rear end shudder on down shift
#1
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rear end shudder on down shift
When I put my A4 into drive (not over drive) and speed up to 55-60 and then back off I can feel a noticable shudder in the rear end, this will happen at any higher speed too, if im cruising at 85 and downshift into 4th gear (D) it shudders harder. Today I took her up to 140 on the way home from work and the shudder needs to be fixed, it was really strong & much louder and i can feel it more up by the tranny, it seems to disapear 135-160 when i dont have my foot into it. The other thing that is bugging me and im not sure if its related, when i spin the tires in reverse I get REAL bad wheel hop... how do i fix that?
I have a lowered car, LCA, LCA relo-brackets, adj panhard and aftermarket torque arm. I had someone measure it for me and they said it was -1.... but it doesnt make sense. any ideas?
i dont have any trouble with the trans? I was thinking a weak u-joint but i checked them and they look good and arent loose. maybe the pinion angle was off but it was measured at -1, maybe the drive shaft is off balance, or could the rear axle not being centered properly cause this?
I have a lowered car, LCA, LCA relo-brackets, adj panhard and aftermarket torque arm. I had someone measure it for me and they said it was -1.... but it doesnt make sense. any ideas?
i dont have any trouble with the trans? I was thinking a weak u-joint but i checked them and they look good and arent loose. maybe the pinion angle was off but it was measured at -1, maybe the drive shaft is off balance, or could the rear axle not being centered properly cause this?
#2
Originally Posted by SoCalZ28
The other thing that is bugging me and im not sure if its related, when i spin the tires in reverse I get REAL bad wheel hop... how do i fix that?
Nothing on the car was designed to go backwards under high torque. So just dont.
#4
Well, people do stupid things to their cars. Thats why I hate buying used performance cars because you never know who thought it might be cool to do a burnout in reverse when they should know that the LCA's and torque arm are on the wrong side of the axle and that the ring and pinion gears in the rear end as well as the little gears in the transmission are all cut the wrong way for that sort of thing.
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yeah, I hear (read) what your saying. I dont go out and try to burn out in reverse; its when I accidentally spin in reverse I instantly get a violent wheel hop. What you said makes total sense, but do you get violent wheel hop when you accidentally spin in reverse? Maybe my 315's are making it worse?
#6
The shudder you're experiencing is probably some slack either in the U-joints like you said or in the rear end itself. -1 for the torque arm is not very extreme BUT I did notice a significant improvement in vibration when i put mine at 0 after having it at 2* negative. So you might try setting yours to 0 to see if that fixes it. if not, go back to negative 1 or 2 if you like. it doesnt cost anything if you do it yourself and its an easy adjustment. if you dont have an angle finder then it'll cost you about 5 bucks.
You might also try posting either in the transmission forum or probably your best bet is in the rear end forum. I wonder if your ring and pinion isn't worn/ out of spec.. ive been wondering the same about mine lately
You might also try posting either in the transmission forum or probably your best bet is in the rear end forum. I wonder if your ring and pinion isn't worn/ out of spec.. ive been wondering the same about mine lately