Polyurethane or Rubber
Thread Starter
Intermediate
Joined: May 2004
Posts: 38
Likes: 0
From: Milwaukee WI
Polyurethane or Rubber
I am tearing apart my rear end on my 1977, because the broken differential cover. As long as I have everything apart I am going to POR-15 everything. But I would like some opinions on rebuilding with polyurethane over rubber bushings. Is it worth the extra money? Is there any that not worth replacing. Example the crossmember cushions seem pretty expensive.
Instructor
Joined: Aug 2002
Posts: 195
Likes: 21
From: Upstate SC
I just rebuilt the whole underside of my 70 a few months ago. The crossmember bushings almost never go bad. You should be able to reuse them. I put a composite spring on the rear with adjustable poly bushed strut rods. I had Bair's rebuild the trailing arms and put in rubber bushings. I put poly bushings in the front susp and 460# front springs. I also rebuilt the steering. I am very pleased with the way my car feels and handles now. I was afraid of the poly bushings at first because I thought the ride may be overly harsh and they might squeak. They aren't really harsh at all and don't squeak. I believe the lack of squeaks is due to the extreme care I used in lubricating them before installation. Good luck.
Le Mans Master
Joined: Apr 2000
Posts: 7,562
Likes: 9
From: B'Ville NY
Cruise-In III Veteran
St. Jude Donor '05
Poly will far outlast the rubber bushings. Unless you're going to NCRS status, I'd do it once with the polys then forget about it for a long time 
It's rare to have to replace the crossmember bushings, but if they're available then some people do need to change them.
To replace the front differential bushing, you'll need to drop the attachment bracket out of the way (2 bolts), then you should be able to access the bolt that goes thru the bushing
It's rare to have to replace the crossmember bushings, but if they're available then some people do need to change them.To replace the front differential bushing, you'll need to drop the attachment bracket out of the way (2 bolts), then you should be able to access the bolt that goes thru the bushing
Le Mans Master
Joined: Oct 2004
Posts: 5,269
Likes: 54
From: Orlando Florida
St. Jude Donor '05
Looking at the old rubber stuff that I removed the decision to buy poly was easy.... you probably (and hopefully) won't need the crossmember cushions - these never go bad and are about $150 ... pretty expensive for two pieces of rubber 
I'm not so sure about the poly cushions for the spring, my rear is pretty harsh, not sure if it would be better with rubber...
I'm not so sure about the poly cushions for the spring, my rear is pretty harsh, not sure if it would be better with rubber...
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