prerunner1982

When in 5th gear I am having a driveline vibration.. I dont feel it in 4th gear at the same speed. Only in 5th.. It is a fast vibration and I belive it to be internal transmission. What do ya'll think?

In the diagram I have it appears that 5th gear is on the opposite end of the output shaft bearing compared to all the other gears. Could the output shaft bearing be going out?

MasterShakeXJ

does it feel like its a driveshaft vibe?

prerunner1982

Perhaps, the rate of vibration is consistant with a driveshaft vib, but the fact it only does it in 5th gear makes me think it is not a driveshaft problem. Wouldnt the driveshaft vibrate regardless of what gear you are in and more dependant on RPM?

MasterShakeXJ

sometimes ds vibes get worse the faster you go. does the vibe progressively get worse/louder as you go faster? might wanna just check your ujoints and hit the ds with some grease to see if it helps.

prerunner1982

I will, but as I said... going the same speed in 4th no vibes.. if I shift to 5th but do not increase my speed I get vibes..

prerunner1982

any ideas?

BowtieGuy3

what rpm/speed are you going when you throw it in 5th?

prerunner1982

Between 45 and 50 mph.. not sure on RPM, but probably about 2000-2200 rpm.

JayM

I know this is low hanging fruit, but are your tires balanced?

I had a similar problem, and it tuned out to be a non balanced tire.

Balance and rotation fixed the issue.

mike37

check for dirt and built up grease on and in you U joints
DL vibration will do all kinds of strange thing
check front end alignment that my cause a front DL vibe because of the lake of locking hubs you will feel it all the way to the transfer case

my U joints had mud in them just a little but i made a vibration on the freeway

prerunner1982

I have been fitting a front end wobble which turned out to be part worn out steering and part out of balanced tires..

I do not believe this to be an out of balance issue. Both rear tires are new and balanced and since rotating my remaining good tires to the front I no longer have a wobble there either.

This vibe has a very quick rotation to it.. almost like a driveshaft..

But if it was out of balance tires.. it would do it at the same speed regardless of what gear you are in.. 50mph in 4th is fine.. 50mph in 5th gear there is a vibe..

If it was an out of balanced driveshaft wouldnt the vibration happen in 4th gear when it went through that RPM range... instead of 5th when the RPMS are lower... even at the same mph?

Or am I wrong here?

mike37

no you have different torque on it in different gears
vibrations are hard one to chase down sometimes it not what you think it is

prerunner1982

Yeah I suppose the torque might have something to do with it.. will check the Ujoints...

worknprogress

I have a similar problem myself. Although I have an automatic transmission, the vibration doesn't start until 55-65 mph. Balance new tires and recent alignment stopped most of it. It's very slight at the moment, but enough to be annoying. I know it's not the front driveshaft because I took that out when the transfer case went bad (looking for a new one now). I also get a knocking noise when I turn my wheel slightly to the left; don't know if this is related.