Trailing Arm Bushes
Discussion
Hi. Advice please.
My trailing arm bushes need replacing, and before I do this do you guys have any advice on 1. ordinary rubber replacement - cheap but difficult to find. 2. Superflex replacement - easy to find but expensive. or 3. The spherical bearing replacement that was done to Engineer1949's orange Wedge. or 4. A method of implementing the later 'A' frame suspension.
I worry about the spherical bearing because to my (simple) mind, any shocks transmitted through the rear wheels will not have any flex in them at all and might eventually stress the chassis plate the bearing is attached to. Is there any feedback on how this mod has worked over the years?
My other wonder about this aspect is how to set up the rear wheel geometry? There seems to be only the shims on the aforesaid bush to play with.
My trailing arm bushes need replacing, and before I do this do you guys have any advice on 1. ordinary rubber replacement - cheap but difficult to find. 2. Superflex replacement - easy to find but expensive. or 3. The spherical bearing replacement that was done to Engineer1949's orange Wedge. or 4. A method of implementing the later 'A' frame suspension.
I worry about the spherical bearing because to my (simple) mind, any shocks transmitted through the rear wheels will not have any flex in them at all and might eventually stress the chassis plate the bearing is attached to. Is there any feedback on how this mod has worked over the years?
My other wonder about this aspect is how to set up the rear wheel geometry? There seems to be only the shims on the aforesaid bush to play with.
Most of the shocks experienced by the rear wheels are transmitted through the springs and shocks directly to the chassis.
Think of the trailing arm as a big lever. With a long lever you don't have to exert much force on the far end to move a heavy weight at the short end.
Similarly, big forces at the short end (hub) translate to smaller forces at the far end, which is why the mounting can be a relatively weedy, such as a pin around 10mm diameter, and a rubber bung.
Think of the trailing arm as a big lever. With a long lever you don't have to exert much force on the far end to move a heavy weight at the short end.
Similarly, big forces at the short end (hub) translate to smaller forces at the far end, which is why the mounting can be a relatively weedy, such as a pin around 10mm diameter, and a rubber bung.
Well I think I understand but...
Given that up and down movements of the hub are handled by the springs and shocks, and merely pivot on the pivot bar, If I remove the rear tie bar and the springs and shocks and the driveshaft, I am then left with a big lever which by applying a force forward or backwards (laterally not up and down) then this will result in a small movement at the pivot bush but a large force.
And judging by this picture there has been some movement allowed by maybe the rear tie bar.
There has to be some compliance in the trailing arm joint as there is in the rear tie bar. The other bush is just as bad so it is not just that the nearside rear bearing has collapsed somewhat.
So Thanks Adam you have made me think more clearly about this and it looks like I'll have to go the expensive superflex approach.
Nick
Given that up and down movements of the hub are handled by the springs and shocks, and merely pivot on the pivot bar, If I remove the rear tie bar and the springs and shocks and the driveshaft, I am then left with a big lever which by applying a force forward or backwards (laterally not up and down) then this will result in a small movement at the pivot bush but a large force.
And judging by this picture there has been some movement allowed by maybe the rear tie bar.
There has to be some compliance in the trailing arm joint as there is in the rear tie bar. The other bush is just as bad so it is not just that the nearside rear bearing has collapsed somewhat.
So Thanks Adam you have made me think more clearly about this and it looks like I'll have to go the expensive superflex approach.
Nick
Have this setup on mine
It's a compromise between the standard setup and going to a solid joint. It's not clear from the picture but the aluminum eye shaped piece is about 20mm thick and takes some of the movement out of the joint by providing extra support. It's not available to buy, so you would have to have the aluminum pieces made.
It is difficult at the moment to decide what type of suspension bushes to fit. I'm just in the process of replacing the front suspension bushes and had to decide between the standard rubber and poly. As the bushes are no longer made by Ford the decision for rubber is 'new old stock' or after market. How long the rubber would last in the 'new old stock' is any ones guess and the quality of the after market stuff is also hard to judge. So in the end I went for Poly and decided on the SuperPro as these seem to get the best reviews.
Cheers Steve
It's a compromise between the standard setup and going to a solid joint. It's not clear from the picture but the aluminum eye shaped piece is about 20mm thick and takes some of the movement out of the joint by providing extra support. It's not available to buy, so you would have to have the aluminum pieces made.
It is difficult at the moment to decide what type of suspension bushes to fit. I'm just in the process of replacing the front suspension bushes and had to decide between the standard rubber and poly. As the bushes are no longer made by Ford the decision for rubber is 'new old stock' or after market. How long the rubber would last in the 'new old stock' is any ones guess and the quality of the after market stuff is also hard to judge. So in the end I went for Poly and decided on the SuperPro as these seem to get the best reviews.
Cheers Steve
Hi Nick
I had the Superflex bushes fitted as at the time the 280i was being supercharged..these are a vast improvement on the original, I also advised Superflex as regards to the steel inserts which originally were too thick, so now they have the correct ones (Or should have
)...
Its good to clean up the arms, especially any skag around the hole....
....take note of how many washer come off per side as this also changes the GEO of the car....
Hope this helps
Ziga
I had the Superflex bushes fitted as at the time the 280i was being supercharged..these are a vast improvement on the original, I also advised Superflex as regards to the steel inserts which originally were too thick, so now they have the correct ones (Or should have
)...Its good to clean up the arms, especially any skag around the hole....
....take note of how many washer come off per side as this also changes the GEO of the car....Hope this helps
Ziga
Cheers Ziga, yes very helpful.
I didn't take account of the original packing washers as it wasn't done terribly professionally and no point setting back to a wrong setting, so once the car is up and running (this year maybe next) then I'll get all the tracking geometry sorted properly.
Thanks Nick
I didn't take account of the original packing washers as it wasn't done terribly professionally and no point setting back to a wrong setting, so once the car is up and running (this year maybe next) then I'll get all the tracking geometry sorted properly.
Thanks Nick
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