axle vibrations
 

Hey guys,

has anyone had experience with Napa axles. I decided to lay some rubber in my driveway after pulling my car off the trailer when I got home from the dyno. Well I snapped a very tired 1994 4 bolt axle. So I decided to replace both with Napa brand axles that were splined on both ends.

after changing them I noticed a pretty decent rear end vibration and howling noise. at around 70mph.

my wheel bearing feel tight, axles feel tight but with it up on jack stands and in 6th gear I can see the axle shafts running out. Im not sure how much runout would be acceptable. The driveshaft is also a 1994 gem unit from my old race car.

I removed the wheels and bolted the rotors down and still got the vibration on the jack stands at 70mph. So that rules out wheel balance.

I guess my big question is how many people have had issues with replacement axles and how many people have had driveshaft issues.

Check your driveline could have a loose u joint.

also way back when I ran the brake shop at Les Schwab I would try to run the car in gear in the air and some cars do really weird stuff. Not sure if a miats would do anything weird. But you might get different results on the road vs air

Yeah I just ran it in the air to see if I could see anything going on with the wheels, the vibration came in at the same time as on the road. Im gonna pull the driveshaft and check out the U joints.

To skip pulling it set your parking brake and in nuteral crawl under and you can check for slop. Also if one is getting g stiff or frozen that could do it but then uou would have to remove to find out