rear torsion flat trailing plate removal

[ericsinaus]

I am trying to remove the flat trailing plate from the torsion bar on the LHS and am afraid that I might pull the bar out of the inner spline.
What confuses me is it also states in a simple Haines manual that you must remove the gearbox to get the torsion bar and trailing flat plate off. ??> Don't understand why.

I just need to remove the outer splined bush and flat plate that bolts to the wishbone with the 4 bolts.

Can I just undo the 4 bolts to the wishbone, then lever the outer bush with spline off the torsion bar.???

Thanks

Eric

[rywats]

The issue is the torsion bars are often ceased into the spring plate.

Take an angle measurement of the spring plate before you pop the spline out of the body, because it’s almost certain to come out. That way you can put it back in at the same spot if you’re keeping the same ride height.

I had to cut my torsion bars to get them out. Didn’t look like they have ever been removed.

If you’re just wanting to lower the car from stock height, 1 spline on the inner body lowers it nicely…

[almostordinary]

Welcome to the Forum Eric.

Those plates can be a real PITA. Below is a good video that will show you what to expect to get them off. In his part 2 there's some good advice in there on how to get the new ones back on.

Video starts where I am assuming you are in your process. But I would start it from the top if you want to take it all in.



There's also another YouTuber called GreasyFingers that has some very in depth explanations on the rear suspension components.

[ericsinaus]

What about the advice to remove the gearbox. Is this necessary as in that Tube video it shows that this guy removed the gearbox.

Why is this necessary, is it really necessary???

[almostordinary]

First what year is your 911?

Second, use that Haines manual for fire tinder.... get yourself a Bentley Service manual for your year car.

https://www.pelicanparts.com/More_Info/PELP989.htm?pn=PEL-P989&bc=c&SVSVSI=0590


The gearbox doesn't need to be removed at all for anything to do w the rear suspension.... any of it.

Like the previous poster said, mark your angle before you remove the spring plate.

You will likely need to pry the cover off as well as the spring plate the rubber is probably seized in the torsion tube... if the bar comes out that's fine... as long as you marked the angle before you took it out... if you didn't mark your angle get a cheap magnetic angle tool, reference your now new Bentley manual and set the proper angle for your ride height.

Setting the height on these cars is a bit of a pain, so you will find yourself pulling the torsion tube on and off multiple times and installing and disassembling the entire setup numerous times until it's right... and you have to do it all over again for the other side. Not a novice task.

Step back, order the manual, do some YouTube searching and use the search tool on this forum. It's not as simple as modern coil over suspension so just take your time.

When you get everything apart, assess what's salvagable and just buy new parts where you can afford.

What was the catalyst to taking it apart?

[ericsinaus]

Thanks for your reply, I couldn't figure why anyone would want to take out the gearbox.
Anyhow, the reason for removing the left torsion plate is because I found a crack in the chassis emanating from the left side lower left outer housing standoff that the lower left bolt goes into. There is a fine crack around the underside of the round boss where it is welded to the chassis and goes further up behind this torsion bar trailing plate. I need to get this plate off, weld it up then replace everything. I think the rubbers are ok.

It is a 1980 911 3ltr, sc Targa.

I feel confident about tackling this now.

The left wheel wears a bit on the inner edge and has more negative camber. I think it might be a good opportunity to maybe try to raise the left side by the cam fine adjustment to get the left wheel more vertical and reduce the negative camber.

I have attached 2 photos of this crack but don't know how successful this has been as I can't see the photo but only the text of the pictures in this box. !!!


Thanks

Eric

[ericsinaus]

I am not intending to remove the right side as there are no cracks here, so Im leaving it alone. Just doing the left.
I did see this UTube video. I just intend to remove the 4 bolts from the wishbone, support the wishbone and then just try to lever off the torsion bar end with plate. I am not disassembling the brakes or anything else.
Weld up the crack and probably put an extra gusset plate in, paint it then reassemble.

[HaroldMHedge]

Since you plan on a gusset plate, did you know there are some premade ones here on Pelican.

Porsche Elephant Racing Spring Plate Reinforcement Kit
Porsche Cover Plate for Rear Torsion Bar/ Spring Plate, Bushings, and Strengthening Kit

[almostordinary]

Here's a fresh off the press video showing your exact car.



I would use something on the torsion bar like a few heavy rags so you don't scratch it if you need to use the vise grip method which they are in this video.

[rwest]

Hi Eric,

The Haynes manual has some good info, you just need to think it through a bit before you follow all of their advice as they base it more on a complete tear down and not as much on each individual repair.

There can be a situation where the bolts holding the trailing arms to the body in the middle near the transmission/torsion bar tube have been installed in a manner that you can’t pull the bolts all the way out because they hit the transmission otherwise there isn’t a need to remove the engine or transmission.