Swapping rear gears

[Odmark]

Hello! The time has come to swap out my 2.73 gears for 3.50 ones.

Since ive never really done this before i was hoping someone could sort of guide me through the process step by step.

I have tried to google for a guide or something but i cant really find it.

I have removed the carrier from the car so im all set with that.

Things ive got: the 3.50 gear ofc, pinion shims, marking grease (correct word?), crush sleeve, all gaskets etc.

How do i shim the pinion correcly? How does the crush sleeve work, just tighten until it cant be tightened no more? any torque specs?

Really would appreciate the help.

 

[Bru]

Type this in your search engine;

youtube ford third member

Bru

 

[Mikes73]

I went from 2.75 to 3.50 gears and noticed a nice improvement. It isn't that hard to install gears, just take your time and triple check everything. There are some excellent videos on YouTube showing the process step by step.

 

[DK73]

Well what difference are there between 3.50 gear and 2.73? [THUMBS UP SIGN] Regards Lars

Sendt fra min E2303 med Tapatalk

 

[73MustangCoupe]

I'd suggest going with a crush sleeve eliminator kit for the pinion. Add shims to the collar, put the yoke on (without the seal to keep from damaging it until final instal) and tighten to 125 ft-lbs. Measure the preload. If the preload is to low, add another shim, and repeat. Once the preload is established, you've not the number and can remove and reinstall, as you need, without having to buy a new crush washer each time. Keep in mind, it takes a LOT of force to crush that crush washer. The crush sleeve eliminator makes things much easier.

Ron

 

[Bentworker]

One must have tool is a good dial type inch pound torque wrench. You have to use one to correctly set preload. If all you think you will work on is ford 9" axles and similar sized axles go with a 0-30 inch pound range one. If you think that you may ever work on larger axles (like the corporate 14 bolt 10.5" out of a Chevy pickup) get a 0-75 inch pound model.

Right now on eBay there is a guy selling used CDI brand 301DI 0-30 inch pound dial type torque wrenches for $75 each, and another seller with new ones for $150

If you ever want to work on something larger a snap on TE6A is nice. It is 0-75 inch pound, but is a pile of cash.

CDI also makes a 0-75 inch pound. If you want a new CDI Zoro tools carries them. Seems like the 0-75 and the 0-30 are both priced within a few dollars of $150

 

[Bentworker]

A crush sleeve elimination kit is a nice upgrade. Like what was allready said it allows you to swap yokes and pinion seals in the future with ease.

First disclaimer... I have never set up a 9". Done a Dana 44, a couple Dana 60's, and a couple corporate 14 bolts.

If you decide to go with a crush sleeve elimator you may want to check the fit of the outer pinion bearing first. When you set up pinion preload with shims you have to put it fully together and take it apart several times to get is set up right. Sometimes the press fit on the outer bearing is so tight that it is a pain to do so. A common practice on axles that use shims for preload is to turn the pinion in a lathe and remove a very small amount of material with emery cloth on the outer bearing surface so that the outer pinion bearing can be installed and removed with a lighter press fit, so that you can use a mallet. With a crush sleeve you just install it once and tighten the pinion nut in small increments until the pinion preload is correct. If you go too far you have to take it apart, pitch the crush sleeve in the trash and start over with a new crush sleeve. Whatever method you choose be sure to use a good dial type inch pound torque wrench to confirm that it takes somewhere between 13-15 inch pounds (double check my numbers) to turn the pinion.

After you get that set up then it is just a guess and check game. Install the pinion support in the third member with a stack of shims the same thickness of the ones you originally removed. Screw the carrier bearing supports in to get backlash correct .010-.016" (again check my numbers). You also want preload on the carrier bearings, so be sure to add whatever "squish" is specified in the instructions you have. You may have to tighten the spanner nuts until it is finger tight, then see how many inch pounds it takes to turn the pinion at that point, then tighten the spanner nuts an equal amount until it takes a few more inch pounds to turn the pinion (confirm this with a manual) Torque the caps and confirm backlash in at least three places on the ring gear equally spaced. Paint 4 of the ring gear teeth with yellow marking compound and check pattern. Reduce or install pinion support shims and increase or reduce backlash to move pattern. Post some pictures. Use the video below as a guide as what you need to do to adjust pattern.

Watch this video, it is the closest to what I have observed after setting up a few sets of gears.

 

[Don C]

If you like to be able to read about it and print it out:

http://diyford.com/ford-9-inch-differential-guide-third-member-assembly/#

 

[barnett468]

I would only use Italian Motive, or US Gear gears and timken bearings.

 

[Odmark]

Thank you all for the tips and help!

Question. I ordered a moroso shim kit, which said to include a crush sleeve.

Here is a picture of the kit:

Correct me if im wrong, but that looks like a crush sleeve eliminator kit right?

 

[Mikes73]

Yup, looks like a solid spacer to me. Take your time and you should have no problems with the install. One trick I use to install pinion bearings is I put the bearing in the oven at 200 degrees for a while, pull it with a glove and it slides right on. Don't go higher than 200 * or you could pull the hardness out of the bearings by over tempering. Make sure the bearing is fully seated after doing this. Good luck.

 

[Bentworker]

That looks like a crush sleeve eliminator. You can turn the pinion in a lathe with some emery cloth on the outboard bearing surface to make it a little easier to setup (since you will assemble and take it apart several times).

 

[Henry Ford]

Thank you all for the tips and help!

Question. I ordered a moroso shim kit, which said to include a crush sleeve.

Here is a picture of the kit:

Correct me if im wrong, but that looks like a crush sleeve eliminator kit right?

yes it is a crush sleeve eliminator

 

[mycoses]

purchase a DIY manual called DIFFERENTIALS, AXLES AND DRIVELINES which also comes w/ a DVD showing how to rebuild different rear gears. www.cartechbooks.com. I used it to rebuild my ford 9 in while i watched the procedure on the DVD and had no problems but did have to buy a couple of new tools...the guy who dies w/ the most tools wins.

 

[Odmark]

Hello again!

Today i started working on the rear end again.

Bearing in oven trick worked great btw!

It all worked out just fine until i was setting pinion preload.

I watched a tutorial that said to put 0.12 inches of shims in for starters, so i did that and pressed the second bearing on.

Then the tutorial said that the pinion should turn freely without any play, wich it does.

And then i read another tutorial, wich said the pinion should take about 7 ft/lbs to turn (with reused bearings), but mine turns at a lower torque than that. And it said to remove shims at this point, is this right?

 

[Bentworker]

Preload numbers are in inch pounds not foot pounds.

Less shims = more preload.

You should be aiming for whatever preload in inch pounds you find in writing.

Did you end up getting a good inch pound dial type torque wrench?

Peter

 

[LCB1]

These guys have a 4 part tutorial on replacing gears in a 9 inch

 

[Bentworker]

These guys have a 4 part tutorial on replacing gears in a 9 inch

The second video in that series shows pinion preload setup with a crush sleeve.  Shims are similar, but you must remove the yoke and drive the pinion back out of the outer bearing to swap shims.  Pretty good video (minus the advertisements and production fluff).  They use a beam type inch pound torque wrench and show sound technique on doing that.  About the only thing I do differently is I put a little RTV on the splines so no gear oil creeps out and leaks at the pinion nut.

A beam type inch pound wrench is fine, typically a dial type would be more accurate.

Nice find on the video!

 

[woodsnake]

As you already have the assembly out of the car, maybe there is a shop locally that can set it up for you? I did the ring and pinion in my 69 Cougar while I was going to tech school, but they had all the tools needed.

For the cost of all the parts involved, it may save you some money just having them done, so all you need to do is install the pumpkin again...