Just wondering, I've got a 2002 F-150 XL 4X4 w/ 66,120 miles, anyone else think its too old (age and mileage) to change the rear end fluid?

 

Actually, mileage wise, I think it's too soon. Age wise, it's a good idea and it's not that difficult. Get the oil, get a new gasket, some RTV, set aside a saturday morning, tune the radio to Car Talk and enjoy.

 

It is always a good idea fo drain and flush the factory fill oil on any system after a break in period. There can be wear materials from break in that can get into the bearings and cause shortened life. Go for it. NEw spec is 75 w 140 synthetic

 

Thanks guys, gonna do it next weekend when its not raining....

should I use RTsealent or find a gasket for it? It has RTsealent on it now...

thanks again,
John

 

Anthing built in the last 10-15 years uses RTV, not a gasket. Make sure the pan face is smooth and flat. Bump with ahammer if needed. I like the Red RTV.

 

I use grey RTV silicon sealant. also, while you have the cover off, it would be a good idea to check to see if you have any mechanical issues, such as metallic shavings, or solid metal pieces in the diff. this could be a sign of serious failure.