Installing an Eaton Posi this weekend - questions

[jsnyng]

Are there any gotchas or tips/tricks I should know about installing one of these? I'm also putting on the SVTPP FRPP finned diff cover. How much gear oil should I get? I'm thinking of going Royal Purple this time around. Any help will be appreciated.

 

[chuck@evoperform]

3 quarts is sufficient. Fill til it comes out the fill hole in the front side of the housing (drivers side).

 

[jsnyng]

3 quarts is sufficient. Fill til it comes out the fill hole in the front side of the housing (drivers side).

Thanks Chuck. That's about what I was guessing. I'm really hoping the Eaton will let me put more power to the ground on the autocross course. Inside wheel spin is a bitch on the OEM LSD. Any installation gotchas, or is it pretty straightforward if I've done gears before?

 

[KJGT]

Just swap it out and check the ring gear backlash, unlike just a gear swap you have to make sure there is enough (or not too much) preload on the side bearings. Make sure you have some shims laying around.

 

[Scott_0]

I believe the Eaton requires a bottle of friction modifier in addition to the gear oil, atleast when I installed one in my Fox Saleen years ago,and if Im not mistaken they recommend you use non synthetic

 

[ArizonaGT]

I believe the Eaton requires a bottle of friction modifier in addition to the gear oil, atleast when I installed one in my Fox Saleen years ago,and if Im not mistaken they recommend you use non synthetic

JASON PLEASE READ THE MANUFACTURER'S RECOMMENDATIONS LISTED ON THE BLUE (?) CARD INSIDE THE BOX!!! It is very specific about what gear oils they want you to use.

Recommended capacity from Ford is 1.7L (3.15 pints)

Additionally, Ford's fill level check is to fill to roughly 1" BELOW the fill hole, with the car level and the axle at ride height. Check out the 05-09 manual page 205-02B-1. You can check the fill level easily by putting a 90* bend into a lightly-colored zip-tie at or just past the required length and then using it as a dipstick of sorts.

 

[jsnyng]

JASON PLEASE READ THE MANUFACTURER'S RECOMMENDATIONS LISTED ON THE BLUE (?) CARD INSIDE THE BOX!!! It is very specific about what gear oils they want you to use.

Recommended capacity from Ford is 1.7L (3.15 pints)

Additionally, Ford's fill level check is to fill to roughly 1" BELOW the fill hole, with the car level and the axle at ride height. Check out the 05-09 manual page 205-02B-1. You can check the fill level easily by putting a 90* bend into a lightly-colored zip-tie at or just past the required length and then using it as a dipstick of sorts.

Thanks man. I haven't even opened the Eaton box that you sent me, so I haven't seen that blue card.

I have a very skilled mechanic who is going to do the install, but he really likes for me to show up with all of the parts/fluids I need when I get there. I will open the box this evening and read that. The Eaton website had very generic instructions, "Remove lubricant fill plug and install recommended volume and type of rear axle gear lubricant and limited slip differential additive. Re-install and securely tighten fill plug."

 

[Intervention]

I believe they recommend ONLY a 80-90w Dino oil...

Say synthetics dont offer enough shear protection or something. Sorry its been a while since I seen the card

 

[Scott_0]

I believe they recommend ONLY a 80-90w Dino oil...

Say synthetics dont offer enough shear protection or something. Sorry its been a while since I seen the card

sounds right, when I had my Eaton installed about 6yrs ago they recommended dino oil and a bottle of friction modifier, but I wasnt sure what if anything had changed

 

[jsnyng]

Here are the two cards that were in the box for future reference...


Untitled by jsnyng, on Flickr


Untitled by jsnyng, on Flickr

 

[Scott_0]

you're all set now then. those Eatons are great diffs!