HELP!! Can't find vibration
 

Need help I have a 99 4x4 auto 2500 cummins and can't find out where this vibration is coming from!!!!!![duhhh] Just above 60 mph and tac reading about 2000 rpm I get this really strong vibration in the floor board just below the brake ped and in the seat. It sound like a Harley is riding in the bed of the truck. I have put in new U-joints removed the front drive shaft and $1500 worth of rims and tires and a front end alinement and still its there.[verymad] I also have a sound like gears whining at both 35 and 45 mph at both speeds tac reads about 1500 rpms let off the throttle and the noise is gone if I'm in nutral or park and tack up to 1500 have no sound. I have flushed out the P/S fluid and replaced the pass hub and lower ball joint and the noise and vibration still there.. The wife is about to kill me this has cost me about $2000 if I have to spend any more I will be living in the truck with the dog!!! Need some help ASAP!! Maybe a tourque converter going bad trans on the way out just need a few ideas or maybe someone has had this problem before I'm lost!!![duhhh] Taking the truck back to have the tire's checked to make sure that I didnt get a bad tire or thrown a weight. Going to change the trans and the diff fluids this weekend might be it I just dont know thanks in advance!!!!

First check the tires lke you said. Look at the driveshaft see if the weight is still on there. Another thing to do to isolate it is to jack up the rear and drive it on jackstands. That will eliminate the whole front end if the noise is still there. Check that stuff and let us know

I did jack the rear end up ran all the way to 70mph and just a very suttle vibration nothing like when driving down the road. Did check the drive shaft all looks good I even rotated the drive shaft 180 just to make sure and vibration still there. Let me know if you have any other ideas..

Its not an engine skip when tc is locked is it? Some times a misfire will cause it to shake when in lock up. Was there a weight on the driveshaft? Is the excessive lash in the rear end? Another thing to look at is the tire. Even though there new I have seen new tires out of round. If its out of round it will give a shake in the air and even worse when its on the ground.

All weights were on the shaft a looks like none are missing. No loss of power or engine misfire or excessive play in the rear end or transfer case. Would the TC be locking in at both 35 and 45 mph?? Driving slow it shift fine no sliping goes into gears just fine and at 60mph tack reading 2000 and at 61mph vibrations starts. Have 156000 miles on truck unsure if bands have ever been tighten or if fluid has been changed I'm going to do a fluid flush this weekend by removing the return on the trans and adding into the fill tube to get rid of all fluid. Fliud not brite red but not to discolored eather. Going to check the TC bolt to make sure they are tight will give up date later..

Is the vibration fast and harmonic or slow and wobbly? Does it follow the speed of the engine?

Ok sounds like you got 410 gears. Converter will lock in 3rd gear also. My truck will lock in 4th at 40mph. So before that your in 3rd locked.

Just got back from the shop and the guy told me that the front wheel hub is bad no play just a knocking/whining sound from the hub... C/K the wheels,lugs and tires a all is good.. The vibration is a very fast hum and letting off the throttle it seems to go away just the mph slow down to fast to tell if its motor or drive line. I guess going to change the drivers hub out this weekend... Will post if its fixed just wondering is the drivers threaded axle nut lefty loosly or righty loosy??? Thanks If this is not it the back seat doesn't look to good to be sleep on after the wife throws me out..... lol

I have this very same issue and heres what Ive done: front ball joints upper lower, track bar, shocks all around, bd diesel steering box stabilizer bar, tie rod end, new rims tires and I still have the same issue when i hit 40 mph it feels like theres a jack hammer in the bed of my truck. So I do know for a fact its not the front end its been checked aligned and rechecked again so its something from ma booty on back somewhere anyone got any ideas? I just think it weird i only get it from 35-40 and thats it, it goes away

try putting a tc lock up switch in don't have to get fancy just something you can use to lock it up and see if its the culprit of your vibration

check your engine mounts

You mentioned that the vibration is fast and not slow so its not wheel/tire related. Doubtful a wheel bearing. If the vibration stops as soon as you get off the throttle then I'd be looking at tranny issues like the torque converter or motor mounts or tranny mounts. If the vibration didnt go away when your off the throttle then I'd be looking at the driveline and driveshafts.

mine does it weather im in or out of the throttle but only between 35-40 mph, and Im not tryin to hijack this post but just seems my problem is almost the same so why start a new thread.

Well it wasn't to long ago that I had the strange "wobble" at around 45 mph. Made the truck kinda hop in the rear. Apparently others were experiencing similar issues because it became a thread topic BUT.....posters seemed to pop in with all kinds of vibration problems which in turn ran the thread off course. I also remember there being some kind of relation to a certain vibration and auto tranny trucks where as us manuals were having a different kind of vibration.

Nonetheless, I looked at lots of possible fixes to get rid of the feeling like my tires were egg shaped at certain speeds only to get new tires later on down the road and find that all the crazy problems went away. Not saying yours is bad tires either.

yea ive narrowed that one too, 3 sets of tires and 2 set of rims and same thing. Im gonna triple check my ujoints and balancing weights on the drive shaft...again but Im stumped

I was just sharing that, but this is what I really think for your issue:

U-joint yoke
 

Have you checked the U-JOINT yoke alignment on your drive shafts to make sure when the joints were replaced that someone didn't remove the slip yoke and not put it back together right. The joints need to be aligned so there is not pressure on them all the time

Thats called u-joint timing. They have to be exactly 90* of eachother or they will vibrate.

yea Im thinking this is where my issue lies, Im gonna get into it this weekend

Not trying to keep you from looking at all possibilities but the only reason I think its not your rear driveshaft (you took off the front driveshaft so thats not it) is because it only does it at certain speeds and it goes away when you're off the throttle. A driveshaft thats bent or out of balance will vibrate or hum after a certain speed and continue no matter if you're in neutral or not. Thats kinda why I thought your problem was related to the tranny/torque converter or engine/tranny mounts. But that of course doesnt mean I'm right. Diagnosing over the internet.....

I have figured it out it was the front driver wheel hub.. If you checked it out there was no play in the hub. Had a HELL of a time removing the axle nut had to take truck to a shop and have them losen it and them drive home and finish the job. Someone had changed out the rotor before me and when they tighten the axle nut back up must have really over tighten it. After I got home and removed the wheel and caliper rotate the hub I could really hear and smell the burnt bearings.. The TQ on the nut is only 120ftlbs and the guys at the shop had to use and 3/4in airgun and really work to get it off. So if anyone works on the front end of a 4x4 double check that the axle nut not over tighten. Thanks for all the ideas and trouble shooting from the guys on here ya'll KICK ***!!!!!!

well so far ive found that my center bearing as well as the rear ujoint is bad but im replacing all the ujoints. Also found the driver side hub is bad now all kind of crunchin and grinding, but now my problem lies with buying parts i go to autozone and they ask me what size ujoints theres 2 diff sizes? hell i dont know its a 2001 dodge ram 2500 4x4 then im asked do you have front or rear abs or all 4 abs for the front hub part? Really? are you seriousyour computer doesnt tell you what i have? why does dodge have to be so **** complicated. Im assuming i have front abs but then again who knows

Dido
 

I've got the same issue and my truck is a 5-speed replaced so much stuff and went through swaping tires 3 time to what I have now which are the best so far. I've found that after taking the wheels off say for a rotation that the vibration almost goes away and that days later comes back.[duhhh] [verymad]

It is not just Dodge. Ford, and I am sure Chevy, also have their idiosyncrisies. I have a friend with a 3/4 ton Ford, and has had a devil of a time getting rear wheel bearings.

Pull a u-joint, and either measure it, or take it with you. I bought the wrong size for mine. Considering what my buddy with the Ford has gone through, I am thankful that there are only two choices of u-joints.