Slight rumble/vibration coming from drivetrain on acceleration..what is it?

[jremington59]

I've lost the cv joint in the front drive shaft and that sure vibrates with accelearation....

 

[my pos mounty]

You described the sensation exactly. Like when driving over rumble strips. Sometimes harsher than others.
Removing the front DS will not harm the transfer case on an AWD X will it?
What does a TC feel like when they shutter?

The CV joint on your front driveshaft may be on its way out, that can cause some strange noises/vibrations under certain conditions.
Removing it serves two purposes, you check it out when removing it (if it falls apart, it isn't any good) and then you drive the truck around without it in place trying to duplicate the issue, if you can't you found the source.

Some say it CAN harm the t/case if you drive it around long term like that, you should be aware of that. This is a short term thing so you can figure it out.
Remember to set your e-brake when you get out, it will creep downhill when it is in park.

 

[blakshukvw]

Sounds good. I'll give it a try I guess.

I was planning on replacing the transfer case fluid as well as the front and rear diffs since this began. Would it be recommended to use sythetic after 144xxx miles? When I was wrenching, I avoided using sythetics in older cars that never used it before and were engineered and built before sythetics existed. I've seen so many Porsche engines leak profusely after having synthetics installed in place of conventional oil.

Is Amsoil the preffered?

 

[my pos mounty]

Is Amsoil the preffered?

Changing diff fluid might even solve your problem.
If you did not want to change it (I think its a good idea to change) you might try just adding the friction modifier to the existing diff oil. Take out the speed sensor and pour in a few ounces at a time. Might work, might be a waste of time/money.
Use regular dino in the front if you want, I have always used the syn. I forget which of the Mercon fluids is in the t/case. Been too long for my foggy brain.
I have used Lucas and Mobil1 synthetic, cheaper than the Amsoil.
I did not need to add the friction modifier to the rear LSD.

 

[blakshukvw]

Since I do not know when the fluids were changed last, I think I'll just do them all. I would guess the truck was maintained well by the looks of the trans fluid. I bought it from the OG owner.

 

[Duncan2000]

I too have the same issues as listed above. I have a 2000 XLT Explorer V6 4x4, with 157k. The vibration starts at 25 mph on acceleration or on an incline. It lets off on the downslope. When I take it out of 4x4 auto and put it in 4x4 High, the vibration diminishes greatly. Does anyone know where this points to as a cause?

 

[Mountaineer50]

i am having the same problem with my 97 Mounty at about 50 MPH (not all the time ) it will feel like i ran over a rumble strip. tomorrow i will be running a complete flush of the system and changing the filter to see if this helps and will post my results

 

[Duncan2000]

The rear u-joints were the cause of my problems. Replaced them and all was well.

 

[Mountaineer50]

i am having the same problem with my 97 Mounty at about 50 MPH (not all the time ) it will feel like i ran over a rumble strip. tomorrow i will be running a complete flush of the system and changing the filter to see if this helps and will post my results

so after changing the fluid and filter still have the vibration but it is only when it goes in to overdrive asked a transmission shop about it and of course they told me that the trans needed to be rebuilt not sure if that is true but have been taken that in to consideration. any ideas guys?


thanks for the help