[Duck]

I've been down this road before - having a bad U-joint.
But this time the symptoms are the opposite of what I had previously.

Before, when I pressed down on the accelerator/gave it gas, I would get a vibration.

Now, I only get vibration when I let off the accelerator/gas.
Feels like I am driving over a rumble strip and it is only heard when going over 50mph.

Are the U-joints going bad again??

 

[Surf and Snow]

Are you bypassed for protection from SMOD? If not, better check your coolant and your tranny fluid. You may be the next guy to add to the SMOD hit list thread.
Posted via Mobile Device

 

[iamamused]

Yea, sorry man - does sound a bit like SMOD. Take a look at the underside of your radiator cap (when the engine is cold) and see if its coated with strawberry milkshake.

If its SMOD, try not to drive it if you can it'll only make things worse. You may be able to save it with some flushes and a new rad.

Otherwise if you need a new transmission, I hope you are still under Nissan's extended warranty.

 

[Ripper]

Dont always jump to conclusons when it comes to the SMOD. Granted I fear the worst when I have a vibration. I just found out my driver front wheel bearing was bad, I only got vibes from between 60 and 80. I figured it out when I put new tires on my X due to a tread seperation on one of my Treadwrights. I am not saying to rule it out but dont let that be the one and only thing you focus on. U jount break down and failure can present many ways. Ive had a bad ujoint present with the same signs and symptoms that youre experiencing on an old Bronco before. The last two times one went bad on my X they were both different.

 

[Duck]

Thanks for the replies, guys.
I am ruling out SMOD because I have a manual tranny.

 

[Red2Thundercat]

^good idea

 

[Duck]

Ok. U-Joints are fine. Tires are fine.

Again, when I let pf the gas at interstate speeds I am getting a rumble or vibration in the drivetrain.
Getting worse.

Pinion? Slip Yolk??

Any ideas would be nice before I decide to take her to the dealership.

 

[Rooney]

This might seem like some work but put the rear of the truck up on jack stand chalk the front tires and shift it in gear getting up to speed and see if its in the drive shaft ? You would need a buddy to drive for you. Or better yet disconect the drive shaft and check the u-joints and rear CV for binding .
Does this happen when decel in gear or nuetral also ?