Butt Sag!

[mountainkowboy]

Lets talk about "butt sag".......the vert has some serious sag and negative camber in the rear. Is that due to worn out torsions? Is it a bushing issue? Can it be indexed out? Do I need to replace the torsions?

Talk to me

[helowrench]

Index it out.
Or, ifn you want a little stiffer for cheap, grab some Porsche 924/944 bars and swap them in

[Piledriver]

Look under the front of the back fenders.
The torsion tubes (actually an extender tube, part of the spring plate) sticks out through holes in the retainer plates.

How centered are they in the hole they poke through?

The bushings hold them centered, they make the good black graphite/moly impregnated ones for the back.
My T3 was so bad when I got it, the outer spring plate tube had been rubbing for _awhile_ on the cover, did some self clearancing. The inner bushings on an IRS behind the torsion tube (inner trailing arm pivot) bushings also go away.

New bushings, all is well.)

[Marc]

Based upon the first picture you posted in your "bring it back" thread I don't see any pronounced squat, the cars had a slightly nose-high stance when new. But after 40+ years, the rubber bushings are bound to be squished out - merely replacing them will probably bring the rear up enough, especially since you're considering dropping the front a couple of inches. You'll need some way of lifting the springplate back up into position after replacing the bushings; there are dedicated tools made for the job or you can improvise, for example with a floorjack and a length of chain...any article describing how to set the torsion bars will offer at least one method.
Get the black ones Piledriver suggested, the red/orange neoprene are stiffer still and infamous for squeaking.
You could go ahead and reindex the bars as well but don't go overboard, the rear camber is supposed to be slightly negative (between -40' and -2°, and within ¾° from side-to-side).
924/944 torsion bars come in 22mm (same as what you have now) as well as 23.5, 24, 24.5, and 25.5mm diameters. Because the spring rate is proportional to the 4th power of the diameter, a small change makes a big difference. 23.5=> 30% stiffer, 24=> 41%, 24.5=> 54%, and 25.5=> 80% ...so you probably wouldn't want anything bigger than 23.5mm for street use. Happily that's what's in most `80-up 924 and non-turbo 944...also in VW Type III Squarebacks, `69-`73.


From 1971 sales brochure: http://www.thesamba.com/vw/archives/lit ... page18.jpg

[Ol'fogasaurus]

I agree that it is very possible that the "donuts" have seen better days and maybe the hole is elongated; mine were like that. Inspecting/upgrading them would be the first thing I looked at before I got too ambitious with other adjustments that can be made. It might even improve your cars ride some.

Maybe this will help on dealing with the torsion bars. It was done for off-road but there is a chart part way down that gives some dimensions for torsion bar adjustment/setting the preload that works for going up or down. viewtopic.php?t=110857&postdays=0&postorder=asc&start=0

[mountainkowboy]

LOL............The rear bushings are trashed! I will be ordering new one soon......as for the extender tube, its firmly set against the top of the retainer plate on both sides.............thanks guys

[Piledriver]

The black Energy Suspension ones are solid lube impregnated:
http://www.jegs.com/p/Energy-Suspension ... 7/10002/-1

Just order with the "G" suffix for black.

the rears are ~ halfway down the page, early SB are right on top

[Jim Ed]

My 1973 Beetle had butt sag. This is not a dealership type of fix but, it cured the butt sag.
I got some coil over shocks like this from aircooled.net.
Ask if they are in stock. I had to wait a little while for these.
http://bugpack.com/index.php?main_page= ... cts_id=541

They should be available from any of these retailers:
http://bugpack.com/index.php?main_page=page&id=4

[Marc]

I vote a big NO on the coil-assisted shocks; the only thing worse would be air shocks. The shock absorber mounting points were never intended to support the weight of the vehicle.

[Ol'fogasaurus]

I vote a big NO on the coil-assisted shocks; the only thing worse would be air shocks. The shock absorber mounting points were never intended to support the weight of the vehicle.

Xs a whole bunch! With these two styles, the torsion bar has been lessened in its work. The shocks on the coil-overs usually aren't as good as you should have and the air shocks if a hose blows/fails there is only ~7#s of pressure reserve and neither of the two styles are designed to be the sole source of support for the vehicle; not good.

Lee

[Jim Ed]

I vote a big NO on the coil-assisted shocks; the only thing worse would be air shocks. The shock absorber mounting points were never intended to support the weight of the vehicle.

I've been using these for over 20 years now without any apparent problems but, since you say it is not a good idea I will save up for some KYB's or something similar.

[Steve Arndt]

First things first. Replace the torsion bar/spring plate bushings and the IRS pivot bushings. It is a great way to get to know how thick your knuckle skin is doing it the first time.

[Ol'fogasaurus]

Jim, as far as the coil-overs go they are a crutch and always have been so. While a lot of people swear by them but they are what they are: a crutch. They take away a lot of the work your torsion bars are there to do as the coil overs are loaded to work before the torsion bars get much of a chance to; the torsion bar becomes the support rather than the other way around. It is also my understanding that the shocks that come with them are not always the best shock/dampener you can get either; figure it this way: they are working/supporting both their coils coils and the torsion bars/packs during loading and unloading of the suspension. Now if you were talking about properly installed King, Fox or similar Gas/air shocks by other manufacturers, that is something completely different as the torsion bars are not in use.

As far as the air shocks you must have read one of my diatribes on them and how I almost went A$$-over-tea-kettle/endowed out on the dunes. I have known about them since in the late 60s and their rep was bad then and just because I didn't know at the time how to preload the torsion bars at the time I left them in place (my buggy came with them) and ended up in a scary situation because of it. The write up I did on preloading torsion bars came directly from that incident. There have been many load shift wrecks in cars and lite trucks because of the dual feed shock replacement air shocks and their nasty, nasty habits.

Do your homework on shocks; there are a lot of good shocks that leave off in certain circumstances. I learned that the hard way.

Marc is right; do things right the first time so you don't have to go back and do them right later on.

[Marc]

...There have been many load shift wrecks in cars and lite trucks because of the dual feed shock replacement air shocks and their nasty, nasty habits...

They're particularly nasty on a swingaxle, since they seem to exacerbate the inherent "tuck and roll" characteristics. They're more benign on IRS, but it's still a good idea to run separate inflation tubes if you must use them.

Jim Ed, avoid the monotube KYB Gas-a-Just (the white ones) - they're far too stiff for street use on a (non-Baja) Bug, even in a warm climate. Come wintertime you'd think you had NO suspension. Their GR-2 AKA Excel-G (once called Gas Ryder) twin-tube shocks work well enough. Personally I prefer to retain the stock rubber snubbers at the front (they are still available new if you look around) so I use stock-style "oil" shocks up there on a BJ Bug, but the GR-2/Excel-Gs are OK.
The stock 22mm Beetle rear torsion bars are fine for most folks. If you frequently carry rear-seat passengers, or you're runnin' moonshine, you might want some bigger ones. New bushings do make a noticeable improvement in the ride and handling over tired, squished-out ones.

[Piledriver]

First things first. Replace the torsion bar/spring plate bushings and the IRS pivot bushings. It is a great way to get to know how thick your knuckle skin is doing it the first time.

It's really not that bad if you consider it to be a large mean Rotweiller ahead of time.