4.10 dif gears: all required parts?

[MrBluGruv]

I'm looking for my next major modification to be a 4.10 rear gear swap. I figure after a tune, an intake, and a nearly wide-open exhaust that it's time to REALLY wake this cat up.

My question comes here though:

If I purchase a new 4.10 high-performance ring gear and pinion set from FPRR (from an online vendor, like say blueovalindustries on eBay), will this box include everything that is needed for a shop to do the swap? If not what else will I need to procure to make this modification complete?

Also, I was fairly certain that it was controlled by the ECU in this car, hence the differences in tunes, but a few older gear heads have been telling me otherwise so I wanna ask for safety's sake: will I need to get a speedo gear with these 4.10s or is the speedometer adjustment handled in, for example, my Lidio 4.10 tune?

Many thanks.

[SC Cheesehead]

You'll need new seals as well, they're not included with the gears. Also suggest you consider a diff. girdle to go with the gear install.

No speedo gear, controlled electronically by the tune.

[fastblackmerc]

Besides the gears you'll need the pinion bearing, carrier bearings, crush collar, gasket, RTV silicone, Locktite, pinion seal, fluid, friction modifier (if you don't use synthetic fluid). You might also need axle bearing and seals. As cheese said it's a good time to install an axle girdle.

[Pat]

All of the above.
I believe Ford sells a differential ring and pinion installation kit.

If you have a lot of miles 50K or better it may be wise to replace the traction-loc clutches in the differential while the unit is apart. doesn't cost much and saves another tear down later. Use the SVT or heavy duty clutch rebuild kit. Should be able to get it from your local ford dealer.

Please get a shop that does this thing regularly and has a good reputation.

Regards,

[Vortech347]

Unless you're 600+ HP with slicks, a girdle wont' do anything but drain your wallet.

[ctrlraven]

I bought my gears from BlueOval and the rest of the stuff from Summit.

Ring & Pinion Install Kit
http://store.summitracing.com/partdetail.asp?autofilter=1&part=FMS-M-4210-A&N=700+4294925134+400070+115&autoview=sku

Axle Bearings
http://store.summitracing.com/partdetail.asp?autofilter=1&part=FMS-M-1225-B&N=700+4294925134+400070+115&autoview=sku

Differential Rebuild Kit (Cobra clutch pak)
http://store.summitracing.com/partdetail.asp?autofilter=1&part=FMS-M-4700-C&N=700+4294925134+400070+115&autoview=sku

[RF Overlord]

what else will I need to procure to make this modification complete?All you need besides the gears is FRPP installation kit M-4210-C. It includes everything fastblackmerc listed (except the fluid): pinion and carrier shims, crush sleeve, pinion seal, pinion nut, ring gear bolts, cover gasket, pinion gear and carrier bearings, axle shaft bearings and axle shaft seals.

[rayjay]

Thanks for the info. I'll be doing this soon also. I had the axle seals replaced last year. Will they need to be done again?

[MrBluGruv]

Once again, you gentlement prove to be an invaluable learning asset for one who is still picking things up on the move (me :D).

To clarify, if I understood this correctly, I wouldn't NEED the clutch rebuild kit, but it would be a prudent purchase regardless? I already have a shop planned if he'll take the job, there are a few mechanics that are handy around Fords and the shop is a bit of a local institution for this small town.

[RoyLPita]

You can get by with just the gears, the pinion seal, 3 bottles of 75-140 synthetic with 1 bottle of friction modifier. The rear cover is sealed with RTV. The carrier shims, bolts, bearings, and pinion nut can and are reused. The crush collar comes with the ring and pinion along with the pinion shims.

[rayjay]

Once again, you gentlement prove to be an invaluable learning asset for one who is still picking things up on the move (me :D).

To clarify, if I understood this correctly, I wouldn't NEED the clutch rebuild kit, but it would be a prudent purchase regardless? I already have a shop planned if he'll take the job, there are a few mechanics that are handy around Fords and the shop is a bit of a local institution for this small town.

Yes. I have 63.5K on my DTR. I don't do a lot of burn outs or racing, but I don't want to have to reopen the rear end a year from now. You will also be standing on it more with the 4.10s. So it makes sense to start out with new clutches as opposed to the old ones.

[UncleLar]

I may end up making out on going to 4.10's.I have the extended warranty and my posi ain't posi anymore so I talked to my service writer and he said he would have no problem with putting the 4.10's and the girdle in while they're repairing it.
What parts will I need that they won't replace under warranty?

[rayjay]

Thanks for the all the info. Parts are ordered! Install is middle of next month. :D

[W4LTD]

Unless you're 600+ HP with slicks, a girdle wont' do anything but drain your wallet.

Exactly what I was told by my local Pro shop...just a waste of money for an N/A vehicle.

[Stranger in the Black Sedan]

Assuming you can reuse carrier shims is not a good idea. Sometimes you may end up being okay but when I installed my gears the pinion depth and carrier shims both changed using ford gears

[fastblackmerc]

NO shims were swapped during my 4:10 install.... what was there before the swap was there after the swap. 40+k trouble free miles.

[rayjay]

My install went perfectly. No noises what so ever from the rear end. Really wakes up the car. Very happy with this mod, like driving a new car. :D