Vibration

[RG75BRONCO]

I am experiencing a vibration beginning at 45 mph on. The tires, u-joints are new; both drive shafts have been balanced. The engine and motor mounts are new and all of the brakes have been replaced. The Bronco has a C-4 tranny. When I picked this Bronco up it was not running. It was a total mess. As for diagnosing the problem this is what steps I have taken. At 55-60 mph when the vibration starts I have slipped the tranny in neutral and the vibration stops. I have looked at the rubber mounts on the cross member at the tranny/transfer case and they look good. Is there any other rubber mounts other than the two that are visible on each side of the transfer case? When I put the tranny in reverse I get a hard engagement. The tranny shifts good at all speeds. Any ideas what maybe causing the vibration? I have checked the torque converter bolts and they are tight.

Thanks

 

[Bronc76]

Since the vibration stops when in neutral, try disconnecting the shaft at rear end and turn it 180 degrees and see if there is an improvement. Mark original position of shaft to return to same location if the problem persists. Might want to check the ****** too. As for the mounts, I think there are only two that I can remember on t-case.

 

[Bully Bob]

Hi RG.,

--Check to see if the pinion nut has worked loose.

--Two mount points on the transfer adaptor...& 1 on ea. end of the crossmember, along with 8 bolts that hold the crossmember brackets.

--Hard shift could be the modulator &/or the attach hoses or hardline.

Do fill in your sig. page so we'll know what we're work'n with here..!!

 

[RG75BRONCO]

Thanks for the advice. I will check these points out.