Differential fluid change

Cummins12V98 wrote:
This squeeze bag works GREAT. No pump needed.

That is what Ron and I used on my last fluid change and the bags work great! Chris

Agesilaus, sure hope the /0volt impact wrench is for removing the cover and not installing! Always best to tighten bolts to the correct torque during install.

I have reconsidered that plan and will use a socket wrench probably a 3/8" and I have a new torque wrench to bring the bolts up to spec.

agesilaus wrote:
Thanks for all the replies, I'm off to get the right permatex.

I got the fluid as specified in the manual, no friction additive that's was for older models I think. And I have a little pump for the fluid and a 20V Dewalt impact wrench for all the bolts.

BarabooBob wrote:
Last week I changed the rear differential gear oil on my 2011 F150. The spec call for 75W-140 full synthetic with a friction modifier added. I used ultra black permatex on the case cover. Everything went great. The bolts on the differential are to be torqued to 33 lb-ft.

Agesilaus, sure hope the /0volt impact wrench is for removing the cover and not installing! Always best to tighten bolts to the correct torque during install.

agesilaus wrote:
No fins and I actually have a gasket from RockAuto but everyone is telling me to use the silicone RTV.

If you have he stamped steel then yes use the RTV. Although now would be he time to install thenOEM finned cover. I bought mine for $55. It was new. I think maybe from Amazon.

Cummins12V98 wrote:
You should forget the gasket! This stuff is AWESOME!!! Never had a leak.

Second pic in appropriate weight if you want to do it BEST.

X2 on second pic. You will also notice a bit of an uptick in MPG. I did.

Another vote for no gasket.

On a previous truck, I installed a gasket instead of sealant. Years later during a hard tow, the gasket failed and a lot of fluid was lost, coating the hitch, where it was evident.

It turned out that all of the bolts were loose. Since I know they were torqued properly and to specs, I think the paper gasket softened and compressed over time, reducing the pressure on the bolts. I tightened the bolts, added a lot more fluid and continued the trip, but a few months later the differential was shot and had to be rebuilt.

That problem never happens to people who use sealant.

FishOnOne wrote:

agesilaus wrote:
OK this is my first time doing this. I have the correct fluid and I hope the correct gasket. My question is: do I use permatex on the gasket or leave it clean?

Curious how many miles you have on your '12 truck.

133K it mostly gets a workout during summer tho that's about to change as we plan to go semi fulltime. If camping ever opens up again.

agesilaus wrote:
OK this is my first time doing this. I have the correct fluid and I hope the correct gasket. My question is: do I use permatex on the gasket or leave it clean?

Curious how many miles you have on your '12 truck.

Good reading thanks to all that posted.

Last week I changed the rear differential gear oil on my 2011 F150. The spec call for 75W-140 full synthetic with a friction modifier added. I used ultra black permatex on the case cover. Everything went great. The bolts on the differential are to be torqued to 33 lb-ft.