Drive Shaft Angles

[NomadJeep]

Alright, now that I have changed my angles almost a half dozen times, here is what I now have after my belly up skid. It is a YJ with leafs...

So what do you all think I should do? I am at my wits end with splitting apart these leaf packs every time.


The part that sucks is I can’t seem to get rid of the vibes, even last time when I thought I had it, I had Tom Woods on the phone, and read them the numbers, then they sent me the degree shim and still, vibes....

Also, anyone know the what the caster is supposed to be on the front. I changed my mount up there and now I think I need to shim my front diff. (steering is a little screwy)

PS: no get a TJ comments

 

[sean_cj7]

Damon, I'll check my angles out, but in the mean time what are those numbers refering to, on the rear DS.

 

[NomadJeep]

they are the degree measurements of my drive train,

T-case output = 4 Degrees
Drive shaft = 25.5 degrees
Pinion= 18.5 degrees

Now from what I have read, the t-case is not as important when you use the double Cardin, so then they say you should try and get the drive shaft within 3 degrees of the pinion? I guess...

If you don't use a double Cardin, then you should match the t-case output angle to the pion angle, so I have read...

 

[sean_cj7]

I checked mine and this is what I have. Rear riveshaft angle 24.5* and pinion angle 24.5*. They are they same as far as I can see. I didn't bother checking the t-case angle, but a will when I return down stairs. As for the front, driveshaft angle is 13* while my pinion angle is 5*, once again no t-case angle. Now I have zero vibrations at any speed. Never had any what so ever. Now my front driveshaft doesn't spin so that takes that out of the equation. Have you tried removing that and seeing if that was the cause. I'm not sure of my caster angle in the front. I don't have any shims and have tried to keep it at stock specs. Another thing, with a driveshaft angle that high I get worried about binding at full droop. I never had a problem but have thought about a limiting strap.

 

[sean_cj7]

I couldn't measure the t-case angle, I didn't have surfaces to go against.

 

[NomadJeep]

so that makes mine in need of 5 to 7 more degrees of pitch... is that possible without burning up my pinion bearing? I already have a 5 degree shim in there....


damn this sucks... :lol:

 

[jeepinrandy]

If you have a CV driveshaft your pinion should point straight at the T-case and then rotate down 1°. So, if your driveshaft is 25°, your pinion should be 24°.

You might want to consider taking out the shims and rotating your axle to the correct angle.

 

[sean_cj7]

I haven't had any pinion problem yet and have driven my Jeep on the road alot (until I got a trailer). I just welded my spring perches at the correct angle, I'm not sure how good it is to have alot of shims, I know someone who had ubolt issues. As for the oil in the diff, I backed up a sharp incline and added more oil, then a little ATF to eliminate foaming. I believe Tom Woods comments on it on his website.

 

[NomadJeep]

Yeah I would like to cut and reweld the perches correctly, however I have been told that being they were more than welded when I put the dana 44 axle in, (Super Strong Detour Welds) It would not be a good idea to try and grind the hell out of them....

 

[Used-TJ]

I see a couple things:
The rear of the t-case is pointed DOWN at 4 deg, so the FRONT should be pointed up at 4deg. I'll assume with the equipment you had that +/- 2 deg was as good as you could read.
But do you have a 2 joint shaft as shown or a CV shaft in the front like you should have?
If it is a 2 joint shaft, the pinion needs to be pointed DOWN 4 deg to be in the same plane as the tcase output, thats why they put the cv shafts in the front, so they can point it up.
From what you show here you would deffinatly be getting vibes from the front.
Have you checked to make shure that the shafts are still straight, no dings or bends?

 

[jon]

used-TJ YJs came with a 2 joint standard driveshaft in the front.

 

[kevinc]

keep in mind for the rear the pinion climbs under load, so a lot of leaf spring users set the pinion angle about 3 degrees under. HTH

Kevin C.

 

[NomadJeep]

Ok, I understand the rear, but what about the front... How do all these guys out there fix the front set up? If you do a motor mount lift, or a T-case drop, the rear of the T-case will drop, thus making the front drop... So how does one correct for an Angle up front?

Like mine, even though my pic shows 6, it is actually 4/5... pointing up,,, so for my 2 joint drive shaft set up to create a level plain between the front pinion and the T-case would mean my diff would have to be at (down 5) which would be impossible... So does a double Cardin correct this for the front?