Spring Plate Bushing Removal - Tip and help
 

I've read numerous descriptions of PITA struggles to get old factory vulcanized bushings off the 911 spring plates. I tried something that worked beautifully and thought I'd share it...

This technique requires sacrificing a wood chisel about 3/4" wide. It doesn't have to be very sharp. Heat the end of the chisel with propane, MAPP gas or oxy-acetylene. I used oxy-acetylene because it heats much faster. The chisel doesn't have to be red hot, but close too it. The hot chisel cuts through the rubber bushing like it was cheddar cheese. Keep the torch going because you need to re-heat the chisel as soon as it cools and stops cutting. The bushing can be carved off in slabs - like boning a ham, if I can use another food simile. It's very quick and satisfying compared with other methods I know of. Residual rubber can be removed with wire wheel or emery cloth.

Now, I need some help on a related problem. I had no trouble getting the bushings off the spring plates that are going on the car, but I'm stuck getting the old spring plates off the car. It's a '71 California T, in good shape, with no rust. Everything came apart nicely up to this point. There was even good paint on the inside of the outer bushing cover.

I've wiggled and pried as hard as I dare without crushing the mounting bosses into the car frame. I can't tell if the bushing is stuck in the car or if the torsion bar is stuck at both ends. I tried heating the end of the T-bar tube with a torch, but no difference. Are there any other tricks? At what point do you drill or chisel out the end cap of the T-bar and use a puller? Are those caps replaceable?

Any help is welcome. Thanks.





http://forums.pelicanparts.com/uploa...1279494483.jpg

Spring plate removal.........
 

Paul,

The spring plates could be hard to removed due to the inner rubber bushing sticking to the body due to corrosion or adhesion. You have to first overcome the bushing's adhesion to the mounting hole by spraying lubricant (penetrating oil) and apply force to extract the unit.

Secondly, even if you are successful in pulling out the spring plate, there is a good chance that the spring plate is stuck to the TB. A suitable tool for separating the TB from the spring plate unit is a gear puller.

It will take some patience to separate a corroded torsion bar cover (spring plate) from the TB. The disc portion of the TB cover is not welded just pressed and crimped. You either remove the disc or drill a hole to conveniently use an appropriate size gear puller. Keep us posted.

Tony

I just did this last night. Oh what fun!

I dont know what they are called, but the things the spring plate cover bolt to. I used a pry bar between the two front thingies and the spring plate. Top, then bottom, then top, then bottom. Came right off.

One side i was able to drill a hole in the cover plate and use a small punch to drive the TB out. The other side I had to use a dremmel to cut out the cover plate and use a BIG punch to drive the TB out.

Thanks for the suggestions.

At this point I believe it's the torsion bar splines stuck in the spring plate. The bushing itself seems supple and moves around a bit in its hole in the frame. So, I'll be popping out the cap and trying a puller tomorrow. I'll let you know how it turns out.

-Paul

All you need to remove the rubber from the springplate is a hacksaw to saw off large chunks, then a torch to cook the small bits off.

just cut the torsion bar with a grinder.
i know you want to upgrade the torsion bar. yes, it's about time you need new one, Paul.

lot's of ways to get the bushings off. Most are pretty horrible experiences.

We just came out with this bushing cutter.

http://forums.pelicanparts.com/uploa...1279522122.jpg

This is the easiest way to get the bushings off. We need to make a video to show has easy this works.

Basically it's a cylindrical cutter with a "T" handle and you work it down over the spring plate to slice the bushing away. It shaves it very close.

So NOW you come out with the bushing cutter. ;)

I am done with my suspension work and you come out with tools to make the job easier. :p

My usual good timing.

use wood shims from above and below with them pointing toward each other and hammer them down and up to slowly wedge the spring plates and bushings out of the hole. works well and is not very labor intensive. I used the plastic "wood" shims commonly used with cabinetry work. They don't bust as easy as wood shims.

Then torch the f*ckers to get em off of the spring plates, but make sure the torsion bars are out fist otherwise you may heat treat the torsion bars.

Packy - that sounds like a good idea, though i worry that if the spring plate is stuck hard enough, then driving a wedge behind it, working against the thin steel of the unibody will end up denting the unibody if the spring plate doesn't let go first.

I think the body is pretty solid right there (high loads in that area) and so is the spring plate. I think you are mostly wedging where the outer tube is welded to the chassis and the bending moment on the spring plate shouldn't be that bad if you stay close to the torsion bar tube. But, your call. It worked great for me and mine was stuck pretty good. no dents. I didn't even worry about it. you could also try to wedge both sides so the whole assembly doesn't get off axis and the load is distributed better.

Try the 'John Walker' method. Drill and tap a zerk fitting in the end of the tube cover and pump grease into it and hydraulic pressure pops it out. Search this out.

Paul,

You already did the hardest part of the job removing the old original bushings. That is a PITA job although your process seemed a bit smarter/easier than mine. Believe it or not, removing the spring plates from the car is a lot easier. I recently replaced my front and rear torsion bars on my 1970 911S. I take it this is your first time removing the rear spring plates and torsion bars of any 911 right?
I don't know the history of your car but if it has been a California car all its life and the spring plates /TB's have never been removed, (although looking at the picture of your bushings they look in decent shape and I suspect that the spring plates have been off before) the removal of the spring plates will be easier than most east coast cars but it still will require a lot of force with the largest crow bar you can get your hands on. PROPER TOOLS ARE THE KEY TO THIS JOB. As others have mentioned and as you have previously attempted, use the car's 4 spring plate cover bolt mounting points as the leverage point to place the LARGEST CROW BAR you can get your hands on between the spring plate and those 4 mounting points. I used a crow bar about 2.5 - 3 feet long and it made the job so much easier. Don't be afraid to use brute force....protect your hands with good gloves and protect the inside/outside of your fenders in the event the crow bar slips. You don't want to dent or scratch your quarter panels or hurt yourself in the process. Loosen/pry away at each of the 4 mounting points equally if you can fit the crow bar at each point and you will get it in due time.

After you get the spring plate loose and away from the body of the car, I am sure the torsion bar will be stuck inside the spring plate. At this point, there are several methods to remove the TB from the spring plate. However, according to your initial post it seems that you already have new spring plates and I assume new torsion bars. If you don't give a flock about your old TB I suggest cutting the TB away from the spring plate which should take about 2 minutes with the proper power tool ...or you can try to wrestle the TB away from the spring plate by holding the TB with vice grips and pounding the inside of the spring plate with a hammer. If that doesen't work and you are determined to save your old TB's, drill a hole in the TB cover and use some type of wheel puller to seperate the TB from the spring plate. Hope this helps.

Keep us posted on your progress. There are many posts with pictures here detailing the process I just describe. If you need pics, PM me.

OK... I'm still at it. I'm determined to get this thing to surrender without doing damage to anything more than the spring plate.

I popped off the end cap of the spring plate tube and have been shooting it with PB Blaster .
I've heated it up with a torch and pried, with plenty of leverage, but it's not moving. Also tried heating the tube with a torch, but it's not ready to come out yet.

I fit the biggest puller I can get into the space. It should be good for about 5 tons of pull, and I've cranked it already about 3/4 as far as I think I can go before folding over the flanges of the spring plate. I'm going to let it soak until I get home tonight, then heat it again, and give it a pull. I might cut the aft ends of the puller jaws off first, so they don't slam into the inside of the fender if all hell breaks loose. Wish me luck....

http://forums.pelicanparts.com/uploa...1279728890.jpg

since the spring plate is destroyed anyway, use a cutoff wheel to make 1 or 2 slits in the splined section of the spring plates.

A couple slits running linearly will loosen the grip on the splines.

Looks like you have the spring plate about halway off as can be seen by the inside bushing showing some of its ugly face.

If the other side proves to be as difficult as this side has been, you may want to use a steel rod..ideally an old front 18mm torsion bar from this car works nicely, and feed it through the empty torsion tube until it reaches the stuck rear torsion bar on the other side. Then hammer on the old 18mm torsion bar to tap the stuck rear bar out.

Hi Chuck,

I'm not planning to reuse the spring plates, but out of curiosity...

They might well be destroyed by the time I'm finished, but what makes you say they're already, destroyed? Is it because I pried the cap out or because they've been heated? I can easily make at new cap that fits precisely (I have a wire EDM machine at my shop) and stake it back in.

-Paul

Targa Guy - Thanks. I'm counting on being able to do that for the other side.

Also, that little bit of clean looking rubber bushing showed itself as soon as I took the outer cover plate off. I haven't been able to increase the amount of ruber I can see the least bit. I assume that is just the portion of the bushing that gets worked with the rotation of the spring when it's all squeezed together.

I wonder if my new Harbor Freight Multi tool will cut the bushing?

I would be worried about the jaws slipping off of the springplate, and the other jaws slamming into the fender. If it were my car, I'd cut the ends of the jaws between the first and second bolt hole, and wrap the thing in a towel.