = 3 33' Tracking LF = -0 09 RF = -0 18' LR = -0 02 RF = -0 02' Settings After Camber LF = -0 54' RF = -0 26' LR = -1 56' RR = -1 41' Caster LF = 3 01' RF = 3 33' Tracking LF = -0.02 RF = -0 04' LR = -0.06 RF = -0 04' |
| Tony |
| Jep, and Tony got my HO already by mail. CU Dieter PS. looking forward, what friends with real experiance say to the cars behavior, according to Tony's F rear toe angles. |
| Dieter |
| Sorry, just read my figures again, gave you the wrong figures for rear, no wonder it looked strange... Doh! It is not minus at the rear at all, so here are the correct rear figures. Before LR = 0 02' RR = 0 02' After LR = 0 06' RR = 0 04' Looks ok now, I think, still need an explanation for the car vibrating over 100kph though. I saw the balancing being done and it looked ok, I know the P7000 give a harder ride but not like this. I could realy do with understanding tyre pressures, the guy at the tyre place said 1.6 for the wider tyre, I would tend towards 1.8 as for the 185 so I have to experement a bit here. |
| Tony |
| Hi, Have You checked right driveshaft dynamic damper ? Some thick Dinol undercoating on mine gave some funny vibrations until scraped away from this rubber "wheel". Also distance ,ie. position on shaft is of importance. Otherwise the damper does just the opposite! What feels as front unbalance can easily be generated at rear wheels. Regards , Carl. |
| Carl |
| Hi, soory, a little late but I hope it helps on understanding the complete story. Here his correction to his true values in comparison to Johns tracking job. See the values of John Thomas tracking on the right side, separated by a ! The question which is not answered is IMO: Why has occured the inner tyre wear (at the left wheel.?) And why shakes his F still at speed > 100km/h (60mph) Tony´s MGF...................... ! John Thomas MGF BEFORE Camber LF = -0 53' RF = -0 27'.....! LF= -0° 59' RF= -0°50' LR = -1 57' RR = -1 39'.....! LR = -1°16' RR = -1° 00' Caster LF = 3 01' RF = 3 33'.........! LF = 4° 53' RF = 4° 08' Tracking LF = -0.09 RF = -0 18'.......! LF= -0°17' RF= -0°17' LR = +0.02 RR =+0 02'.....! LR= +0° 36' RR= -0° 08' Settings AFTER Camber LF = -0 54' RF = -0 26'.....! LF= -0° 59' RF= -0°55' LR = -1 56' RR = -1 41'.....! LR = -1°03' RR = -1° 06' Caster LF = 3 01' RF = 3 33'.......! LF = 4° 53' RF = 4° 08' Tracking LF = -0.02 RF = -0 04'.....! LF= -0°04' RF= -0°04' LR =+0.06 RR =+0 04'.....! LR= +0°04' RR= +0°05' IMHO his steer ahead position was not OK before the tracking. (Not stated here) The different front toe angles LF -0°09' and -0°18' indicate that. I am better quiet on the shaking problem, could be everything ? from worn ball joints until different tyres. See Carls instruction. Roger, its your turn :-/ |
| Dieter |
| Two things come to mind. One is the actual tyre shape and if I remember correctly the Pirelli has a quite squared off profile in the shyoulder area between sidewall and tread area. The camber settings could exaggerate the wear factor on this shape of tyre, assuming that the tyre itself is not faulty in some way, which is another possibility. This latter thought moves on to thought number two, which is that the tyre can cause the imbalance. If the tyre was perhaps poorly stored and became slightly distorted, the original balance may well have shown acceptable readings. As you use the tyre it heats up and after a short period of time will alter in shape to one that it usually holds for the rest of it's life. A rebalance could well show up new imbalance. New tyres do have to be 'run in' for between 50 and 100 miles, but when was the last time you were told that by a tyre fitter/company. Whilst on this tack, when was the last time anyone who has removed a wheel/tyre from your car told you to check the wheel nuts by retorquing after you have done 50 miles? Rog |
| Roger Parker Tamworth roger.parker@virgin.net |
| >New tyres do have to be 'run in' for between 50 and 100 miles, but when was the last time you were told that by a tyre fitter/company. < Now if you were a biker you would know this - the first hundred miles the tyre hardley any grip at all until the coating (whatever it is on new tyres) is worn off. Ted |
| Ted Newman |
| If I were a betting person I would have laid money on you picking up that point Ted. True to from then!! Rog |
| Roger Parker Tamworth roger.parker@virgin.net |
| Hi, I'm just a little confused here. How can the front toe-in (if that's what tracking means) have different values for each side? Surely the toe-in would, in theory at least, be equalised automatically once the car is moving? That is, after all, the way the car is used. Do the alignment measurers set the steeing wheel straight ahead and then measure the toe-in? This can't be right as they would then be measuring one error (steering wheel alignment) as another (toe-in). But if this is so then why was Tony's steering setup incorrect after the alignment was done? Somebody put me right, please, as I'll worry about this all night. Regards, Kes. |
| Kes |
| >After.. >LF = -0.02 RF = -0 04' Kes did I understand it right that you men the row ? with incorrect ? If yes. IMO this is a very low toe failure near the tolerance of measurement. short word to different front toe angles. i.e. the car looks like this /--F--! /--R--/ LF -xx RF +/-0 Its right what you say. The toe angles of both side get equal when you ride. But the car does'nt run any longer along its middle axle. It runs in 'Dackellauf' (scrabbing?). This behavior is not so bad on front driven cars but at the F with his short axle distance it is not good. The steering stands slightly to one side. As if you go in a curve. Recall if you turn into a curve then the steering design lets the steering wheel pull back. (How in heaven is the english name for that). However in the moment when you turn the steeringwheel, all other angles including toe change a little, so that one wheel is mor worn on the inner side. :-/ (OK poorly explained.) Need translations. Cheers Dieter PS have a look at the even under construction Webside: http://members.tripod.de/MGF/technik.htm |
| Dieter FAO Kes |
| Roger And bikers have to get used to it more often, in these days of very soft compound tyres we are lucky if we get 8000 miles from a set. But I prefer that to the 'old days' tyres that lasted longer but lost grip when they saw abned coming up. Ted |
| Ted Newman |
| Dieter, >>Recall if you turn into a curve then the steering design lets the steering wheel pull back. (How in heaven is the english name for that).<< We call it "self centering". Tony, looking at the camber results, one thing strikes me: the cambers on the left hand side of the car are more 'severe' than on the right. Is the ride height the same on the left and the right hand side of the car? It is entirely possible for it not to be. Regarding the vibrations, it is possible that one of the weights may have fallen off to result in this phenomena- it is certainly worth getting checked again. Robin had very similar problems to this a few months ago- and it was the wheel balance that caused the problem. HTH Rob N7 RMB |
| Rob |
| When doing wheel aligment on some other brands ( ie. Porsche ) there is a conical bolt inserted in steering gear that mates with correct setting of gear. Then values are set and finally stering-wheel is adjusted. The adjustment bolt is removed and replaced with a much shorter one to cover up hole. Don´t think our "F" has this item.....will have a look in workshop manual this evening. Regards , Carl. |
| Carl |
| Rob, this is entirly possible as the dealer only took 15 minutes changing the ride height (no two hours standing etc.). I will check the height, if I can find a flat bit of land where I can leave the car for a couple of hours. My ride height is (or should be) 365mm so Rover can't say my car is too low. I have the car booked in at another specialist to have it all checked again next Monday so I will be able to compare results and maybe get my steering wheel straight this time. I did think that maybe the vibration will get better as the tyres get worn in. My wheels were pretty dirty so maybe a weight did come off after the tyres were fitted, I know the guy had been to the hospital to get something removed from his eye that morning, so his eyes were not 100% :-) Please remember my Hydrogas failed on the right a couple of weeks ago, so it may not be quite right still, I will also try the tyre pressure at 1.8 on the way home, maybe this will help, I will also have a look at the plastic damper wheel thingie on Monday. I am assuming the tyre ware problem is fixed now, jus concentrate on getting the Vibration cleared up now. |
| Tony |
| Hi, I read your message and my and Carls comments now 25 times ... ;-) I hope I understood it now. Looking at your thoughts according to ONLY front toe measurements you are RIGHT. The steering wheel must not be locked for that. BUT: At a four wheel alignement job the whole range of the computer controlled measurement is running. Starting with the rear axle. And for the rear axle alignement the steering wheel must be locked. (i.e. at a Porsche or other cars by a prepared bolt or something like that.) Now the rear axle will be adjusted vertical to the middle axle of the car. If this is done, then the front axle follows as last part. Hope this helps. http://members.tripod.de/MGF/ebezachs.htm or http://members.tripod.de/MGF/technik.htm tells the whole story (crap translated, only the first sides are checked) but the pictures say more then a 1000 words. CU Dieter |
| Dieter |
| Hi, Thanks Dieter, Carl and everyone for the explanations, now I understand how it's done (just about). I often wondered how they managed to get the steering wheel aligned at the factory when the car was set up, and I'm still not sure. Does someone sit in the car whilst someone else fiddles underneath? I saw the wheels being aligned at a factory visit in April '98 but there wasn't enough time to really see what was going off, and my memory is hazy now! How is the steering wheel held during 'aftermarket' four-wheel alignments? Did you see this, Tony? Regards, Kes. |
| Kes |
| Kes, they did not hold the wheel, so I assume they did it wrong. I just ran round my car with a tape measure, according to this my ride height is 345mm and not 365 as I requested, this would explain why the figures look ok but the car feels like s**t. I think the only way to get this right is to stand next to the guy while he does the height. I don't think temperature was the problem here. I should have checked it myself, I should know by now I can't trust a dealer to do things properly. So now I have to get the height right again before I get my alignment done again next monday. I think I should be able to nip into any Rover dealer and get this done. Maybe I should get it pumped over and then lower it again myself. I think it is really bad when I can do a better job than the dealer and I am no mechanic, what is wrong with these people? I have to get this fixed as I just paid out for some expensive tyres on the front. |
| Tony |
| Kes asked >How is the steering wheel held during 'aftermarket' four-wheel alignments? .. with a special clamp, I didn't study it closely but it somehow sends readings to the Hunter alignment rig as my report includes a 'steer ahead' wheel position measurement. See http://www.bath.ac.uk/~ccsjst/before.jpg http://www.bath.ac.uk/~ccsjst/after.jpg jt a10jst |
| john Thomas |
| Hi Tony, you know older people need sometimes a little longer..... So I do :-) Caster.....................i.e. John Thomas value LF = 3 01' RF = 3 33' ! LF = 4° 53' RF = 4° 08' I just compared the caster with 'several' other measurement sheets Reason: The only cars with such caster about 3° are lowered by a knuckle set or by release of the 'green stuff' in the hydra system :-/ Cars in my data store are then about 338 mm low ???????? no longer confused Dieter PS. I Hope some more people beleaave now why I have no convinience to 'some' workshops. |
| Dieter |
| Ride Height is now correct, Yesterday I got the car pumped up to 365mm, 380mm by the time I got home. Today Found most even spot I car park at work, Left the car to stand for 2 hours, Took off the handbrake and pushed it forward 1m, Bounced it up and down a bit (front and Back), Lowered it to around 365 each side and bounced it up and down a bit, Took it for a quick thrash down the Motorway, My even spot was still free in the car park, Went through the bouncing etc. again. Left it another two hours before going through the checking process again. Checked it again and it is around 365-368 on both sides, so it looks spot on now. Monday Get another 4 wheel alignment and it should now be OK with any luck At this height the space in the wheel arch is about even all round the wheel so it look OK. No more shake in the steering wheel, It goes round corners without leaning over like a 2cv and goes over uneven bits in the road without jarring my teeth or giving major shock to my spine. Rover total time to get it wrong 2 years. Me total time to get right around 4 hours and 20 Minutes. I think the problem is that the dealers don't realise the importance of waiting two hours before pumping up (or letting it down) and ignore the need to find a flat bit of ground to take the measurements. The importance of this cannot be stressed enough, I saw it with my own eyes, this explains why Rover Dealers think they are setting the car to the right heigh, it looks ok when it is first done, but by the time you get the car home it is too high if they have pumped it up or too low when they have lowered it. I will update this thread with the new alignment figures on Monday afternoon. |
| Tony |
| Ride Height is now correct, Yesterday I got the car pumped up to 365mm, 380mm by the time I got home. Today 1. Found most even spot I car park at work. 2. Left the car to stand for 2 hours. 3. Took off the handbrake and pushed it forward 1m. 4. Bounced it up and down a bit (front and Back). 5. Lowered it to around 365 each side and bounced it up and down a bit. 6. Took it for a quick thrash down the Motorway. 7. My even flat spot was still free in the car park. 8. Went through the bouncing etc. again. 9. Left it another two hours before going through the checking process again. 10. Checked it again and it is around 365-368 on both sides, so it looks spot on now. Monday Get another 4 wheel alignment and it should now be OK with any luck At this height the space in the wheel arch is about even all round the wheel so it look OK. No more shake in the steering wheel, It goes round corners without leaning over like a 2cv and goes over uneven bits in the road without jarring my teeth or giving major shock to my spine. Rover, total time to get it wrong 2 years. Me, total time to get right around 4 hours and 20 Minutes. I think the problem is that the dealers don't realise the importance of waiting two hours before pumping up (or letting it down) and ignore the need to find a flat bit of ground to take the measurements. The importance of this cannot be stressed enough, I saw it with my own eyes, this explains why Rover Dealers think they are setting the car to the right heigh, it looks ok when it is first done, but by the time you get the car home it is too high if they have pumped it up or too low when they have lowered it. I will update this thread with the new alignment figures on Monday afternoon. Many thanks to the MGF FAQ and more recently the MGF workshop manual. If you want something doing right..... |
| Tony |
| ... hope you catched the released 'green stuff', or was it to little ? :) CU on monday Dieter PS. according to Email ... that part is named 'flexible truck tyre valve extension' and costs UKP 4.5 (DM14) |
| Dieter FAO Tony :) |
| Dieter, I'll send you the rag I used to soak it up if you like :-) |
| Tony |
| Tony, I've a better idea ...LOL... put the wet rag in a 'laundry centrifuge' (says Altavista to Waescheschleuder) and catch the rest... But only if it looks green. :) Cheers Dieter PS now really offline. I promise !! |
| Dieter |
| Well done Tony. You have very eloquently explained exactly all the pitfalls that [many] dealers usually fall into when setting up the F's suspension. The process you have decribed is what I would recommend anyone do if they are concerned about abnormal tyre wear or incorrect ride height. And the most important thing after doing this is getting an alignment check at a decent tyre centre- but *always* after the final ride height has been established. Rob N7 RMB http://go.to/mgfgallery |
| Rob |
| >You have very eloquently explained exactly all the pitfalls that [many] dealers usually fall into when setting up the F's suspension. Twice :-) |
| Tony |
| Ok, I did the tracking again using Hunter test gear, I think the other test I had was not done properly as the range figures are totally different. Front Camber FL -0º28’ FR +0º27’ (Range -1º00’ to +0º00’ *) Toe FL -0º09’ FR -0º11’ (Range -0º16’ to -0º04’) Caster FL +2º37’ FR +3º30’ (Range +4º05’ to +5º55’ *) Rear Camber RL -1º53’ RR -1º20’ (Range -1º50’ to -0º10’ *) Toe RL +0º11’ RR +0º11’ (Range +0º04 to +0º16’) Items marked with * are out of specification and can’t be adjusted (as far as I know). Caster confuses the hell out of me, from looking at other figures I would have thought that this would increase as the car got higher. I would have expected this to come within specification when the car is at the right height. Do the 205 tyres on the front change this reading? Camber is something that as far as I know cannot be changed without some major engineering, so I assume we are just stuck with it. I will just have to put up with the fact that tyres just won’t last as long on the front of an MGF. The guy gets a lot of MGFs from the dealer down the road (my current dealer) and said he never checks the caster, as it is always wrong and he can do nothing about it. He also said that the camber is nearly always different on both sides and is nearly always wrong. Anyway, much less shake and more stability, it has lost that slight driving on ice feel when damp. The shake should reduce as tyres get worn in to the new alignment, next month two new Pirellis on the back for 200 NLG (+/-60 quid)less than the the two I put on the front last week. BTW my dealer only charges me 10 NLG (3 Quid) to drive my car 200m to the alignment specialist and back :-) |
| Tony |
| Well, your suspension height adjustment does seem to have done the trick, insofar as all the camber readings are pretty much in spec. and equivalent all round. Don't worry too much about the 3 minute angle abnormality of the rear left wheel- it really isn't going to cause any problems. Also bear in mind that even laser wheel alignment rigs have error tolerances when producing measurements. The caster abnormality is odd. You are quite right, it is unadjustable, so there is nothing that can be done about it without replacing the front subframe/suspension. Unless someone knows different? (For anyone who doesn't know about suspension terms, and wants to find out, have a look at http://go.to/mgfgallery and go to the technical index/ suspension page.) Overall, job well done Tony. Unless there is some gross handling abnormality, then leave well alone. Rob |
| Rob |
| Tony - did the Hunter give you readings for wheelbase on each side and front/rear track. When mine was done the technician took pains to point out that he'd first adjusted the sub-frames position - there is some tolerance on the fixing holes. When viewing my figures remember mine is not at standard ride height - it's quite low ~ 320 jt |
| John Thomas |
| I got the following. Wheelbase Front Left 2370mm Front Right 2380mm, Track Width Rear??? 1423mm and my ride height is around 365mm. Sorry if it's confusing, it's all in Dutch.. Doh! |
| Tony |
| So lets see, this get this done properly, within Rover Spec.) 1. Get someone (cheeper than your dealer) to pump up your car to around 380mm. 2. Lower it to just above where you want it 368mm +/- 10mm youreslf (the car will settle another 3 or 4mm after a while), strictly following procedure in the MGF FAQ (or manual). 3. Take it to a wheel alignment specialist with decent test gear (Hunter gear seems to work well) and MOST IMPORTANT make sure the guy knows how to use it (for me this has taken some trial and error). Is it not a quality issue to make sure the cars are built within specification, or do the unadjustable things go wrong over time, excluding accidents, naturally? |
| Tony |
| Tony I am afriad you could have wasted alot of time and money having your supension set up, you see your wheel base seams to be incorect 10mm difference, possobility of your sub frames being out of alingment. this means although the wheel aligment appears to be correct. the car may be in effect crabbing down the road diff to explain and impossoble to draw on this bbs. |
| Mark The Tech |
| Hi Tony, according to 'Mark the tech' hints For a humble german's understanding. Does wheel base mean the distance from FL to RL and/or FR to RR or is that the distance FL to FR and/or RL to RR ? FL---FR RL---RR Tony, forward that paper by fax or send it scanned by Email or upload it to Karin's account. I would like to see that. A comparison to the other 6 alignement sheets should clear up the dutch written terms too. Cheers Dieter +49 2133 210617 |
| Dieter |
| Mark, so what you are saying is I have a fault that can't be fixed without replacing the front subframe. And naturally I can't expect Rover to pay for it even though this is a fault that has no doubt existed from new because Rover don't bother checking cars as they come off the production line. |
| Tony |
| Hi, the subframe mount (front) was changed in 1997 at VIN 24605. (green coloured if assembled at new cars) Tony's F is a for my knowledge a little older.... and has still the old ones which could be for my knowledge sometimes to weak. Could the probably misaligned subframe relate to probably to weak front subframe mounts ? Thanks for your hints Dieter PS. everything without VIN24605 is 'IMO', sorry for my poor english |
| Dieter |
| From reading through the workshop manual I note that the data for checking the vehcilke body alignement is based on a number of points including the position of some of the subframe mounting bolt holes. Additionally I did not immediately see any reference to having full realignement checks done following reassembly following major jobs such as engine or gearbox removal/refit. The inference I draw, subject to someone like Mark with more current data, is that the assembly process assumes that the subframe mounting bolt holes are going to be correctly aligned. The subframe mountings if new and the subframe itself clearly seems to be a straight forward bolt in arangement leaving no leeway for any alternative positioning. The further inference I draw is that any misalignement in these areas involves jigging, if the problem is with the shell, or replacement frames and mountings if it lies there. Someone correct me if they can, but thats the way I read it from a scan through a number of different sections of the manual. I think that many of us will be going out and mauring between front and rear wheel centres. I expect that 2 to 3mm will be a common differential, any more I would be concerned pending information from a Rover based source saying it was alright. 10mm as Tony has and I don't think that any comforting words will be found. Rog |
| Roger Parker |
| Hi, <I think that many of us will be going out and measuring between front and rear wheel centres> Indeed I did, on the day that Tony first mentioned it. I made it 2370 mm each side (from memory the book says 2376) but it is not easy, if at all possible, to get a measurement by hand - and eye - accurate to a few mm's. Have you done your own measurements, Tony? I agree with Roger, I would not think that there was anything more than the smallest amount of leeway in the subframe fixing holes to adjust the alignment. The consequences, if there were, would be horrendous. 10mm is not a massive amount. I'm curious to know how the tracking equipment was set up to get the wheelbase measurement. Was there some alignment by eye there, I wonder? Regards, Kes. |
| Kes |
| Sorry, a little late this facts because I had some system problems to add this message tonight Here some facts collected from the Hunter equipment result sheet dutch - german - english Wielvlucht = Sturz= Camber FL -0°28' FR 0°27' RL -1°53' RR -1°20' Front right is out of tolerance (-1° to 0°) Left rear is slightly out (-1°50' to -0°10') Askanteling = Nachlauf = Caster FL 2°37' FR 3°30' Out of tolerance. (4°05' to 5°55') Sporing = Spur = tracking (toe) FL -0°09' FR -0°11' RL 0°11' RR 0°11' Front totals -------------- Wielvlucht l/r versch = ????? Sturz= ????? Camber = -0°55' [no idea what that is.] Askanteling verschil = ????? Nachlauf = ????? Caster = -0°53' [no idea what that is.] Totale Spor = Gesamt Spur = Tolal tracking -0°19' [IMO a little to much negative] Rear totals -------------- Totale Spor = Gesamt Spur = Tolal tracking +0°22' [IMO a little to much positive] Rijhoek = ??????? = ???????? = 0°00' [no idea what that is.] .. and now this for Tony (and me) confusing Actual values for: Front: Wielbasis = Rad Basis ? = 'wheel base'? LF= 2370mm RF = 2380mm [Axle distance, see Rogers and Kes comment] Rear Spoorbreedte = Spurweite = 'track width ?' 1423mm So far the data from Tony's paper. :-/ See http://www.01019freenet.de/mgf/dutch_measure.jpg Translation of a dutch tech freak required. |
| Dieter Koennecke |
| The figures are all from the Hunter test gear. The car still vibrates but is now getting better, it only vobrates badly at 140kph now and is improving, so I assume the tyres are being scrubbed into shape now. I am due for a new set of rear tyres in a couple of weeks so I'll get the balance double checked on the front tyres again, just in case. The car handles and brakes like a dream with the new Pirelli rubber on the front. |
| Tony Smith |
| This is not the first time I have heard of the sub frames being out of line. The first time was a few months ago when an MGF owner took his car to Wicliffe in Gloucester and they found out that the sub frames were out by 17mm. The car had a new gearbox early in its life - and the fact that the manual didn't suggest an alignment check afterwards was deemed to be the cause of the problem. New sub frame was fitted under warranty. I have posted on the BBS before about this case. On another car that had handling problems & tyre wear problems from new, the owner also took his car to Wicliffe and they found his sub frames out by 12mm -his car had not had any engine or gearbox work done on it. Although the car was well out of warranty a new sub frame was fitted and paid for by Rover. You are not alone Tony. Paul P9 VLS |
| Paul |
| Re the alignment of subframe, I've hastilly put up the rest of the info I gote when Howards did my alignment. Check out http://www.bath.ac.uk/~ccsjst/howards.html You'll see the change in wheel base (4mm) and track jt - in haste |
| John Thomas |
| :-)) Thanks John, a lot of useful stuff. Pictures explain more then 1000 words. I think I have to rework my old sides... I did not compare anything to Tony's data, but hope everybody realises that a misaligned wheelbase does not force to change the subframe. Toe adjustments have influence on the wheel base !!! Cheers Dieter PS. I found all pictures, but please check the dimens.htm |
| Dieter Koennecke |
| With reference to sub frame mtn positions the front subframe mts this the forward mtns I am talking about here have elongated slots in it Also the front mtns of the rear subframe are the same Now then think about this if the mtns are miss aligned on both front and rear this could in fact give a major alignment proplem ie if both frames are closer together say on the N/s then the O/S will be further apart / / / / |
| mark the tech |
| Just as a matter of interest (still shakin'), Has anyone any views on things that can cause the car to shake (now at +/-125mpk), it is a little better but still shakey. Now in my experience it is normally tracking or balance (sometimes other). I want to know if the symptoms for each case be identified by the nature of the shake. For example, what would you say the each of following symptoms may be diagnosed as tracking, balance or tyres, front or back. 1.Steering wheel shakes from side to side at most speeds. 2.vibration through the whole car at 125kph plus. I would say 1. would be tracking problems at the front, and 2. could be a balance problem on the front or a tyre/balance problem on the back. It this correct thinking? I really must find out if 10mm wb mismatch will mean that I will never get the car right now (the caster was also very strange). I also want to know if a collapesd hydrogas unit could cause this problem. I ask because the mechanic came and drove the car back to the garage 7 or 8 miles away with the hydrogas collapsed on one side. So, let's see, First things to check/do... wheels were properly balanced in the first place (?) new tyres on the back (coming anyway). Second things to check/do new (better) bushes check subframe alignment etc. check subframe mounts check for any suspension problems. check for damaged shocks check pressure in hydrogas just in case they forgot (is that Hydra or hydro?) Last resort Beg, plead, tell them Ann (is that with or without an E?) Robinson is my mother, anything, just fix my F'ing MG :-/ Anyway, I got the 60,000km service coming up in 3000km, any Ideas folks (?????:-( Sorry about the length of this, it gives the night owls something to read tonight. Goodnight... |
| Tony Smith |
| Well this night owl reckons some shake is 'normal'. I have minimal tyre problems (the usual indicator of tracking problems), but suffer from the shakes at intermittant speeds. I can't pin-point the problem - sometimes it shakes, sometimes it doesn't. I am talking about ~160km/h speeds. Yet another thing to live with. Don't take it all too seriously. Goodnight too, . |
| Dot |
This thread was discussed between 23/09/1999 and 14/10/1999
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