Calgary Jeep Association

4x4 Related Groups => Tech Talk => Topic started by: JackstandJohnny on March 23, 2009, 09:01:25 AM

Title: Grand Cherokee clunking
Post by: JackstandJohnny on March 23, 2009, 09:01:25 AM
on the way to work (and noticed it last night) jeeps making bad noises when under acceleration. its clunking and grinding real bad, at least thats what it sounds like. sounds like its coming from the front. so at a stop light i revved the engine and nothing. no bad sounds, it also did not do it while coasting, i dropped it into neutral and revved engine. still no bad clunks. this leads me to believe its something like a u joint or CV join (as the WJ only has CVs up front and on the drive shaft) again, only under acceleration can i notice it.

does anyone have any ideas? like i said, i'm thinking its a ujoint somewhere or a Cv. tonight i can crawl underneith it and check for play, but until then it will drive me nuts.
any ideas?
Title: Re: Grand Cherokee clunking
Post by: Bnine on March 23, 2009, 10:09:03 AM
CV should be quiet until turned. If doing a uturn and the CV clunks, bangs, grinds, then thats a sign its going bad.

With luck it might be a driveshaft.

Without luck, it might be that AWD system that are so infamous for blowing up on WJ's. Good luck, hopefully its the later.
Title: Re: Grand Cherokee clunking
Post by: JackstandJohnny on March 23, 2009, 10:21:42 AM
thanks bill. its definitely doing it while going in a straight line.  and its definitely while under acceleration...  by AWD system do you figure its just teh 247 tcase?  cause i've ZERO qualms about swappin in a 242

i will be able to crawl around underneith tonight or tomorrow to take a real look, and test driveshafts, hopefully its a stupid ujoint. if not,  ummmmmmmmm............
Title: Re: Grand Cherokee clunking
Post by: Bnine on March 23, 2009, 11:22:15 AM
I've only ever had one in that wasnt working, and it was quiet about it. Just never had 4wd. My experience with that awd is limited to say the least.

But yeah, it should be in the case. Thats where I beleive the viscous coupler that controls the awd resides.

My money is on the front shaft. Fingers crossed.
Title: Re: Grand Cherokee clunking
Post by: JackstandJohnny on March 23, 2009, 12:30:58 PM
my fingers are crossed to. i always thought when u had a bad VC you also couldn't turn worth a damn. well the jeep is still fine wheel lock to lock, so i'm bettin driveshaft too...... or i guess, ujoint on the driveshaft. or the CV joint thingy at the axle end...... oye tonight will tell
Title: Re: Grand Cherokee clunking
Post by: LifesGrand on March 23, 2009, 03:41:19 PM
Does it have the double cardon u joint assembly on the t-case end of the drive shaft?
If so, I'll bet dollars to doughnuts the ball bearing inside this assembly has failed.
I've already gone through 2 on mine, I think greasing this assembly is part of reg maintenance.
Title: Re: Grand Cherokee clunking
Post by: cLAY on March 23, 2009, 05:02:57 PM
Did you have the "angry squirrels" sound leading up to the clunking? This often signals that the CV in the front shaft is failing.
Title: Re: Grand Cherokee clunking
Post by: JackstandJohnny on March 23, 2009, 09:59:49 PM
possibly clay. kind of like a chattering kind of deal?  i think so. there are also some big clunks too.  hopefully i can diagnose tomorrow
Title: Re: Grand Cherokee clunking
Post by: cLAY on March 24, 2009, 09:01:59 PM
Just reach under and give the front shaft a good shake. It shouldn't move, turn a bit maybe but shouldn't move laterally.
Title: Re: Grand Cherokee clunking
Post by: JackstandJohnny on March 24, 2009, 10:46:05 PM
hey clay, i gave it a shake, and yea its VERY loose.

which will bring me to next question.  its got some sort of CVs on both ends. can i just get replacement parts from auto value (and ummmm, how the heck do i change it?)

or do i pull the shaft and brng it in to get rebuilt or something????
Title: Re: Grand Cherokee clunking
Post by: esi on March 24, 2009, 11:16:06 PM
Drive systems  has replacement CVs. Or you could switch out the drive shaft for a U-joint shaft. I got one from Jeep Stuff  $200 for  a shaft and maching diff hub, Then your U-joints go bad you can change them yourself.
Title: Re: Grand Cherokee clunking
Post by: JackstandJohnny on March 24, 2009, 11:18:37 PM
i'd like that, and would think of doing it if i were to swap tcases. but this thing has a CV on both ends. it must be a GC thing or something......
Title: Re: Grand Cherokee clunking
Post by: JackstandJohnny on March 25, 2009, 08:20:14 PM
so took the driveshaft off, and i effectively grenaded the CV joint at the tcase end.  went to pats and they had a driveshaft in stock.  just easier than waiting for the replacement CV and hoping it would work (price difference minimal)
so grands back up and running
Title: Re: Grand Cherokee clunking
Post by: Immortal on March 25, 2009, 08:30:39 PM
yay!! go team GC!!
Title: Re: Grand Cherokee clunking
Post by: JackstandJohnny on March 25, 2009, 08:31:21 PM
it'll be good to go for 101 Trev!
Title: Re: Grand Cherokee clunking
Post by: Immortal on March 25, 2009, 08:33:18 PM
really?
i want front tow points....  :'(
my wife still wouldn't let me take it out.
Title: Re: Grand Cherokee clunking
Post by: WhiteOut on March 25, 2009, 09:35:08 PM
Im sure we can find some A/T's for it and some tow hooks.  Just tell her its getting a paint "job".

If Johnny's in with the WJ for 101 we have  my ZJ, his WJ, Aarons XJ, your XJ.  Team grocery getter!
Title: Re: Grand Cherokee clunking
Post by: JackstandJohnny on March 25, 2009, 09:38:24 PM
mounting pressure trevor...............
Title: Re: Grand Cherokee clunking
Post by: Immortal on March 25, 2009, 09:57:37 PM
it already has BFG TA/KOs on it....
as if... leave my black beast at home? c'mon now, don't be silly.
Title: Re: Grand Cherokee clunking
Post by: LifesGrand on March 26, 2009, 08:23:30 AM
Hey JOhnnyC,

When you refer to the part being a CV on the t-case end, is it an assembly of 2 u-joints with a center ball in the center? If so this is better known as a double cardon u-joint.

Glad it was an easy fix for you..
Title: Re: Grand Cherokee clunking
Post by: JackstandJohnny on March 26, 2009, 08:59:01 AM
lol i know the double cardan joint quite well. its on most jeeps.   this is a different animal alltogether.  shoulda takena  picture of it.  maybe i'll crawl underneith and take a pic for you. it is indeed a CV just like the front of the axleshaft.  no u joints whatsoever.  me no likey
Title: Re: Grand Cherokee clunking
Post by: LifesGrand on March 26, 2009, 09:01:39 AM
weird... talk about going all wrong with the front drive shaft...
If it's a cv, please no pic's...lol
So can you get a cv to u-joint conversion for both ends of that driveshaft?
Title: Re: Grand Cherokee clunking
Post by: JackstandJohnny on March 26, 2009, 09:05:05 AM
if i were to order the parts, yea. but i'd have to take apart tcase, replace yoke on D30, THEN find a drive shaft with a  double cardan on it of a suitable length to fit.  lotta work and price would end up being similar, not to mention jeep being down for a few weeks.  Pats had the stock driveshaft in stock..... easier to jsut swap it in
Title: Re: Grand Cherokee clunking
Post by: esi on March 26, 2009, 07:57:03 PM
if i were to order the parts, yea. but i'd have to take apart tcase, replace yoke on D30, THEN find a drive shaft with a  double cardan on it of a suitable length to fit.  lotta work and price would end up being similar, not to mention jeep being down for a few weeks.  Pats had the stock driveshaft in stock..... easier to jsut swap it in

I had mine converted in about  a hour at Jeep Stuff, with a new yoke and proper length driveshaft, u-joint one end and double cardan on the other. On ZJ's the driveshaft shrinks as the axle drops down with short arms, who would have thought.
Title: Re: Grand Cherokee clunking
Post by: w squared on March 26, 2009, 08:03:15 PM
I had mine converted in about  a hour at Jeep Stuff, with a new yoke and proper length driveshaft, u-joint one end and double cardigan on the other. On ZJ's the driveshaft shrinks as the axle drops down with short arms, who would have thought.

Do you find that all those sweaters mess with the balancing of your driveshaft at highway speeds?  ;D
Title: Re: Grand Cherokee clunking
Post by: Immortal on March 26, 2009, 08:10:33 PM
dork....
Title: Re: Grand Cherokee clunking
Post by: esi on March 26, 2009, 08:21:02 PM
I fixed it, typing while the wife is talking=nonsense
Title: Re: Grand Cherokee clunking
Post by: JackstandJohnny on March 26, 2009, 08:26:13 PM
lol

so i figured i'd pos some pics, show ya what i was talkin about

this is the tcase end
(http://i148.photobucket.com/albums/s37/johnnyzj/DSC00100.jpg)

axle end

(http://i148.photobucket.com/albums/s37/johnnyzj/DSC00101.jpg)

yea there are parts out there to convert to a regular ujoint driveshaft. i'm also lazy and won't be wheeling this particular jeep hard, so meh. one shaft out, one shaft in.
PS pinion seal looks worse than it is. diff is full of fluid and holding oil........
Title: Re: Grand Cherokee clunking
Post by: w squared on March 26, 2009, 08:49:26 PM
dork....

Yes. I am. What's yer point?