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Intellectually challenged and reindexing rear torsion bars
I am about to embarrass myself here. While it's probably neither the first time nor the last, I don't mind sayin' that I need help with getting pointed in the right direction.
Goal:
Lower ride height in the rear by some 2.5" on a 1987 924s track car while the car sits on the upper part of a four post, drive-on lift. (Where it shall remain until I can park the car under it on the street (April 1st?).
Efforts to date:
Clean, clean, cleaned the spring plates et al.
Attempted to get an education by:
Reading Clarks Garage who recommends dropping the entire suspension cradle (?)
Read Marc Belanger's write-up which is what ^^^^^based his efforts on.
Wrote emails to Marc Belanger (mail returned, mail unanswered but that's okay).
Reading a zillion posts here and on Pelican.
Consulting workshop manual and Haynes.
Trying/tried praying for Divine Intervention (no luck)
Searched Youtube.
And so here are my requests:
Can I reindex the torsion bars in situ? And if so...
Is there an idiot-proof, step-by-step, handholding write up/video/diarama/book/etc that can help a brother out? And, if so, where, where, where can I get my hands on it???
My resources:
Spread sheets.
Formulas.
Tooth to degree of angulation charts.
It's not my first rodeo when it comes to working on the car.
Using the angles and measurements method I believe described on Clark's, I was able to index my new bars with the entire suspension assembly out of the car (on the driveway).
It was over 5 years ago so details are fuzzy but it's doable.
I think what I did was a deviation from the normal instructions, measuring unloaded spring plate travel vs spring rate and back-calculating to my new spring rate (stiffer spring, shorter travel).
When I got it back into the car I was within about 1/4" so I adjusted the spring plate eccentrics to compensate.
No its definitely doable in the car.
I just prefer to pull major assemblies out to have maximum working room, being under the car or head in a wheel well is frustrating enough by itself, without bolts getting stuck etc.
That's why I pull the engine when doing a 944 clutch..
I re-indexed my old Bugs no problem. PS some dollar stores have inclination gauges ... basically a moving-needle protractor with a magnet so you can mount on the arm and check angle
I don't remember if I did this on my '69, but definitely on my '60 swing-axle. It was so easy, I indexed multiple times in one day, driving around until I was satisfied with the result.
I would imagine the later IRS isn't too different, maybe some more work disconnecting the other end. When I get home tonight, I'll take a pic of the angle meter I got... I recall being very surprised howv accurate it is
It was a year and a half ago but if I remember correctly this is how I did it:
I took a measurement from the wheel hub to the the upper curved plate with the shocks off and the suspension unloaded. I pulled the torsion bar out enough to disengage from the trailing arm, jacked up hub the amount I wanted to drop the car and reinstalled the torsion bar. Bear in mind, I have the caps on the end of the torsion bars removed, bolts welded into the end of torsion bar for slide hammer, and holes drilled in the body of the car. Mine is a track car.
I don't remember if I did this on my '69, but definitely on my '60 swing-axle. It was so easy, I indexed multiple times in one day, driving around until I was satisfied with the result.
I would imagine the later IRS isn't too different, maybe some more work disconnecting the other end. When I get home tonight, I'll take a pic of the angle meter I got... I recall being very surprised howv accurate it is
Much of the suspension is nearly identical if not exactly the same in the early VWs. In fact, the picture of the 'unhappy camper' is lifted from a video that makes this pretty obvious. Ain't that angle measuring device grand? I have one. Technically, they're called a goniometer.
Roger , don't be cheap and get some coilovers for the rear ...
I spent half a day on my 911 trying to get the rear suspension even as there was a .250 difference
that was driving me nuts !
It was a year and a half ago but if I remember correctly this is how I did it:
I took a measurement from the wheel hub to the the upper curved plate with the shocks off and the suspension unloaded. I pulled the torsion bar out enough to disengage from the trailing arm, jacked up hub the amount I wanted to drop the car and reinstalled the torsion bar. Bear in mind, I have the caps on the end of the torsion bars removed, bolts welded into the end of torsion bar for slide hammer, and holes drilled in the body of the car. Mine is a track car.
TC,
If it's really that simple, then I don't know if I should cheer or cry! I think it goes without saying that the number of steps outlined elsewhere are a few more than what you describe. So let me see if I've got this right.
With car on ground or hoist make necessary measurements.
jack up the car
use jack stands to hold the car.
remove wheels
by using a goniometer determine the pitch the
disconnect shocks.
Optionally, cut an access hole in the rocker panel to assist the removal of the torsion bar.
Remove cap to access the torsion bar with a screw driver or awl (it's only sheet metal anyways).
Using any number of possibilities (markers, scratch-awl, laser beam) create an alignment mark on the TB tube end and the torsion bar.
Drill and tap the end of the torsion bar (TB) to accept a 13 mm bolt or similar. This will serve as a way to connect a slide-hammer to the TB. You can also weld a washer or a bolt to/across the TB end (to serve as a grip for future reindexing).
Heave! Heave! Heave! Voila!
Place jack under trailing arm and move the spring plate assembly to a position that equates to the desired height as determined by the accompanying chart.
Find something to work as a cap for the now exposed TB end.
Sorry, I had a brain fart while posting earlier and didn't realize you were just lowering/raising the bars that are already installed.
My posts were referring to upgrading the bars to larger stiffer ones so there's math involved.
If you're just changing ride height yes just slide out adjust and slide in.
set the car level on jackstands using the door sill as a guide.
shoot for 14 degrees from horizontal both sides being equal. each offset is 0.8 degrees....ie opposite index of one on both splined ends.
imho.... your goal of a 2.5" drop might be good for asthetics but your handling will be compromised. once you hit the bump stop, there is no travel which can produce undesirable results
Now that I see it again, I don't think it was dollar-store; made-in-USA. Probably Home Hardware. Cheap, whatever it was
I also recall using a level with a metal protractor with a rotating arm. Anyway, simple thing on a Bug..., but... "...cut an access hole in the rocker panel..."?? Oh My!
In the Bugs, I didn't have to weld, tap, or slide-hammer anything; the torsion bars just came out... maybe a little pulling with an adjustable...