Squeal Diagnosis

[WyoSyclone]

Hey Guys,
Drove 35 miles to a nice car show yesterday. On the way back I started hearing a bad squeal.

Conditions...
Highway speeds (55-75)
Accelerating - no squeal
Decelerating - squeal starts mild then gets worse.
Putting Sy in neutral makes no difference - squeal still happens only while decelerating.
Sy in neutral and rev engine no change in squeal.
Apply brakes during squeal - little change in noise.

This is a hard, almost dry journal bearing sound of squeal. I replaced both front spindle hubs approximately 300 miles ago with Timken brand hubs. Differential fluid level is fine.
When I stopped on the highway to check rim temps the right rim felt a tad warmer than the left.

I'm hoping it's not an axle stub bearing in the front diff.

Any Ideas??

TIA

Rob

 

[cloneman315]

Re: Squeal Diagnosis

Rob

I had mine do this before on the way to the auto fair,drove me nuts.took me forever to find it.It was a bad u joint in the front prop shaft

 

[WyoSyclone]

Re: Squeal Diagnosis

Rob

I had mine do this before on the way to the auto fair,drove me nuts.took me forever to find it.It was a bad u joint in the front prop shaft

Thanks Brian :tup:
I'll check that out. I've got the Gilbert shaft, but did notice that after I'd lubed it one day that it had spit a bunch of grease out... I thought I had just overdone it on the grease. I'll inspect it, regrease it, and see if the noise changes. If so, I'll replace the joint.

Does anyone know offhand which U-joint the Gilbert takes?

 

[WyoSyclone]

Re: Squeal Diagnosis

Cross and needle joints won't squeak continuously. It will be cyclic because the movement within the end cap starts and stops twice per revolution. BUT: There is a center-pivot bearing in the double-joint at the T-case end of a stock style shaft. These do squeak, and fail. There is a little 'cup' fitting on the housing that greases this bearing with a needle fitting in your gun. But I think Gilberts use single joints. So it won't have this bearing, and won't squeak from this source.

You worked on the hubs and bearings. Double check that the brake dust shield isn't rubbing on the back of the brake rotor. That will make a squeak such as you describe.

I'll check out the dust shields Dave. It's kind of strange that it is quiet under load/acceleration but squeaks when freewheeling/decelerating.

 

[cloneman315]

Re: Squeal Diagnosis

Theory or not,my front joint was the squeak.

 

[IRISHTY]

Re: Squeal Diagnosis

Not sure what your sound is but I had a squeek on my 96 Bravada that just drove me nuts while trying to find it. Same symptons. It started after I rebuilt the TC. Two months ago I rebuilt my TC and replaced the converter in my Ty. Just last week it started making the SAME exact squeek the Bravada had. I used the same rebuild kit/seals on both. It turned out to be the rear TC/driveshaft seal. Dry squeek. Drove me crazy. Put a little white grease in around the front yoke and noise is gone. I do know I will not use the same brand kit if I have to do this again. Just thought I would toss that out. Dan.

PS. Still have the Bravada with 30K more on the od and I still have to service the front yoke from time to time.

 

[WyoSyclone]

Re: Squeal Diagnosis

Sorry about the delay in closing up this thread.... I just got the Sy back on the road after the CAI install.

A drive on the highway showed the squeal to now be gone. The only thing I did was grease the front u-joint on the Gilbert propshaft.

It wasn't as hot out as when the squeal first appeared but I don't think that is much of a factor in this instance.

I won't be driving it again on the highway till next Summer.

 

[Tony Dipatri]

Re: Squeal Diagnosis

Rob,

I have the same situation about at the same speed but the sound is different, It almost sounds like a hollow grinding sound. I changed the u's on the front shaft cause one was hammered but the sound didn't go away. On the highway slightly while under power at cruising about 50 to 70 MPH I hear it but if I add a little more throttle the sound goes away. The same at when I let off the throttle. I had this problem before the truck blew up.

Any suggestions?

 

[WyoSyclone]

Re: Squeal Diagnosis

Rob,

I have the same situation about at the same speed but the sound is different, It almost sounds like a hollow grinding sound. I changed the u's on the front shaft cause one was hammered but the sound didn't go away. On the highway slightly while under power at cruising about 50 to 70 MPH I hear it but if I add a little more throttle the sound goes away. The same at when I let off the throttle. I had this problem before the truck blew up.

Any suggestions?

In my experience those hollow sounding noises are a front hub bearing. I had one starting to make that noise on mine, put on a new set of spindle bearings, and the noise went away.

 

[Tony Dipatri]

Re: Squeal Diagnosis

Ok thanks,

I will start there....

Thanks