Loud thumping when in 4x4

mikebboy · 07-03-2012, 09:47 AM

Sorry if this is a repost, I searched for a while and didn't see anything on this.

I have a 2004 bone stock Liberty that hasn't seen much off road action. It is at 120,000kms and has been working great.

The other day I decided to do some light off road activities. I came to a rocky hill and decided to put it in 4x4 high. The light came on I stepped on the gas and the loudest thumping noise came from the front. Its a type of noise that you definitely don't want to re-create very often. I then switched it back to 4x2 and no noises.

When backed down to the bottom of the hill i put it back in 4x4 thinking that maybe it would be different on flat land. But no, the nasty thumping was back. It is definitely related to the drive train since standing still no noise and increases with speed.

Now let me explain the noise... its like a big gear set is slipping. it isn't a grind, squeak or howl. It is a thump that can be heard and felt. I am not too sure if it was from the front end or the transfer case.

I crawled under the truck and grabbed the front drive shaft, drivers and passenger CVs... all tight. The inner passenger side had a small amount of play maybe 1/32". Not too sure if that is the culprit. I am fearing the diff.

Any ideas on how/what i should check next?

**John Strenk** · 07-03-2012, 09:56 AM

On mine it was the CV joint.

The expensive ones on the drive shaft not the cheap axles ones. I think I spent about $100 doing it myself and had to get two CV's as the first replacement one binded (bound?). Instructions said to check the new one, it should move freely but stuck at one spot.

After a while it will start making noise in 2WD also.

mikebboy · 07-03-2012, 10:22 PM

Ok awesome, those don't look too bad to change. Is there a way to tell if one is bad without removing it?

sens · 07-04-2012, 02:53 AM

Are you in part time or full time 4wd?
Also were you just going in a straight line?

mikebboy · 07-04-2012, 09:20 AM

I tried it in 4Hi and 4Low (Command-Trac) and it does the same thing.

Ya, as soon as I put it in 4x4 and started moving forward there would be some loud thumping. I was moving in a straight line. I think it even did it in reverse, I will have to double check that.

**John Strenk** · 07-04-2012, 07:43 PM

Quote:

Originally Posted by mikebboy

Ok awesome, those don't look too bad to change. Is there a way to tell if one is bad without removing it?

First I found the boot bad and then a little slop in the joint.

mikebboy · 07-05-2012, 08:18 AM

I will check it tonight. Thank you.

tjkj2002 · 07-05-2012, 08:57 AM

Quote:

Originally Posted by John Strenk

On mine it was the CV joint.

The expensive ones on the drive shaft not the cheap axles ones. I think I spent about $100 doing it myself and had to get two CV's as the first replacement one binded (bound?). Instructions said to check the new one, it should move freely but stuck at one spot.

After a while it will start making noise in 2WD also.

Your driveshaft is installed backwards.

mikebboy · 07-23-2012, 02:21 PM

I received the new CV today. I see that there is a grease seal. Which side is it on? I am guessing the beveled side, so would that end face outward from the driveshaft or inward?

mikebboy · 07-28-2012, 05:29 PM

Ok, figured it out and installed it... pretty easy overall. The old one was a little loose but not that bad... I guess i have an emergency spare now.

Didn't fix the problem, still have a thump when in 4x4. I did notice that when I removed the drive shaft that I could turn the yoke on the diff about 1/8 to 1/4 turn before it would engage the front wheels.

Also when i turned the output shaft from the transfer case there was some weird clank noise. Doesn't sound very good.

tjkj2002 · 07-28-2012, 05:45 PM

Quote:

Originally Posted by mikebboy

Ok, figured it out and installed it... pretty easy overall. The old one was a little loose but not that bad... I guess i have an emergency spare now.

Didn't fix the problem, still have a thump when in 4x4. I did notice that when I removed the drive shaft that I could turn the yoke on the diff about 1/8 to 1/4 turn before it would engage the front wheels.

Also when i turned the output shaft from the transfer case there was some weird clank noise. Doesn't sound very good.

The slack in the front diff is normal but the clank in the t-case is not.

mikebboy · 07-29-2012, 10:33 AM

Thanks, I bet the chain is loose... and its the chain whacking the case.

I see there is an adjustment but you have to take the case apart... rebuild it or find one at a wrecker, such decisions.

j888dth · 09-20-2012, 01:17 PM

Quote:

Originally Posted by mikebboy

Thanks, I bet the chain is loose... and its the chain whacking the case.

I see there is an adjustment but you have to take the case apart... rebuild it or find one at a wrecker, such decisions.

Hi think i have this problem was it ever sorted and how?

mikebboy · 09-21-2012, 11:33 AM

Replaced transfer case...

j888dth · 09-21-2012, 04:13 PM

ok Thanks will have look into what can be done to repair as finding one thats good in breaker can be hard here as lots of the breakers her will just clean and ship you dont know if its any good untill its fitted so some times its just better to repair the old unit and refit it then I knows whats what good and whats bad.