Windshield Crank Rebuild
by Kip "Kip's41" Bonds
|Wow, so now you've got that special pre-'47 truck with the killer crank-out windshield. Only you've found out that no-one (and I mean NO ONE!!) re-pops those suckers and originals will run you a fortune! What to do -- live without that cool feature?? No way! Kip Bonds figured out how to rebuild the windshield regulator on his 1941 Chevy 3/4-ton and now will help you ....|
When I began to disassemble the cracked windshield on my 1941 3/4-ton, I quickly realized there would be much more involved than a simple glass replacement. One item that was painfully obvious was that the stainless steel strip for the regulator was not attached to the windshield frame. (slide #1) After more investigation and the removal of the regulator mechanism, I found that the whole thing was in need of a lot of TLC.
The next step was to look around for a functioning replacement. Turns out that they are available for a fairly steep price, but only if you have an almost perfect one as a trade in. Lot of good that does.
It was time to see if my unit could be rebuilt. First, I found that the worm gear was out of position. It had screwed itself out beyond the wheel gear that it is supposed to engage. (slide #2) A few light taps on the splined (crank) end of the worm gear shaft and it came right out.
Next was the shaft holding the large wheel that engages the stainless steel strip. One end of this shaft is knurled to fit tightly into the die-cast housing; the other is not held in place. These die-castings are somewhat brittle so be careful when hammering or clamping on them. I placed the assembly on my vice with the knurled end of the shaft loosely in between the open jaws and gently tapped the shaft out with a small punch. At this point, the unit was completely disassembled (slide #3) except the brass thrust stop that was supposed to keep the worm gear / shaft in place engaged with the wheel gear on the main shaft. Getting this piece of brass out was a bit of a challenge. First, I removed the small rivet holding it in place (slide #4). I then drilled a 1/8 inch hole through the die-cast housing directly above the brass stop (slide #5). Using a small punch through the new hole, I drove what was left of the brass thrust stop out.
Next, I found that the hole where the main wheel shaft passes through the casting on the worm gear side had worn into an elongated shape allowing the wheel gear to move away from the worm gear (slide #6). I drilled this hole out to 3/8” and inserted a very short piece of 3/8” aluminum rod as a bushing. Then I drilled the aluminum piece off center so the shaft would be supported in its original position. To keep both the shaft and the new aluminum bushing on place, I drilled the shaft and tapped it for a 10 X 24 stove bolt about 3/8” long.
I made a new brass thrust stop from 1/8” stock found at the local hardware store (slide #7). This piece was made with only a hacksaw, electric drill, flat and rat tail files. I had to insert it several times to check my filing progress
Next, the complete mechanism was assembled and tested. It worked just fine.
Now it was time to tackle the stainless steel strip. This piece was badly twisted and the end that attaches to the windshield was torn off and missing. A little twisting, bending and some light hammering got the strip back into its original shape. I purchased the windshield connecting bracket from Chevs of the ‘40s (slide #8). Since the end of the stainless strip was missing, I fabricated a small aluminum detail, bolted it to the windshield connecting bracket with a 3/16” binging post and riveted it to two new holes drilled in the stainless strip.
The entire unit is now installed in the truck and seems to work fine.
1941 Chevy Master 3/4-Ton
Bolter # 9342
Kip is also the author of another tech tip on Emergency Brake Cable Replacement Pulley. Be sure to check out our extensive Forums discussions -- from General Truck talk, Electrical Bay, Big Bolts, Panels and Burbs, Engine and Driveline, Paint and Body, Interiors, Tool Chest -- The Stovebolt Collective can help in your quest and walk you through the mire and magic of working with old iron. ~~ Editor.
v. March 2007
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