mobile one 75w90

[kc2aku]

Has anyone used this in there front differential?  I bought some cheap from my local parts store.  I have the grape smelling Gm stuff for the rear but was wondering if anyone has run the mobile one in there front.

[Bulldog]

I know a bunch of other people on another truck site use this stuff regularly and they speak highly of it.  I'm looking into changing mine to Red Line.

[Nick2000Gmc]

I just use the organic stuff from valvoline and thats what they reccomend, They say you have to have a special vent valve or something if you wanna run synthetic in the front. makes sense though that the synthetic would it certain rubber. I look at it like this the rear end takes all my abuse and the front end is just there too look pretty in the snow. I live in Canada and find the autotrac is the best 4wd I have seen except for lockers ( but who drives them doing 60 mph )

[Bish]

I've been running Mobil 1 front and rear since 5K miles. I''m at 105K now and no leaks.

[Pancho]

I have ran it front and back now w 47,000 miles w no problems.

[ridnlow]

How hard is it to change the front and rear diff fluids??

[Bish]

On a scale of 1-5 where 1 is equivalent to changing the oil and 5 being an engine rebuild.

 

Front 1

Rear 1.5

 

Front amounts to pulling the drain plug, replacing the drain plug, removing fill plug, squezing in gear oil until it overflows, installing the fill plug. Warm up the fluid a little by driving it in 4wd for a few miles. Hardest part is finding a way to hold the container so you can sqeeze it into the fill hole.

 

Rears are slightly more difficult. Pull drain plug, pull cover. Clean cover and housing to remove any gasket/material. Needs to be bare metal. Clean magnet...should be some powdered filings on it. I spray brake cleaner into the rear end to clean thoroughly but you can skip this if you want. Use new gasket. Don't use RTV if you're using synthetic as I have found it will leak eventually. I coat the housing with gasket adhesive, install the gasket, smear oil on the outside of gasket and then put the cover on. Next time I change the fluid, I just rap the cover with a rubber mallet and it comes off clean leaving the gasket on the housing. Don't have to buy any more gaskets Careful with the fill. On mine the fill level is something like 15mm BELOW the fill hole. I use an L shaped hex wrench to measure. If you overfill, the rear seal will eventually start leaking.

 

Both jobs are easily done by anyone with simple mechanical skills.

[Highbeam]

I have been using mobile 1 synthetic 75-90 in both differentials for the last 60,000 miles. No problem at all. This is on my 98 k1500.

 

The front diff is easier to change than your engine oil.

[robsawatsky]

The front axle is compatible with synthetic axle lube, however, there were a few years where the vent tube was not compatible with synthetic. You an tell based upon whether it is a white/clear or black tube. I can't remember which is which, but if it is the same colour as the rear vent tube it should be fine. Otherwise, it is a simple switch of the vent tube.

[MarkD]

How hard is it to change the front and rear diff fluids??

It depends on if the fluid really wants to change. (shrink joke)

[Black02Silverado]

How hard is it to change the front and rear diff fluids??

It depends on if the fluid really wants to change. (shrink joke)

So if it doesn't want to change then your stuck with the old stuff????

 

I'd make it change.