Idenifying Transmission Clunk

L

LordReginaldCockswain

Member
Joined
Feb 1, 2019
Messages
31
Location
Tri-Cities, Wa
I've had this 2001 Jeep Sport 4.0l 5-speed 82k miles for about a year now and the whole time it's made this noise if I hit the gas a little too suddenly/early.

Seems to happen if I press the gas suddenly while the wheels are spinning down or if I'm just off the gas slowing down for a red light and hit the gas when traffic starts moving before I get there.

Originally I tried changing out the transmission mount, motor mounts, which did tighten up the feel of the overall ride, didn't fix the issue.

Recently I decided to really look and try to at least narrow down where the noise is coming from exactly. Had the a** end jacked up and in gear and I could recreate the noise! Well after getting down there it's very clearly coming from the transmission/bell housing area.

Took the rear driveshaft out and the sound was non-existent.

I don't know if it's related but even just shifting into gear is usually accompanied with a similar sounding metallic clunk and can feel it through the gear lever.

Switched to Redline MTL and smoothed it out a bit but still real noisy crunchy shifts and the worrying clunk noise hasn't changed a bit.

Here's some video of the said sound:

Jacked up rear end

Sound from inside cab
 
Just to be clear, the noise is independent of the clutch? I.e. it happens when you give it gas with the clutch fully engaged?
 
bromel said:
Just to be clear, the noise is independent of the clutch? I.e. it happens when you give it gas with the clutch fully engaged?
Click to expand...
Correct. Only happens when in gear. I've even thought it was the clutch fork so tried pushing in the clutch pedal a bit just enough so I could get the Jeep to still move with the gas pedal and know that the slave had to be pushing on the fork.

Can't repeat it in neuteral or in gear with the rear drive shaft removed.

Another thing I don't know if it's related but sometimes (seems to happen when engine braking) when the clutch pedal is pushed in I get a similar single clunk, sounds and feels like the same area, and can definitely feel it transmit through to my left foot. Again, don't know if it's related or not. Just want to miss any possibly important info.
 
LordReginaldCockswain said:
Correct. Only happens when in gear. I've even thought it was the clutch fork so tried pushing in the clutch pedal a bit just enough so I could get the Jeep to still move with the gas pedal and know that the slave had to be pushing on the fork.

Can't repeat it in neuteral or in gear with the rear drive shaft removed.

Another thing I don't know if it's related but sometimes (seems to happen when engine braking) when the clutch pedal is pushed in I get a similar single clunk, sounds and feels like the same area, and can definitely feel it transmit through to my left foot. Again, don't know if it's related or not. Just want to miss any possibly important info.
Click to expand...
Did you ever figure this one out? I have the same thing happening.
 
The clutch disc has springs in it that allow play. When you take the driveline on and off load there are two sections that compress the springs and have some give. It can make this noise if the disc is old and the springs are worn. Sometimes when you cook a disc it'll also fry the springs or weaken them.
 
1. Is the sound still there if you drive in 4WD?
2. Is the sound still there if you remove the rear driveshaft and drive in 4WD?

You said the sound was non-existent when you removed the rear driveshaft before. Was that just with the vehicle jacked up or did you drive around? Either way, have you investigated that it may be something in the transfer case, the rear DS u-joint, or in the rear end? It may be a long shot, but I'd even get eyes on your control arm bushings and sway bar links to see if there's some odd movement when the rear end is loaded up.
 
I had a similar sound I was 100% convinced was in the clutch too. Turned out the control arm bushings were shit. And allowed (on mine) the front axle to shift front and back a bit. D.Shaft transferred the noise to the clutch banging around between shifts and when changing load on the engine. Could be you have an axle moving a bit too?
 
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