AX15 rattle under highway cruise/load

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May 21, 2018 | 05:16 PM

CLSegraves1

Thread Starter

Member

Joined: Feb 2018

Posts: 207

Likes: 4

From: Peoria, AZ

Year: 2001

Engine: 4.0

AX15 rattle under highway cruise/load

The AX15 in my 2001 XJ makes a rattling noise when cruising on the highway under load. It gets worse when accelerating on the highway (speeding up/passing/etc.) and is quieter (not silent) coasting. It does this in all gears and does not go away when I push the clutch (while coasting). I’ve placed the T-case in neutral and run it through gears, but then there’s no load on anything.

The noise isn’t “bad” (to me it give my bucket of bolts character) but certainly wouldn’t be adverse to it going away. It has standard 75W90 oil in it.

The transmission shifts like a dream (butter smooth) and never grinds. I’d guess it has near 250,000 miles as it came from my old 1991 XJ (which was near 250k when I parted it out).

May 21, 2018 | 05:44 PM

TrailerTrash

CF Veteran

Joined: Jun 2017

Posts: 2,215

Likes: 635

From: Hangover, PA

Year: 1998

Model: Cherokee(XJ)

Engine: 4.0L

Are you 100% positive that the noise is coming from the transmission?

May 21, 2018 | 08:33 PM

investinwaffles

CF Veteran

Joined: Oct 2013

Posts: 2,097

Likes: 12

From: Tarpon Springs, FL / Denver, CO

Year: '98

Engine: 4.0 I6

Quote:

Originally Posted by CLSegraves1

It has standard 75W90 oil in it.

The transmission shifts like a dream (butter smooth) and never grinds. I’d guess it has near 250,000 miles as it came from my old 1991 XJ (which was near 250k when I parted it out).

Apparently GL5 Gear oil will eat the brass synchronizer rings in the AX15 over time. GL3 is recommended but was phased out. Redline MT-90 is the recommended fluid now, and I have been running it for 15k miles and it helped shifting quite a bit.

I am coming up on 280k miles and the stock clutch only on really steep inclines off road, shifts great otherwise.

For the rattling, check the flexplate bolts because they can loosen over time

Edit:
I thought my trans was making a rattle but it turned out to be 2 things. My transfer case shift linkage rattling and my timing chain rattling at high load/low Rpm conditions.

Last edited by investinwaffles; May 21, 2018 at 08:35 PM.

May 21, 2018 | 10:17 PM

CLSegraves1

Thread Starter

Member

Joined: Feb 2018

Posts: 207

Likes: 4

From: Peoria, AZ

Year: 2001

Engine: 4.0

Quote:

Originally Posted by TrailerTrash

Are you 100% positive that the noise is coming from the transmission?

Nope, I'm not but I hear it under the mid/front area of the console (around the shifter and forward) which makes me think it's NOT the T-Case.

May 22, 2018 | 12:13 PM

PatHenry

CF Veteran

Joined: Nov 2017

Posts: 3,700

Likes: 238

From: Groton, MA

Year: 1995

Model: Cherokee(XJ)

Engine: I6 4.0L

Have you checked that it's not the exhaust hitting the cross-member?
You could also check that the lower bolts on the spacer-plate-to-bell-housing are all tight.