Rear Ride Height

I know this has been discussed several times in previous topics, but I have a couple questions concerning the rear torque arm adjustment process. I have read Gordon Nichols excellant explanation in the knowledge section and understand the mechanics and the math. My question is, when sliding the torsion bar cover/spring plate off the splines of the torsion bar, how far does the cover have to move outward before it is clear of the splines? Is there room to mark relative position of the bar and cover before uncoupling? Also, is it difficult to tell by feel how many spline positions are being changed on the inner connection when rotating the torsion bar itself? I need to drop my right side 2 1/2" and my left side 1". The right side will only require 1 up outer spline change, however the left side will require 7 up on the outer and 6 down on the inner. Thanks!

Ron; we've done it several times and you need a lot of concentration to get the feel of the inner splines. I would suggest you get the adjustable spring plates as sold by G. Serrano for only $85.00 per pair but please be aware that you'll only be able to install them in your car with the body on if it's a swingaxle. On IRS cars you'll need to install them before the body is bolted to the pan.

Ricardo, I have a 69 pan with IRS, so I plan to adjust my stock suspension. I have about 4 inches clearance between the outer torsion bar cover and the body. I hope that is enough. I wish I had the adjustable plates or an I.M. with the adjustable bolt stops.

You can certainly play with it and adjust it with that much room; I was just saying that adjusting the ride height with a set of adjustable spring plates is easy; you do it in seconds with an Allen wrench instead of having to go through the process which is a little tedious. If you're still working on the pan and the body isn't on it, INSTALL THEM NOW!! For $85.00 a pair from Serrano's it's a great deal. Good luck on the job!

Ron, were you sucessful in dropping you IRS rear?

I just did the adjustments this past weekend and it wasn't bad. I needed to drop the RR 2.5 inches and the LR 1 inch. I began on the RR first since calculations told me the outer spline needed to be "raised" (to lower body) one spline. The only difficult part was removing one of the front 4 torsion bar cover retainer bolts due to it's close proximity with a body mount bracket. Once all 4 bolts were out, I had to wiggle the cover itself quite a bit to free it from the outer bars spline. I had to be really careful not to pull the bar out of the inner spline connection. Before pulling the cover off, I used a $9 Lowes angle protractor to measure the trailing arm angle with the tension released. Understanding that 1 spline was equal to 8 degrees, I made what I believed to be 1 spline change and rechecked the angle. It was dead on. The interesting outcome was that after allowing the suspension to re-level, the LR did not need to be changed. I haven't figured this out yet, but the RR and LR are now within 1/4 inch of each other. The height only came down approx 1 1/2 to 2 inches, but I really don't want to give up any more suspension travel. I did have to sand an 1/8 inch from the fender lip for tire sidewall clearance. Recommendation: Buy the angle protractor. It's a great way to verify the angle change of the trailing arm before and after changing splines.

Sweet I have the same project ahead of me. Mine has never been lowered in the rear. She looks like a funny car speedster.

Ricardo,

You said:

"adjusting the ride height with a set of adjustable spring plates is easy; you do it in seconds with an Allen wrench instead of having to go through the process which is a little tedious. If you're still working on the pan and the body isn't on it, INSTALL THEM NOW!! For $85.00 a pair from Serrano's it's a great deal."

Is this the do-dad I saw on one of the recent speedsters from Vintage?

I recall it was an Allen wrench. How hard is it to install?

Got a photo?

Michael

Yes, Kirk sometimes installs them in his cars. In my 2004 model I had an adjustable one on one side and a regular one on the other.....I ended up buying a pair from Serrano's to install the missing one. I have a "spare" left.... They're not that hard to install as long as you have the special spring plate compressing tool (available from Bugpack, EMPI, etc. for around $20.00 and worth every penny). Here's a link to the ad:

http://www.thesamba.com/vw/classifieds/detail.php?id=194572

I'd like to lower my IRS Speedster about another inch, however I'm concerned about rear suspension travel.
I have about 3" or rear travel before the Rear Stock VW Shocks bottom out.
Does anyone know what shorter shocks will work? It hasn't bottomed out yet, but I'm afraid that any lower and I'm going to have to remove the rubber snubber stops on the frame horns and use different shocks.
What's everyone using for rear (and front) shocks?

Greg B

I think you'll be fine with the rear shocks. When lowering a VW chassis, it's generally only the fronts which need to be swapped for shorter items.

Rather than removing the rubber bump stops at the rear, cut them down. Mine are cut down a bit from standard, and leave about an inch of travel. This seems to be fine on my car. If you have urethane rear bump stops, file them under 'trash' and fit some rubber ones.

Has anyone ever checked to see how much suspension "up travel" above the parked level (static) position occurs with the IRS? I recall someone writing about cutting the cover from an old front shock and placing an o-ring or something on the piston rod using it as a movement indicator. I have about 2 inches clearance between my stock rubber caps on the trailing arms and the upper stops after I adjusted the rear suspension. I would like to go an additional 1 inch, but am concerned about not having enough travel.

Ron,
That was me RE: shock travel indicator.
I cut the dust cover off the shock and put a tie wrap around the shaft. Do some of your typical driving then check to see where the tie wrap ends up on the shaft.
You should be able to lower your car another inch without problems. Mine is lowered (IRS stock spring plates) with 3" clearance between cut off (to 1") rubber stops and the stop on the suspension frame horn. The rear stock shocks have the same 3" travel before bottoming out.
I'd like to go about an inch lower, but I'm concerned about running out of Suspension travel. I may need shorter shocks. I may cut off the stops on the suspension frame horn and figure some other way to limit suspension travel.

Greg B

When attempting to adjust the ride height of an IRS, should the rear wheels both be off the ground, on the ground, one at a time,...?

Brian.......I suppose you could adjust one side at a time using a jack stand and a floor jack, but if both sides need adjusted, you might as well go ahead and support the frame on two jack stands to begin with. You will need the jack to relax the torsion rod spring tension from the trailing arm before adjusting the height of the arm itself. If you're not familiar with the adjustment procedure, look in the knowledge section for a fine article by Gordon Nichols. He explains calculations used to know the amount of change to the suspension that will be needed for a given change in ride height. If you do a search using "ride height" or "rear suspension adjustment", etc., several members including Gordon go into details on every basic procedure needed. It's not difficult, just time consuming if it's your first time.

Its easier if the car is level. You should level it front to back also. You can get a cheap angle finder from HF p#34214-5vga for 2.99. If you level it from F to B you wont have to do it on the other side. I have the spring plate tool but it can be done with a floor jack. It is much easier with the tool. For $20 its your call.

Once you do it 3 or 4 times(and you will) you will get the hang of it.

Brian, if your car is level/even(side to side)but just too high. Search the web for the correct increments, if memory serves (I don't trust it) I think the inner splines and the outer splines have a different incremental effect on the height. 1 inner spline movement/notch will give you 2 1/4", or so I remember.

Someone check me on this ... I'll use a driver's side example, reverse it for the passenger's ...

If you relax the driver's side blade and mark 12:00, moving the torsion bar four clicks to the right and the blade four clicks to the left (back to 12:00) should adjust the ride height up by one inch on the back, left side.

The ratio is one spline on the outer cap to four splines on the inside ring of the torsion tube. Count the splines on the torsion bar to make sure, but a 1:4 ratio makes an inch on my car.

When the rear ride height is lowered,
What rear shocks is everyone using?
I'm looking for some shorter ones that'll fit IRS

GREG

WHAT!
No one knows?
or
No one cares to answer?

Greg

I'm going with the KYB gas shocks. GS2s, specifically.
My IRS has been hacked away in favor of swing.

Swingaxle is sturdier Cory so you'll be alright. Greg; I guess you can still use stock shocks when lowering the car. My VS has adjustable springplates and has KYB shocks.