Panhard Rod and anti tramp bars

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Old Boy Racer
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Joined: Wed Apr 09, 2008 3:07 pm

Panhard Rod and anti tramp bars

Post by Old Boy Racer »

Since my BRA has been working so well this year I have of course taken it to bits. The back axle had the famous MG clonk. Nothing is obviously loose and I doubt it had little done to it at donation time, so like its owner I'm sure it's just old and knackered. It's now with Brown & Gammons for a rebuild. While I'm at it I intend to add a Panhard rod and anti-tramp bars - which I want to make myself. Apart from being a scrooge, I don't see the sense of buying things intended for a Hawk (or an MG come to that) and then cutting them about to fit. Anyway, the rear springs already have substantial bottom plates fitted to mount the Spax shock absorbers. Out came the carboard to make templates which proved that 10mins with a cutter and a bit a steel plate will provide the necessary fittings for the chassis and add-ons for the spring mounts. I have a few rod-ends doing nothing, so question is - what size and material spec should I use for the bars themselves? Ditto for the Panhard rod. Space for that is tight between the back of the axle and the "tray" that the fuel tank sits but unless the Panhard Rod needs to be massive, I reckon I can get one in. Should it really be a tube or could it literally be a solid rod - smaller diameter. Again, I'll fabricate my own brackets.

Cheers

Robin
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StewbieC
T289R Committee
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Joined: Mon Oct 13, 2008 12:50 pm
Location: out in the sticks, Shropshire

Re: Panhard Rod and anti tramp bars

Post by StewbieC »

I wouldn't fit a solid bar, for the loads that they will endure something like a mild steel 30-40mm tube with 3-4mm wall thickness would be ample. Tensile loading would be more than a few tonnes and buckling load for the length required would be at least 5 Hawks (or BRA's) if you really want to I'll work out the specs for you.

Let me know, although you'll probably find that the solution is a 13 mm tube with 0.9mm wall thickness that you cant get off the shelf and is no fun to weld. :wink:
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Stu
Hawk 289, 66 Mustang Fastback with a 289 maximum smiles per mile..
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Roger King
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Location: St Ives, Cambs

Re: Panhard Rod and anti tramp bars

Post by Roger King »

Robin,

I have these on the Mustang - a bit 'old school' compared with the many fancy modern offerings, but they seem to work very well. I have cut a short section out of the main tubes and welded a threaded section into the tube on one cut end, and a nut on the other - this gives me an element of adjustability which helps resolve the 'once it's welded, you're stuck' problem. I would personally advise against using solid rod-end type connections as the result would be very unforgiving over bumps etc. This is because you cannot get the front mount to be common with the front spring mount, and the different radius of travel will require a bit of 'give' if you don't want to overstress everything. I have poly bushes in the TMs on the 'Stang.

http://tractionmaster.com/index.html
Old Boy Racer
Posts: 698
Joined: Wed Apr 09, 2008 3:07 pm

Re: Panhard Rod and anti tramp bars

Post by Old Boy Racer »

Thanks chaps. I can get hold of most bits and materials via friends with specialist engineering businesses. I also "make use" of their facilities :)
Cheers
Robin
CobStang
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Joined: Sat Dec 10, 2011 3:21 pm

Re: Panhard Rod and anti tramp bars

Post by CobStang »

I made my Panhard rod out of 1" thick wall seamless tube. I have one end with a polybush and one end with a 1/2" x 1/2" rodend.
Couple of things to note are , The best location is from the rear chassis rail on oneside of the car, to as far over on the axle you can get it on the other side. DO NOT go and bolt onto the diff cover bolts.
At RIDE HEIGHT the bar should be level, and run along the axle centre line heightwise.
A substantial bracket needs to be made to drop the chassis location down low enough to be at the same height as the axle centreline, I ripped the MK 1 version of mine off the car !!! MK 2 is triangulated across the car.
HTH
Mark
Early B.R.A. Warmed 3.9 Rover, 5 sp, 3.07 rear, Fully adjustable front suspension with AVO coilovers, 4 link rear suspension AVO coilovers and Panhard bar, Big 2 pot front calipers, rear discs, servo'd, adjustable front / rear bias, scruffy paint job !
Old Boy Racer
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Joined: Wed Apr 09, 2008 3:07 pm

Re: Panhard Rod and anti tramp bars

Post by Old Boy Racer »

Thanks Mark. The refurbished axle is back in (the crown wheel and pinion was Donald - hence the clunk) along with a tidy up of the brakes pipe mountings etc. Anti-tramp bars nearly done so should be on this weekend. I've got an under boot floor fuel tank that makes things very tight for a Panhard rod. Found this pic from a racing MGB while poking around the web. I get the 4 leading arms and Watts Linkage but still can't figure if those additional sideays radius arms affect up and down axle movement.
Watts Linkage.jpg
Cheers

Robin
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CobStang
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Re: Panhard Rod and anti tramp bars

Post by CobStang »

Some things in life are made to make your brain hurt. All I can think of is its a way of lowering the roll centre.
Check out the sexy composite springs, some money been thrown at that !
Early B.R.A. Warmed 3.9 Rover, 5 sp, 3.07 rear, Fully adjustable front suspension with AVO coilovers, 4 link rear suspension AVO coilovers and Panhard bar, Big 2 pot front calipers, rear discs, servo'd, adjustable front / rear bias, scruffy paint job !
Old Boy Racer
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Re: Panhard Rod and anti tramp bars

Post by Old Boy Racer »

You may be right about lowering the roll centre. But - how do the radius rods affect the movement of the Watts linkage and why do you need both? Interesting that it's all based on the earlier axle as well. As you say, loadsa money. I'll dig out the link to the other pics.

Cheers

Robin
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