Problem of the Week, T-Case Shake/Wobble

[WillySLC]

You know, when you have almost 280K miles on the XJ, things happen faster than you can deal with them. It gets kinda discouraging...

This isn't a new problem, but I just was reminded of it when I recently used the 4WD in rainy conditions. This is the NP242 Select-Trac model. When in 4WD there is a distinct shake/wobble/vibration as you accelerate through about 25 MPH. If you engage the 4WD in motion at say 45 MPH there does not seem to be a problem. It almost seems like something is binding, cause it seems to take alot of umph to get the car moving through the 20 - 30 MPH speed.

Any ideas?

Thanks as always,

WillySLC

[95steel]

check your fluids and u-joints. Sorry I don't have any better advice.

[WillySLC]

Thanks for the ideas and I'll check. Anyone else have some ideas? My son thinks it might be the drive chain. What are symptoms of a bad chain?

[satan]

Ignoring the "load" thing , I'd be thingking about the front u-joints, front yoke and it's bearing -- with the 4wd disengaged that would all be free turning - basically the front wheels through diff to the yoke area -- with the 4wd engaged the yoke would be coupled (you didn't say which 4wd part/full) and presumedly powered --- sounds like worn u-joints in the front shaft or some run-out in the front output bearing/yoke -- have you recently hit the front driveshaft on anything - could be that it's out of balance or that it's slip-splines are dried out, worn, and are offering excessive play...

[azxjman]

Well I can tell you its not a worn chain usally with that it will either skip like hell and you will no it when its doing this it is a horrible sound or... it will just break and you will also know when this happens. I would check the tranny mount to while your at it.