Just remember, you have to put the right stuff in that rear end or it will let you know if you haven't in time. I couldn't keep that 98 in one lane on the expressway when my fluid broke down. It vibrated so bad it shook the truck @ 55mph - Bad! - I thought it was the trans at the time, but it was the rear gear oil - The 98 didn't go under water, my 90 did tho . The 98's viscosity just broke down with time.

That oil is expensive, but you need it.. - absolutely.. + the required Friction Modifier = 4-8 oz's.

BTW - After I changed the rear gear oil, it took about 50 miles or so before the rear end stopped vibrating totally - It took time to heal.

 

that is exactly what i have going on it shakes and vibrates like crazy coming from the rear.

Not to mention the little slip when i first get on the gas

 

- Yea, I went thru the same thing man. Ford dealer back then told me that you should never need to change the dif oil in the rear. ??

I think I came here when that happened and people here fixed me up with answers. I think that was back in 05.

 

Ya thats what the mechanics around here say. I would rather change it myself to see what is really going on in there just in case its something besides the fluid.

I also tow a landscape trailer daily so maybe i need to chang ethe diff fluid more often?

 

Best advice is change it every 100k on general principle.

 

update changed fluid


improvements

slip is a lot better now it is just the bald tires
no more shuddering around corners
no more steering wheel vibration


and best of all now more noises coming from the rear end