ryan_89_mustang

I was the axles I replaced them both one was worse then the other. The po must have done something stupid to accomplish that.

NickSezz

My car is smooth at all speeds except for above 100mph mostly during deceleration. I was going to mess with the pinion angle but now that I think about it...wheel hop could bend the axles and I know I did a lot of that in the rain before I upgraded the LCAs...

I see these options for myself...Measure all drive line angles and adjust if needed. The pinion is set to -3ish to account for axle wind up, but if anything else is off it would need to be adjusted. The T-5 tail shaft is said to go bad and cause vibrations also... Other than that I would just replace the whole axle with an 8.8 since replacing the shafts in the 7.5 will likely cost about the same...

What do you think?? If you can explain exactly what your car used to do that would help me out man...thanks

ryan_89_mustang

It's hard to explain it was just an overall shake and this was on my old car now too which i no longer have. And I finally saw what it was by adjusting my mirror in such a way that i could see the rear tire. When I did this I saw that the tire was physically wobbling.
I went home and jacked the rear end up and took the tires off and put her in first gear and let it idle along. I could see that the face of the hub was true when i did this.

Have you got underneath to see if there is play where the yoke goes into the the transmission? Also the fact that you say it is worse during deceleration, is this when you are gearing down or say coasting/putting on the brakes? If it happens when there would be less strain on the driveline then it could be something as simple as a u-joint.

NickSezz

I looked into it more last night and I am hoping I can solve this by adjusting the pinion angle up a few degrees. I don't think the wheels are wobbling because I would have seen that on the dyno. It is worse when I am coasting and I use the brake to get to speeds that don't make my rear view mirror want to fall off lol. It vibrates so bad I can't see in the mirrors! The car itself doesn't shake, its more of a high frequency vibration being transferred from the drive line throughout the car that is loud. It makes a similar sound as a failing bearing does when it spins and vibrates itself to a stop...just louder and on a larger scale. I checked for play by the trans by had and everything seemed ok...The shaftmasters DS has a slip joint near the trans joint that had some up and down play though...

nightmare90gt

you find a fix yet

NickSezz

Me, not yet. Don't have much time to mess with it cause of finals but I tried adjusting my UCA but couldnt do it laying under the car with a pipe wrench....plus it was like 28 degrees so I have to wait until someone can help me out with that. That be step one...going from -3 to -1