rear suspension bushing replacement Options

[rfuerst911sc]

I just removed the trailing arms from my 75 chassis because I was welding in a GT stiffening kit. Anyway to my eyes the OEM rubber bushings don't look too bad but " while I'm in there " I figure maybe I'll replace them. I am on the Eric Shea waiting list for the group buy Delrin bushings but if that doesn't pan out what are you guys useing? I like the Elephant Racing poly bronze setup but at $300.00 it's a little pricey. And how do you remove the OEM bushings? Do you burn them out? The car will be daily driver,autocross and DE machine with a 3.0 Porsche six with fairly wide rims ( 17x7, 17x9 ). Any advice is appreciated (IMG:style_emoticons/default/biggrin.gif)

[Eric_Shea]

It will happen. The new bushings with the proper hardness have been ordered and we've paid a restocking fee for the old ones. Weeeeeeee (IMG:style_emoticons/default/dry.gif)

Sorry for the delays.

Next: I like to measure the old ones top and bottom for variance. This will tell if you need new bushings.

Removal: I like to have a shop press for this. Others burn them out but man, that's a huge mess. A simple shop press takes about 10 minutes.

I heat the rod with a MAPP torch and press it through one of the bushings. The heat allows it to slide through like butter. Once the rod is through that bushing, take a large screwdriver and pry it out. Next, re-adjust the press shelf and turn the control arm over and begin pressing the other side down. You'll have to press the rod back into this bushing. Again, heat from a MAPP torch helps it slice through. Finally, re-adjust the shelf back up a notch and press the rod the remaining way out through the bushing. Take the large screwdriver and pry the final bushing out.

Done.

[rfuerst911sc]

Eric I'm glad the Delrin bushings are a go (IMG:style_emoticons/default/biggrin.gif) So if I understand your directions the OEM rubber bushings are not vulcanized to the trailing arms? I assume this is correct based on your statement of prying them out with a screwdriver? And in previous email conversations I think you said the Delrin bushings have to be "massaged" to fit? Is it the I.D. or O.D. or both that have to be massaged? And what about cutting grease grooves into the bushings? Any special grease to be used with Delrin? Sorry for all the questions (IMG:style_emoticons/default/blink.gif)

[scotty b]

(IMG:style_emoticons/default/idea.gif) Sounds like a GREAT tech article !!

[Eric_Shea]

I think they're vulcanized... they are vulcanized against a painted surface. In many, I see a white powder like substance on the side walls. Just stick a large screw driver in the hole and leverage up and they come loose.

OD may have to be massaged on the bushings but ID would be for sure. You can cut grooves in them or you can simply put a zerk on them... I don't think grooves are a huge issue, they don't move all that much. I think a zerk and a tube of Mobil1 synthetic and you're good to go. Lube them every so often until you see sone coming out of the shaft area...

I've been planning on doing a write up on those once I get them.

[John]

Those rubber bushings actually have a 914 part number cast into them.

I took a picture of them once and posted the pic on this site (before the changeover).

I don't think they are vulcanized.

I don't know how the factory pressed them together, but I suppose that they were chilled significantly before inserting them into the trailing arm.


I missed the group buy on the Delrin bushings. How much were they and do you have any more available?

[neo914-6]

I just removed the trailing arms from my 75 chassis because I was welding in a GT stiffening kit. Anyway to my eyes the OEM rubber bushings don't look too bad but " while I'm in there " I figure maybe I'll replace them. I am on the Eric Shea waiting list for the group buy Delrin bushings but if that doesn't pan out what are you guys useing? I like the Elephant Racing poly bronze setup but at $300.00 it's a little pricey. And how do you remove the OEM bushings? Do you burn them out? The car will be daily driver,autocross and DE machine with a 3.0 Porsche six with fairly wide rims ( 17x7, 17x9 ). Any advice is appreciated (IMG:style_emoticons/default/biggrin.gif)

I'm writing a tech procedure on roller/needle bearings that references alot of this forums threads. There's a good thread on OEM bushing removal on post 3...