Im in the process of putting in 4.56 gears in my newly lifted 2005 FX4. Im also going ahead and pulling both axle shafts and checking them and replacing my bearings and seal while im at it. But im having trouble finding the exact parts list im needing to get the correct barrings and seals. can any one help me out on a rear axle install kit parts guide or link to buy it at? I have never fooled with an axle before so im learning as I go and i dont want to miss anything.
Also my rear Ring & Pinion's Gear is 9.75" 12 Bolt Cover if i buy as a complete ring and pinion kit is my front going to be an 8.8" 10 Bolt Cover 4.56 Front? I havent looked at my front yet but im just wanting to verify this is correct before I buy. Thanks

2005 Fx4 4"lift 35'' Mud Hogs

 

All front diffs on 4x4 trucks from 97-16 use the IFS 8.8, they require the reverse cut gears. 4.56 is a good ratio to go to and they are available for the front and rear axles. Depending on your miles, you might want to consider rebuilding the rear trac-loc while your in there changing gears.

 

Get all the information off the tag on the rear diff and use that info to order.

Probably doesn't apply to your truck but mine had 2 different axles listed and of course I ordered the wrong one because i didn't use all of the info on the tag.

 

Thanks, are there any brands that I need to stay away from on the seal and bearing kits? And any thing I may need to know before I start this?

 

The truck just started making a "gears grinding" noise. I jacked up the rear end just off the ground and spun my back tires and when the teeth get to a certain point it grinds again... Could this just be bad teeth meshing from a shim or could this be something else? broken tooth, bearing maybe? I just bought the truck 2 months ago and when I checked the rear dope I couldn't even get any oil on my piney. so I put some in it to get me by till I could get my new gears in and redo the axle seals. Any ideas?

 

The axle I bought was a Dorman from rockauto and I used a Timken bearing made in the usa, even though the axle came with a bearing made in China. The Chinese bearing is probably ok but I didn't want to take the chance on ruining my new axle.

Sounds like that rear differential is on borrowed time.

 

I put Yukon bearings and seals in my 04 axle, they have a great reputation in many different automotive aspects from off road racing, rock crawling, you name it. I have heard good things about Randy's ring and pinion for gears and sets.

 

am doing this same thin right now.... this exact second.

you need to know a couple things about your rearend.
1st. look at the axle tube where the brake baking plate bolts on. is it necked down smaller? yes= you have 1.62 dia axles and axle bearings.
2nd The outer pinion bearing has a BIG and small also (yes and the seal).
PITA

I can/will post ALL the part numbers so you can buy BOTH to have on hand.. then simply return which one you don't use.

KOYO bearings is what ford used... sometimes. Can't go wrong with Timken or National.
YUKON makes decent gears.
Motive has come a LONGGGGG way now!

 

ok... update time.
Motive r975fr (bearing kit) comes with the SMALL outer pinion bearing!!!
Dorman 630-320 is the small (1.620 bearing ) axle.

Neither company chose to include this tidbit of INFO ...
now we know.

Bearings:
axle, 1.620 , #6408
carrier, NP343847, race, NP372019
pinion, INNER NP576375, race, NP434567
pinion OUTER small M88048, race M88010
pinion OUTER LARGE HM89443, race HM89411

I would have ordered from Rockauto but ...
of course i opened up the rearend and saw the right axle was wiped out, all the gear oil coming out had GLITTER in it.. I couldn't put it back together and drive it for 5 days waiting on parts for fear it would completely wipe things out.