Vibration

Anybody have an idea of what will cause a vibration in the drive line with the jakes on? Vibration appears to be worst between 1700 and 1200. Only happens when rolling the jakes when you're on the foot feed at the same RPM nothing, and it's in the band not speed related so I didn't figure it'd be in the tires or anything else looking for ideas on what to check. I've had the driveline out a couple times for u joints and pretty sure I got it back in right or close enough to where it wouldn't make a difference, and I would think that I'd feel it all the time as opposed to just when the jakes are being used if I didn't get the driveshaft lined up correctly.

 

it's not as bad on 1 and 2 as it is on 3 but it's still there. I have wondered that myself but haven't had time to pull the valve covers and check the solenoids, nor have I had time to even run the overhead. I do know one of the outside solenoids isn't working correctly as at times on setting 2 and setting 3 I will be short one pair of cyilnders I can hear it and feel it, but I havn't looked into it much farther as I don't use my jakes all that often anymore since they seem to be really weak now that the motor has been overhauled.

I'm at a loss I had one mechanic tell me to check the rear ends really well as it could potentially be in the rearend but those are like the drive shaft I would think, they're spinning constantly and I would think I would feel it while in the foot feed or coasting not just when the jakes are running. I'm at a bit of a loss here right now with what could be going on.

 

Driveline is slightly off I currently have 24.5 tall rubber on the steer and 22.5lp drives steers will be replaced rather soon. I won't rule that out but I didn't notice a problem with a vibration after changing the tire size. I just began to notice the vibration about 3 weeks ago after I had some transmission work done. Not trying to pin anything on a shop either just having trouble figuring out what is going on with the truck.

If the ride height wasn't correct would I be hearing a griding when I let off the foot feed in conjunction with the vibration with the jakes? I'm just curious on that I have had times when I have either blown an air bag, they have come up slow, or I just forgot to air the truck back up and I could always listen to something grinding in the transmission. I do not hear that now or with the jakes on just the vibration.

 

If it went out again in a matter of 3 weeks me and pete are going to have a discussion. No oil in coolant so I wouldn't think it went out again and there's still water in the rad after that many miles it should be low on water if it's putting water into the trans fluid again.

I'll check the driveline again carrier bearing was fine when I had it out and when it was out at pete as i checked to make sure their tech checked. I would assume they put it back in there correctly it wasn't near as dirty when they put it back together as it was when I did the ujoints. I mark everything with tape and cut the tape to line everything up so I don't run into the problem of misalinging a driveline and having the vibration issues.