Engine/Transmission (1998.5 - 2002) Need Help Diagnosing Drivetrain Problem????

[Challenger-II]

A couple weeks ago, I posted that I was having a groaning vibration at 70mph on my '99. Many responded that there is a common vibration issue at this speed on our trucks. Well..... my truck never did it before and it has steadily gotten worse. :{ Now... . when I let off the throttle and get back into it, I hear a clunk from up front. I can feel it in under my feet. The vibration can be felt like a droaning or groaning through the body. I suspect a universal joint? Should I be able to flex the front drive shaft at all? Please help with your best guess as to where to look or what to check.



Thanks in advance!

 

[rkressg]

maybe a u-joint up front. Put it in 4wd and try making a hard left or hard right turn (crawling speed, wheel at stops). If you have a bad u-joint, it will make a loud clunk.



Could also be the CV joint in the drive shaft going bad. There are no grease fittings and those little neadle bearings get dry and wear out.



The front drive shaft should spin freely when not in 4wd. When you say flex, in what direction. There should be some freeplay front to back to allow the driveshaft to change in length as the front end moves up and down, but this play should be minimal.

 

[kess]

I think I had posted before about this problem. I know each problem may be different, but I will post my frustration. I also have a howling at 70 mph and a slight vibration on the floor board. It is amazing but there is no sound at 60. Truck seems to be driving great. At 70 the howling goes and comes. I have driven it this way for almost three months, luckily the sound has never gotten worse. I thought it was the u-joints and changed all of them, no different. I had the shafts balanced still no different. I have been told that maybe it is a bad bearing, but I would not think the sound would come and go if it were a bad bearing. I don't know, and I don't know if I can live with the sound. The other amazing thing is that even after a long run, nothing on either axle is hot to the touch. At 66K this truck is about to get a new home. If you find anything please post.

Thanks,

Kess

 

[Challenger-II]

Kess..... that sucks! It is very frustrating to not be able to resolve a problem. Fortunately for me, the source of my problem was vey obvious. My rear U-joint was destroyed. The needle bearings were gone and I was a day away from probably getting towed. Funny thing is when this whole thing started, I checked that U-joint and it appeared Ok.



As far as your problem..... Could it be a resonance due to your 4" exhaust?

 

[fox]

Kess, check the carrier bearing on the driveshaft. This is the assembly that hold it to the support, in the middle of the DS.

 

[kess]

Hey thanks for the replies. My truck is a regular cab, so it does not have a carrier bearing. I too thought that it maybe the exhaust, but I do not think that anymore. The sound is something else, and it coincides with a bit of floor vibration. Thanks again,

Kess

 

[Ereynolds72]

Has anyone seen those driveshafts with the "harmonic-balancer-looking" disc on them. I was looking at the GMCs the other day and they have them on their rear shafts. I wonder if that would work to eliminate that vibration.

 

[CORed]

Has anyone tried removing the front driveshaft completely and testing again? Just a thought.



Steve

 

[Ereynolds72]

I'm driving without a front driveshaft right now. The front driveshaft has another vibration that is directly related to the pinion angle. After adjusting the caster all the way positive, I got a bad vibration which went away when I adjusted the caster back again. Until I figure this one out, I'll leave the caster all the way positive without the driveshaft as I'd prefer to have it handle the way it does with the caster adjusted positive.



Someone suggested I have a front driveshaft made with just a single joint at each end and get rid of the cv joint at the transfer case. I'm thinking of trying this. Hell! It's only money right? Hah! The other vibration I think is in the rear and I plan to try the engine/transmission mount fixed discussed elsewhere. Just gotta do it now.

 

[Huff N Puff]

I'm driving without a front driveshaft right now. The front driveshaft has another vibration that is directly related to the pinion angle. After adjusting the caster all the way positive, I got a bad vibration which went away when I adjusted the caster back again. Until I figure this one out, I'll leave the caster all the way positive without the driveshaft as I'd prefer to have it handle the way it does with the caster adjusted positive.



Someone suggested I have a front driveshaft made with just a single joint at each end and get rid of the cv joint at the transfer case. I'm thinking of trying this. Hell! It's only money right? Hah! The other vibration I think is in the rear and I plan to try the engine/transmission mount fixed discussed elsewhere. Just gotta do it now.

All you folks with potential front ujoint problems do you guys drive around in 4 wheel drive,cause thats the only way the front drive shaft will be a problem. In 2 wheel drive the front drive shaft does not spin.

 

[K-80]

I have the same problem ,I took out the front shaft and it seems alot better. I think it is in the front carrier .

 

[Ereynolds72]

All you folks with potential front ujoint problems do you guys drive around in 4 wheel drive,cause thats the only way the front drive shaft will be a problem. In 2 wheel drive the front drive shaft does not spin.

For the '02 model year, DC did away with the center axle disconnect (CAD). I'm not sure why but my front driveshaft turns constantly. I'm pretty sure this is true for '02 thru the present models.

 

[OTRPU]

Mine started a wobbling, between Bristol and Angola, IN, bout 49 miles. It kept gettng worse'n'worse so I kept slowing my speed from 55 down to 40, then 35. Whole truck was a really vibratin. DOC's at Dave's Diesel really laughed. Said they don't know how I made it at all. The little shafts that ride in the bearings were sorta rounded. Nuther mile and I prolly wouldn't have made it. Course they're accustomed to me coming in on a hook. I'm on my 3rd yoke in about a month.



Cheers,

Steve J