Slow window fix

Nader · 03-09-2012, 10:20 PM

My power windows have been slow and grabby for about 10 years. Passenger side motor finally failed, so I decided to refurbish both sides.

Passenger side had a stiff main pivot in the regulator, and one of its arms was out of the window's track. Didn't get pics of that since it was nothing special. But I did take pics of the driver's side since it had a failure of the spring tensioner. I've seen this happen in other people's posts when searching this topic. The motor has to struggle a bit getting the window up without the spring assist (kind of like garage doors).

The peg that holds that spring coil is some kind of non-ferrous pot metal that was peened into the slot in the middle of the regulator. Strange because it's holding a lot of tension, especially with the window down.

So I used a combination of a stainless button head bolt and a coupler nut to recreate the peg. Loctite red makes it semipermanent. Had to use a button head for the low clearance between the regulator's arms.

Cut to size and painted the cut end for rust protection. There, spring tension restored.

Nader · 03-09-2012, 10:44 PM

The combination of corroded, chunked up window felts and stiff, malpositioned regulator killed the passenger side window motor. I didn't want to spend nearly $200 for a new stock motor (Sorry Wayne), so I took a chance on another cheaper Bosch window motor I found on eBay. It's listed for some Mercedes sedans from the '90's, but it looks nearly identical to the Porsche motor, including the right number of teeth on the gear. And it's only $65.

Upon closer inspection, the castings are not identical. The mounting holes in the gear case (attaching the assembly to the window regulator) are taller in the replacement motor, and the male plug is on the wrong side of the motor. So I merely switched the actual motor from the newer unit to the old stock gearcase. Perfect fit, and the pinion gear turns smoothly.

The irony fixing the slow, struggling window occurs because the replacement motor is not as fast as the stock unit. Now I'm not even sure that this replacement motor is a genuine Bosch product versus a Chinese knock-off. But it's running smoothly, and at a third the cost of the real deal, I can live with a slightly slower but healthy and smoothly functional power window. I was satisfied enough with the passenger window motor fix that I bought another motor to prophylactically replace the driver's side as well.

bigel · bigel's Garage

Quote:

Originally Posted by Nader

Cut to size and painted the cut end for rust protection. There, spring tension restored.

Nice job Nader...it's always satisfying when you successfully utilize a cheaper and compatible replacement part.

One question, it appears from your photos that the spring tensioner, having lost its pot metal post, would have only rotated ~20 degrees until it rested on the far mounting post. Would that have caused significant loss in spring tension?

Steve

ace123 · 03-10-2012, 05:38 PM

I worked on my Window regulator today as well. Are replacing the felt? How do you do that?

Nader · 08:43 PM

Steve, if you look at the very first picture you'll see it closer to 100 degrees of travel before reaching the post. The spring tension at that far post's point was minimal. And that picture of me holding the spring in the second photo is about as far as I could push it myself. Those last few centimeters of spring movement are really strong.

Ace, the outer felt is held to the door frame with metal snaps. You can pry them out with a pick or small slotted screwdriver. The inner felt is a rubber channel that slides over the inner sill. Here's a pic of the driver's side felt, which was in much better condition than the passenger side, which crumbled into a pile of rust flakes during disassembly.

I learned that a misaligned window frame may be another hindrance to smooth window operation, if it's putting undue pressure on the window glass. You can realign the window frame by loosening the bolts that hold it to the door. Here's a couple that hide under black rubber plugs. There's another down low on this side, and a couple more on the other (forward) side, as well as a couple accessed through the uncovered door panel. You can figure it out when you get everything apart. I loosened the bolts, then slid the window up and down and closed the door a few times to further loosen and knock everything into place. It may not be the right way, but it seemed to work for me.

ace123 · 03-10-2012, 10:01 PM

Yanks for the info.

ace123 · 03-10-2012, 10:03 PM

How tough is it to replace the squeegee rubber part on the outside part of the window. Is it just held bt pressure? Is removal just prying it out? Where should the window be when I do it?

pete3799 · pete3799's Garage

Quote:

Originally Posted by ace123

How tough is it to replace the squeegee rubber part on the outside part of the window. Is it just held bt pressure? Is removal just prying it out? Where should the window be when I do it?

There are metal clips that are pushed down into the top of the door.
Pry it up. Doesn't matter what position the window is in.

SoCalSK8r · 03-29-2012, 11:53 AM

This is a great post, I now can fully understand why I found this piece floating around inside my door when replacing the speakers, and it also explains why the window moves so slowly!!

Can you tell me what size screw and coupler you used? I wanna swing by the hardware store on to grab these parts while I still have the door panels off.

Any tricks or anything to removing that whole assembly? I can't even see the spring, so I'm assuming this all has to come out to fix it.

Thanks!

88911coupe · 03-29-2012, 03:35 PM

I found one of those in my door years ago but it was not broken. I guess I'll need to put it back!

Nader · 03-29-2012, 03:48 PM

Apparently, this happens to the mighty 959s as well.

I used a 6mm screw and coupler. No reason you can't go with 1/4" if metric is harder to find. To remove the regulator, you have to first remove the window motor. And tape the window in the up position once you've detached the regulator from the window's bottom track. Or else it'll slide down and get in the way. Be patient in wiggling out the regulator. It's awkward with the parts dangling and stuff getting caught on the door innards.

Good luck.

DRACO A5OG · DRACO A5OG's Garage

My Compliments, Been meaning to tackle this on my passenger side window.

howard freeman · howard freeman's Garage

What causes these problems are, Old felts,dry filthy regulators & frames out of adjustment & bent. Pull the frame out check for bends,clean all the tar & gue out of the channels. Replace the felts,clean the regulator & lube it,i use Aero Shell 5 & LPS 3. Make sure the window rail attached to the bottom of the glass hasn't moved or loose. Disassemble the motor,clean the gearbox & relube & clean the commutator with a fine scotch pad & check the brushes. If the brushes are worn,trash the motor. I have use this procedure on all my 911's,works every time . If its a clients car do all of the above,except you must replace the motor.

ballyn · 04-07-2012, 05:43 AM

Good stuff. My passenger window has been slow so I opened it up and found this peg lying in the bottom of the door. I guess I know my next project. I'll order the window channel felt and do this next weekend... Way too nice today! Thanks!

Porboynz · Porboynz's Garage

One small tip is if you replace the door frame mount bolts make sure they are exactly the same length as the factory bolts. If they are a few mm longer they push on the door channel felt runners and you jam up the window operation giving you, slow windows. Great thread.

maclaren65 · maclaren65's Garage

Great thread!

The passenger window on my 87 Carrera coupe moves much slower than the driver's side window. Is this most likely a motor issue?

When I roll down the driver's side window an inch or two something rattles inside the door. This only happens after the window has been lowered a few inches. Any thoughts on this mystery?

Thanks.

twistoffat · 08-02-2012, 11:59 PM

My passenger side window was slow and I cleaned up the felts which helped somewhat. Its still slower than the drivers side though. Is there a reason why the passenger side seems to suffer more than the drivers side?

Mitch Leland · Mitch Leland's Garage

Talk about timing... I was just ready to install my new re-upholstered door panels after replacing the door arresters when I read this post. I had cleaned out the bottom of my doors and found these parts, but couldn't figure out where they came from. Unfortunately now I know... So another "while I was there project".

Peter Zimmermann · 02:10 PM

This might help...'82 SC coupe with agonizingly slow passenger window.
1. The book really doesn't show when to remove/install the motor. I did it with the reg in the bottom of the door.
2. I put a new felt guide in the frame - don't glue the side pieces, only the top. I used 3M black weatherstrip cement.
3. Don't forget to grease the drive gear on the new motor.
4. Don't forget to align the frame for clearance to the body before you shut the door.
5. Grease the regulator wheels and their channels - be very careful that no grease gets on the weatherstrip inside the top of the door - you will never get it off the glass. Work clean, and wear latex gloves! When you slide the glass back into the door, be sure that it is spotless!

And, yes, in a "race" between the driver and passenger window, even with all the new parts in the right side, it's still about one second slower, bottom to top, than the left side.

Mitch Leland · Mitch Leland's Garage

After reading this post and finding out that the coil spring post on both doors of my car had fallen out I removed the driver's side this afternoon. I looked up the regulator removal in Bentleys, but they didn't say to remove the "L" bracket on the forward lower window channel so you can remove the regulator.

I bought a 1/4-20 coupling nut and I already had a S.S. button head bolt of the same size. If the hole isn't big enough in the regulator plate I'll drill it out for the 1/4-20 bolt.

I'll follow up after completing the work...