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Topic Review (Newest First)
08-07-2013 09:21 PM
NJO
Quote:
Originally Posted by 97tjsport View Post
UPDATE!!! Ok so I saw that after I rolled the rear-end that the Track bar bolt was hitting the gas tank. So I had a different Track bar bracket to fix that problem. So I figured, hell why im in there im going to put my old springs back in to see if any of this will fix my pinion angle problem. Well after fixing the track bar and changing out the springs the pinion angle was correct again, which means I had to roll the rear end back where its suppose to be. Im not sure if it was the springs or track bar that was messing up my pinion up but either way its correct now. thanks for everyones help
Ahhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh hh.........OK!
08-07-2013 09:03 PM
GoldenSahara00 If you somehow got the trackbar bolted in first then did the rest it could have sort of propped the pinion up a bit but that seems weird. Glad you got it fixed.
08-07-2013 08:43 PM
97tjsport UPDATE!!! Ok so I saw that after I rolled the rear-end that the Track bar bolt was hitting the gas tank. So I had a different Track bar bracket to fix that problem. So I figured, hell why im in there im going to put my old springs back in to see if any of this will fix my pinion angle problem. Well after fixing the track bar and changing out the springs the pinion angle was correct again, which means I had to roll the rear end back where its suppose to be. Im not sure if it was the springs or track bar that was messing up my pinion up but either way its correct now. thanks for everyones help
07-19-2013 03:09 PM
Evpjr this may be a stupid question, but is your Jeep sill on the Jack Stands in those pics?
07-18-2013 08:50 PM
GoldenSahara00
07-18-2013 07:08 PM
O_M_Jeep
Quote:
Originally Posted by GoldenSahara00 View Post
If you aren't going to take our advice or listen then I can't help you. The only thing left is that your new arms are not truly the same length.
This.

Enjoy.
07-18-2013 12:07 PM
NJO More pics needed.......
07-18-2013 11:43 AM
FireMike
Quote:
Originally Posted by All Terrain TJ View Post
I don't think anyone including the OP is questioning that the PA needs adjustment. The question is if the axles are both stock TJs, why did the driveline angle change so drastically. And the DS will shorten a bit at the slip joint when the pinion is rotated up towards the tcase output.
The only thing I can think of are the UCA's. Aside from the LCA's which were already measured to be the right length there is nothing else that effects PA. Is there anything else that effects PA???

And O M jeep you are a lost cause
07-18-2013 08:33 AM
All Terrain JK I don't think anyone including the OP is questioning that the PA needs adjustment. The question is if the axles are both stock TJs, why did the driveline angle change so drastically. And the DS will shorten a bit at the slip joint when the pinion is rotated up towards the tcase output.
07-18-2013 08:06 AM
O_M_Jeep
Quote:
Originally Posted by FireMike View Post
So what YOU are saying is there is no need for a SYE or to lengthen the DS? Am I getting that right?
It already has a SYE and the drive shaft is plenty long enough, if you look at the 2 pics, you'll see that the drive line has no issues at all as far as length, the problem, the whole problem, the only problem is the pinion angle.

Quote:
Originally Posted by Dusty Rhodes View Post
On the LCA's in the picture, any chance they were reversed? Could you unbolt it, and install it with the side that was facing the ground, now pointed up?
The control arms in the pics are the same length no matter which end is in the frame, the bend has to be toward the ground, the only time it matters what end you have where is when you have adjustables or different style bushings at each end.
07-18-2013 07:26 AM
NJO
Quote:
Originally Posted by 97tjsport View Post
yes I have known my jeep and the donor jeep since new. So I know that neither of the rear ends have been modified. my upper adjustable arms came in today and im going to fix it with the uppers but I still would like to know why I even have to fix it, cause it shouldn't be like this in the first place. I don't see how the DS would affect the pinion angle. It doesn't matter if the DS is hooked up or not the pinion angle stays the same. If you look at the pictures, the rear end is angled down to much and that is the problem.
Are you going to post any more pics? Up close pics.........
07-17-2013 11:36 PM
Dusty Rhodes On the LCA's in the picture, any chance they were reversed? Could you unbolt it, and install it with the side that was facing the ground, now pointed up?
07-17-2013 11:03 PM
FireMike
Quote:
Originally Posted by O_M_Jeep View Post
A change in springs won't affect pinion angle at all, the only way to change pinion angle is with adjustable arms, rotating the tubes or moving the mounts, that's it, but I repeat myself (yet again).
Yes but it would increase the vertical distance the drive shaft would have to travel in the same amount of distance. So you are correct. But the issue is not pinion angle by its self! it's a combo of low pinion angle(too flat) and high DS angle(too steep). So what YOU are saying is there is no need for a SYE or to lengthen the DS? Am I getting that right?
07-17-2013 10:31 PM
O_M_Jeep
Quote:
Originally Posted by FireMike View Post
a drastic change in springs would effect PA
A change in springs won't affect pinion angle at all, the only way to change pinion angle is with adjustable arms, rotating the tubes or moving the mounts, that's it, but I repeat myself (yet again).
07-17-2013 09:55 PM
FireMike And did the TJ it came off of have any mods done to it? If so what kind? anything crazy like 40 inch tires?

And a drastic change in springs would effect PA but from the sounds of it there wasn't.

Its good you know and have the fix though!!
07-17-2013 09:52 PM
FireMike
Quote:
Originally Posted by O_M_Jeep View Post
That's what I thought too, perhaps it isn't.
What is not simple about it? there are only two factors. Control arm length and bracket positions. And I bet you they are stock brackets! And ADJ's will fix even "IF" they aren't stock brackets.
07-17-2013 09:49 PM
GoldenSahara00 If you aren't going to take our advice or listen then I can't help you. The only thing left is that your new arms are not truly the same length.
07-17-2013 09:30 PM
O_M_Jeep
Quote:
Originally Posted by GoldenSahara00 View Post
It's pretty dang simple.
That's what I thought too, perhaps it isn't.
07-17-2013 05:59 PM
FireMike Idk If this has already been suggested or tested. So sorry if I'm repeating anything.

It seems you already measured the LCA's, and they were the same. Did you measure the UCA's to see if they were the same length?

Does not really matter now because you have the Uppers adj's. And that IS the fix. Judging by the oil marks you can see from pics one to two there is no need to shorten the DS.

I really don't think someone cut and re-welded your brackets. Especially when you have been keeping track of the donor its whole life. But ONLY if you know its history!

Please let me know how it works out for you!!
07-17-2013 04:46 PM
97tjsport yes I have known my jeep and the donor jeep since new. So I know that neither of the rear ends have been modified. my upper adjustable arms came in today and im going to fix it with the uppers but I still would like to know why I even have to fix it, cause it shouldn't be like this in the first place. I don't see how the DS would affect the pinion angle. It doesn't matter if the DS is hooked up or not the pinion angle stays the same. If you look at the pictures, the rear end is angled down to much and that is the problem.
07-17-2013 11:15 AM
GoldenSahara00 Actually the length of the drive shaft does change what the pinion angle should be as far as yoke to yoke measurement. However the change is only a few degrees in most cases. I'm not spelling it out, if you don't understand go google pirate driveshaft tech. It's simple geometry.

It's obvious from the first picture that at some point the d35 brackets were altered to set the pinion for the sye/cv. A stock axle does not have that kind of pinion angle. The arms are stock/stock length according to the poster. So that means that either the brackets were moved or the tubes were somehow moved on his 35. When he swapped in the d44 with regular positioned brackets he got a stock pinion angle. It's pretty dang simple.

OP, please look at your brackets. Set your d35 axle with the pinion matching the current angle of the d44. Then measure and record respective angles of things like upper and lower arm mounts. You can then compare and figure out if that's your issue.


Did you buy this jeep new or where did it originate?
07-17-2013 08:33 AM
All Terrain JK I never said his pinnion angle changed but obviously his driveline angle did. As far as drive shaft length, if you have 4" of height difference between tcase output and pinion with a 12" shaft ( hypothetical numbers) then shorten the distance by 1" now the shaft is 11", the shaft angle will change. The pinion angle will not (and will need adjustment). The driveline angle will be steeper because it has less length to account fot the 4" height difference.
When the OP adjusts PA to point at the tcase output, if he changes nothing else, the DS will shorten via the slip joint.
07-17-2013 07:17 AM
O_M_Jeep But the pinion angle has nothing to do with the length of the drive line, if there were no drive line installed at all the pinion angle wouldn't change, the length of the pinion and drive line are irrelevant.


This is a proper pinion angle for a slip-yoke drive line




Just like his D-35 pic -

This is the proper pinion angle for a SYE / CV drive line -


This is NOT what he has now with the D-44 -


Drive line length has nothing to do with this and suspension height would only matter if the suspension were raised a distance equal to the offset from the pinion to the SYE.
07-16-2013 10:48 PM
98 tj sport The driveshafts are different lengths depending on if u have a d35 or d44 I know cuz when I swapped in the d44 into my jeep the stock driveshaft was to long and I had to cut it down until I was able to get a dc shaft and sye, therefore the d44 yoke is most deffintely longer that the 35 trust me I went thu this like 6 months ago, and if u take a driveshaft from a jeep with a d35 and set it next to a driveshaft from a d44 the d35 shaft will be longer by about an inch or so
07-16-2013 09:05 PM
All Terrain JK A change in the height between the tcase and pinion can have a major effect on driveline angle. So does a change in the distance from tcase output and pinion. That is the reason we install SYEs to lengthen the drive shaft.
07-16-2013 08:53 PM
O_M_Jeep One set of control arms connect at the top of the axle, one set of arms connect to the bottom of the axle, the length of the control arms determine the pinion angle NO OTHER FACTOR matters as far as pinion angle, it can be a longer or shorter pinion, the angle will be the same, it can be a larger or smaller diff housing, the angle will be the same, the only other way to change pinion angle is to rotate the differential housing on the axle tubes.

If the pinion is off, and you can see in the pictures that it is very different, then it has to be the control arms. That's all it can be, you changed control arms too, so either the old axle was on different length arms, the old axle was rotated on the axle tubes, or the new axle is rotated on the tubes, those are your choices.
07-16-2013 08:32 PM
97tjsport
Quote:
Originally Posted by All Terrain TJ View Post
That's why I asked if you gained any height. From looking at the pics that's the only thing I can figure. Let us know.
Yea after having it out in the open today at work, I did notice it seems to be sitting a "little" higher in the back then it was. So im guessing the springs are the problem. again im guessing.
07-16-2013 08:29 PM
All Terrain JK
Quote:
Originally Posted by 97tjsport View Post

Yes I thought the same thing, so I measured the two rear ends and there is almost no difference in the lengths from pinion to edge of diff cover.
That's good to know. I was going to ask you to measure them since you have both axles right there.
07-16-2013 08:27 PM
All Terrain JK That's why I asked if you gained any height. From looking at the pics that's the only thing I can figure. Let us know.
07-16-2013 08:25 PM
97tjsport
Quote:
Originally Posted by All Terrain TJ View Post
As I stated in my first post, I thought that was the case. Then I second guessed myself. Thanks for the confirmation.
Yes I thought the same thing, so I measured the two rear ends and there is almost no difference in the lengths from pinion to edge of diff cover.
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