Ok guys,
I have read about the shudder and the 70 mile vibration. I have had a vibration ever since I replace the original clutch @ 200,00 mile. It now has 265, XXX miles on it now I have since replaced the clutch again. The original time I also replace all U-joints with greasables and center bearing. My vibrqation comes in about 22 mph and leaves about 33 mph. I can create it in any gear and the vibration is there under power and coasting. It does go away when the clutch is push in. My First thoughts was the front driveshaft that was not it. I remove and drove it for about 3000 miles no different.Now I am thinking about either a rear driveshaft out of "phase" , out of balance, or bad ujoints. Does anybody have any experience with this type of vibration.. thanks,


Scott

 

Bumpp....
Nobody has even an opinion?

Thanks,
Scott

 

u-joints, carrier bearing????

 

I'll guess at carrier bearing.

 

It sounds like that the drive line could be a couple splines out of time.

 

Update:
I pulled the rear driveshaft and lock it in 4wd hi pulled down the road and 98% of the vibration is gone. I am going to get the driveshaft balanced and all ujoints replaced. So hopefully this will resolve the vibration for good.

Thanks guys for all of your help!!!!

Scott

 

I am looking to do just that on mine to troubleshoot my vibration, so you just pull the driveshaft and drive right? no worries about anything leaking from the t-case or anything? I would think not but just want to be sure. I have the 70 mph vibration.

 

I had some fluid come out from the transfercase. But not enough to hurt anything... hope it works for you. A Word of caution I would not 70 on a highway remember you are lock n 4wd hi. Must take extreme care the front is the only axle pulling and when turning must go slow.

Scott

 

I have a 70 MPH vibration in my truck. I have had the rear driveshaft balanced, and brand new greasable ujoints installed. It took most of the vibration out, but not all of it. I fought with 2 stealerships and they argued with me and said that it was tires. I even swapped out a set of "clean" tread with one of my neighbors and they (***********) said that they can't fix it unless it's broke. So, I just drive it 68 or 78 and go through the Vibration. I have even gone as far as to have a drivetrain specialist look at it because I also have about 3/16" of backlash in the pinion rotation while parking brake is on and the trans is in neutral. The drivetrain shop said that it should be 7 to 10 one thousandths on back lash. They also said that there may be a shim in the pinion bearing that is going down. This repair, it the rear diff doesn't blow up, shouldn't be more than $900.00. This is just my own experience and could be a different situation for you. Unfortunately I just passed the 70,000 powertrain warranty, but have a log in the dealerships computer of the complaint, they said that they will leave the repair request ticket open in their computer for 2 more weeks just in case. WOW!

 

Had a '99 that had that vibration between 63 and 72 mph. If someone was doing 65 in front of me it made for a long trip if there was no passing zones. Pulled rear end apart it was allright. Pulled the transfer case down three times seemed to be alright. Pulled rear driveline and taped plastic baggy on end cover of transfer case, drove it around outside of town and the vibration was completely gone. Had complete new driveshaft with new end yokes made including balancing. Put the new driveshaft in and the vibration was back. drove it that way until I traded it off. My next attempt was going to be putting a dial idicator somewhere on the frame and indicate the output shaft in the tansfer case to see if it was bent. With the torque put on those shafts it wouldn't surprise me if it wasn't bent.

 

Are you talking about the output shaft at the back of the trans? In theory, are you ssaying that you could pull the driveshaft and maybe rotate it over a couple of splines and then hook it back up to change the phase? It sounds like something worth giving a shot.

 

Well just got a call fom the Republic Diesel. "the drivelines specialist" her in Louisville,KY. Chuck stated the driveshaft was 12 thousandths out and the yokes were twisted. He got it straight so now we will see it that takes care of it

Thanks guys

 

keep us updated......only think I can think of doing now is playing with some shimes on the carrier bearing to see what that would do. I know thats how alot of vibration is eliminated in lifted/lowered trucks. they use driveline spacer to create a better angle and it seems to work okay. i have used them on both kinds of vehicles and seemed to work for that application. just a thought!

 

[roll

ITS FIXED. got it put back together. NO Vibration what so ever.I had 3 new joints put in it. GET THIS????/ The front was 12 thousandths and the back 35 thousandths.... I was told it should be about 3-7 thousandths out at the max. So I don't know how many this will help but it has toally fixed mine. I did a 50 mile trip to insure.
Thanks again guys for all of the suggestions.

Scott

 

I'm glad one of us has finally solved their mysterious 70MPH vibration mystery. I love my truck, hate the fact that I can't drive it at 70, so I go 67 for mileage, or 77 if I need to get there faster! I'm going to go back to my driveline specialist and have them check out the phase on the yokes. Thanks for exerybody's input.