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Torsion bars procedure with hole saw
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TOPIC: Torsion bars procedure with hole saw

Torsion bars procedure with hole saw 14 years, 6 months ago #5820

  • Jump07
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I am thinking about cutting holes in the body to put in new 29mm torsion bars...and then just slapping a sticker over the holes afterwards. I hear this saves hours of work/headache. What is the procedure for replacing the bars and lowering the rear suspension with these holes cut?
Jeremy Mathews
NorCal
1985 944 #07
2003 GMC 1500 Sierra Z71

Re:Torsion bars procedure with hole saw 14 years, 6 months ago #5822

  • Gary_44
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www.9magazine.com/files/Issue_30.pdf

page 25

I'll be doing it soon too, as soon as I get my front perches.
\"There are only three sports: bullfighting, motor racing, and mountaineering; all the rest are merely games.\"
--- Ernest Hemmingway
Last Edit: 14 years, 6 months ago by Gary_44.

Re:Torsion bars procedure with hole saw 14 years, 6 months ago #5824

  • rd7839
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Just want to add my 2 cents and give a little of my hard earned insight into torsion bars. I grew up in Southern California in the 80's when Volkswagens were THE car to have. I owned 14 total and worked on/built several dozens if not hundreds. I've lowered and raised torsion bar suspensions many times and learned one immutable fact; it is VERY easy to screw up getting the ride height even side to side.Different size splines on each end of the bar makes for a lot of different combinations of settings. Once correctly set, I have never had to go back and change anything. The method in the article about making a removable plate and pulling the bar out "911" style sounds like more work than it's worth, not to mention drilling into a torsion bar or welding onto one doesn't sound like a good idea to me. I'm no metallurgist but i remember lowering old hotrods by heating springs until they sagged which didn't help the ride any. I have also seen quite a few bars break from just getting scratches in the paint so I'm sure drilling into spring steel isn't a wise thing to do. Plus the adjustability factor will only get you into trouble.

If you follow the procedure on this website and take your time, the bars are a one time deal. Every body knows I'm not the brightest guy and I did mine by myself in my garage first time. Both of you guys live close enough to me that I can come over and help you do yours when you want me to.

Ron

Re:Torsion bars procedure with hole saw 14 years, 6 months ago #5825

  • rd7839
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I left out a few little details that should make things a little more clear. What happens when they are easily accessible is when you are trying to adjust say one notch outside spline but the bar slides out of the inside splines. It will be harder to get that right again than it would be if you just did them the old fashion way. You will have to make an educated guess, put it all back together, measure everything and do it all again, usually several times. Granted, you won't have to drop the whole suspension, but after several tries you will be very frustrated, trust me I know!!

Re:Torsion bars procedure with hole saw 14 years, 6 months ago #5826

  • Weston
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Jump07 wrote:
I am thinking about cutting holes in the body to put in new 29mm torsion bars...and then just slapping a sticker over the holes afterwards. I hear this saves hours of work/headache. What is the procedure for replacing the bars and lowering the rear suspension with these holes cut?


I did this and it saved me quite a bit of trouble. You actually don't even need to drill the holes in the side of the 944 unless you want to pull the bars all the way out. I have tabs welded onto the end of my bars and re-indexing them only requires pulling them a couple of inches, so there's already plenty of room for that on a 944. Once you get it right, you should never have to mess with it again unless you want to change bars or bushings, but it will take a little trial & error to decide what ride height you want in the first place, so this makes that work much easier and faster.

Ride height changes only take a few minutes once you get the hang of things... Smaller adjustments are easy enough with the eccentric bolts, so this is assuming that you want to make a bigger change by adjusting the torsion bars... You just put a floor jack under the suspension, unload the torsion bars, grab the tabs with pliers, and wiggle until the bar slides out. Then simply raise or lower the jack to change the ride height (remember it has the opposite affect... raise the jack = lower the car), slide the bar back in, and you're done once the teeth are fully engaged. To get both sides even, I just set the eccentric adjusters in the middle on both sides, then measure and even-up the spring plate angle on both sides.

As for worries about drilling or welding onto the torsion bars, keep in mind that the modification is only done to the very end of the bars... If it does affect anything, it only affects the end of the spline section, which doesn't really matter, because the portion that acts as the spring is still a few inches further down. Even with a welder, not a lot of heat is going to make it a few inches to the spring portion when you have a big 30mm diameter piece of solid cold steel (ie a giant heat-sink), and you only need to make two quick 1" welds.
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Last Edit: 14 years, 6 months ago by Weston.

Re:Torsion bars procedure with hole saw 14 years, 6 months ago #5827

  • Jump07
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I would love to have some help, Ron. Maybe we can set a date and meet at Ken's shop soon?
I want to replace the stock bars with 29mm Sway-a-way bars I've had sitting in my garage for the last 6 months. Right now my car has been hot-rodding with lowered 400lb springs and coilovers in the front and stock height in the rear.
I need to even it out.

Let me know if/when you have a day free, and we can see if Ken will let us take over his shop.

Jeremy
Jeremy Mathews
NorCal
1985 944 #07
2003 GMC 1500 Sierra Z71
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