Help W/Torsion Bars/Ride Height

[der Geist]

I needed as many expert opinions on this problem and this definitely seems to be the place for it. I hope someone here can help.

I have a 1969 911T that I am restoring. This is my 1st restoration project but I have been working on cars for a long time. The back story is that I bought it to restore in '01, got really sick so I hired someone to do it for me, got the car back and found that he hacked the car REALLY bad. I can tell ya stories..... haha

Car was sitting very low on one side, measured 16" at the center of the torsion bar on the passenger side and 13" to the center of the torsion bar on the drivers side. The drivers side is so low is causes the passenger front to rise 3". The first thing I did was switch shocks, they are brand new Boge right to left. I didn't think it would do anything and it didn't. So I disconnected the spring plates. When I did, the spring plate on the drivers side was set at 30 degrees and the passenger side was set at a whopping 45 degrees. The bushings are all completely shot and I am going to order new ones.

I think that when the last restorer put this car back together he just threw the spring plates on any old which way.

One of the 4 bolts holding the torsion bar cover plate on the drivers side was completely stripped out. I drilled that out and re-tapped it today. Not sure if that had anything to do with this or not but the bolt was bent in the hole.

Because of all this could the torsion bars have gone bad? I hate to have to spend $500 on torsion bars if they are still good. The car has 60K miles on it and it has not been driven in about 15 years. Is there a way I can tell these torsion bars are still good?

Can anyone offer me advice on where to go from here? Also, I read on one person's DIY that 22 1/2 degrees (roughly) is where the spring plates would be set. Would this hold true for a '69 as well? I think he had a newer model but I couldn't be sure. My concern it that if the side that was sitting lower at 30 degrees than the side that was set at 45 degrees what will happen if I set both sides to 23 degrees?

Thanks in advance!

Marty

[RWebb]

pull the bars out and inspect for rust pitting, etc.

[911Freak]

I will be doing new rear spring plate bushings on my SC soon and want to make it least painful as possible so I will be following this thread!

Btw. You can almost always find good condition used rear TB in the classified section here. I have seen guys use SC and Carrera TB in their early cars as they are an affordable and reliable option to buying NOS or aftermarket TB. Also most seem to prefer the added stiffness of the SC/Carrera TB. I think they are 19 front and 24 rear. I sold a full set recently for <$100

Good luck!

[Flieger]

Your spring plate setting depends on the ride height you want and the size of the bars. I had a setting of more like 15 degrees.

[der Geist]

RWebb-I did pull out the bars and look at them. 1 had a few spots of paint missing but the both were coated very heavily with great. No rust or corrosion of any kind.

911 freak- I took off 1 of the bushings this afternoon. What a project! Someone said an air chisel is the way to go, wish I had one haha! I'll keep my eye out for the used ones.

Fleiger-Is your car lowered? It sure sounds like it!

Tomorrow I think that I will switch the right an left TB and set them both to 25 degrees, put it all back together and see what happens. Hopefully I'll have an update tomorrow or Monday

[Flieger]

Ride height is about 10" center of torsion bar to ground. 29mm bars.

[Flieger]

If you know how much the car weighs you can estimate the angle you need, even more accurate if you know the weight distribution.

[mreid]

I have a set of 84 911 TBs in excellent condition. I upgraded mine when I recently rebuilt the suspension. Full set $100 shipped. Just the rears $60 shipped.

[der Geist]

Originally Posted by Flieger

Ride height is about 10" center of torsion bar to ground. 29mm bars.

Interesting....29mm is going to be on the stiff side, no? I think mine are pretty light comparatively, maybe 26mm is stock?? I'll look it up.

Before I disconnected everything I measured and the "low" side was 13" from the center of the TB to the ground. The "high" side was 16". The car had a wide body kit on it and the first thing I did was cut that off. With the quality of work this guy did I think he may have put the TB's on haphazardly screwing up the ride height and then fit the fiberglass wide body to the incorrect height. Nothing was rubbing and the clearances looked OK with the WB. It's another rainy day here so i'll have plenty of time to devote to this today.

I'll do a couple of tests today with different setting and see how the car looks. Maybe 15º and 25º to start with.

Think I am going to start another thread here entitled "Worst restoration Ever" haha

[der Geist]

Well here is the update.

The torsion bar that was on the drivers side is shot. I moved it to the passenger side and now the passenger side is 2 1/2" lower than the drivers side. Both set at 25º and from the ground I have 11" to the center of the TB on the drivers side and 8 1/2" on the passenger side. I think both must be shot as this thing is riding really low in the back. Gonna go play with it a little more and see what happens. Time for new TB bars now for sure.

[tonythetarga]

Originally Posted by der Geist

RWebb-I did pull out the bars and look at them. 1 had a few spots of paint missing but the both were coated very heavily with great. No rust or corrosion of any kind.

911 freak- I took off 1 of the bushings this afternoon. What a project! Someone said an air chisel is the way to go, wish I had one haha! I'll keep my eye out for the used ones.

Fleiger-Is your car lowered? It sure sounds like it!

Tomorrow I think that I will switch the right an left TB and set them both to 25 degrees, put it all back together and see what happens. Hopefully I'll have an update tomorrow or Monday

WAIT...DON'T SWITCH RIGHT AND LEFT T-BARS
keep them on the same sides as they were. the metal has been sprung in one direction only with use and if you switch sides, you will increase the chances of breaking the T-bars as they will now have to twist in the opposite direction and may shear.

If the bars are not pitted and worn, clean them up, touch up the paint and coat them again with grease and reinsert. Now follow the procedures for spring plate angles. make sure you check the door sill with a level to know if you are dead level on both sides. This makes your angle gauge more accurate.

[der Geist]

Tony-

Thanks for the info. You are right of course but I wanted to see how much travel was in these. I am sure that it is time for new TBars. These are gone.

[Flieger]

Springs don't usually loose rate. They can sag slightly, but setting the spring plates to the same angle would eliminate that. Something else is up. Are they the same diameter?

[Flieger]

Originally Posted by der Geist

Interesting....29mm is going to be on the stiff side, no? I think mine are pretty light comparatively, maybe 26mm is stock?? I'll look it up.

Before I disconnected everything I measured and the "low" side was 13" from the center of the TB to the ground. The "high" side was 16". The car had a wide body kit on it and the first thing I did was cut that off. With the quality of work this guy did I think he may have put the TB's on haphazardly screwing up the ride height and then fit the fiberglass wide body to the incorrect height. Nothing was rubbing and the clearances looked OK with the WB. It's another rainy day here so i'll have plenty of time to devote to this today.

I'll do a couple of tests today with different setting and see how the car looks. Maybe 15º and 25º to start with.

Think I am going to start another thread here entitled "Worst restoration Ever" haha

19 and 23 was stock for my car, currently I have 22/29. So that is 80% stiffer in front and 150% stiffer in back, which turns out to be a good match for my weight distribution (when you lighten a 911 most of it comes off the front so it ends up even more rear heavy). The ride is better than with 22/27 because the car stays level over bumps, rather than the pitching that would happen before as the weight of the engine bounced on the soft rear springs with the front acting as a pivot.

[der Geist]

Max-I see you have a 1971 so your car should be very similar. What perplexes me is that even when the center of the torsion bar is at 11"the back of the car is sooooo low. It is so low in the back it actually makes the front rise and the muffler is almost dragging on the ground. The bottom of the engine lid is below my knee, 14'' from the floor I think. At any rate I know at least 1 TB is toast as whatever side it goes on will drop 2 1/2" to 3". I think I should definitely get something heavier than those worn out stock 23' stock TB's.

I stripped the old worn out bushings today got 'em all ready for new ones. I found that one of my TB covers was rusted out so I'll need to get a new pair of those as well.

[James Brown]

think about this backwards, where do you want the car to sit? seems there a bit to low? and off center? than you have to add some more angle to get the final result. the bars are good till they snap in half. there is a ton of adjustment left in them. the angle guides are good if you know the weight before but there just guides, the adjust and check ride hight is a slow process but it does work. You still have to corner balance the car afterwards.

[der Geist]

James-
I want the car to sit at a normal height. The guy who did the previous restoration made it into a low riding wide body. I took all the wide body garbage off and want to return it to a factory look. It was really sitting low when I got it back. The passenger side spring plate was set at 45º. It really snapped when I took the spring plate off, I don't know how anyone could set it to anything more than 45º. If you go past 45º you will need to turn the spring plate more than a 10º before you can tie it into the rear hub. How can that be accomplished?

I understand what you are saying when you state that they are good until they break but just like springs they must wear out, no?

[James Brown]

remove the shock and place a jack under the trailing arm. also, where is the front of the car, even?

[Flieger]

Originally Posted by der Geist

James-
I want the car to sit at a normal height. The guy who did the previous restoration made it into a low riding wide body. I took all the wide body garbage off and want to return it to a factory look. It was really sitting low when I got it back. The passenger side spring plate was set at 45º. It really snapped when I took the spring plate off, I don't know how anyone could set it to anything more than 45º. If you go past 45º you will need to turn the spring plate more than a 10º before you can tie it into the rear hub. How can that be accomplished?

I understand what you are saying when you state that they are good until they break but just like springs they must wear out, no?

They could "sag" a bit, but the rate should be the same- so if you set the spring plates to the same angle on each side the rear should be level unless the front is off and switching the bars should not result in the low side following one of the bars. That was why I asked if you were sure both bars were the same size.

[Flieger]

Originally Posted by James Brown

remove the shock and place a jack under the trailing arm. also, where is the front of the car, even?

In line with what James Brown says, here are some pictures from the recent suspension work I had done.

Suspension Work June 2013 - a set on Flickr