Rear spring plate removal – question

[sailchef]

Background info- the PO had the ride height set way to low. I forgot to measure before putting it up on blocks but it was lower than euro. The rear fender lips came down over the sidewalls. I actually measured it a few years ago and I’m thinking it was set around 24”.

I’m thinking it still has the original T-bars. The T-bar covers and bushings are trashed. The renewal process has begun.

Where I’m at- The car is up, shocks and sway bar disconnected, the four T-bar cover bolts are loose with the bottom stop-bolt removed. The two bolts holding the spring plate to the trailing arm are broken loose; I haven’t touched the other four yet.

Here’s what happening- When I drop the trailing arm as far as it will go, the lower edge of the spring plate doesn’t clear the lower bolt hole for the T-bar cover. After all my reading, I fully expected the lower edge of the spring plate to fall well below this hole. It doesn’t. The half shaft is keeping it from dropping any farther. Is this because the ride height was set too low to begin with?

I’m hesitant to remove the bolts connecting it to the trailing arm until I’m sure the tension is off the T-bars.




Its hanging freely @ 32 degrees.



The distance between the scribe mark and the top of spring plate is all the travel I got after removing the shock and sway bar.



Any Ideas? I'm thinking I'm good to go with caution.

[Driven97]

That's a lot of droop. The shock is undone? If there's tension in it still, you'll have a bear of a time getting the bolts to the trailing arm out. Should be able to tell by that.

[sailchef]

Not sure what I thought it would look like at full droop. I'm going to give it a shot. What had me puzzled was the fact that the spring plate didn't move much lower after the shock was removed.

[Flieger]

The damper will keep it from drooping further I believe. Not sure if it can go far enough to damage the CV's.

[mreid]

Leave the lower bolt with the spacer in place. That way the arm can rest on the spacer while you remove the bolts connecting to the trailing arm. Then place a jack under the now free plate and lift it just enough to clear the spacer and remove that bolt. remove the jack, measure the angle, and you are good to go.

[dipso]

It doesn't droop as long as it is connected to the torsion bar. Once it is off the torsion bar it will fall to the ground.
You want to pull it off the bar, the, bar may come out of the Transmission side with it. If it does, just put it back together at your new height and you will be fine.

Remember the Torsion bar at the transmission side has different notch sizing than the end at the spring plate. Sometimes to get the exact height you want you have to rotate the bar 1 notch and then the spring plate 1 notch.
That will give you a split height vs just moving the spring plate side 2 notches.

I don't use an angle finder. I use a tape measure.
Measure the distance from the tip of the spring plate to the ground once everything is disconnected from it. Lets say it is 8". If you want to lower your car 1", reassemble everything so the tip is at 9".
It's a lot simpler that way.
If you want to raise it 1", reassemble at 7''.

It won't be exactly in 1" increments, but you will see how it works with a combination of rotating the torsion bar and the spring plate.

[hank911]

Great thread
Getting ready to lower my 78SC, looks like a 4x4!

[sailchef]

OK, that was a whole lot of over thinking on my part. I envisioned a broken arm and bloody chin if I didn’t get it right.

When it came down to it, after I “drooped” the trailing arm, I loosened all the bolts, and using a small jack I maneuvered the trailing arm up and down a little until everything was lined up right and I could see the loosened mounting bolts twitch a little. I did one at a time like that and they came out with no problem; then I raised the trailing arm back up and out of the way. Two years of armchair prep made it easy. I’ll do the other side tomorrow.

Now I need to decide on whether or not I will use the larger bars and new bushings I bought a few years ago or use the original bars and just raise it a little. It was easy enough that I might use the method explained by dipso and raise it an inch to see how I like it.

The bushings show signs of flowing and are a little chewed up so replacing them makes sense.
I’ll make that decision after I see what the other side looks like. Then it’ll be ‘’To glue, or not to glue”.

Done


done,


and done


the flow


and more flow


Heck, it’s been a while since I’ve been down the slippery slope and it feels good to be working on my car again.

[mrhaydndownes]

Hey Sailchef,

I have a question for you, what type of bushing are you going to re-install??

There are multiple threads regarding Stock rubber bushings "squeaking" after installation.

Options around this are:
- Glue as you already mentioned
- poly bushings (which require shaving or turning to ensure an accurate fit)
- elephant racing poly/bronze bushings, which apparently drop in with no noise issues

Just raising a potential issue for you, as it's easier to correct now before assembly, because otherwise you're in a re-do situation if they squeak, which is never nice.

Let us know what you decide to do.

H

[E Sully]

911 Spring Plate Angle Calculator

[sailchef]

mrhaydndownes,

I plan to use a set of netrix bushings that have been waiting on a shelf for several years now. I will use a tube of super glue with each one and call it a day. A lot of info out there on bushings, I plan to keep it simple and see what happens.

My plan to upgrade to bigger bars will be put on hold as well. I bought a set of 22/29 T-bars last year to install but have changed my mind on that all in the spirit of keeping this project simple. When I removed the spring plates they came off the outer splines without any issues. The inner splines are in there pretty snug, I haven't really tried to pull them out yet but again, in keeping this as pain free as possible I think I will put the car back together using the stock bars that are in there, and just raise the car up a bit; raising the rear end has always been the whole point of doing this project. It was set way to low by the PO.

Taking apart the second side took all of an hour and then another hour later in the day to remove the old bushings on one of the spring plates. I figure It'll all be put back together on my next couple days off.

One down, one to go.



I'll do a little parts cleaning before it all goes back together.

[dipso]

You may have to take out the torsion bar to rotate it.
One spline move on the spring plate side is pretty far.
If I remember, rotating the torsion bar one notch and then the spring plate one notch. Lowers or raises about 3/4".
One move on the torsion bar side alone moves it quite a bit. Probably 1 1/2". That's too much.
You'll see.

[dipso]

I just measured. I used to be at 23 3/4", now I am at 24 1/4". That was one spline move on the bar, then I put the spring plate back on, probably in the same notch.

[juanbenae]

Originally Posted by E Sully

911 Spring Plate Angle Calculator

don't fret on where it was because it was not where you wanted it with tired old bushings as I read it. reset things with the calculator link ed supplies. start from scratch with the "new" desired droop of the spring plates with the adjustments, both camber/toe & height dead center so adjustment is possible when being aligned w/o re-indexing the plates. save $$!!! you will have to fiddle around as noted above with the spline size differing from side to side on the torsion bar, just be patient, and grease everthing up good so the reindex try & retry is easy to rework ether end's splines to hit yir sweet spot.

also, should you push one tbar in too far the other wont sit deep enough to reattach. don't panick, you just need to push the deep side back. not sure, but the inside ends of the tbars must be very close when installed correctly.

[sailchef]

Hey guys, thanks for the help. It's all the little things that you don't think about. I'm making a check list. I'll shoot theT-bars with liquid wrench and let them soak a few days while I work on the spring plates.

[sailchef]

What is everyone paying to have their plates zink coated and could you share with us the shop that did it for you.

I've have an estimate for $250 locally for Cadmium plating but read another thread where someone did what I'm assuming is yellow zink for $60. Big price difference.

[tirwin]

What is everyone paying to have their plates zink coated and could you share with us the shop that did it for you.



I've have an estimate for $250 locally for Cadmium plating but read another thread where someone did what I'm assuming is yellow zink for $60. Big price difference.

That sounds about right. From what I understand, the EPA is trying to eliminate cad plating by effectively pricing it out of existence.

[mreid]

Gold spray paint from Lowes for $12:

[a930pilot]

Just paid $50 to get them done in yellow zinc. This was their shop minimum charge and I was happy to pay it! They turned out fantastic.

[hank911]

Sounds good if your just adjusting height.
What if your changing to a stiffer bar?

Originally Posted by dipso

It doesn't droop as long as it is connected to the torsion bar. Once it is off the torsion bar it will fall to the ground.
You want to pull it off the bar, the, bar may come out of the Transmission side with it. If it does, just put it back together at your new height and you will be fine.

Remember the Torsion bar at the transmission side has different notch sizing than the end at the spring plate. Sometimes to get the exact height you want you have to rotate the bar 1 notch and then the spring plate 1 notch.
That will give you a split height vs just moving the spring plate side 2 notches.

I don't use an angle finder. I use a tape measure.
Measure the distance from the tip of the spring plate to the ground once everything is disconnected from it. Lets say it is 8". If you want to lower your car 1", reassemble everything so the tip is at 9".
It's a lot simpler that way.
If you want to raise it 1", reassemble at 7''.

It won't be exactly in 1" increments, but you will see how it works with a combination of rotating the torsion bar and the spring plate.