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Old 08-01-2015, 01:43 AM   #91
JPBrecheisen
Senior Member
 
Join Date: Jul 2012
Location: Harrisville, New York
Posts: 458
Re: Spring Swap Thread - 1963 K15

Quote:
Originally Posted by '63GENIII View Post
Sorry Jason. It will be a breeze for you though. You've got some pretty mad skills! I've got the trans to tcase joints parallel and a working angle of 2 degrees. The tcase to Pinion was parallel as well with around 5 deg working angle but it felt like I was getting a little axle wrap as I would take off so having nothing but a 5 degree shim, I put it in and pointed the Pinion down. The vibration did change but its a little stronger. I almost think that the tcase may be moving around a little too. More investigating. May have to mount a GoPro underneath to see what's going on
I had a head scratching vibration once after i switched from a SM318 to a SM420 and had a drive line built to fit.

I will spare the lengthy version, but what mine ended up being is one of the nylon washers that fits between the u-joint cap and the actual cardan cross portion itself. While I was installing the drive line, both u-joint caps at the differential end came off. I simply put them back on except one of those little washers stuck to the cardan cross, the other stuck inside the u-joint cap...I failed to notice this when i put the caps back on...and ended up having one cap with 2 washers and another with zero. This obviously off-centers the drive line and thus causes a vibration.

Not all u-joints have those washers in them, but if yours do, you might give it a look. It just about drove me nuts but it ended up being that simple.

Just an idea.

Great thread and great work on your truck.
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1960 GMC K1500 LB Fleet Side
1962 GMC K1000 LB Step Side
1988 Chevrolet C2500
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