Help with Groaning Rear!!

[93gc40]

I shimmed my rear springs and now it Groans under power. I know I need a SYE but can't afford it now.

I had minor vibes so I checked my pinion angles. I could feel, but others couldn't. I added a 4 deg shim. Vibes gone but noise is increased.

Before TC = -4 DS = ? Pinion = 11, After TC = -4, DS = -12, pinion = 6

I did had a slight groan before the shim, but only when in curves under power, now the graon is there anytime my foot is on the gas. U-joints are NOT binding. Do i need a 6 deg shim? That should get the pinion to 3-4 deg. Can't feel any movement when shacking the wheels,, but the ax;e bearing do feel a little rough when I rotate the wheels.

[JRW7072009]

Check the fluid level, you may need to add more gear oil the higher you raise the pinion. You might be starving the pinion bearings for gear oil.
Also are you running a T-case drop?

[93gc40]

Well I lowered the pinion by 4 degrees, so if anything, the pinion is getting more lube. Level is good, and was changed, 2 months ago. Yes I have a 1" drop. Next week I am going to remove or reduce the drop, too see. Rear Pinion is still pointed a little above the TC. Next step will be SYE. But I have to get a JOB first.
I'm starting to think the noise is reverberation from the exhaust. Stock Muffler with a turn down dump, in front of the axle, but the muffler rests against the frame rail.

Actually will be redoing rear springs next week. Have a set of S-10 spring coming, for new Bastard pack. So if I can steal more cash for the wifes purse, I'll do the U-joints, in the DS, while the axle is off.

[96xj]

are you lowering it or lifting it ? cause if you are lifting it you need to shim pinion up

[93gc40]

are you lowering it or lifting it ? cause if you are lifting it you need to shim pinion up

Neither really, Target height will be 3.5"-4", 4.5" max. I'm at 3.5" now with a Wrangler based bastard pack, (2 mains per side). I'm replacing that with a S-10 bastard pack. When I get the springs in I will shim and adjust the TC drop accordingly. My TC drop is made up 5, 3/16" stacked plates, so it's adjustable.
When I get a job and the cash, I will do SYE.

[4.3LXJ]

Well I lowered the pinion by 4 degrees, so if anything, the pinion is getting more lube. Level is good, and was changed, 2 months ago. Yes I have a 1" drop. Next week I am going to remove or reduce the drop, too see. Rear Pinion is still pointed a little above the TC. Next step will be SYE. But I have to get a JOB first.
I'm starting to think the noise is reverberation from the exhaust. Stock Muffler with a turn down dump, in front of the axle, but the muffler rests against the frame rail.

Actually will be redoing rear springs next week. Have a set of S-10 spring coming, for new Bastard pack. So if I can steal more cash for the wifes purse, I'll do the U-joints, in the DS, while the axle is off.

From the numbers you have given, I am surprised you don't have really bad vibes. Take that angle finder and then shim the axle to where it is 3* or less within being the same angle. As far as the groaning goes, that is from worn gears. If you have a D35, they are famous for that with high miles. You can try adding Power Punch, the black stuff to your diff. That will help with getting oil on the pinion bearings as well as the moly in it will fill the pits on the gear teeth and take care of some of the noise.

[96xj]

i don't get it , if you are lifting the xj then why are you lowing the pinion angel ?

[93gc40]

From the numbers you have given, I am surprised you don't have really bad vibes. Take that angle finder and then shim the axle to where it is 3* or less within being the same angle. As far as the groaning goes, that is from worn gears. If you have a D35, they are famous for that with high miles. You can try adding Power Punch, the black stuff to your diff. That will help with getting oil on the pinion bearings as well as the moly in it will fill the pits on the gear teeth and take care of some of the noise.

Where do you get this Power Punch, stuff?
Me, too as far as vibes go. But there are none. And they were very minor even with the rear pointed 6 degs above the TC output. I'm now sitting only 1 deg over. I am going to start over on the pinion adjustments. Mainly because I am going to redo the springs and maybe put my stock shackle back in.
It's a 8.25 with 3.55. Ring and pinion look good, but the spiders may be worn. I can feel them in the wheel when I spin the tire by hand. I had them out last time I changed the fluid, In December. Pulled the axel to inspect the bearings. Maybe I switched positions, of spiders and/or axels when I put them back. Changed wear pattern relationships. Just didn't notice the noise till I mess with the angles.

[96xj]

ok i got it now , you never said that you where 6*over

[4.3LXJ]

Where do you get this Power Punch, stuff?
Me, too as far as vibes go. But there are none. And they were very minor even with the rear pointed 6 degs above the TC output. I'm now sitting only 1 deg over. I am going to start over on the pinion adjustments. Mainly because I am going to redo the springs and maybe put my stock shackle back in.
It's a 8.25 with 3.55. Ring and pinion look good, but the spiders may be worn. I can feel them in the wheel when I spin the tire by hand. I had them out last time I changed the fluid, In December. Pulled the axel to inspect the bearings. Maybe I switched positions, of spiders and/or axels when I put them back. Changed wear pattern relationships. Just didn't notice the noise till I mess with the angles.

First thing, the Power Punch is an old brand that has been around 40 years that I can remember and is sold in real auto parts stores, not the wanna bes that only sell filters and such. I buy it at NAPA.

Second if you are feeling something worn or rough when spinning the wheels I would suggest that it is not spiders, but wheel bearings instead. They also will growl when worn.

[93gc40]

First thing, the Power Punch is an old brand that has been around 40 years that I can remember and is sold in real auto parts stores, not the wanna bes that only sell filters and such. I buy it at NAPA.

Second if you are feeling something worn or rough when spinning the wheels I would suggest that it is not spiders, but wheel bearings instead. They also will growl when worn.

I'll ask at Napa when I pickup the Ujoints.
Thank for the confirmation on the bearings vs Spiders. Was my first thought, also. Might as well change, em, probably originals anyway. I know I haven't done them yet, had this Jeep only 2 years. I hate throughing money at a problem. but in this case since I haven't do it yet, I have to assume the POS didn't eaither, at 160K they'd be due.

Can carrier bearing be changed without messing with the ring and pinion gears?

[4.3LXJ]

I'll ask at Napa when I pickup the Ujoints.
Thank for the confirmation on the bearings vs Spiders. Was my first thought, also. Might as well change, em, probably originals anyway. I know I haven't done them yet, had this Jeep only 2 years. I hate throughing money at a problem. but in this case since I haven't do it yet, I have to assume the POS didn't eaither, at 160K they'd be due.

Can carrier bearing be changed without messing with the ring and pinion gears?

No, you have to pull the carrier to do it. Don't do that until you get a dial indicator and measure the back lash on the gears. You will have to match it after changing those bearings.

[93gc40]

i don't get it , if you are lifting the xj then why are you lowing the pinion angel ?

Because my pinion is to high... look at this picture, this is the correct orientaion, TC output and Pinion parallel, to pinion slightly 1-3 deg below TC. My TC is pointing at 4deg Down and my Pinion is at 5deg up, so my pinion is 1-4 deg too high. It started before shimming TC 4deg down and the pinion 11deg up, 7-10 deg too high. I'm still off but may live with it till I can do the SYE.
http://i367.photobucket.com/albums/oo117/93gc40/2joint_angle.gif

[93gc40]

No, you have to pull the carrier to do it. Don't do that until you get a dial indicator and measure the back lash on the gears. You will have to match it after changing those bearings.

I have the gauges needed.. I just don't want to do the job. This just gives me an excuse not too.