4" lift driveshaft problems 88 blazer
 

I put a 4" pro comp lift on a stock 1988 chevy k10 blazer. The rear driveshaft has developed a vibration and a chatter when rolling but not under power. I put 4" blocks with a wedge molded on them and I also stacked another wedge under the block. Has anybody put this lift in and kept the stock driveshafts or do u have lengthen them?

Re: 4" lift driveshaft problems 88 blazer
 

I've never lifted one that much but they say at 4" the drive-shafts have to be lengthened; you may need to put a transfer case drop kit on it as well to decrease the drive-line angles.

Re: 4" lift driveshaft problems 88 blazer
 

I'd at least try dropping the T-case down and see how it feels. I have a 2.5" lift and need a T-case drop. This will help but isn't really a long term solution if you want to do it properly.

In the rear, you should only have one lifting block. If you are shimming it, be sure it's a steel shim that bolts to your spring pack. Generally though, the 4" block already had the angle built in.

If you have your same driveshaft, it's going to be too short. Dropping the t-case will help but again, to do it correctly, you may have to lengthen your driveshaft.

How much more is now sticking out when compared to the stock height? You can generally see at the slip yoke where it use to be due to the shinny part.....

Do NOT use the stock spacers from the t-case crossover braket as your "dropping spacers". They are too small to use a spacers, so you need to get the propper ones. The stock spacers on top are to allow for bolt stretch only. Not too expensive either.

Re: 4" lift driveshaft problems 88 blazer
 

check the pinion on your rear diff i know this doesnt really pertain to your lift kit but my old 86 used to do that. Driving it would be ok but coasting the rear end would scream and i had all sorts of driveline chatter. found out one day in a home depot parking lot that my pinion nut had backed off some. i am unsure how but it did. I put locktite on the nut and never had the issue again.

Re: 4" lift driveshaft problems 88 blazer
 

you will need to have a custom drive shaft made that has a CV or double u joint at the T-case this is the only way you will achieve the correct drive shaft angle and eliminate all the vibrations and pre-mature wear