Power seat disassembly

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GRWeldon

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Hope everyone is having a good day. I just spent the afternoon disassembling my power drivers seat. What an ordeal!

Once I got the passenger side rail off the mechanism, I couldn't get it to move at all. I hit it a few times with a 16-oz hammer in both directons with a very big swing and it would move about a thirty-second of an inch. I ended up using a 10-ton hydraulic press to push it out. It required several setups in the press to clear all the protruding bits as the slide moved.

When I finally got it out about 2 hours later, the inside of the track was severely rusted. Because I couldn't get to the rear bolt when removing the seat because the seat was covering the bolt and wouldn't move, I had to pry the bottom part of the track out of the way in order to get a socket on the nut. Of course the nut was supposed to come off, but instead the entire stud came out...the nut never moved.

So I've got the track soaking in evap-o-rust at the moment. I'll have to straighten it when the rust is gone. But, for some reason took off the motors from the gearbox. I'm sure I could have reassembled it with much difficulty and aggrivation, that was until I dropped one of the motor cans and broke the magnet. Great, now I have to remove another seat for parts. Hopefully the donor will be in better shape than the original and I can use that mechanism!

I do hear people talking about removing all that old grease and replacing it with fresh. Are these fold talking about the grease in the slides? If so, my slides are dry as in no grease whatsoever. I'm hoping that the suggestions don't refer to disassembling the gearbox and replacing that grease. That would involve drilling out rivets and looking for alternate fasteners for reassembly. Please tell me this isn't the grease folk are referring to....

I guess I now know way more than I ever wanted to concerning MN12 power seats!
 
I'd sell you a manual track, but I'm all out, plus you'd lose the tilt. They are hard to find.

How are you going to fix that stud that came out? Does it need to be welded?

From my junkyard travels, since there's no battery, I've only had the opportunity to try the power seats once (because that car hadn't been prepped for the yard yet, so I had access to power). It was a very clean '95 with dual power seats, and they both didn't work; they clicked and tried to move the seat, but they couldn't. That's why I dropped the idea of installing power seats in my car.

While you have the seat out, if you have cloth, this is a great opportunity to remove the cloth and wash it. Gentle cycle, gentle detergent, air dry.
 
1997ThunderbirdLXV6 said:
How are you going to fix that stud that came out? Does it need to be welded?
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Since the nut on the stud was seized bad enough not to come off, I'm just going to reinstall it like it were a bolt.

1997ThunderbirdLXV6 said:
While you have the seat out, if you have cloth, this is a great opportunity to remove the cloth and wash it. Gentle cycle, gentle detergent, air dry.
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As I was removing the seat back I noticed that the edge of the seat that gets contacted first when you sit in the car... well it's so thin it looks like it would rip in a heartbeat. Washing would be out of the question, but even if it were sturdy enough to wash, it would be too clean and would look out of place with the rest of the interior. Spot cleaning with Blue Magic will have to do. That shit works amazingly well!

I have been trying to come up with something to reinforce the fabric from the underside but short of some sort of cloth tape, I am not coming up with anything.

I took another seized seat rack from one of my parts cars and I'm trying to un-seize it. It's heavily rusted. I may use it for replacement parts if I can't free it enough to work well. This unit also had zero lubricant from the factory. Going to wash it out with WD40 today and work it back and forth assisting the motion by using a pipe wrench on the shaft that ties the gears together from one side to another. I was able to break it free using this method but the motor is still not strong enough to make the entire distance unassisted. Hopefully the WD40 will wash out more rust and the track will move freely.
 
I believe these have an early version of the JCI WITS 1 track in them. It has been a while since I've looked at one, but from what I recall it was two vertical channels on each side with a semi-floating rack. We used to just use Delrin "shoes" that the tracks would slide together on, but we used extruded aluminum tracks instead of steel. If I had to guess, I would say they probably did not apply any grease to them originally. No way Ford would let us and risk grease coming off and onto the carpet or upholstery. I would clean them up the best you can and apply a dry film lubricant to the slides and maybe a very small amount of grease to the rack, but not much.
 
KevinVarnes said:
I would clean them up the best you can and apply a dry film lubricant to the slides and maybe a very small amount of grease to the rack, but not much.
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Thanks. Apparently it takes very little rust in the tracks to seize them. I have the offending track soaking in evaporust to remove what I can't get to with the wire wheel.

Regarding slow, weak motors...I've heard stories of dried, caked-on white grease inside the gearbox making it difficult to turn. I have one motor that sounds weak when just free-wheeling. Am I correct in assuming that the gearbox pictured in the attachment, with the rivets all around the edge, is what people speak if when they say the grease must be removed, the unit cleaned, and grease replaced?

I guess I can do such if it will work. Do you, Kevin, (or anybody else) have personal experience doing this? I'd hate to go to all that effort and find out it didn't make much difference.
 

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I've never taken one of those gear boxes apart to be honest. When we had those tracks on durability it was usually the motors that failed, but that was in a controlled test lab environment and in a compressed time frame. I believe those motors had thermal protection devices that would shut them down if they got too hot. Once they cooled down they would work again, but they were never as strong after that. We used to blow air over the motors to cool them down a bit, but that was with the tracks constantly running for weeks on end.

I'd kind of be surprised if the grease in there is slowing it down, but whatever is in there is 30 years old so it can't hurt to take it apart and clean and regrease. It looks like 10-11 rivets that would need to be drilled out. I believe the motors for the vertical actuators are the same as the horizontal actuator so you could also try swapping motors around. The verticals don't get used nearly as much as the horizontals.

If it makes you feel any better, I've been needing to do this to our '97 for a couple of years now and keep putting it off. If I have time this upcoming weekend I'll try to dig into it and let you know what I find.
 
KevinVarnes said:
If I have time this upcoming weekend I'll try to dig into it and let you know what I find.
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You will find this! All the drive chains are worm gear driven. The long worms have tiny metal disks at the end of the shafts. Keep track of them! The grease was in good shape but I cleaned it out anyway.

The rivets spin when you drill them. They get hot and melt the plastic and push out. I wouldn't recommend anybody take one apart for that reason.
 

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