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MG MGB GT V8 Factory Originals Technical - Got the shakes......
|HI Everyone , I got the shakes , well not me but my car . Before the meet in Tenn. it shook a little at around 57 to 60 . I took it in for new boots / alignment & also had them check the balance , it was ok . The next day I took the top off the steering box & it was completly dry , I wasent sure what to use so I just put in some 80/90 tranny oil ? I also took out the thinest shim because I felt the steering needed tightened up a bit and I couldnt see any other adjustment . The following day we left for Tenn. & immediatly on the interstate had a worse shake from [ now this is wierd because it changed?] about 62 or 3 up to almost 70 ? 60 fine , 70 fine anything slower or faster fine ? I've checked all bolts & nuts , tire pressures , retorqed all wheel lugs , but were still shakin ? Where to next ? As always Thanks in advance for your excellent help . Meanie for sale ? I dont know ? still droolin over a t top xjs but still like the B [cant afford both .] OHH what to do ?|
Check or replace your tie rod ends.
|How's you damper oil. If it has run dry the car will bounce around like a pogo stick with no damping feels like poor wheel balance bumpy roads make it worse.|
|Check no bulges/damage to tyres,I had 12inches of tread, half the with of the tyre bulge, 100 miles from home.|
|I agree with Justin. Drive shaft uni joint/s|
|Denny, also check your wheels. I don't remember what type you had on there but wires are a real problem with a V8, and regardless they need to run true and be balanced.|
|Heck I'd start with the bolts that bolt the drive shaft to the rear differential. If those came loose, you would have exactly the symptoms you're describing.|
|A friend used a bubble balancer on his wire wheels and it took care of the shake. The wheels were "computer balanced" at a tire shop several times with no improvement. We will be holding a tech session at his house tonight with several other wire wheel cars that that currently shake at various speeds. I will report the results.|
My conversion suffers from the same affliction as Denny's between 60 & 70mph. A couple of years ago I had my front rotor and hub assemblies checked for balance at my local machine shop and discovered that one rotor was way out of balance. I replaced both rotors with a matched pair and verified balance before installing. This seemed to cure the vibration all of last year's driving season. For whatever reason, the vibration is back again this year, I do not believe that it is the driveshaft - it was checked for balance when new two years ago. The vibration definately is coming from the front axle/suspension area. Occasionally, depending on the road surface it seems to disappear only to reappear again.
Since my conversion has been lowered, it now has some negative camber and coupled with the wide rims and 225/50-15 rubber, I'm wondering if there isn't a hint of bump steer that's exacerbated by road surface.
Until such time that I can afford Ted Lathrup's state of the art fully adjustable coil over front axle assembly I guess I'll live with driving at 70mph.
|Grahm: Our MG afflictions sound similar. On the trip down to Gatlinburg it was a very smooth ride. On the way back I felt more vibration. Everyone in our group was complaining about it. We were all blaming the aggressive driving on the Dragon and not the different route we took back. I did see a great improvement when I put your mini lite wheels on a few years ago.|
Our wheel balance tech session was canceled due to rain. I will update when we have it.
|OK ,, I'm always surprised to the responses on this v/8 thread [not to mention FREE fixin's at the meets.] To Carl [nice work on my push rod , still using it, although I plan to replace rods & springs shortly] I have not checked or can I find reciepts from p.o. about tie rod ends , I have no idea How to check that? He [p.o.] did replace all rubber bushings with the neoprean stuff , have reciepts & they all look new . Justin , I cant see it bein a u joint [although I havent checked bolts , I will , just for the fact that I've found many things loose] cant imagine how this stuff comes loose drivin on glorified cow paths at breakneck speeds ?? but anyway the steering wheel shakes & its definatly in the front end . I have driven vehicles around many times with bad u joints , in my younger [no money] years and thats not it. However the driveshaft could be out of balance ,the car has shook since I got it , but not this bad & after the new boots / aliginment/& me adding oil 80/90 trans. ??? is that right?? I also removed a thin shim , that didnt make a difference in the small amount of slop I had at the steering wheel. To M.Mallaby shocks have been changed to tube type , if thats what ya call em & their not that old [ approx. 20,000 mi.] & look fine. To Dave Lowe tires have No bulges and are almost like new , however the inside of the fronts are wearing more than the outside ? which leads me BACK to Carl's theory [worn out tie rod ends?]I think I'll rotate tires front to rear & see what happens. Wow OK to Jim Blackwood [I really need a ride in that crazy car of yours I am very curious about it , have been for some time , when seeing pic's & then seeing it at meet , perhaps a 2 up down the drag strip at next years meet? Please ? Please? anyway I have 14" cast wheels [look at the v/8 site , Thanks Curtis , I really will send you some money , I spend alot of time there.] anyway balance was computer spun tested OK.. & That leads me to Justin , I dont think thats it [see above] & thanks . Now to Jim Miller , I havent read your links ,but can imagine , old , careful tech is probablly better than new / kids / dont give a s**t tech ? & I will look at those links you posted. Anyway I have cast wheels . Now to Graham Chreswich, I have never thought of the front rotors , they were drilled by p.o. nuts on calipers are tight , and they [from jacking front up] & spinning front wheels , do not seem warped, good even , slight dragging . So I guess its back to a full overall check with the tie rod ends in question ?? Any other suggestions are as always welcome. I will check if the shop that I go to can spin the rotors & see if thats it , but I do have extensive reciepts from p.o. & none for tie rod ends or for that matter rotor balance .So I guess I'll start at the tie rods [how do you check these ? I have jacked it up & wiggled wheels up& down , nothin obvious ], no binding back & forth , brakes have even drag [not much] on both sides , goes down level road , Hands off Wheel , Great! as long as its not 62 or 3 to 69 ?? There is very , very considerable tire / steering wheel shake at those speeds . Above / or below its great ? I have taken hands off steering wheel at 75 + down interstate [ with Sue raisen Hell !] on way to Tenn. meet & we cruised I|
|[sorry] I say a mile , NO problem , nice & straight , no shakes . It is odd ? Probally somethin stupid as is most of the time with anything British. Thanks All, keep responding , We'll figure it out.|
I'll have still have to go with wheel balance. As a British car mechanic for 30+ years I've chased vibrations all over the place. 95% of them come back to wheels/tires. Being that most of the wheels don't have a true center, they are hard to balance on modern equipment. If you can find someone to balance them on the car (old school) or use an adapter plate that uses the bolt patern to mount the wheel on a balancer, you'll more than likely find your problem.
I've seen brand new wheels and tires un-balanceable (is that a word?)If ygood indicator that your wheels/tires are the point to work with.
BTW- I've got the same issue. I've got a LE wheel that runs and looks true but will not work on the front.
some time ago, I also had this problem on my 1973 BGT V8 and first checked the end float of the front hubs. After adjusting them according to the procedure explaned in the workshop manual and ballancing the front wheels first without tyres than a second time with tyres mounted, there was no further wheelshake left.
Rims are Dunloop 5.5x14 (Reliant Scimitar GTE), Tyres are 175/80/14H, Armstrong lever dampers 30% uprated by changing the valve. Brakes normal V8 but with cross drilled rotors, 3/4 inch handling kit.
|Whatever you do, do one change at the time.|
A bent wheel will do the same, loose bearing will only shacke during braking. old tie rod ends will shacke, bad shock, loose rack.
But, if you have a RB car lowered to CB specs, then one possibility is the angle of the steering rods as Grahm pointed out.
The fix is easy an the following should be perform to all RB lowered to CB specs.
Removed the steering arm from the spindle and swap with the other side. What this will do, it will place the streering arm upside down and the tie rod will fit from the bottom instead of the top. this will lowered the steering angle of the rods and place them paralell to the ground eliminating bump steer which can cause shacking combine with a loose rack.
This is one possibility for your shacke.
I'm curious, did you get this resolved?
|Hi ,SM , Ohio . No I havent done a thing . Took it out & got 1/2 mile from house & a nasty noise , the bottom bolt on the alternator came loose & cooling fins went down & hit the fender [WOW!] that'll wake you up ! Ends up its sripped out so I retapped it [ the lug on engine "215"] for a bigger bolt , then the alt. bolt hole had to be drilled out a little bigger , then the slot in the bottom bracket was a hair to small , so I dremeled that & havent put it all back together yet [ maybe tomorrow ?] Phone has been ringing off the hook [self employed] and I had to get B.S.A. m/c ready for a meet, I just got back from it 2 hrs. ago , so I kinda been busy , like a cat on a tin roof , tryin to cover up a turd . Seems like everybody needs their stuff fixed & at the same time my stuff starts breakin ? After I get this alt. thing back together & if the phone gives me a break this week , I'll rotate tires & see what that does . Thanks again , everybody , hope to see a few of you at the Meeting of the Marques in Boiling Springs Pa. [sept. 24 th. ] just 25 miles or so from here . Got 1 spare bed here if anyone is considering the trip ... Have fun . [ firstname.lastname@example.org ]event chairman / or [www.SVVSCC.org] club site , this is a great British car show , come on out , winters fast approaching .|
This thread was discussed between 25/08/2006 and 11/09/2006
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