Pinion Angle with 4" lift

I have a 1974 CJ5. It's stock other than the 4" lift. I had someone install it for me a long time ago and they did it very wrong. My setup is a 258 motor with ford T-18 tranny and the stock Dana 20 transfer case. I am wondering if anyone else has this setup and how they did the angles for the transfer case to the rear pinion. I still have the T-14 tranny that I was thinking about putting back into it since it is a few inches shorter and it takes the advance adapter out which is around 3 inches. It would help a lot with the short pinion angles. The guy who installed it did it half right. He did use some 2 inch boxed tubing to shim the drive train lower to point more at the rear diff.

Can anyone help me out? Anyone have this setup. Should I sell my T-18 and try and find a "Jeep" T-18 tranny?

 

I have a T18 in my 75. I only have a 2-12" lift. I added wedges under the rear axles.. Mine is marginal. Sometime in the next year I am going to spring for a CV driveline..

 

I think taking the t18 out would be a bit like thowing the baby out with the bath water. Its a much stronger and better geared tranny than the t14. I believe I would take the cross member spacers back out and put the transfer case back where it belongs and go for a Cv driveline. The prices are pretty reasonable at around $350-$450 With the new transfer case yolk. Then just cut the spring perches, align the shaft and weld it back in.

On the other hand, I can know a guy that wouldnt mind taking the t18 off your hands

 

I have wedges in mine also. BigJohn I would rather leave my T-18 in. What setup do you have? I also have a CV drive shaft too. Forgot to mention it. I have/had 3 shims installed. Seems like over kill. just don't know how to figure out what angle I need to have to get rid of my bad vibrations. BigJohn, If you are running a 4" lift do you have any pictures of what your drive angle looks like or any visual information that I could go off of. I was going to leave the 2in drive train spacers and leave 1 shim in place and rotate the rear pinion back down some and go for a ride. Kind of a sucky way to find the right settings, but this is the first time I've done anything with the suspension.

Thanks for the quick replies!

 

Ya, I can go out and snap a picture a little later. If you have a CV shaft already then check the pinion angle. The shaft should be right in line with the shaft. If there is any noticeable angle difference between the drive shaft and the axle pinion there will be vibrations. I think mine is a few degrees off so I get vibration over 60 mph, but I never drive 60 so its fine. Mine is lifted about roughly 5" by the way.

Here is a link from Tom Woods website. Scroll down to the "Proper Geometry for a CV shaft" picture and there is a great drawing that illustrates what your angles should look like.

I would think with the length of your tranny/transfer case combo, the amount of shims you would need to correct the pinion angle would make your Jeep a death trap. So the best thing I would think would be fix it all in one shot, lifting your transfer case to where it belongs and cutting the spring perches from the axle and clocking the pinion to the correct angle and weld the perches back on.

Good luck and Ill snap a shot and post it in a few. Also, dont remove shims and test drive it just yet. That drive could cost you some $$$.

 

Here are a few shots for ya. Sorry about the grease. Haha

 

Here are several pictures of my setup. I would think I would want to drop the drive train down to get it more inline with the rear diff. Correct me if I'm wrong. I read through the Tom Woods information and some other articles about setting the pinion angle. Still a little unsure about. my setup and how sharp the angles are for it. I'll take more tonight when I get home if you need some more shots.

 

Hmm, I could be wrong but that drive shaft does not look like a double cardan CV shaft. If you would, post a picture of both ends of the shaft. The two different types are set up differently is the reason I ask, as noted on Tom Woods page.

 

It's the same shaft you have. I don't have one installed in the pitures. I take a pic of it tonight and upload it later. it's the XC model one.

 

I typically set pinion angle down about 1-2* with a double cardan joint to allow for spring wrap under acceleration/load. Typically it will climb about that much. I've found this reduces vibrations at higher speeds.

 

Well I put it back together Sunday. I didn't get it right. I get some vibrations around 30 MPH. I've not driven my Jeep in almost 2 years it was nice to drive it even with the vibrations. I am going to have a guy from around the corner come and help my finish fixing it and set the pinion angle correct.

Is there an offset from the transfercase to the rear pinion? I am wondering if there if the transfercase sits to the right some and the rear end sits to the left. Ths is if you're facing from the rear to the front.

Thanks!

 

The offset of the transfer case should line up with the offset of the axle, mostly. The longer the driveshaft, the less this matters.

For CJs, there are offset rear axles and there are centered rear axles, and the difference is obvious by just looking at them.

 

Yeah mine is a Dana 44 axle. with no offset, but for some reason mine don't line up. Could someone take a photo of how close they should be? It would be a big help!

I'll try and take a pictire tonight. I lost my camera over the weekend.

 

Your dana 44 axle will have the pinion offset a couple inches. No way around it with equal length axle shafts. That's pretty normal for any CJ with a centered output transfer case and a centered rear axle. Even though it's considered a centered axle, which in effect it is because the axles are equal length, it's not a centered drive pinion gear. That small amount shouldn't make a huge difference. I'd worry more about u-joint angles in the vertical plane.

 

:iagree: mine looks off but has no issues

 

i run a 4 inch lift springs a 2 inch shakle drop and have half inch shims in the rear only and dont have any problems
go wheelin often and the drive train has never let me down

 

silly question but have you checked to make sure your drive shaft "ears" are clocked the same? (might have gotten misaligned after greasing the splines?) Also, has the drive shaft been balanced? Any weeping or play in the transfer case output shaft or axle pinion?