Adjustable Strut with Poly Bushing Failure
Thread Starter
Instructor
Joined: Jun 2006
Posts: 104
Likes: 0
From: Missouri City Texas
Adjustable Strut with Poly Bushing Failure
I replaced my rear struts with the adjustable kind and poly bushings, about 1.5 years ago. Trailing arms where also rebuilt, about 2 years ago. Since then I have put about 500-1000 miles on the 78 corvette.
This week, I noticed that the passenger side rear tire top was leaning inward, severely. So I was ready to readjust the strut, but found the lower bushing (nearest the tire) was completely deformed and over stressed. Driver side still looks ok, but also lean inward slightly.
Before I replace the bushings in the adjustable struts, is there another cause for the poly bushing failure. I think there is excess differential yoke end play. Would this cause the strut bushing failure?
This week, I noticed that the passenger side rear tire top was leaning inward, severely. So I was ready to readjust the strut, but found the lower bushing (nearest the tire) was completely deformed and over stressed. Driver side still looks ok, but also lean inward slightly.
Before I replace the bushings in the adjustable struts, is there another cause for the poly bushing failure. I think there is excess differential yoke end play. Would this cause the strut bushing failure?
Pro
Joined: Jun 2005
Posts: 725
Likes: 1
From: FL.
I replaced my rear struts with the adjustable kind and poly bushings, about 1.5 years ago. Trailing arms where also rebuilt, about 2 years ago. Since then I have put about 500-1000 miles on the 78 corvette.
This week, I noticed that the passenger side rear tire top was leaning inward, severely. So I was ready to readjust the strut, but found the lower bushing (nearest the tire) was completely deformed and over stressed. Driver side still looks ok, but also lean inward slightly.
Before I replace the bushings in the adjustable struts, is there another cause for the poly bushing failure. I think there is excess differential yoke end play. Would this cause the strut bushing failure?
This week, I noticed that the passenger side rear tire top was leaning inward, severely. So I was ready to readjust the strut, but found the lower bushing (nearest the tire) was completely deformed and over stressed. Driver side still looks ok, but also lean inward slightly.
Before I replace the bushings in the adjustable struts, is there another cause for the poly bushing failure. I think there is excess differential yoke end play. Would this cause the strut bushing failure?
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,118
From: Crossville TN
I'm no expert, but poly doesn't have a lot of "give" and that could have hastened its demise. Try syntetic rubber on the replacements and see how they work out. 1000 miles to failure would indicate that the material was defective [to begin with] or that material is incapable of performing that function.
Team Owner
Joined: Apr 1999
Posts: 21,953
Likes: 1,445
From: Reno Nevada
2024 C3 of the Year Finalist- Modified
You have something bad going on. Your diff yokes are probably completely missing the tips clear down to the keepers allowing excessive lateral movement.
The poly end struts are a vast improvement over OEM rubber bushing guys!
The poly end struts are a vast improvement over OEM rubber bushing guys!
Melting Slicks
Joined: Feb 2001
Posts: 3,330
Likes: 13
From: Europe , Luxembourg
Hi
The poly end struts are a vast improvement over OEM rubber bushing guys!
Yes, if you use the Heim eyeball ends.
I also use the fixed poly end fittings and find lots of torsional movement deforming the bushings.
Next replacement will be the eyeball end fittings.
Rgds. Günther
The poly end struts are a vast improvement over OEM rubber bushing guys!
Yes, if you use the Heim eyeball ends.
I also use the fixed poly end fittings and find lots of torsional movement deforming the bushings.
Next replacement will be the eyeball end fittings.
Rgds. Günther
Burning Brakes
Joined: Dec 2007
Posts: 952
Likes: 0
That would depend on the application. Poly has very little compliance.
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Michael S. Palmer
Team Owner
Joined: Apr 1999
Posts: 21,953
Likes: 1,445
From: Reno Nevada
2024 C3 of the Year Finalist- Modified
Well my poly end smart struts are still perfect looking and I race my car around a track. I'm also redoing all the poly bushing on my front a-arms this winter. They look OK, but they have have been beat on for 10-12 years also.
Rear heim metal joints. I don't mind a minor deflection. true ability to generate high speed turning ability is the tires and alignment. My rear 335/35/17 Kumhos really hold the road
Rear heim metal joints. I don't mind a minor deflection. true ability to generate high speed turning ability is the tires and alignment. My rear 335/35/17 Kumhos really hold the road
Race Director
Joined: Jul 2001
Posts: 15,892
Likes: 42
If you cannot achieve normal camber with the strut rods, that's another matter.
Thread Starter
Instructor
Joined: Jun 2006
Posts: 104
Likes: 0
From: Missouri City Texas
Just so you don't go on a wild goose chase, end play in the yokes (no matter how bad it is) has NO effect on strut rod geometry and has not contributed to the deterioration of the present bushings.
If you cannot achieve normal camber with the strut rods, that's another matter.
If you cannot achieve normal camber with the strut rods, that's another matter.
I did notice the tire wear on the inner side, confirming the camber was not set correctly. I do know the adjustable strut was as twisted as tight as possble, as this was done at the alignment shop.
What else would you recommend I look at, if the yoke wear is not an issue?
Race Director
Joined: Jul 2001
Posts: 15,892
Likes: 42
Mike,
I did notice the tire wear on the inner side, confirming the camber was not set correctly. I do know the adjustable strut was as twisted as tight as possble, as this was done at the alignment shop.
What else would you recommend I look at, if the yoke wear is not an issue?
I did notice the tire wear on the inner side, confirming the camber was not set correctly. I do know the adjustable strut was as twisted as tight as possble, as this was done at the alignment shop.
What else would you recommend I look at, if the yoke wear is not an issue?
I was saying above that bad camber will not cause strut rod bushings to fail.
Le Mans Master
Joined: Apr 2007
Posts: 7,353
Likes: 72
From: Graceland in a Not Correctly Restored Stingray
Few listen, but while poly is fine for control arm and anti-roll bar bushings, as mentioned above it isn't best suited to applications which move in 3D by design, such as is the case with rear camber struts. Yes, other issues may cause camber issues, but I'd suggest going back to fresh rubber or stepping up to heim-jointed struts in any event for the long haul.
TSW
