Trouble shooting a squeak (1 Viewer)

[Haggs]

Hey Guys,

Sorry for the title of the post but that is pretty much what I am doing. My 1988 BJ74 has an annoying squeak that has developed that is coming from the engine bay. It isn't related to rpm as when it is in park and if I rev up it doesn't do it. It happens only when moving and gets faster the faster I go. Above about 70km/h the noise stops.

Any thoughts for where to even start?

Thanks,

Drew

 

[Ron R]

What happens to the sound if you press the clutch while driving? Does the sound alter at all, does it alter with engine speed? Or with declining speed?

 

[Haggs]

It is an automatic, and it gets faster when you speed up and slower when you slow down. However if I am going 60km/h and put it in neutral the rpm's slow right down but the squeaking stays constant until the truck begins to slow down in speed.

 

[John Galt]

It is an automatic, and it gets faster when you speed up and slower when you slow down. However if I am going 60km/h and put it in neutral the rpm's slow right down but the squeaking stays constant until the truck begins to slow down in speed.

Check all U-joints

 

[Ron R]

Check all U-joints

Yep, agree on that.
If nothing strange found there then eventually check the brake pads (think you've disks up front).
Drive 60(?) or so, put it in neutral and tap the brakes.
Any change in sound-->probably brake pad.

Bad case scenario is a bearing in the drive train (not in a U-joint)

 

[Haggs]

U-joints are good, I think it may be a wheel bearing. I will start there and keep going from there.

 

[jb BJ73]

check for play in the diff pinion and transfer case output bearings as well. my bj73 has got a fair bit of play in the transfer output bearing and it whines at about 70km/h. not related to engine speed (does it in 4th and 5th), does it with clutch in or out.