E36 Seat Gear Replacement

This write up pertains to 98 328i Powered Sport seats. 

I've written this as a companion to the great write up from Odometer Gears here: http://www.odometergears.com/howto/E36_Seat_Gear_Replacement.pdf

 

Remove seat from the car. Have a friend help you take out the weighed beasts to help avoid scratching up all your plastics in there. Since the backs were stuck in the laid back position it was easier for us to pull them out through the back doors. 

There are two 16mm front nuts on the seat. They have black plastic cover caps on them. Note: You can move power seats without having the key in the ignition. There are two 16mm bolts out back. They are not covered with caps. 

 

Please note that if your seat is heated then, you will have a few extra wires clips to separate. 

 



 Drivers side - 5 clips.

  Passenger side - 6 clips

 

Turn the seats upside down. Remove the plastic cover off the bottom of the seat. 1 star - T30 is holding it in place. This exposes the motors.
 

 

Now is a great time to clean your carpet and suck all the nasty's out. I made almost $3 during this whole thing as well. It's hard to tell from this picture but, due to the amount of glitter this car has in it we have dubbed it the stellar glittercorn.
 

Getting the first motor out is a pain. We struggled with getting the right extensions to the two star T25 bolts on it. We used a normal 1/4 drive short ext and a twisty socket. After the first one comes out, the second is not as difficult.

We discovered that there is a bracket holding both motors together. Removing one of the T25s from this made getting the second motor out of the way much easier. I'll do this first next time. 
 

  

Here's a template I made with cardboard. The two T25s are the bottom side by side.

The gear box has six bolts holding it together. 4 are about an inch long T20s. Two at the bottom are about 4 inches long. They are T25s. 

 

When we took the cover off the passenger seat, the plastic gear just fell out in pieces. This is the worm gear, c clip, and broken green seat gear.

 

Be sure to clean any remaining pieces out just as the Odometer Gear walk through suggests. Having broken pieces of plastic coming in between that worm gear and the drive seems like a bad idea. Unless of course you enjoy replacing your seat gears. Its an easy step but, I'm sure it can be just as easily overlooked.

Getting the cover off was a bit challenging. As well as getting it back on. Those two large round discs in the center of the gear box is where the tough part seems to come in. The diameter on the cover is very close, not a press fit, just snug. My buddy helping me just wiggled it by hand until it popped off.

Installed the green seat gear. Different color lube. Bearing grease and lithium grease are the same right?

 

  

We used the tapping method described in the odometer gears guide. I sat the gear on the piece of 2x4 we were using. Then I sat the metal worm drive on top of the gear. To start it I tapped it very gently. I didn't want to break this one. Then, after its started, I tapped with a standard metal hammer until the gear was snugly fit in place.

It helps to have a hole, or make a hole, just bigger than the size of the worm gear in the 2x4 (or whatever smooth, flat piece of wood) that you are using. There was a convenient nail hole that fit just right. This helps near the end of the "press fit" for he gear. The worm drive shaft is proud of the green plastic gear by just a bit. I didn't take a measurement but, I'd say maybe 1/8 of an inch.
 

 

The seat belt bracket bolt is a T50. The angle faces inward toward the seat. Don't forget to put this through the plastic seat rail cover first. To remove this: There are two push clips holding the seat rail cover on. One in front underneath and one on the side of the rail on the back. The front ones had center pins that were supposed to come out first. I was unaware of this so I broke one of them. The two back ones heads are facing towards the center of the car. 

 

Also note that you won't be able to access this T50 when the seat is mounted in its correct position. Put the seat belt back on first then, position the seat in place.

There you have it. Now if all is back together correctly you should be able to enjoy moving the back of your seats again. Another check off the list. I'm getting there.