I had a similar problem with my passenger seat--mine would move back, but
not forward. Someone had run the seat all the way back and apparently the
screws that move the seat had become stuck at that position. I could hear
the motor clunk when I pushed the switch, but no movement. I took the
switch apart and it was fine. It is a pain in the neck getting it back
together. I used a small bit of glue to stick the ball bearings to the
springs! In front of the seat is a plastic cover, held on by 2 screws,
that hides the fore/aft motor. I pulled the cables out of the motor and
used a small crescent wrench to turn them (the ends are square). This
freed the shafts from their bound position and now everything works fine.
1989 S4, AT, blk, musical rev cone megaphone exhaust
Thought this might interest someone out there as I've never heard this
particular problem mentioned. Since I bought my 88 S4 6 years ago, the driver
seat fore/aft motion has been extremely slow, and would usually just stop moving
before traveling the full distance, and you'd have to let it rest a few minutes
before it would go the rest of the way.
Took the seat out yesterday to clean and lube the drive and electrical contracts, but really they looked fine. When I went to put the seat back in I noticed that I was unable to get all the bolts back in. But the seat was now moving fore/aft briskly! After struggling with it for some time, and cursing a fair amount, I accepted that the left rail was about 1cm too far back with respect to the right rail. Took the seat out again to get a better look, though it turns out this was unnecessary as once you remove the little black plastic cover at the front of the seat, you can pull the left fore/aft drive cable out of the transmission at the motor. I gave it a twist as needed to line up the rails correctly. Got the seat bolted back in easily, and it continues to work fore/aft without tiring out halfway.
So I really think some previous mechanic had just gorilla'd it in there, putting a lot of tension on the drive and causing the motor to bind.
Sometimes one of the drive cables will come out, and after you try to move
the seat back and forth without noticing the cable is out, and notice only one
side is moving about 1/2 inch, you look under there and see that a drive cable
is out, and just put it back in again. By that time the two sides aren't lined
up anymore, and you get that slow-moving seat syndrome, and blame it on a bad
motor, carpet pile, lack of lube, etc.
Yes, I have first hand knowledge of this. Twice.
The seat is held in place with some cap bolts and some fairly large threaded plates. It is very important to use the threaded plates to hold the seat and not the nuts and washers. The plates are designed to get the seats a better mounting point in case of an accident. If the plates are not used then the seats can pull off the floor in a rear collision causing the driver to be pushed backwards causing neck and back injuries.
When removing the seats it is easy for the cap bolts to fall back into the track. When the seat is out of the car the bolts will be loose enough to allow free travel. When the seat is bolted into the car these extra misplaced loose cap bolts can bind up the track and prevent the seat for traveling fully or even slow down its travel.
Remove the seat again and turn it up and down and listen for something rattling. You will probably hear one or more bolts rattling around in the track. It takes a little patience and moving the seat back and forth to get the loose bolts out of the track.
Alternatively, if the car has been in an accident - especially hit from the rear the seat frame could be bent. There are a lot of bad condition seats floating around. It is not much of a job to remove the upholstery from one seat frame and put it on another. About an hour or so at a upholstery shop.
Dan the Pod Guy