Installing spring plate at correct angle

na2ub · 10-31-2010, 08:05 AM

I put my new, bigger Tbars in, and checked the spring plate angle calculator to estimate my new spring plate angle. Question is, when I go to put my spring plate back in, what happens when I pull it on with the longer bolts? From what I understand, the outer splines are 8 or 9 degrees apart. I already did one, and bolted the spring plate in at the correct angle, but did I just get really lucky? Seems like after you put the tbar in the tube, that you will only be able to bolt the spring plate in, in increments of 8 or 9 degrees.

Is it possible to mess up the spring plates, trying to bolt them in at an angle that the splines don't match up with, essentially flattening splines?

Thanks,
Doug

dad911 · 08:48 AM

The inner and outer splines are different, so you have to pull out the torsion bar and rotate it to get different angles.

Do not try to force the wrong angle.

edit: From another thread:
This is because there are 40 inner splines and 44 outer splines on the rear torsion bars.
One inner spline = 9 degree change.
One outer spline = 8.18 degree change.

boyt911sc · boyt911sc's Garage

Quote:

Originally Posted by dad911

The inner and outer splines are different, so you have to pull out the torsion bar and rotate it to get different angles.

Do not try to force the wrong angle.

edit: From another thread:
This is because there are 40 inner splines and 44 outer splines on the rear torsion bars.
One inner spline = 9 degree change.
One outer spline = 8.18 degree change.

So in summary based from the above information, you could do a 0.82° change in setting. To get this smallest increment change you need to rotate the inner spline in the opposite direction of the outer spline to get a resulting angle of 0.82°.

Tony

porschenut · 10-31-2010, 08:59 AM

You must engage the splines at both ends BEFORE you begin to push the bushing into the tube. There should be just enough of the TB end sticking out so that you can "hang" the spring plate on it with the splines engaged, without the bushing started in the hole. If there isn't, you may have pushed the TB in a little too far. Try wiggling it a little to pull it out just enough to get the spring plate splines on the end (be careful not to pull the inner splines all the way out).

Wil Ferch · 10-31-2010, 09:45 AM

Correct...the different number of teeth on the inner and outer splines allows for "fine tuning" the height. Depending upon "only" one end will allow ( maybe) for 2" adjustment at a time....too coarse.

Also correct. Move inner tooth one direction and outer tooth the other direction....to the get the fine-amount of adjustment required...some fraction of an inch ride height change.

The G50 cars use an even greater number of teeth on both ends compared to the bars used for 915 cars.... ( still a different number at each end)...to allow an even finer degree of adjustment.

na2ub · 10-31-2010, 12:23 PM

That explains it. I must have the T bar too far in, because I cannot seat the spring plate on the spines before I have to start pressing the bushing into the tube, at which time, you cannot "feel" anything. Hope I didn't F'up my splines. On the other side, I will make sure I leave the tbar out just enough to be able to hand the spring plate on the splines before I start to press in the bushing.

Thanks all.

Doug

na2ub · 11-01-2010, 11:06 AM

Confirmed. I had my tbar inserted too far. I pulled the spring plate off, and fortunately, all the splines on the tbar and inside the spring plate appeare to be undamaged. It is a carefull balance to get the bar out far enough to hang the spring plate on it. Sure would be nice if there was a "stop" in the tube to keep the tbar at the correct depth. Anyway, I am super relieved and even was checking out the costs of new spring plates earlier today. I did not have the time to get the angle right at lunch break today, but armed with the information provided, I am in the home stretch. Thanks all! Now I just need to attempt the camber and toe, and eccentric ride height, if needed. That will be the next bridge to cross.

NoLift911 · 11-01-2010, 11:16 AM

Yeah there does not seem to be a "stop" in the tube. I noticed this this weekend also when I was getting my new bars off of the garage floor and decided to store them in my torsion tube - I tapped one side in thinking it would bottom out and it basically pushed out the other torsion bar I just put in the other side - thought I was going crazy.

na2ub · 12:51 PM

Heh, heh. Jokes on us, you crazy Germans..

Kinda like the card that says "how do you keep a moron busy for hours - see other side," on both sides.