The rear of my 411 4 doors has always sagged a lot so I have been running those rubber spacers between the coils to raise it an inch and a half or so. Not a very good long term solution, as the spacers tend to split and fall out. Since I have my engine and trany out right now, it looked very easy to pull the rear springs out, so I went at it and in short order out they came. I talked to several spring shops and local antique car enthusiasts but nobody knew how to stretch a coil spring. A couple of the spring shops said that they could wind me some new ones, but I was leary of how close they could get to the right ride height after I paid them a lot of money to try. I scratched my head some more and came up with several ideas on how to possibly stretch the springs an inch or so without overly stretching them or otherwise damaging them. I finally decided I might be able to do it with a Hi-lift Jack. I removed the foot from the jack and slipped the stanchion through the spring. I then chained one end of the spring to the bottom on the stanchion and the other end to the jack's lifting tongue. It took some trial and error to figure out how to pull evenly on the coils, I didn't want to mess things up and have to find another set. It took me about 2 hours to do the first spring and an hour to do the second one, being carefull to not go too far, and to keep the coils properly spaced. I ended up with each of the springs being 1.5 inches longer than when I started, with both having identical spacing, something they lacked when I started. I will know in a couple of weeks when I get everything back together if I went far enough or too far.
This seemed to be a reasonably safe way to go at it. The spring is held captive by the stanchion and can't get loose and flight around to room, but it was still a little scary. Each spring was probably stretched out at least 12 or 14 inches to get enough force on it to permenantly deform the metal, and I would guess that took 3-4 thousand pounds of force from the jack to do that. I would say that this is one of those "don't try this at home type" projects.
Wow, you are the man! I wouldnt have tried that one like you said at home,lol! I would have probably made some kinda spacer for the bottom or something but that does sound cool that you got it to change! I do remember Ray saying there were two kinds of springs maybe with two different color codes of I think green or yellow on them. I wonder if the springs will still hold the stretched lenght? Have you redone the front end and struts yet? I thought I remember Ray saying something about the front height making the rear seeming low? Sounds like you are working it though! Thanks for the posts! Bill
STOP! Springs are not stretchable ...period! Those rae wound while heated cherry red. They are tempered. The rear springs tend to lose maybe...10%. They also drop...maybe 1/2-3/4" max. the main problem you are having is that the front end is HIGH. The front was naturally high on all type 4's. As the front rebound system wears...its higher. If your castor is off...its higher. Since the front end and the rear end are technically on the same plane...as the front goes up...the rear goes down...its an angle issue..not really a rear sagging issue. Put the good KYB gas-justs on the rear...and either od the front strut mods to install the Audi strut cartridge...or put 200+ lbs of ballast in teh front trunk right between the headlights. Do nothing to thesprings...until you have seen what its supposed to look like once the front is brought properly level. You will be pleasemtly surprised.
If you do wat you are thinking...with the springs...they will be ruined...and they don't grow on trees. Ray
Actually most coil springs of the size used on 411 & 412 are just plain cold rolled from tempered steel wire, instead of being hot rolled and then quenched/tempered. They also may or may not be shot peened to place the surfaces under compression to prevent crack formation. A basic problem with coil springs is that they can not be properly prestressed, as can a leaf spring, and therefore tend to sag with age. By stretching the springs I have actually prestressed them in the wrong direction which will lead to premature sagging, which is why I went to 1.5 inches of additional length verses the 3/4 to 1 inch I figured I would need.
Assuming that my local spring fabricator can shot peen the springs for me I will have that done.
As for my 411's front suspension, the height is absolutely normal, and all the geometry checks out to spec. If I were to lower the front I would have to buy another house that didn't have a long gravel drive.
While thats generally true....I happen to know that the solid wire versions of the 411/412 spring...those that do not have the top part of the spring ground flat...were wound while hot, then annealed. So were the blue series springs up front. You may get away with this, but the longevity will be short...and the resulting sag when the memory in the metal gives out....will be much more severe. Just make sure you have a properly calibrated replacment spring available before you start this. Just a suggestion. Ray
