9-inch rebuild/re-gear kits?

[Pedestrian]

Hey all,

Shooting to re-gear my 9" soon after I install my D44 this weekend to match the 4.56's. I've got a couple questions. I've never re-geared an automotive differential, but do have experience shimming and setting backlash and preload in aircraft gearboxes that are a very similar concept.

Anything big I need to look out for? Also wondering if anyone can recommend a kit for this job that will include everything I need, minus the gears i can buy separate.

Thanks!

 

[bronconut73]

Ebay will be your friend.
Many, many vendors sell gears and kits or just kits.
Master kits include bearings.

But the vendors on this page have all that stuff and they can help you identify which 9" eb axle you have making sure you get all the pieces you need.
A 9" is really easy.
Countless write-ups on line you can follow.

Lots of support.
YouTube videos too.
No axle has more support.

 

[DirtDonk]

We have kits if you decide to go that route Pedestrian. https://www.wildhorses4x4.com/category/s?keyword=master+rebuild+kit

Two things I can think of to look for are the bearing size for the carrier bearings, and possibly needing to grind some material off of the 3rd member/chunk/hogshead to clear a potentially larger diameter gear.
And yes, this grinding is apparently something they even did at the factory for some of ours with 4.11 and 4.56 gears. So not an unknown thing.

Is your 3rd member out yet? If so you can measure the side bearings to see what yours had.
I'm guessing Broncos "should" all have come with the same size consistently, but aside from changing over the years the units could have been swapped out as well.
The biggest bearings were only found on aftermarket and some of the big engine muscle cars like Boss 429's and things like that. I think.

We list them by year, but it still usually pays to verify yours.

Paul

 

[okie4570]

Wildhorses kit and Youtube makes it easy.

 

[DirtDonk]

You can also build it with a solid pinion spacer rather than the crush sleeve: https://www.wildhorses4x4.com/produ...id-Spacer-With-Shims/bronco_Rear_Differential

And better gaskets: https://www.wildhorses4x4.com/produ...rential-Cover-Gasket/bronco_Rear_Differential

I don't know how many have found the Daytona pinion supports an advantage, but you can consider that upgrade as well if you're building for max strength, or something is wrong with your existing one: https://www.wildhorses4x4.com/produ...m-Pinion-Support-Clear/earlybroncothirdmember
I've never had an issue with the stock one, but I'm not a racer either.

Paul

 

[yakelys69]

I don't remember where I got my kit from but the 1st one didn't have a good selection of Pinion Depth Shims, I ended up having to order another Pinion Depth Shim Kit I think from strange and it had what I needed.

(1) .005″ shim
(1) .006″ shim
(1) .007″ shim
(1) .008″ shim
(1) .009″ shim
(2) .010″ shims

 

[Apogee]

All of the above suggestions are good...I used Quick Peformance for my master rebuild kit, and they were very competitive on price and delivery and had good tech support. I was installing an ARB and they made a few recommendations that helped with the install, one of which was the solid bearing preload spacer which is much better than the crush sleeve IMO. I went with the Daytona pinion support because why not? Bigger pinion bearings can't be a bad thing, and the cost wasn't that significant in the grand scheme of things.

 

[ngsd]

I just got mine finished. Did the crush sleeve eliminator as well from Randys but forgot that WH has kits as well. My buddy did the work though as I am not experienced enough to trust my own work on the set up.

 

[DirtDonk]

I've managed to avoid it over the years as well. But I'm finally going to tackle one myself soon.
Figured the 9" is the way to go for a first-timer like me. I bought a fully assembled unit with Truetrac and 4.11's but I want to try some other setups and figured I really needed to figure out if I could do it or not.
After all, buying pre-built 3rd members gets expensive real quick!

Paul

 

[Pedestrian]

Thanks everyone for the replies.

There's nothing wrong with my current setup, its held up very strong and has given me nothing to complain about just need to re-gear. Called Super Duty HQ (local AZ shop) just out of curiosity and they want almost a grand to do the work. I'll figure it out lol. The application is for wheeling, so I feel my factory support will suffice as it has all these years.

Time to do some more digging! I'm starting my front end swap tomorrow, if all goes well, I'm yanking the rear third and hitting the bench...

 

[Pedestrian]

We have kits if you decide to go that route Pedestrian. https://www.wildhorses4x4.com/category/s?keyword=master+rebuild+kit

Two things I can think of to look for are the bearing size for the carrier bearings, and possibly needing to grind some material off of the 3rd member/chunk/hogshead to clear a potentially larger diameter gear.
And yes, this grinding is apparently something they even did at the factory for some of ours with 4.11 and 4.56 gears. So not an unknown thing.

Is your 3rd member out yet? If so you can measure the side bearings to see what yours had.
I'm guessing Broncos "should" all have come with the same size consistently, but aside from changing over the years the units could have been swapped out as well.
The biggest bearings were only found on aftermarket and some of the big engine muscle cars like Boss 429's and things like that. I think.

We list them by year, but it still usually pays to verify yours.

Paul

I don't, I have to my sure my front end conversion goes smoothly before I yank the rear, but I will keep this thread updated!

 

[bronco loco]

Great post Pedestrian!
I am in the process of collecting parts for my 1972 bronco 28 spline. Changing from 4:10 to 4:56. It originally came with the 4.10's and 225's tires, changed the tires to 31 BFG AT'S. I have a 98 explorer drivetrain including the 4r70w. I already have the motive gears and will be buying the install kit for it. Is there one specific for the 28 spline? thanks in advance.

 

[Timmy390]

Solid pinion spacer is the only way to go. I refuse to use crush sleeves in anything that I can use a solid in. Even on my Samurai........

My guess is you WILL have to do some grinding. I had to with my 4.11 swap.

Tim

 

[bronco loco]

Do you recall where the grinding needed to be done?

 

[Timmy390]

Do you recall where the grinding needed to be done?

Casting seam/ridge on the inside of the case where the pinion slips into....Not sure the proper name for that area. It holds the little bearing that;s pressed into the case.

I just needed to clean it up a bit

Tim

 

[bronco loco]

Thanks Tim.

 

[bronconut73]

I didn't need to grind anything with my 4.11 swap

I used a Nine Inch Nodular Strange Case with a Detroit locker and the oversized bearings if that makes a difference but no grinding for me.

 

[Timmy390]

I didn't need to grind anything with my 4.11 swap

I used a Nine Inch Nodular Strange Case with a Detroit locker and the oversized bearings if that makes a difference but no grinding for me.

Mine was a factory Ford case far as i know original to my Bronco

Tim

 

[bronconut73]

Mine was a factory Ford case far as i know original to my Bronco

Tim

Maybe the aftermarket case moves the ring gear slightly.
It was my first aftermarket case. Never broke a stock case, never even seen a broken stock case. Only reason I had one is that it was a package deal from Nine Inch Nodular on Ebay. They are nice folk that work heavily with the Nascar teams.

 

[yakelys69]

I had a stock ford 9" and had to do grinding for the ARB, ended up grinding more than I was comfortable with (over did it) so I purchased a Nine Inch Nodular Strange Case like bronconut73 and no grinding was needed on that one.