Rear shaft angle?

[Jeeping Hillbilly]

Being new to CJs and springs i am not a 100% sure of the lift on the 5 but it seems to be a 2 1/2 inch lift? Is there a measurement i can take somewhere to get it exact? like frame to ground in a certain area or do you guys just go by experience of being around it so long you can just tell?

Also do you think a 1" Transfer Case drop would be enough to ease this angle on the joint to an acceptable one?

Thanks,
HB

Forgot to add it sits on 33s and i plan to keep it that way. I cannot remember if it had a Transfer Case drop or not since it was 2 years ago and 2 frames ago.

 

[Torxhead]

You driveshaft angle should change when you put a body on it or comparible distributed weight on the frame, then you can determine if it is off and how much. It is a factor though, where too much of an angle can cause vibration and increase u-joint wear or even can bind up and break the u-joint. It can be adjusted by shims to change the pinion angle at the differential and lowering the skid plate to change the angle of the Transfer Case u-joint.

 

[Jeeping Hillbilly]

Ahhh, wait till I get it all back together and the normal weight it carries distributed and compressing the springs , makes perfect since, boy I just keep looking dumber.

Thanks for the info Torxhead.

HB

 

[BusaDave9]

It looks like you have a double cardan joint. If that's true the rear pinion should point to the TCase yoke and there is no need to lower your TCase.

Let me add a couple notes on drive line angles.
If the U Joint angles on a drive shaft are not strait (they never are on an off road vehicle) then they actually speed up and slow down on each rotation. This can produce a bad vibration. But a drive shaft is made so the vibration of the front U Joint cancels the vibration of the rear U Joint. This works great if the the angle of the front U Joint to match the rear. This is how every manufacture makes vehicles.

But this only works at small drive line angles. The UJoints don't like too much angle so when you lift your jeep you may have to angle the rear differential upward. This can be done with angled shims at the leaf springs. Then to keep both u Joint angles the same you can lower your TCase. If the drive line angles get to be too much you should then go to double cardan joint or a CV joint at the front of the drive shaft. A double cardan joint is 2 U Joints together.

These 2 U Joints cancel each others vibrations. In that case the U Joint at the differential should not have any angle. To keep it from vibrating it should be strait like this.

Now you can see how the pinion is much higher than the manufacturer intended.

 

[Jimbos76cj]

Doesnt look like a CV shaft to me.. also look like his rear is turned up pretty far already.

 

[Torxhead]

Doesnt look like a CV shaft to me.. also look like his rear is turned up pretty far already.

Yeah Dave, i'm with Jimbo on that one.

 

[Jeeping Hillbilly]

Correct, not a CV it is the stock shaft. Sorry I should have made that clear in the first post. Hard to see in the small photo.

If my memory serves me well, i remember it having lots of washers under each bolt for a drop?... but how much I dont know and I should have measured it and kept better notes back then but didnt. Helped with to many Jeeps in two years to remember which one was what and maybe age has a little something to do with it also. lol

Thanks for the input, gotta get down there now and weld in sleeves for my thru bolts on the center cross member just to be safe, even though I find it hard to believe my frame will collapse inwards on itself from the small holes,but....with my black cloud I aint taking no chances with Murphy and her dang law showing up and picking on me like always.

Thanks,
HB

 

[73CJ]

Double cardan for sure. Mine used to look like that. I bought the lifetime ujoints at Champion and got 8 replacements. The lower usually failed. if the front would have a new driveshaft will probably be needed.


Check out Tom Woods.

 

[BusaDave9]

Double cardan for sure.

I'm with 73CJ, you should get a double cardan drive shaft. Contact Tom Wood's.
You have a steep angle and the pinion already looks like it's pointed to the TCase yoke (but I was wrong about the cardan joint too)

 

[Jeeping Hillbilly]

Really dont want to put that kinda of money in this. Its just to get my daughter back and forth to college basically and it better not ever be wheeled, or at least that I know of anyway.... Hate to get into having to buy a new shaft with a DBL CV joint. I have 4 Rockmen lower adjustable control arms and a Ox locker I just bought for daddys toy so funds are Limited on hers. lol Waited 5 years to get these and finally have an OX front and rear in the TJ since all the kids are gone, well...somewhat.

I am hoping like Torxhead said it will level out close under weight distribution and spring compression and then I can just get it to the 1 degree under for thrust angle with a simple Transfer Case drop, I hope. If not, well there goes my Rockmen uppers next month. It is also I should have pointed out sitting on jack stands, so I am hoping that will help a lot also when it sets back down.

Thanks,

HB

 

[Jeeping Hillbilly]

Not to do a double post, but if I end up having to use the shims to adjust pinion angle later I am not familiar at all with springs and have heard good and bad things about shims. By the way BusaDave thanks for that very informative post and schematic on pinion angles and u-joints, good read. Back to question, are any of you all running them and do they slip or is there another alternative to adjusting pinion angle rather than shims?


Thanks,

HB

 

[73CJ]

Tom Woods runs around $270 plus a yoke. End of problems.

Do you really want your daughter stranded along side the road?

Mileage is gonna suck so maybe get her a car. Then wheel with her on the weekends!

 

[Jeeping Hillbilly]

There really isn't a problem yet? Wont know till its done as Torxhead said. And she has a car and is just going to run the CJ on nice days and such, other than that it will be tucked away under cover. Dont know if you have put a kid thru medical college or not or maybe your rich, but on a constructions workers salary and kids in college $250 is a lot of money compared to a piece of tube for a drop if it works.lol

I am planning on her getting me a CJ and and Tom Wood shaft when she gets out of medical school. But I really dont think she will be sitting on the side of the road from a Transfer Case drop as long as the pinion angle works out. If not as I said in the above post I will make it right, I would never put my daughter in danger. I ran one in my TJ for years before going SYE and super short with a TW shaft.

 

[73CJ]

Sounds like you have it figured out. Have to be real careful these days.

If your angle is less than 15 deg, you'll be fine. The picture looks pretty severe though.