How do I know what size diff I have ( Identifiers )
2015-3.5 EB XL

Also- dont look like there is much room up front to take the diff cover off- is there some trick to it?

Wanting to change out fluids in both since I am @ the recommended mileage

Thanks fellas

 

On my 2012 you would have to tear things apart to do the front diff. I vacuum pulled mine on the front. The rear I pulled the cover for axle seal job, then did RTV on the cover. I will probably just vacuum the rear out like the front when I do it again.

I have a 8.8 on my base motor truck. I would assume you have the bigger axle. The 8.8 axle cover is more roundish in shape. The bigger 9.75 is not even close to round.

What rear end do I have? - Ford F150 Forum - Community of Ford Truck Fans

 

Thanks for the help
would have thought more would chime in but guess most dont know

 

I just did my front diff fluid change a couple weeks ago on my front diff, 2018. the cover doesn't come off without tearing a lot of stuff apart and dropping the axle. use a vacuum pump and just suck it out through the fill hole. I was surprised I actually got the recommended capacity out of it so my hose must have been pretty close to the bottom. a lot easier to do it this way so that you don't have to reseal the cover....I'll do the rear soon this way also as well as the trans next time I need to do that....the vac I got worked awesome and I will be using it a lot more.

 

Thanks

 

From memory here:.hope this helps
Record the axle code on the vin sticker located on your LF door..... Then google that # (code (for example F150 9 or H 19 axle code.... these codes are both 3..55 ratio but one is limited slip...the 9 simply is the open diff.)......google should tell you axle size either 9.75 or 8.8....
eg: can also be 3.15...3.31...3.73/ or 4.10 ratios.........suffix " L" + a letter ... usually is electric locker & your 4x4 hi-lo switch will pull out to active locker??

 

i checked all the local parts houses looking for lube locker gasket and no one carries them
I just ordered it off of amazon along with the syn fluid- have 153K so its over due
Guess I will have to buy one of those fluid evacuators for the front

 

Shoot me the last eight digits of your VIN and I can tell you exactly what it is.

-Steve

 

I think its the 9.75 with the 3:31 locking

 

That's exactly what it is. 3.31, 9.75 e-locker.

-Steve


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