Grinding Rattling noise when turning from a stop

Eilermoon · Jul 18, 2026

Hey y'all I've had my 97 4.0 for about 6 months and am still figuring it out. I've got the AX-15 transmission in it that is definitely a bit worn but okay, it struggles and grinds getting into 2nd often, and 3rd sometimes. I've put Red Line MT-90 in it that's helped a bit. It grinds pretty bad coasting in first though.

The bigger issue is when I turn hard from a stop. It'll grind or rattle kind of for a few seconds in a way that sounds like the driveshaft maybe? Worse when I reverse, turn the wheel hard, then go in 1st like from parallel parking. I know the last owner lifted it about 3" and it's on 33's. Stock gearing, so I suspect it may have to do with the angle of the driveshaft or something? Anyway here's a link to a video of it: https://immich.azulas.dad/share/tLU_AFZLHqDjx1X_ZvTln48riGLHtuinye3TU_2La6ZF-ZQdB6J4qwB_8yPh8CfpZ6o

I did just swap the rear differential carrier but checked the backlash to be .011" which seemed good, so I doubt that's the issue here.

Eilermoon · Jul 18, 2026

Side note: this came with the Jeep with almost no info. is this a rear track bar? Came with stickers that say BSP, and the shipping address said it was from deeponeauto. I haven't been able to find what exact part it is online.

Feralkid · Jul 18, 2026

It's hard to figure things out over the internet but if it only does this when you turn the front wheels it's probably something loose in the front suspension or steering: u-joints, ball joints, rod ends, or control arms. Have someone turn the wheel back and forth while you go underneath and inspect the joints for slop. If it has an aftermarket lift it would be wise to put a torque wrench on everything that was modified.

With 3 inches of lift you should have a double cardan drive shaft in the rear. If the previous owner was running the factory slip yoke shaft and the u-joints were misaligned it created vibrations that could have damaged the transmission.

Eilermoon · Jul 18, 2026

Feralkid said:
It's hard to figure things out over the internet but if it only does this when you turn the front wheels it's probably something loose in the front suspension or steering: u-joints, ball joints, rod ends, or control arms. Have someone turn the wheel back and forth while you go underneath and inspect the joints for slop. If it has an aftermarket lift it would be wise to put a torque wrench on everything that was modified.

With 3 inches of lift you should have a double cardan drive shaft in the rear. If the previous owner was running the factory slip yoke shaft and the u-joints were misaligned it created vibrations that could have damaged the transmission.

Yeah I think you're right. I was stuck on the diff since I messed with it but the more I hear it I think it's a steering or front end joint issue.

Great suggestion for retorquing everything put on, I'll go around and do that too.

I'll be honest I only about 60% understand the last paragraph. The rest driveshaft looks stock to me, I imagine a double cardan is longer to be able to reach? Would love some pointers on determining what I have and how to check if it's okay. Will grab some photos

Feralkid · Jul 18, 2026

The stock rear drive shaft has 2 u-joints and the slip joint is at the transfer case yoke. A double cardan has 3 u-joints and the slip joint is at the middle of the shaft. The factory front drive shaft is double cardan for reference.

Eilermoon · Jul 18, 2026

Feralkid said:
The stock rear drive shaft has 2 u-joints and the slip joint is at the transfer case yoke. A double cardan has 3 u-joints and the slip joint is at the middle of the shaft. The factory front drive shaft is double cardan for reference.

Here's some pics of the rear. Only got 2 u joints. Is this angle concerning?

Eilermoon · Jul 18, 2026

As far as the front steering components go though, it really doesn't feel like like slop in the steering. It's only when driven in first gear, not when steering hard in reverse, for example.

Feralkid · Jul 18, 2026

Yeah... those u-joints are definitely out of alignment.

Fixed aftermarket lower arms and stock uppers. There is no way to dial in the differential pinion angle.

In a drive shaft with two u-joints the axle and transfer case pinions need to be parallel or the u joints will rotate at different speeds causing vibrations that will damage bearings in the drive train. It's probably why your transmission and rear diff are having problems. Most likely case is the engine crank shaft bearings are chewed up as well.

Eilermoon · Jul 18, 2026

Gotcha so to fix that angle I need to grab an aftermarket drive shaft and check the bearings. sounds like double cardan is the move?

I think the lift was done not too long ago and I haven't driven it a ton, hopefully it hasn't done too much damage in the meantime.

Something like this in addition to a slip yoke eliminator kit? https://4xshaft.com/products/tj-rear-drive-shaft-cv?rq=mk_jeep~md_wrangler-tj-lj~yr_1997-2006

Really appreciate your help. I knew there might be issues that were left unaddressed when the previous guy said it was recently lifted, but I'm new to working on Jeeps

Feralkid · Jul 18, 2026

Eilermoon said:
hopefully it hasn't done too much damage in the meantime

Hopefully the transmission took all the abuse.

What you need to do first is install a fixed yoke (slip yoke eliminator kit) on the rear of the transfer case and replace the control arms with something adjustable so you can dial in the differential pinion angle, then you can install a double cardan shaft and maybe even get rid of that transfer case skid plate drop spacer. The way you described your transmission grinding under the load of front wheels turned to lock it seems like you should be searching the junkyards for a replacement AX15 as well. One from an old XJ might work, I don't know about compatibility though.

Also while installing the SYE kit it would be wise to do a rebuild of the transfer case replacing the bearings that could have been damaged from the vibes or replace it with one you get from the junkyard along with the transmission.

Eilermoon · Jul 19, 2026

Super helpful info. I was reading about swapping the AX15 the other day, that's probably a future job for me for sure.

I was just reading about Motor Mount Lifts - would you say that's an option here? Trying to weigh all my options since a SYE + CV drive shaft + upper arms is a big and expensive job. Would a 1" MML help me get some of that angle down, at least partially?

Also, did you see a transfer case skid plate spacer in my photos? First I've heard of it.

TheBoogieman · Jul 19, 2026

Did you measure the spring height as it sits? That rear driveshaft angle looks too steep for a 3" lift and your large t-case drop. This is my Rubicon with a 3" lift, stock control arms, no MML or t-case drop.

Eilermoon · Jul 19, 2026

Ooooh that's a great question, that looks much less aggressive than mine. I haven't, will do!

OldBuzzard · Jul 19, 2026

Eilermoon said:
Also, did you see a transfer case skid plate spacer in my photos? First I've heard of it.

Eilermoon · Aug 29, 2026

Hey y'all I finished putting in a SYE kit and CV shaft. It seemed to help quite a bit but I took it out on the highway today and noticed a pretty strong vibration when going faster about 40+. I'm not really sure what's causing it - is it possible the angel is still bad enough? I just removed the spacers on the transfer case skid plate and it seems like it's now pulling on the rear driveshaft a bit. Maybe it's too short? Pic I took of it today.

macleanflood · Aug 29, 2026

That's pretty normal. You now need to adjust your rear control arms to dial out the vibrations.

Start here:

-Mac

Eilermoon · Aug 29, 2026

Okay good to know that's pretty normal and might just be the rear pinion alignment. Ordering adjustable uppers for now, might follow up with adjustable lowers after that if it looks like it's pushing the axle too far. Thanks!

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Grinding Rattling noise when turning from a stop

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