Suspension Bushings
Discussion
Remember reading in the past about how too soft the supplied suspension bushing were.
Well, they might be OK for the front, but the sole one at the bottom of the rear upright sure didn't last long.
Noticed yesterday some play in the right wheel when I went to torque the wheel nuts while the car was on jackstands. The problem was the bushing which not only did no longer have a round hole in it for the bolt to go through, but it had also shrunk in width about .050".
And that was only after 5000 miles of very gentle driving.
If you look at the mechanics of the rear suspension, that little bushings take a hell of a beating, and is far too soft for the job.
Did I see in the past some alternates that were mentioned for these bushings.
thanks
Jack
Well, they might be OK for the front, but the sole one at the bottom of the rear upright sure didn't last long.
Noticed yesterday some play in the right wheel when I went to torque the wheel nuts while the car was on jackstands. The problem was the bushing which not only did no longer have a round hole in it for the bolt to go through, but it had also shrunk in width about .050".
And that was only after 5000 miles of very gentle driving.
If you look at the mechanics of the rear suspension, that little bushings take a hell of a beating, and is far too soft for the job.
Did I see in the past some alternates that were mentioned for these bushings.
thanks
Jack
Thanks Paul, but if the black ones wear, I'd like to find a better solution.
These bushings would be very easy to machine. Am going to look into getting some materials and try it.
Does anybody have any idea what material might work?
I've made bushing out of teflon, but I think it might be too soft. Might even investigate bronze with a grease fitting installed.
Jack
These bushings would be very easy to machine. Am going to look into getting some materials and try it.
Does anybody have any idea what material might work?
I've made bushing out of teflon, but I think it might be too soft. Might even investigate bronze with a grease fitting installed.
Jack
I machined all the suspension bushings on my famous Real Street Eliminator Championship winning Cadillac Fleetwood from Delrin with grease fittings. After nine years on a heavy car that gets drag raced and road race regularly they're still tight. If you make some I'll buy a set Jack.
Jeff
Jeff
You could always go for an extreme solution and replace the lower rear wishbones with fully rose jointed ones!
Thinking along similar lines I wonder why the rear wishbone has that Nylatron(?) bush at all? All of the other outboard joints on the suspension have hard ball or rose joints. Would it not make sense to have a big rose joint on the outer end of the bottom wishbone but still keep the softer more forgiving bushes on the inboard side? There is probably a deep and complicated reason why it is the way it is beyond the small cost increase....
Given the weight of the engine and the fact you don't have steering to contend with I wouldn't have thought that comfort was likely to be an issue either?
Thinking along similar lines I wonder why the rear wishbone has that Nylatron(?) bush at all? All of the other outboard joints on the suspension have hard ball or rose joints. Would it not make sense to have a big rose joint on the outer end of the bottom wishbone but still keep the softer more forgiving bushes on the inboard side? There is probably a deep and complicated reason why it is the way it is beyond the small cost increase....
Given the weight of the engine and the fact you don't have steering to contend with I wouldn't have thought that comfort was likely to be an issue either?
Check with my friend who is building the Porsche Ultima, and they're using Heim (rose) joints. Obviously that eliminates the problem, except for converting over.
Jeff, I'm going to give Commercial Plastics a call today and look into the Delrin, but since a Heim joint is fairly solid, that's why I thought about the bronze.
What do you think?
Will pass on any info I'm able find.
Jack
Jeff, I'm going to give Commercial Plastics a call today and look into the Delrin, but since a Heim joint is fairly solid, that's why I thought about the bronze.
What do you think?
Will pass on any info I'm able find.
Jack
You can't use anything too rigid like bronze. You need a fairly compliant material to allow you to set the rear toe-in and deal with any alignment issues when the upright goes up and down. Hence the squidgy plastic or rose joint.
Another issue I can see with using bronze is the lubrication. The bearing surfaces in rose joints have clever hardened plastic coatings which provide lifelong lubrication (in theory). If you make your own you'll have to address this somehow.
Another issue I can see with using bronze is the lubrication. The bearing surfaces in rose joints have clever hardened plastic coatings which provide lifelong lubrication (in theory). If you make your own you'll have to address this somehow.
Good point Dave about the bronze.
Before I go into my possible solution to this problem, I feel that the factory must be aware of the problem and should have made buyers aware of it. Having these bushing wear out in a few hundred miles is ridiculous.
I had a car that had some play in the rear, and on the track the rear end was steering the car, not a nice feeling. Since then, I make a practice to keep all suspension joints tight.
At this point I feel the best solution is to retro-fit with a rose joint, which is how the factory should supply it as standard.
I know if I were to discuss this bushing problem with the factory, I'd be told it's not a problem. But it seems that others have it too, and in my opinion, it's not right.
The easiest way right now is to fabricate new bushings, so at Jeff S.'s suggestion, I went out today and bought a bar of Delvin which I will use to fabricate a new set for Jeff and I tomorrow.
The good thing is they're easy to change and check on, so every so often I'll check them. The car is scheduled to be on the track Sept 20 & 21, which will be the hardest the car has been driven to date. Will check and see how the Delrin held up right after the track days.
Will also be looking at what's involved in fitting rose joints.
Jack
Before I go into my possible solution to this problem, I feel that the factory must be aware of the problem and should have made buyers aware of it. Having these bushing wear out in a few hundred miles is ridiculous.
I had a car that had some play in the rear, and on the track the rear end was steering the car, not a nice feeling. Since then, I make a practice to keep all suspension joints tight.
At this point I feel the best solution is to retro-fit with a rose joint, which is how the factory should supply it as standard.
I know if I were to discuss this bushing problem with the factory, I'd be told it's not a problem. But it seems that others have it too, and in my opinion, it's not right.
The easiest way right now is to fabricate new bushings, so at Jeff S.'s suggestion, I went out today and bought a bar of Delvin which I will use to fabricate a new set for Jeff and I tomorrow.
The good thing is they're easy to change and check on, so every so often I'll check them. The car is scheduled to be on the track Sept 20 & 21, which will be the hardest the car has been driven to date. Will check and see how the Delrin held up right after the track days.
Will also be looking at what's involved in fitting rose joints.
Jack
Count me in too if it works..... Ive found that it is the lower rear bush (as you've described) but also the upper front bushes that wear on the rear.
I will say that when mine first went (1000miles) I showed the car to the factory and they supplied new ones (only £20-30 for full set anyhow), so maybe its not every car that's a problem.
Also the Nylatron bushes are much stiffer and it may be better to get a set of these just for the rear.
I will say that when mine first went (1000miles) I showed the car to the factory and they supplied new ones (only £20-30 for full set anyhow), so maybe its not every car that's a problem.
Also the Nylatron bushes are much stiffer and it may be better to get a set of these just for the rear.
I checked mine last night and the bushing on the lower A arm that attaches to the rear of the spindle is sloppy. The other 4 that bolt to the chassis are pretty tight. This after 8000 miles. I'm also set to attend a track event Sept 27th and a magazine competition Oct 16- 18 in Bristol TN. Need to have everything right. This might explain the wheel ho problem I've had lately.
Jeff
Jeff
Updates;
Have been asked how to check for play.
Jack rear end of car up.
Set emergency brake.
Get breaker bar or torque wrench with 7/8" socket and standing at rear of car, put wrench on a wheel nut and exert a lifting motion. If the bushing is sloppy, you'll feel the whole upright move.
It's not a matter of the supplied bushing wearing, it's a matter of the bushing deforming.
We made a set today out of delrin and installed one set on the right side. Because of the hardness of the delrin, it's not quite as easy to install as the soft molded ones, but a little gentle force will help.
Jeff, will get you a set made in between repairing the rear clip. When we went for a test drive and didn't secure the engine cover, I now highly recommend a micro switch warning light.
Jack
Have been asked how to check for play.
Jack rear end of car up.
Set emergency brake.
Get breaker bar or torque wrench with 7/8" socket and standing at rear of car, put wrench on a wheel nut and exert a lifting motion. If the bushing is sloppy, you'll feel the whole upright move.
It's not a matter of the supplied bushing wearing, it's a matter of the bushing deforming.
We made a set today out of delrin and installed one set on the right side. Because of the hardness of the delrin, it's not quite as easy to install as the soft molded ones, but a little gentle force will help.
Jeff, will get you a set made in between repairing the rear clip. When we went for a test drive and didn't secure the engine cover, I now highly recommend a micro switch warning light.
Jack
Same bushing at bottom of my rear uprights had some play when brand new, on both sides! The inner steel bushings protruded about 1-2mm from the urethane so when clamped by bolt and big washer, urethane could still slide back and fore a little bit. Would imagine any play at all down there would result in serious wear very quickly. Fixed it by dressing of the inner steel bushing to leave zero play (small preload on plastic). Not a problem on any of the inner wishbone bushings. I'm keeping a close eye on wear, none yet.
GDR
We did the same thing to the left side of car with the factory bushings. Machined .040" off inner spacer, and that tightened everything up.
What we did with the Delrin bushings was to assemble everything, torque the bolt, then measured the play with a feeler gauge. Re-machined the innerspacer to leave .002" clearance.
http://home.comcast.net/~rosenracing5/wsb/html/view.cgi-photo.html--SiteID-941121.html
Will give update on new bushings after the two trackdates.
Jack
We did the same thing to the left side of car with the factory bushings. Machined .040" off inner spacer, and that tightened everything up.
What we did with the Delrin bushings was to assemble everything, torque the bolt, then measured the play with a feeler gauge. Re-machined the innerspacer to leave .002" clearance.
http://home.comcast.net/~rosenracing5/wsb/html/view.cgi-photo.html--SiteID-941121.html
Will give update on new bushings after the two trackdates.
Jack
Further update.
Driving the car with both lower bushings tight, the car seems to wander a little less, but that could also be because of the new Pirelli Rossos, rather than the Michelin Pilots that were on the rear.
As for changing over that bushing to a Heim (rose) joint, it can be done, but it would involve some very careful cutting and fitting of a threaded insert into the tube, as there is another tube that interfers at the junction. The geometry has to be perfect, as any changing in the position of that bearing will affect the wheelbase, and the tire will not fit in the wheelwell if just slightly off.
The easiest solution might be to just buy a lower control arm and associated parts from the factory which will probably mean you'll have to convert the inner lower bushings over to heim also, unless they have, or will fabricate a special one for you that retains the nylon inner bushings.
If someone will, or already has discussed this with the factory, would like to hear the results.
Jack
Driving the car with both lower bushings tight, the car seems to wander a little less, but that could also be because of the new Pirelli Rossos, rather than the Michelin Pilots that were on the rear.
As for changing over that bushing to a Heim (rose) joint, it can be done, but it would involve some very careful cutting and fitting of a threaded insert into the tube, as there is another tube that interfers at the junction. The geometry has to be perfect, as any changing in the position of that bearing will affect the wheelbase, and the tire will not fit in the wheelwell if just slightly off.
The easiest solution might be to just buy a lower control arm and associated parts from the factory which will probably mean you'll have to convert the inner lower bushings over to heim also, unless they have, or will fabricate a special one for you that retains the nylon inner bushings.
If someone will, or already has discussed this with the factory, would like to hear the results.
Jack
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