Rear Springplate Bushing Replacement
 

Hi All,

I am getting ready to replace my very wornout rear spring plate bushings (sorry Chuck, but my wallet said to go with the Neatrix although Steve W showed me your product and under other circumstances, it would be the way to go).

Anyway, as near as I can tell, the sequence goes something like:

-Jack up car and support rear by torsion bar tubes
-Support lower shock mount and remove bolt
-Remove eccentric bolts (mark location/orientation for reinstallation)
-Remove bolts at wheel and allow spring plate to "droop"
-Measure droop angle for reinstallation
-Remove springplate cover
-Remove springplate from torsion bar (this is supposed to be "big fun")
-Cut/burn old bushing off of spring plate
-Clean and paint springplate
-Install new bushings
-As Haynes sez, reverse to reinstall.

While I am in there I will be replacing the shocks as well before I bring it in for lower/align/corner balance at the local speed shop.

Any comments are appreciated.

SmileWavy

Take note of car angle before beginning if you aren't doing both sides at the same time. This is going to effect angle finder on droop.

Good time to lower her before the corner balance and you'll already have the bars out. Think about it before its too late.

Burning bushings REALLY stink so make sure your garage door is cracked or your wife will &*#( you.

Only fun/challenge in disassembly is if/when the torsion bar gets corroded and stuck in outside splines. I ended up placing the torsion bar loose against bushing and gently persuading the cover with a precision metallic object attached to a hard wood handle.

Too bad you don't live next door. Just removed Neatrix bushings this weekend. Redoing whole rear supsension....nothing went wrong with the Neatrix bushings.

Here is a tip:

Use a torch to heat the metal ID of the spring plate tube. This will melt the rubber bush where it attaches. Then work a flat-blade screw driver between rubber and metal to detach the bushing. It will then come off (95%) in one big donut.


I also advise having the spring plates replated instead of painting. Should cost about $50.

Thanks.

Luke, I discussed the advantage (saving $$) to lowering the car before I bring it to the shop but they discouraged me since they will most likely undo what I did anyway to get the corner balance right.

Chuck, All I have is a propane torch, will that do the trick?

im going to have this done by a shop in the next few monthes (dont trust myself). any ideas what i should expect to pay in labor for replacing spring plate bushings, bannana arm bushings, lowering the ride height and alignment?

Harry,

I have about $800 for parts (shocks (set of four), spring plate bushings, and spring plate covers). I am figuring about 6-8 hours of shop time to align, lower, and orner balance.

Add another 6-8 hrs to install my parts (bushings and shocks) and you should have most of your answer. I am not doing the banana arm bushes.

Hope this helps.

HarryD, done it a couple of times. First time it took some 12-14 hrs for two guys, my self and a friend. We had no previous experince, but the Haynes "manual". Now last I did the left side in 1,5 hrs incl. one short sandwich and Coke break.

Then make sure the car is very secured when lifted, as huge pressure is needed when removing old spring plates.

Kris

well i have all new struts already in the car. the rears i did myself 2 years ago, the fronts were done this past spring when i had my mechanic replace the front pan (a little 'while youre in there' work).

but my rear bushings are toast and im sick of the 'paris dakar' look. also my rear wheel bearings need replaced. i know how much bushings cost, neatrix and elephant racing, as well as other parts (wheel bearings).

i want to go with elephant racing bushings as i had originally planned on.. but that might have gone to the crapper since ive decided to have the engine rebuilt rather than go with a slightly used runner. it will all depend on the final bill when i get the engine back.

but if a shop were to do it, how much would it cost minus parts? is it a $1000 job? $1500 job?

i would attempt it myself, but my parents are selling their house and i no longer have access to my parents garage.

the garage at my place.. well.. its a cracker jack box with barely enough room to allow me to open the doors. as far as doing it in the drive way, my driveway is on a slope that goes down hill towards the road.

http://gallery.rennlist.com/albums/albup76/garage.jpg

on top of that since i have never done it and i dont know anyone in the area who could help me if i get over my head, i think its best i take it to the shop.

Harry,
Your in a lot better location, that being Columbus than me in Terre Haute, so just get out and meet some guys this spring. I never did this before, either, but this forum can get you through most things IF you've worked around cars in the past. If NOT, then certainly hire a shop. A local Porsche dealership could probably quote you a price and then you could figure this to be on the high side for a private shop.

Seems like I've seen a $3-350 thrown around for an alignment and balance only. I too, will have to have this done before she leaves the garage.

Many of the UK guys would envy your garage size :)

I did this not too long ago. I also wanted to get rid of the rally ride height. Once I had the spring plates at full droop, I measured from the floor to the lowest point on the spring plate. So, if I wanted to lower the car 1 inch, I just added 1 inch to the measurement and got the spring plate indexed on the torsion bars as close as I could. When all said and done, I was what my mechanic called "dead nuts on". I was lucky. Also, getting the torsion bar covers on was an ordeal itself. The first time I put one back on , 3 of the 4 holes would not line up. I got some advice to purchase some long bolts with the same thread pitch and some medium length ones. Start with the long and tighten down each one little by little. Then switch to the medium, the original. Worked like a charm.

Good Luck!

911 Brian,

Thanks for the tip about the bolts. I'll pick some up at my local Ace Hardware. What sizes did you use?

The next time you need to do spring plate angles, go to http://rennlight.com/cgi-bin/spring.cgi

I used a propane torch to remove mine. Worked great! It takes some time though. Pics of my installation are here last time I checked. This thread made me go ahead and do mine, and lower it.

http://www.dorkiphus.com/porsche/viewtopic.php?t=1618

Harry,

What shop do you usually use. I go to Acceleration on North High St. $60 / hour and the Porsche guy knows what he is doing. I would help but my two jobs, house getting ready for sale, and finance (third job) eat up just about every waking hour.

Doug
Columbus, OH

Hmm.... I disagree. The real labor expense is in getting the torsion bars indexed close enough that you can dial in ride height +/- 3/4" using the spring plate eccentric adjusters. While you have it all disassembled you can get that close, making sure you adjust your eccentrics to "center" when you reassemble to allow up/down adjustment.

Otherwise, the shop is going to charge you to reindex those torsion bars and that is the really time consuming part.

harry

here's how mine went.

http://forums.pelicanparts.com/showthread.php?s=&threadid=136886&highlight=angle+ finder

good luck.

Doug,

i go to Ed Pimm, who is up in powell. he does everything from 356s to 996s. but his real expertice is in full restos of vintage porsches. does paint, mechanicals, engine rebuilds, gear box rebuilds, everything. he charges the same as well, 60/hr. i guess im just currious how many hours the job is. ill just give him a call and get an estimate.

I see your point but the guy doing my lowering was the Crew Chief for a winning Lemans car a few years back. Hate to second guess him.

I don't remember. I took the bolts with me to Home Depot and there was some type of device there where I could match up thread pitch and all. I think they were almost 3 inches or so for the long ones.

The hard part was getting the darn things off in the first place.

911 Brian,

I had seen this note of using longer bolts to seat the springplate cover before.

Did you reuse your original cover one? I have heard that they are quite grungy/rusty and "while you got it apart" you should replace it for the next 30+ years of service. I wonder if that has something to do with the difficulty in getting it to fit.