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Chevrolet TSB 87-T-51 rear power window slow

Metrodps

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OK I was browsing TSBs on Alldata at my friends garage today and thought I would post it. Thought it might help someone (like me in future). Sorry the pictures didn't come through.


CHEVROLET NUMBER:87-T-51
SECTION:10 - Body Section
DATE:January, 1987
SUBJECT:TAILGATE WINDOW ALIGNMENT
MODELS:1984-1987 C/K-R/V JIMMY/BLAZER

Some 1984-1987 C/K - R/V Jimmy/Blazer models equipped with a power tailgate window may experience a tailgate window that operates slowly or does not fully return to its upward or closed position. This condition can be caused by misalignment of the rear tailgate window, cable, guide pins, sash assembly, regulator assembly or the tailgate. The following checks and adjustments should be used to correct this condition.

1.Battery Condition - Check the charge of the battery while the engine is running and also when the engine is stopped. A low battery charge can cause the window to move slowly.

2.Rubber Wedge - Some models have a rubber wedge (5" long) installed at the base of the roof housing between the window track and the glass run seal. If equipped with the wedge, remove it and glue the glass run seal to the roof using weather strip adhesive (P/N 12345097) or equivalent (see Figure No. 1).
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3.Cable Assembly - The cable assembly should not interfere with the movement of the window. The cable should run below the lower window stop and through the holding tab (clip) mounted on the tailgate (see Figures No. 2 and 3). Any tight bends in the cable will reduce the power transferred to the regulator assembly.
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4.Window Regulator - Check window regulator and left regulator arm for any binding (see Figure No. 4). Marks will be visible where the regulator arm and sash have contacted. If left regulator arm is catching on the window sash, carefully bend regulator arm as required. Check the meshing of the regulator teeth. An overly tight meshing will cause unnecessary binding and the regulator assembly should be replaced.
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5.Window and Sash Assembly - Remove glass and sash assembly for inspection. This can be accomplished by removing the four bolts that connect the sash assembly to the regulator arms.

-If sash is not centered on glass, remove the sash and center it on the glass assembly (see Figure No. 5).
-Remove any excess sash filler at the ends of the sash assembly.
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-Check the angle of the sash channel guides to ensure they follow the curvature of the glass and sash channel (see Figure No. 6). If adjustment is required, carefully bend the guides to the same curvature as the glass and sash channel. Ensure that the guides travel through the channel smoothly.
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6.Tailgate Glass - Check curvature of the tailgate window. Lay straight edge on glass and observe the clearance between straight edge and glass at center of window (see Figure No. 7). If clearance exceeds 1/4 of an inch replace the glass.
7.Ground Strap - Install a ground strap (12 gauge wire) from the tailgate to the frame. Attachment can be made from one of the tailgate hinge bolts to one of the holes in the rear frame crossmember. Use a star washer with each bolt to provide good metal to metal contact. Make sure the ground strap does not become kinked when the tailgate is closed. Ensure that the motor is grounded properly to the tailgate. This can be accomplished by replacing one of the window regulator motor bolts with a zinc chromate coated bolt, P/N 9419004.8.Tailgate Fit To Body - Check flushness and height of tailgate to the rear quarter panels. If the top of the tailgate is misaligned (in or out), loosen the strikers on the inside of the rear quarter panels and adjust accordingly. If alignment (in or out) is off on the bottom of the tailgate, loosen hinges and adjust as required.
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9.Window Centering - Loosen the two channel adjusting bolts on each side of the tailgate (see Figure No. 8). Close tailgate and run window up and down. Open tailgate enough to access the adjustment bolts and tighten.
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Nice..think ill do the ground strap for sure. The other stuff looks "messy" lol.
 
I don't see the figures you have referenced...any ideas why?

OK I was browsing TSBs on Alldata at my friends garage today and thought I would post it. Thought it might help someone (like me in future). Sorry the pictures didn't come through.

Because there not there! :rolleyes: Like I said AllData figures don't copy over. I will print it and then try to post. Most should be self explainatory if you have it in front of you.
 
I'll add another that you may run into. When working on the tailgate double check that the motor has not been inadvertantly bent inwards by crawling on and over the tailgate while working on it. It causes the glass/sash assembly to catch the bottom edge of the motor. I gently pulled my motor upwards until I had a good 1/8"-1/4" clearance, then screwed the cover back on.

I lubed my regulator with 90 weight, it adheres very nicely and improved the smoothness. Time will tell how long it lasts. At the very least clean the old gunky grease and re-apply the lube of your choice.

Also, check the nylon rollers and the tracks the rollers run in. Very common to have seized or missing rollers, or chunks in the tracks. The felt in the window tracks needs to be in decent shape too.

Overall, it's a little tedious to work on but when it all works like it should you'll be very happy with it. I was able to get my gate working like a champ for next to nothing money wise, and a few hours of my time.

Rene
 
I'm going to use STP Gear Treatment on my tailgate tracks,its sticky as glue yet is slippery as can be too...I found about 6 tubes of it at a "Big Lots" store years ago,never saw it before then,or since then either!..looks like a giant toothpaste tube..stuff clings like crazy and is a very good lube for things like garage door tracks and rollers,chains,and as an engine assembly lube..

I found adding a tube to a leaky NP205 slowed the leak down a lot,I only added a quart over a years time versus a quart every month without it..
 
Printed the figures will scan them Sunday and post. Be warned they aren't that good. Anyone who has used AllData knows what I am talking about. Diagrams are ok but their pics sux.
 
OK added figures and here is more info on slow rear window.
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Interesting stuff, thanks for bringing it back up.

I didn't think the bolts that hold the window channels in were adjustable, but I may play with that when I tear it down to replace a flat spotted roller.
 
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