Parts Catalog Accessories Catalog Tech Info Tech Forums
 
  Search our site:    
 Cart  | Project List | Order Status | Help    
Go Back   Pelican Parts Technical BBS > 1- Porsche Technical Forums > Porsche 911 Technical Forum

Reply
 
LinkBack Thread Tools Rate Thread
Author
Thread Post New Thread    Reply
Registered User
 
Join Date: Jan 2011
Posts: 260
Garage
Need help reindexing rear torsion bar

I need to reindex my rear torsion bar and have a few questions. A number of posts on the forum explain swapping torsion bars and bushings but all I want to do is reindex to lower the car an inch or 2. Do I need to pull the torsion bar for this? I was hoping I could do the following.

1. Jack car so it's level, remove wheels, etc.

2. Remove 4 bolts 2 lower bolts and 2 for camber and toe

3. Remove lower rear shock bolt

4. With spring plate hanging free mark for reference and take measurements

5. Remove 4 spring plate bolts.

6. Pull spring plate cover off and reinstall spring plate on torsion bar reducing the angle to lower

7. Reinstall

8 Follow the same steps on the other side making sure all measurements are the same.

What missing? I know that was a high level description but is it much more than that?
Old 06-12-2012, 06:16 AM
  Recommend this thread for the PelicanWiki    Reply With Quote #1 (permalink)
Registered User
 
moneymanager's Avatar
 
Join Date: Jan 2006
Location: Santa Barbara, CA
Posts: 2,119
What's missing is that the tooth counts at the inner and outer ends of the torsion bar are different, so you may well need to move the inner end position down one tooth and the outer one up one tooth, or vice versa, to get the small change you need. The different ends give you the ability to make very small changes, near a tenth of a degree if I remember correctly.
In addition, you may well find as I did, that when you put everything together after all your careful measuring, the angle isn't what you thought it was, so it needs to be redone. Or the angle is wonderful but when you finally get the car to the ground the height isn't what you wanted!
And, you will be lucky to get the spring plate out without bringing the torsion bar with it.
I can do this in a couple of hours these days, but the first attempt took much of a weekend. Maybe you'll be luckier.
__________________
jhtaylor
santa barbara
74 911 coupe. 2.7 motor by Schneider Auto Santa Barbara. Case blueprinted, shuffle-pinned, boat-tailed by Competition Engineering. Elgin mod-S cams. J&E 9.5's. PMO's.
73 Targa (gone but not forgotten)

Last edited by moneymanager; 06-12-2012 at 09:51 AM.. Reason: spelling
Old 06-12-2012, 07:01 AM
  Recommend this thread for the PelicanWiki    Reply With Quote #2 (permalink)
Registered User
 
pete3799's Avatar
 
Join Date: Nov 2008
Location: Vermont
Posts: 5,038
Garage
This will be helpful also
911 Spring Plate Angle Calculator
__________________
Pete
79 911SC RoW
"Tornadoes come out of frikkin nowhere. One minute everything is all sunshine and puppies the next thing you know you've got flying cows".- Stomachmonkey
Old 06-12-2012, 07:05 AM
  Recommend this thread for the PelicanWiki    Reply With Quote #3 (permalink)
Registered User
 
vesnyder's Avatar
 
Join Date: Nov 2001
Location: NE Ohio
Posts: 1,599
Garage
Send a message via AIM to vesnyder Send a message via Yahoo to vesnyder
Not only do you have the inner and outre t-bar that have different number of splines, but you alos have fine adjustment at the spring plate with the adjustment screws. It took me 2-3 times each side to get it right. Needless to say, you get pretty proficient at taking apart and reassembling.
__________________
Vance
'83 SC Cabriolet - The "Matrix"
'73 914 - "Spicy Mustard" - SOLD
Old 06-12-2012, 07:25 AM
  Recommend this thread for the PelicanWiki    Reply With Quote #4 (permalink)
Registered User
 
Join Date: Jan 2011
Posts: 260
Garage
My goal is to lower the rear about 2in. I just installed Bilstein sports and it raised the rear to a little over 27". What is the best way to start making adjustments to lower it this much? Turn the inner end position first and then the outer? Turn just the outer or turn both? It seems that turning both would make things very difficult. It would be nice to make one change at a time.
Old 06-12-2012, 07:48 AM
  Recommend this thread for the PelicanWiki    Reply With Quote #5 (permalink)
Registered User
 
cmcfaul's Avatar
 
Join Date: Feb 2003
Posts: 1,033
Garage
Send a message via AIM to cmcfaul Send a message via Yahoo to cmcfaul Send a message via Skype™ to cmcfaul
The way I did it was to scribe a line along the trailing arm onto the body of the car. Pull the t bar our just enough to get the spleens disengaged and move it one tooth up. Then scribe another line to verify the change and compare it to the other side when making the change there.

Seemed to work first try.

Chris
73 911 E
Old 06-12-2012, 08:34 AM
  Recommend this thread for the PelicanWiki    Reply With Quote #6 (permalink)
 
Now Available for Ordering:   101 Projects For Your BMW 3 Series 1982-2000  [more info]
Registered User
 
Join Date: Jan 2011
Posts: 260
Garage
So by moving the t-bar up 1 spleen on the inner lowered it roughly how much?
Old 06-12-2012, 08:44 AM
  Recommend this thread for the PelicanWiki    Reply With Quote #7 (permalink)
Registered User
 
Join Date: Nov 2009
Location: London, Ontario
Posts: 92
The amount it lowers the car will depend on both the weight of the car as well as the thickness of the bar. I am afraid to say, you will probably end up with a trial and error exercise to get the ride height you want. The spring plate calculator referred to above is about as close to a reference as you will get.
As the others say, you will find that the second time you do the adjustment it takes about one third of the time of the first.
Old 06-12-2012, 08:53 AM
  Recommend this thread for the PelicanWiki    Reply With Quote #8 (permalink)
Registered User
 
cmcfaul's Avatar
 
Join Date: Feb 2003
Posts: 1,033
Garage
Send a message via AIM to cmcfaul Send a message via Yahoo to cmcfaul Send a message via Skype™ to cmcfaul
On my car, with one size thicker t bars then stock, one speen changed ride hight by about an inch. Like others have said results vary but a good place to start.

Chris

73 911 E
Old 06-12-2012, 09:08 AM
  Recommend this thread for the PelicanWiki    Reply With Quote #9 (permalink)
Registered User
 
Join Date: Jan 2011
Posts: 260
Garage
Thanks guys!
Old 06-12-2012, 09:14 AM
  Recommend this thread for the PelicanWiki    Reply With Quote #10 (permalink)
Registered User
 
toddu's Avatar
 
Join Date: Jul 2006
Location: Charlotte, NC
Posts: 1,502
If you have stock bars, I think your order is a little out of sequence. The spring plate will want to drop past the lowest spring plate cover bolt (bottom right as you look at it). Since you are lowering, scribing the line probably won't matter much however. But, the torsion bar is "sprung", so be careful taking all that apart. You'll want the spring plate at it's lower droop before removing the remaining bolts near the axle. So, you'll have to support it a bit to get it off that lowest spring plate cover bolt, then slowley lower it to it's full droop.

Todd
__________________
'81 SC
Old 06-12-2012, 12:12 PM
  Recommend this thread for the PelicanWiki    Reply With Quote #11 (permalink)
I Calls em as I sees Em
 
afterburn 549's Avatar
 
Join Date: Jul 2003
Location: Cross Roads
Posts: 9,495
One up and one dwn...and you might want some scales there
__________________
.*Looking for a Cayman "S" with PASM*
No silver, no Blah colors, no beige interiors .
Old 06-12-2012, 12:47 PM
  Recommend this thread for the PelicanWiki    Reply With Quote #12 (permalink)
Senior Advisor
 
James Brown's Avatar
 
Join Date: Apr 2007
Location: Bellingham, WA
Posts: 5,006
Garage
Send a message via Yahoo to James Brown
your missing the chance to learn. take the bars out all the way and use the calculator and the repair manual and do it from scratch. then you can help anyone with there project buy knowing the right way to do it. pay it forward. But the one notch method does work
__________________
911, allroad
Old 06-12-2012, 01:29 PM
  Recommend this thread for the PelicanWiki    Reply With Quote #13 (permalink)
I Calls em as I sees Em
 
afterburn 549's Avatar
 
Join Date: Jul 2003
Location: Cross Roads
Posts: 9,495
It is not as hard as some things..you just have to have patience.and if you take it somewhere..you have to pay them to be patient ! LOL
And hope they did it right!
__________________
.*Looking for a Cayman "S" with PASM*
No silver, no Blah colors, no beige interiors .
Old 06-12-2012, 01:33 PM
  Recommend this thread for the PelicanWiki    Reply With Quote #14 (permalink)
Registered User
 
Join Date: Mar 2002
Location: Philadelphia, PA
Posts: 6,026
Garage
Understand the basic adjustment.........

Quote:
Originally Posted by Matt7127 View Post
My goal is to lower the rear about 2in. I just installed Bilstein sports and it raised the rear to a little over 27". What is the best way to start making adjustments to lower it this much? Turn the inner end position first and then the outer? Turn just the outer or turn both? It seems that turning both would make things very difficult. It would be nice to make one change at a time.

Matt,

Before you delve into re-indexing your torsion bars, prepare your self by understanding how the inner and outer splines deliver the desired height or angle. It would be nice to get to your desired ride height by tweaking one side only. What happens if you accidentally dislodge the inner end of the torsion bar? Everything you have marked might be lost for reference. But knowing how to read and set the spring plate angle would give you flexibility in your project. The easiest way to re-index your torsion bar is by being able to read the angle at different spline combination/positions. My very first time to do this project took me the whole weekend and was dead tired. Nowadays, I'll be disappointed if not done by 3 - 4 hours including wheel alignment. Practice and more hands-on would make you proficient (hopefully).



Tony
Old 06-12-2012, 04:43 PM
  Recommend this thread for the PelicanWiki    Reply With Quote #15 (permalink)
Registered User
 
Join Date: Jan 2011
Posts: 260
Garage
Ok guys I removed the spring plate and everything came apart no problem. I'm having a hard time pulling the TB from the inner sleeve but I think I just need to work it back and forth a bit more to free it up. I'm a bit confused on how each inner and outer should be reindexed to lower. If I'm looking to lower the rear 2in should I turn the passanger side inner TB CW and also the outer spring plate CW to reduce the angle. Seems to me I would just be better off moving the spring plate CW to reduce the angle. If I'm removing the entire TB I have no starting point other than my starting angle I marked on the fender well. Same goes for the Driver side, in order to lower should everything be turned CCW(counter clock wise)?
Old 06-21-2012, 05:23 AM
  Recommend this thread for the PelicanWiki    Reply With Quote #16 (permalink)
Registered User
 
Join Date: Nov 2000
Location: Dallas
Posts: 2,826
Just fought this myself a while back but it was b/c I was replacing all the bushings... the second time, but that's another story. Anyway, you also need to be clear on which torsion bars you have b/c they changed the splines at some point. I got confused a few times reading posts about the degrees of change then realized what I was reading did not apply to my '88 Carrera. You need to work backwards from the amount of height change you want to the degrees of angle change you need. There are some great threads on it but just make sure the data applies to YOUR particular car.
BTW, changing the rear usually means changing the front so you retain or achieve the correct slightly nose down stance.
It's a project I don't look forward to doing again for some time, although I have taken a couple of days off to replace the front A Arm bushings...I love the pain...LOL!
__________________
Buck
'88 Coupe, '87 Cab,
'88 535i sold '07 A4 sold, '14 C250 DD
Warren Hall, gone but not forgotten
Old 06-21-2012, 06:47 AM
  Recommend this thread for the PelicanWiki    Reply With Quote #17 (permalink)
jonbjornclark
 
Join Date: May 2012
Location: Knoxville, TN
Posts: 14
Garage
Please keep this thread going! I'm looking down the barrel of exactly the same project this weekend on a '71coupe that looks like its ready for Dakar.....
Old 06-21-2012, 06:48 AM
  Recommend this thread for the PelicanWiki    Reply With Quote #18 (permalink)
Home of the Whopper
 
BK911's Avatar
 
Join Date: Mar 2001
Location: Rocky Top, TN
Posts: 3,666
Garage
The easiest way I have found to set rear ride height is to:
Determine how much you want to raise/lower the rear of the vehicle
See if the adjustable spring plates have enough adjustment
If not, put the rear of the car on jack stands
Take everything apart so spring plates are hanging free
Measure height from rear edge of spring plate to the ground
Remove spring plate / torsion bar
Adjust spring plate to middle of it's adjustment
Re-index torsion bar and spring plate until the rear edge of the spring plate changed ~1/2 of the desired ride height change.
Bolt everything back together
Use adjustments on spring plate to fine tune.

Basically, if you want to drop the car 2", you need to raise the rear edge of the spring plate by ~1".
__________________
'71 911E Targa rustbucket
'78 911SC Targa
Old 06-21-2012, 06:54 AM
  Recommend this thread for the PelicanWiki    Reply With Quote #19 (permalink)
Registered User
 
Join Date: Jan 2011
Posts: 260
Garage
So the only reason you're reindexing the inner is because you might not be able to achieve the proper angle for ride height by only adjusting the outers correct? For instance say I want the rear edge of the spring plate to be 1in from the floor, due to the way the TB is Key'd (splines) on the outer I might only be able to turn it 3/4in from the floor by using the outer spring plate. The next possible setting for the outer spring plate would be say 1.5in which would be way to much. In this case I would need to pull the TB and reindex the inner a few splines and then attach the spring plate and see if I can achieve the 1in. This is strictly an example, I'm just trying to understand it better.
Old 06-21-2012, 07:48 AM
  Recommend this thread for the PelicanWiki    Reply With Quote #20 (permalink)
Old 06-21-2012, 07:48 AM
Reply

Thread Tools
Rate This Thread
Rate This Thread:

 



All times are GMT -8. The time now is 12:39 AM.


 
Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2011 Pelican Parts - Posts may be archived for display on the Pelican Parts Website -    DMCA Registered Agent Contact Page
 

DTO Garage Plus vBulletin Plugins by Drive Thru Online, Inc.