MG-Cars.com
MG MGB Technical Panhard Rod BBS discussion at MG-Cars.net
MG-Cars.net
Welcome to our resource for MG Car Information.
Recommendations
Parts
MG parts spares and accessories are available for MG T Series (TA, MG TB, MG TC, MG TD, MG TF), Magnette, MGA, Twin cam, MGB, MGBGT, MGC, MGC GT, MG Midget, Sprite and other MG models from British car spares company LBCarCo.
|
|
MG MGB Technical - Panhard Rod
| Does anyone have the length of a Panhard rod handy for an MGB? Thanks Daniel |
| Daniel |
| personally not daniel, but i would like to lurk as am interested to hear if users who have installed one are impressed with how it has tightened up the back end. are you thinking of making your own? i must admit it crossed my mind as there doesn't look to be much to them....and a bracket looks fairly straightforward to fabricate. do kit car supplier sell them? G |
| Graham Moore |
| MGB Daniel? Coincidentally, I was only thinking about this yesterday. |
| Dave O'Neill 2 |
| A term I am not familiar with. Could you clarify what it is and does? |
| Bruce Cunha |
| Google it for a good description |
| A J Dee |
| MGOC do a kit for £300 and Frontline for £295 + VAT, but it should be relatively easy to fabricate something for much less. |
| Dave O'Neill 2 |
| Simple answer to length............as long as possible! They will always move your axle laterally as the axle and body move vertically, As they get longer this sideways shift is reduced. Watts linkages don't do this but are more complicated and heavier. |
| Allan Reeling |
| Brian Laban - 'MGB The Complete Story': As a prototype for the MGB a modified MGA had coil springs, trailing arms and a Watt's linkage. After Roy Brocklehurst survived turning this over in testing it was dropped. Also dropped was a Panhard rod which presented problems with attachment points breaking, and then with rear-wheel steering. |
| paulh4 |
| Is a Panhard rod the same as a DiDion rod? Cheers Gary 79 MGB |
| gary hansen |
| I just want to know the length for a writing project. The Sprite/midget panhard rod is typically 30 inches so I just wanted a figure for the MGB such as 31 inches or 32 inches or whatever. |
| Daniel |
| looks like adjustable panhard rods are pretty cheap and easily bought. search on 'adjustable panhard rod' less than £50 so down to sizing and bracketary. G |
| Graham Moore |
| Gary
Short answer--No Long answer-- A Panhard rod is a basic rod that attaches to the diff housing on one side and the body on the other to stop the diff moving sideways in the car A DeDion rear end is a completely different setup--It is basically an independant rear end with the diff centre mounted to the body or frame as normal with live axles driving out to each hub/wheel, It differs from normal independant rear ends by having both the rear hubs connected to each other by a largish sliding tube assembly which in theory keeps both rear wheels at rightangles to the road at all times similar to a normal tube type rear axle It has been said that it combines the worst of both axles types, but it works ,-heavy, but works--Most common on early Mercedes etc willy |
| William Revit |
| De-Dion was another one considered for the MGB, but rejected for reasons of cost and weight, and so many solid axles were being made and used elsewhere. Good job that latter school of thought didn't prevail for everything. |
| paulh4 |
| Rover used a De-Dion setup in their P6 http://p6v8.wordpress.com/2009/08/24/new-radiator/ |
| R.A Davis |
| So no-one knows the length then? |
| Daniel |
| i have read 'approximately 36"' but cannot vouch for accuracy G |
| Graham Moore |
| I agree with Graham's 3feet But I think I can recall stretching it out to 38" but it was more work for little if any advantage |
| William Revit |
| Dan, find one for sale and ask them to measure it! |
| Allan Reeling |
| If it is just a writing project then accuracy does not really matter, does it ? Not like you need to make it to fit a car !! |
| A J Dee |
| I have one fitted to my MGA (an MGB without wind-up windows) and the length is 840 mm (33"). Depending on how you construct mounting you could add a few inches. Rose joints each end with with threaded adjuster. Mike (sorry about the dust but hillclimb return road is unsealed!)  |
| Mike Ellsmore |
| This photo shows connection to diff housing - fabricated box bracket. The other side is simpler on an MGA as it is just a drop bracket welded to the chassis arch. Mike  |
| Mike Ellsmore |
| 985mm between centre of eyes. Mine is off the car at the moment. My panhard rod connects to the right brake backing plate bolt (longer bolt)and to the extreme left hand side of the boot floor which has reinforcing brackets. I removed it years ago because I didn't like the way it made the car feel under heavy cornering. Ian |
| Ian Buckley |
| Funny you should say that, Ian.
I made a PR similar to Mike's ie rose jointed and attached to a bracket at the far left of the boot floor and attached to a similar clamp arrangement at far right of axle tube. I made this before I had access to Interweb, so cribbed the MGOC design that I'd seen in a picture. I too removed mine because the car seemed to go suddenly to snap oversteer on Quarry Corner at my local race circuit, Castle Combe. I hadn't come across this before, the car always having controllable tail out understeer hitherto. Chatting about it with my father in law, a car nut of long standing, he reckoned it was down to my budget tyres. However, now I'm not too sure........ |
| Peter Allen |
| At last, others that don't like P-bars on leaf spring cars
I've had some 'interesting' discussions on the things I don't know why but having the bar mounted to the body on the passengers side feels completely different to having it on the driver's side--- When it's mounted to the body on the driver's side, It feels better for the driver because,I think, you ride up and down with the arc of the bar. I don't know how ,but you can feel the arc working against you when it's mounted on the passenger side I'll shoot myself in the foot here and say-- Mike, I reckon your bar is mounted wrong way round and way too high--If you are intent on running one it needs to be at least 2-3" lower than that or more- Honestly, I've tried them all over the place and without one at all is better for cornering traction--The idea of tying the back down is strange to me, much better off letting it move around but dampened so it can move with the surface of the road and get a grip instead of skipping around willy |
| William Revit |
| You maybe right Willie. My car has had this panhard rod since I acquired it 7 years ago. Design and installation was done by MG Workshops back in the mid 90s. My trouble is I’m not a good enough driver to tell whether it is causing a problem or not (over the years I have had spins at Sandown and Mallala but not sure I can blame the panhard rod!) Mike |
| Mike Ellsmore |
| these are the only two negative reviews of panhard install that i have read. others have said that it really installs confidence in the back end on hard cornering. could it be just coincidence that they are both DIY versions? suggesting that maybe not quite as simple to design as might first appear...? G |
| Graham Moore |
| Willy,Peter and Mike, interesting comments. I am pleased I am not the only one who felt uncomfortable with a PR. I read positive reports years ago and wanted a PR. Partly because my car is a V8 conversion and I have wider tyres which brings clearance problems. The PR was not the easy answer for me. My PR was professionally made. Ian |
| Ian Buckley |
| Mike
I think you are being a bit harsh on youself Your lap times at Natmeets would back up your steering ability-------- Maybe if you don't have any clearance issues you could have a run without the bar and see what difference you get--Lowering your rear roll centre (which is what would happen in your case with the bar off) should give you a bit more mid corner traction and improved drive out of the corner Most MGA-B's when pushed to the limit will end up spinning out--Lots of people say they push in the front but it's not the case Driven hard there is an understeer/pushing feeling on initial turn in, but it's only a driver's feeling thing as the rear axle is steered by the body roll but that feeling is only a transition/temporary thing and soon transfers to mid corner oversteer and the faster you go the more you get it till the inevitable spin out----------in my opinion You never see an A or a B spearing into a corner with the steering right round but still going straight on, it's always tail out Honestly I think people get tricked with P-bars--They put them on and they feel different because everything is held rigid and it gives a sporty feel but as far as traction goes, unless it's to change roll centre height for a particular problem then I don't think they do a real lot for improved lap times Locating for guard clearance is a different issue willy |
| William Revit |
| I might give it a go Willie. I don't appear to have clearance issues even though running 6" rims. Inside flanges of guards have been flattened and running 205/50/15 tyres help. I have had a re-read of Fred Puhn's book "How to make your car handle" re roll centres and locating devices that backs up what you say. Mike |
| Mike Ellsmore |
| Thanks Willie! I took the panhard rod off for the hill climb at Rob Roy last Sunday and had my best time ever, felt good. Mike |
| Mike Ellsmore |
| Good stuff Mike - It was concourse weekend here, and the black twincam from WA has come to live here. I couldn't stay till the end but I suspect it would have cleaned up in the results I couldn't see a spec of dust anywhere willy  |
| William Revit |
| I know the car, beautiful! The owner has stable of concours cars, WAs loss, Tassie gain. Mike |
| Mike Ellsmore |
| i just read my last post. didn't read well. no offence intended, though the phrasing may suggest otherwise. please accept my apologies. G |
| Graham Moore |
| Graham ---- You're worrying about nothing We'd all be rich if we got a dollar for everything we thought that maybe we could have said/written differently Cheers willy |
| William Revit |
| Interesting thought, was black a standard MGA colour? If not then the car isn't concours as it's not original! The OED definition is'an exhibition or parade of vintage or classic motor vehicles in which prizes are awarded for those in the best or most original condition.' Don't shoot me just thinking aloud. |
| Pat Gregory |
| Pat looked it up in my twincam info and yes black was a std twinky colour BUT with red or green trim - this car has beige trim and roof Might have to keep that in mind as we have the National meeting here next Easter |
| William Revit |
| Originality is only 200 points out of 600 in Oz National Concours judging the rest is for Cleanliness and Condition of the varous areas. Most you can lose for wrong colour is 50 points and 50 points for wrong trim - that would be an awful hard mark to give zero for a section like Body meaning you get nothing for the other components of Body that are original. Concours judging in Oz is judging a car against others on display.
You have to judge all the other cars the same way if you gave it zero for paint, if someone esle had none original part in the engine compartment you would need to give them zero for this section. Becomes nonsense. I would take off say 25 points for non standard colour and maybe 20 points for wrong colour trim. Happy to debate concours judging ad nauseam! Mike (judged several National MGA concours over the years) |
| Mike Ellsmore |
| I run a Panhard on the race car.
It is essential that the mounting points be as far apart as possible and that they be level with each other when the car is at rest height so the bar isn't trying to lever the rear end out one side of the car. A tab welded on a lower leaf spring plate works for one side, but the other side takes more work and to get it level you need to weld a hefty bracket on the frame. Don't undersize the tubing and rod ends either - the forces are hefty. To complete the ensemble you really need torque rods to control rotation of the diff. Can be 4 link or 3 link (I use the latter) but it requires arranging for the leaf springs to slide between the spring plates so few people do this for the street. |
| Bill Spohn |
| Bill, i would be interested in a photo of your 3 link torque rods to explain their layout. Mike |
| Mike Ellsmore |
| Bill-Mike
Don't forget the golden rule--keep it simple Surely ,retaining leaf springs (sliding or not) while using other locating links is only a way to use the suspension links that you think you need while retaining the leaves to comply to the rulebook for whatever class you are running in. otherwise the logical step would be to throw the leaves and have coilovers and a proper torque active rear suspension The problem with Mike's car and the P-bar that it had was/is that the bar was mounted way too high, probably a couple of inches above the natural roll centre which was creating heaps of weight transfer during hard cornering-- The natural roll centre height is 'roughly' at about the top of the spring where the diff bolts onto it, depending on the curve of the spring and mounting a P-bar at this height will merely locate the diff sideways without changing rollcentre height or handling habits If you were going to refit it, to notice any benefit it needs to be lower, roughly about the height of the bottom of the spring as Bill has his- this 'should' give less weight transfer at the tyres during cornering and better drive off the corner- BUT ONLY IF you have an issue there with mid corner speed Testing is the only way--other factors like spring rates,sway bar strength etc come first- using spring travel measurements is your best friend willy willy |
| William Revit |
| Mike, you run a long rod from a tab on the bottom spring plate to an attachment point created by welding a couple of drilled tabs under the front spring eye. The upper rod (you could have two, but one suffices) is attached to a bracket welded to the top of the diff casing, and runs to a bracket attached to the frame/body.
With leaf springs that set up will result in the leaves and the lower rods forming a parallelogram that fights itself, so you need to arrange for the springs to be able to slide between the upper and lower spring plates, using tubular spacers on the U bolts. Mine was patterned after a method that Huffaker designed for use on the Midgets. The axle can't rotate axially at all so no wind up. If you are allowed to run coil overs that would eliminate the need to have the sliding leaf springs. It gets a bit busy under there especially if you run a rear sway bar as well. Sorry I couldn't find a picture. |
| Bill Spohn |
| has anyone tried the dave headley axle locator solution instead of panhard? www.fast-mg.com G |
| Graham Moore |
| Graham I couldn’t see any pictures only a mention in the price list. Does anyone have a pic? Mike |
| Mike Ellsmore |
| or a Jacobs link like the racers run |
| William Revit |
| oops---Jacobs ladder |
| William Revit |
| A Watt's linkage is effective, but on the MGA there is not much space between the back of the axle and the gas tank. Can't remember if the MGB is the same. |
| Bill Spohn |
This thread was discussed between 04/11/2017 and 28/01/2018
MG MGB Technical index
This thread is from the archive. The Live MG MGB Technical BBS is active now.