How does my rear driveshaft angle look

[Jwhite]

I just finished replacing 6/8 of my control arms and I tried to match my old angle as best as I can. Does it look okay? It’s the stock rear driveshaft with a 2.5 inch lift

 

[OldBuzzard]

It's pretty difficult to just eyeball it and say if it looks right or not.

You could measure the pinion and tranny shaft angles (should be the same with that type of driveshaft).

Does it have driveline vibes at 70 MPH? If not, it's probably fine.

 

[AndyG]

It's pretty difficult to just eyeball it and say if it looks right or not.

You could measure the pinion and tranny shaft angles (should be the same with that type of driveshaft).

Does it have driveline vibes at 70 MPH? If not, it's probably fine.

Agree.


I get my best results with a digital angle finder.


Offhand, I think you’re in the neighborhood.

 

[Jwhite]

It's pretty difficult to just eyeball it and say if it looks right or not.

You could measure the pinion and tranny shaft angles (should be the same with that type of driveshaft).

Does it have driveline vibes at 70 MPH? If not, it's probably fine.

Vibrations start around 70-75 and before I changed the control arms they started around 80. The only issue is the upper control arms are now bottomed out so I have ran out of adjustability.

 

[P man]

Pinion looks a little low

 

[OldBuzzard]

Vibrations start around 70-75 and before I changed the control arms they started around 80. The only issue is the upper control arms are now bottomed out so I have ran out of adjustability.

If you're getting up to 70 before the vibes start, it's pretty close to correct. You might want to adjust the pinion back a little. Sometimes going the opposite direction of what you think it needs actually hits the sweet spot. Do you feel lucky?

Why can't you tweak it with your LCAs?

 

[Jwhite]

If you're getting up to 70 before the vibes start, it's pretty close to correct. You might want to adjust the pinion back a little. Sometimes going the opposite direction of what you think it needs actually hits the sweet spot. Do you feel lucky?

Why can't you tweak it with your LCAs?

I don’t wanna adjust the lcas because they are now equal to the front Lcas and I don’t want to shorten my wheel base. When you say adjust my pinion angle back, do you mean lower the differential down or raise it up?

 

[OldBuzzard]

I don’t wanna adjust the lcas because they are now equal to the front Lcas and I don’t want to shorten my wheel base. When you say adjust my pinion angle back, do you mean lower the differential down or raise it up?

So you think shortening your wheelbase by about 1/8" is a bad thing? Why?

If your UCAs are bottomed out, you can only adjust it one way. So try it, see what happens. You usually don't have to get the pinion and tranny angles absolutely identical, just within a degree or so. And even then, sometimes you have to bump it one way or the other to make it happy.

 

[LONGJP2]

The only issue is the upper control arms are now bottomed out so I have ran out of adjustability.

Ideally, you should adjust both upper and lower (in opposite directions) to pivot the pinion. That way it rotates around its center axis and doesn't change the wheelbase.