4x4 vibration at high speeds

[moellertime]

I have a 97 OBS with a stock front end and warn manual hubs and when I have it in 4x4 and get up to 50-60 mph I hear a growling/vibration noise coming from the front end. It only happens when I'm on the gas a little bit, if coast or floor it the vibration stops. I don't think it's the hubs because I can lock them and disengage the manual transfer case and there is a little noise but no vibration or growling at high speeds. Any help would be much appreciated , thanks.

[1Dieselman]

I would do a very close inspection of the drive shaft u-joints and all three front axle u-joints

[madpogue]

Is this on dry pavement?

Have you tried pushing in the clutch and letting it back out (or shifting to Neutral and then back to Drive), to see if the NVH "resets" and doesn't come back until you get down the road a little further?

[garyeco]

I've had the same problem before and it turned that drive-shaft from the transfer case to the front end was the culprit. If not in the single u-joint then in double U-joints in the rear.Stick a screw driver or whatever in them and see if there's any play.Buggers are hard to grease.Good luck!

[greenwhite1]

Originally Posted by garyeco

I've had the same problem before and it turned that drive-shaft from the transfer case to the front end was the culprit. If not in the single u-joint then in double U-joints in the rear.Stick a screw driver or whatever in them and see if there's any play.Buggers are hard to grease.Good luck!

I agree with him. I had a similar situation two winters ago and I had already rebuilt the front axle so I knew my problem wasnt up there. My double cardinal u joints were bad.

[sgg93]

Mine was making a lot more than a slight growl, it was like firing a full auto .22 rifle when you got to about 35 mph. Same thing, it was the two u-joints by the T Case. The yoke was also bad, I'm lucky to have a drivetrain supply shop in town and picked it up for $35.