hey guys,
i got an '84 k5 blazer, got it lifted 6 inches and put some 35's on it. but,, theres some sort of problem coming from either the transfercase or the rear differential. when im goin down the road at 25+ mph, and let off the gas,it starts making this horrible grinding noise. i dont know exactly where its coming from or what it is, but it sure doesnt sound healthy. it sounds like gears or something scraping against eachother. the tranfsercse has fluid and so does the rear diff. thanks!

 

How does your pinion angle relate to how it was stock? Did you install this lift yourself? It might be a stretch, but it is possible that the angle of your rear driveshaft may be messing up how your rear diff gears are meshing together causing that grinding noise above 25mph.

 

well, i got it lifted at a place called "fly-n-hi". i took my truck in to get the tranny looked at and the guy knew a lot about off road trucks (mine in particular) and he said that the angle was wayyy off and that instead of the transfer case turning the driveshaft , it was actually trying to wag it like a tail, its that bad. the tranny was fine though. he said something about a "cv" joint or something and that it would solve the problem. he also mentioned, when i told him about the noise, that it may be from the rear differential and that i might need new gears like 3.71.

 

All sounds like good info. A heavy duty CV is exactly what gets installed on big lift trucks for the drive shaft. Do you know what gears are in there right now?

 

imnot really sure what gears, its pretty much stock in that department. so whatever they came with i guess.