cluck when shifting in FT

[uss2defiant]

I was camping this weekend and had the jeep in FT mode due to the terrain.

I noticed that there is a clunk sound then I shift gears from one to another.
In 2WD I have no issues shifting.

I do know that my TF sensor does not light up the FT indicator on the dash. The indicator on the dash is working so it is probably the sensor. The other indicators for the other 4x4 modes work properly.

I didn't think to try the shifting when I am in the other 4x4 modes.

1. Is this a ****** issue?
2. Is this a TF case issue?
3. Is it cause by the bad TF case sensor, the PCM doesn't know it's in FT mode?

Thanks.

 

[HoosierJeeper]

The transfer case position sensor doesn't do anything related to the transmission. Doesn't really do much beyond the indicator, just maybe changes ABS programming and air bag programming in 4LO.

 

[LibertyTC]

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I hate it when it goes "Cluck- Cluck- Clunk" (see your Title) ha ha..

Ok so you have selec-trac and auto transmission and it goes clunk when shifting though gears only, or does it go clunk going into 4x4 mode?
Checked Fluid levels in TC & front diff lately?

 

[uss2defiant]

only when shifting from P to D or D to R, etc...
No clunks when driving in D.

No clunks with the 4x4 shifter.

Fluids all good.

 

[LibertyTC]

Sounds like driveshaft related. It does not go clunk when shifting P to D-R in 2 WD right?
Intermediate or Front Prop shaft comes to mind.

 

[uss2defiant]

correct. No issues at all in 2wd.
so it's a big clunk and the jeep jerks as well as though it's a rough gear engagement.

I don't know about the other 4x4 modes thought. didn't try it.

 

[tommudd]

I would as others have suggested check the front driveshaft first. It may not be bad enough in 2 wheel to show up but putting pressure on it makes it way worse.
Remove it, check it out and see whats going on from there

 

[uss2defiant]

I would as others have suggested check the front driveshaft first. It may not be bad enough in 2 wheel to show up but putting pressure on it makes it way worse.
Remove it, check it out and see whats going on from there

what am I checking for?
The CVs?
or what test do I do on the front driveshaft after pulling it out?

thanks.

 

[jettyspicer]

Before you take it out, get underneath and try to wiggle the front driveshaft back and forth. There should be no play with 4 wheel high engaged.Also look at the rubber boots as they will usually be cracked and leaking grease. Sure sigh that the CV joint is bad.
If you need to take it out, its not a hard job. A1 Auto has a good video that shows how to do it. They also sell the parts, although I got mine off e-bay.

 

[uss2defiant]

I know from my experience from removing the front driveshaft when i had to replace the rear CV that there was some front to back play which from my understanding is normal due to the front CV joint.

Are you saying that with what ever 4 wheel drive mode engage, there will be no front to back movement?

 

[jettyspicer]

There could be movement from front to back as the CV joints are moveable in that direction. What I was referring to was side to side movement. There should be none in the 4 wheel drive mode and probably won't be any even if the CV's are bad. If there is any movement, you know you have a problem. Biggest indicator will be tear in the boot or boots and an absence of grease. Usually pretty easy to spot. Biggest problem is getting the Liberty high enough to get underneath, unless you have a lift. This is a $50-$75 repair if you do it yourself, but $800 at the shops.

 

[TwoBobsKJ]

There is a little more backlash in the front diff gears than the rear, and when shifting you may be feeling the backlash as the pressure is applied and relieved in the front diff.

So the clunk is there from P to D; what about as the ****** is shifting from 1st to 2nd, etc?


Bob

 

[uss2defiant]

There is a little more backlash in the front diff gears than the rear, and when shifting you may be feeling the backlash as the pressure is applied and relieved in the front diff.

So the clunk is there from P to D; what about as the ****** is shifting from 1st to 2nd, etc?


Bob

Clunk is there from P to D, D to N, N to D, D to R.
No clunks in D shifting from 1 to 2, etc.

 

[HoosierJeeper]

Never heard of this issue on a KJ but with WKs and XKs it's common to have worn diff mount bushings that cause that type of clunk.

Intermediate shaft would likely cause a noise like that.

 

[TwoBobsKJ]

Clunk is there from P to D, D to N, N to D, D to R.
No clunks in D shifting from 1 to 2, etc.

I'd blame it on the backlash in the front diff gears. I can make mine clunk a bit in Full Time 4WD by accelerating, coasting then applying some gas. Did it with the original 3.73 gears as well as the 4.10's I have in it now.

Not sure there's a problem but hard to say without actually driving it myself. Has it done this before?


Bob

 

[uss2defiant]

I'd blame it on the backlash in the front diff gears. I can make mine clunk a bit in Full Time 4WD by accelerating, coasting then applying some gas. Did it with the original 3.73 gears as well as the 4.10's I have in it now.

Not sure there's a problem but hard to say without actually driving it myself. Has it done this before?


Bob

well I was married into the KJ so I've only been keeping it going the past few years so I don't know whether it's been like this in the start.
Mine does not cluck at all at any other time point besides when I shift the auto gear lever. Clunk and jerk I would call it.
No issues at all when driving and when in D and smooth up shifts or downshifts.

I suppose I could have someone change the auto gear lever in a 4x4 mode while I'm looking at the front driveshaft to try to pinpoint the issue.

So what actually happens when I shift into a 4x4 mode? I thought it was just a change in gears in the TF case?

 

[tommudd]

When you put it into 4 wheel drive it changes the gearing in the transfer case to split between the front and rear diffs instead of just the rear
Not exactly but you get the gist

 

[tommudd]

Do you have a way to get all 4 tires up off the ground on good solid jackstands?
have someone go between gears to see if you see anything? Won't be the same of course as being on the ground with full weight but something may show up

 

[uss2defiant]

Do you have a way to get all 4 tires up off the ground on good solid jackstands?
have someone go between gears to see if you see anything? Won't be the same of course as being on the ground with full weight but something may show up

not in the immediate future.
but I can still fit under the jeep on the ground to see what's going on if I the jeep doesn't need to go through its paces in D.

Are you asking me to put the jeep through its paces in D as well?

Thanks

 

[uss2defiant]

getting a list of things to check.

Could this be caused by worn out engine/****** mounts?