Bushes instead of bearings for rear wishbone and hub carrier

[Maikel]

Hello,

I now came across this topic for a second time.
An old guy told me the other day of using brass bushes for the rear wishbones instead of the needle bearing. As there is not much spinning and brass would be do a perfect job, just like at the earliest brake pedal which was sitting on a brass bush.

Now these days I received a package with various parts and found again those bushes. Please see pictures.

Why do we need to use these needle bearing if there is no high speed spinning at the rear end.

Many thanks for your contribution. I would like to install them.

Maikel

[phil.dobson@mac.com]

I am sure many will join in this thread who are far more technically qualified than me but....... I have never seen poly bushes offered for the joints you show in the diagram. I can only believe that using this type of bush in these locations would add a lot more play in the rear end. Brass and roller bearings would not. As for your suggestion to change from the original style to brass i would ask one simple question... what problem are you trying to fix? It is generally recognised that the Jaguar independent rear suspension is a remarkable piece of engineering and when maintained in good working order gives a superb ride and road holing FOR NORMAL (and spirited) road use. Its a labour of love to rebuild the read end properly but when its done its very rewarding.

Just my humble opinion.
Best regards
Phil D.

[Maikel]

Counterquestion,

why are there polybushes at the front suspension and no bearings?

[alfazagato]

The whole of the E Type suspension is, effectively, rubber mounted from the rubber bushes at the front on the suspension and steering rack to the cradle mounts and trailing arm mounts at the rear. However, the design of the rear suspension is such that cornering movement in the hub carrier would compromise the geometry and thus bearings were used.

[Maikel]

Here is an example of bearing removed from the IRS. Can not see an advantage compared to the bushes.
OK, we agree both can fail, but what does speak against the bushes. In contradiction I would even go further and say the bushes are more handy to install and to maintain.

Your turn now.

[christopher storey]

I don't know who the "old" fellow was but in my view he has some VERY dangerous ideas. If you substitute for the precision location of the rear bearings as they are , the highly imprecise - and compliant in all directions and in response to all forces - rubber/plastic bushes, what you will get is highly unpredictable rear wheel steering, and if you were not off the road backwards at the first bend I would be very surprised. The wheels will splay outwards at the front under acceleration , and toe in under braking, and what happens when you combine these with the effects of cornering I shudder to think

[Series1 Stu]

Is someone actually selling these as an 'upgrade' kit?

They're going to kill somebody!

As Christopher says. They are subject to lots of very high forces, especially the torque of the driveshafts. There is potentially close to 12 times as much torque at the rear wheels as there is at the flywheel. Who knows how the polyurethane is going to react to that?

I suppose you're right about them being easier to fit and replace. Just as well really because you'll be doing it regularly. If you manage to survive your first journey...

Regards

[mgcjag]

Hi Maikel.....agree with Christopher above.....where were the bushes from and what was they supposed to be used on...Jaguar rear suspension is used on many kit cars......was this aplication for some kind of off road use

[Maikel]

Indeed,

I found those bushes in a box of parts ready to be used on a kit car.
But why is it good on a kit car and not on an E Type?

I will stick to the needle bearings but still wonder why it can be used on other cars?

In Germany we are not that familiar with kit cars as we would not get a permission to drive them on the road.
Maikel

[mgcjag]

May be some kind of dune/sand buggy that could have problems with roller bearings...who knows.. Steve

[chrisfell]

Your turn now.

Snap!

[Maikel]

Steve, you have a point there.

Chris, equal problem. Also of 2+2? My where of a 2+2 which I recently restored, now doing a couple of FHC's where I disassembled 6 rear hub carriers from the earlier cars with none of them having this kind of issue.
Might be a 2+2 illness.

OK, but reasons enough to stick to the needle bearings. Was however interesting to get someone elses theory.

Many thanks
Maikel

[JagWaugh]

The roller bearings only see a very small angular motion. Even with regular lubrication the inner fulcrum could well be mistaken for a test rig to accelerate brinelling.

There was a discussion about using bronze bushes on JL about 8 years ago iirc. Making the bushes on the outer fulcrums eccentric would make it easier to adjust camber for track use, but at the end of the day by the time you design, make and test a substitute for the roller bearings on the inner or the outer you've spend about as much time and more effort than it takes to just drop the IRS and replace a worn set of bearings.

[norman m. macleod]

Hi All,
OK, so here we go with my tuppence worth......The application of needle roller bearings in an application like this is not good practice, the limited angular arc of motion will ensure extreme brinelling in time, over that arc. All of these that I have dismantled have displayed this. I replaced the Jaguar set-up with phosphor-bronze bushes in my own car some time back, a far better engineering solution. These are available as a complete kit from CJ (Classic Jaguar) in the USA, about US$275, excellent quality....( No connection with the company, other than a satisfied customer......)
Hope this helps,
Regards,
Norman.