Front Differential

[Rickb1b]

Why do I read about guys rebuilding the rear differential but not the front. Is there something harder or more complicated about the front.

 

[Broncobowsher]

Little more work using shims instead of adjuster screws. You have to work on the axle and can't just take the center section out and work on it. There are seals that are installed from inside the housing.

So I would say it is a bit more work. The tear down and prep is more. Pulling the rear axle is quick and easy. The fronts are more involved just to get the shafts out. Steering is typically in the way.

No single job is worse, but there are more of them.

 

[bronconut73]

9" is fun to rebuild.

A Dana axle is a completely different kettle of fish.

Even a Ford 8.8 is easier.

Bowsher actually thinks a lot of this stuff is easy....lol...

 

[Broncobowsher]

If you break it down to each step, none are that bad. There are just a lot more of them. Some are different.

 

[DJs74]

Yep, what they said. I just finished a ring and pinion change in the Dana 44. I started off with the plan to do the work with it still in the Bronco but quickly realized the extra 30 minutes to remove springs, tie rod, track bar and radius arms was definitely worth it versus doing all that crap on my back... plus I have arthritis in both knees and my back so up and down repeatedly is no fun.
The hardest part with mine was getting the carrier out, after that things went smooth. I purposely did the Dana first to get it out of the way.


DJs74

 

[SteveL]

Much easier if you have a case spreader and good bearing puller. Also set up bearings because you have to take em on and off a few times to get shims right. You can grind out your old carrier bearings to make a set. Also if your swapping gears you need a different carrier at 393 but it's been a while. Can't remember if it's 393 and or 393 and down where it's different. Stock is a 3 series for 350s.

 

[Skiddy]

Yep, what they said. I just finished a ring and pinion change in the Dana 44. I started off with the plan to do the work with it still in the Bronco but quickly realized the extra 30 minutes to remove springs, tie rod, track bar and radius arms was definitely worth it versus doing all that crap on my back... plus I have arthritis in both knees and my back so up and down repeatedly is no fun.
The hardest part with mine was getting the carrier out, after that things went smooth. I purposely did the Dana first to get it out of the way.


DJs74

LOL I almost removed mine a couple weeks ago when I did the locker. my carrier was a pain to get out too a couple of times

 

[DJs74]

LOL I almost removed mine a couple weeks ago when I did the locker. my carrier was a pain to get out too a couple of times

I was actually able to get the carrier out with the Dana 44 while it was still in the Bronco. My first approach was the traditional prying but the floor and the oil pan said no. So I thought for a little bit and come up with the idea to use a turnbuckle and a chain... wrapped the chain around the carrier body, hooked the turnbuckle to chain and on other end to a hole in the frame up by the steering box, caps on loosely so the carrier didn't come at me like a cannon ball. Started cranking and nothing, gave it a couple more and still nothing - by this time the chain was more than tight so I gave one of the ring bolts a gentle tap with the sledge to introduce a little shock and it popped right out.
I knew the carrier would require a lot of install / uninstall until I got the shims right so I decided to pull the whole thing out.
I was going to purchase the carrier setup bearings until the guy at Randy's told me the price so I ordered 2 extra new ones and machined them so they slid on by hand. $15 + some labor beats the hell out of $90


DJs74

 

[bronconut73]

I got my set up bearings from Rosser(?) Jeep.
$40 bucks.

 

[Timmy390]

I did my D44. Jut takes more time to get it setup right. Big thing is the pinion depth is set with sims under the pinion bearing race. So to change depth you have to remove the race and add or subtract shims then drive the race back in.

I had mine in and out 20 plus times before getting it right. Just takes time. I borrowed a set of setup bearings.

Here's a great read and Tech article. It's for a dana 60 but the 44 is the same
http://www.pirate4x4.com/articles/tech/billavista/Gear_Setup

Tim

 

[Skiddy]

I was actually able to get the carrier out with the Dana 44 while it was still in the Bronco. My first approach was the traditional prying but the floor and the oil pan said no. So I thought for a little bit and come up with the idea to use a turnbuckle and a chain... wrapped the chain around the carrier body, hooked the turnbuckle to chain and on other end to a hole in the frame up by the steering box, caps on loosely so the carrier didn't come at me like a cannon ball. Started cranking and nothing, gave it a couple more and still nothing - by this time the chain was more than tight so I gave one of the ring bolts a gentle tap with the sledge to introduce a little shock and it popped right out.
I knew the carrier would require a lot of install / uninstall until I got the shims right so I decided to pull the whole thing out.
I was going to purchase the carrier setup bearings until the guy at Randy's told me the price so I ordered 2 extra new ones and machined them so they slid on by hand. $15 + some labor beats the hell out of $90


DJs74

I did the same thing with the bearings, can't believe they want so much. brother has a set that he made as well, I just wanted my own as I hate borrowing stuff. good idea on the removal, I just pried mine out. I think if I could make a small enough bar with a curve/hook or something would work. pretty sure the easy why is remove the pinion%)

 

[DirtDonk]

One other reason for possibly fewer jobs being done on the front than the rear is that, if you're not changing the gear ratios, the fronts are hardly ever used in most Broncos and therefore don't need any work done to them.
Yes, the seals do wear out, but almost more from age than from use. The more they're used, the less they fail it seems.

I bet most Broncos have maybe 500 miles on the front gears, vs 100k miles on the rear.
And nowadays, after the rebuilds, I bet most EB's will have zero miles on the front for every 20k miles driven. If they get driven much.

Now, if you specifically meant rebuilding the diffs themselves vs having a shop do it, then none of that applies. But if you just meant rebuilding at all, vs not rebuilding, then it's mostly not needed in the front.

Many rebuilds (maybe even most?) start due to a gear change anyway most likely. So in those cases, both have to be done almost every time.

Paul

 

[DJs74]

Much easier if you have a case spreader and good bearing puller. Also set up bearings because you have to take em on and off a few times to get shims right. You can grind out your old carrier bearings to make a set. Also if your swapping gears you need a different carrier at 393 but it's been a while. Can't remember if it's 393 and or 393 and down where it's different. Stock is a 3 series for 350s.

Good memory, I printed this information when I started my R&P change

For the D44:
*3.73 and down (thick ring gear) for carriers with hub to deck height of 2.090"

*3.92 and up (thinner ring gear) for carriers with hub to deck height of 2.410"

Some aftermarket gear manufacturers offer a "thick" ring gear in the lower ratio sets (ie. 4.56, 4.88, etc. ) to fit the 3.73 and down carriers

For the 9":
No breaks / all the same


DJs74

 

[okie4570]

Putting the bronco up on a lift for this job takes about 90% of the work out of it. It's one of those jobs you tip toe into the first time, then jump right in after that.

 

[OX1]

Putting the bronco up on a lift for this job takes about 90% of the work out of it. It's one of those jobs you tip toe into the first time, then jump right in after that.

Not kidding. I have HD ratchet straps from the rear arms to the front axle, so the radius arm don't "ski" down the front arm lift points. %)

 

[Nothing Special]

One other reason for possibly fewer jobs being done on the front than the rear is that, if you're not changing the gear ratios, the fronts are hardly ever used in most Broncos and therefore don't need any work done to them....

I think another reason is that for mild to moderate off-roading a rear locker will give you all you need, so there's no need to go to the expense of changing 2 diffs (assuming you are sticking with the original gear ratio). I know that was my rationale for both my old CJ5 (4.27 gears stock) and my Bronco (4.10s). I didn't see the need to regear with 33" tires for moderate off-roading, so I started with just a locker in the rear, figuring I'd add a locker in fronr when it seemed necessary. It hasn't yet for the driving I do so I haven't needed to touch a front diff.

 

[OX1]

For the common everyday diffs we encounter with most old fords.
Dana's are the hardest, while the ford 9" is the easiest.

The only thing "easier" on dana's is no crush sleeve, but
I always ditch the crush sleeve on all my 8.8/9" setups
in favor of a solid setup...........

 

[Brent13]

I am days away from beginning my Dana 44 gear swap. I have all my parts, just need to dive into it. I did the rear 9" a couple months ago, my first ever R&P swap, plus added a Yukon Grizzly. You all say it is easy, and I guess I would kind of agree, after what I learned. The 9" is still a pile of work, took me forever! The Dana 44 has me nervous, sounds plenty difficult. I like the idea of getting the axle up on the bench. My plan is to powder coat the front axle to match the rear, so hopefully I stick with that plan. The 9" center section being on the bench, that made it much easier. Not breaking your back and knees, light is good, etc., everything is right in front of you..... I have 4.27's going in the front with a Power Lock. I had no choice but to buy a new carrier, 4.27's are not available in thick gears.

Brent

 

[DirtDonk]

I'd say with your recent experience you could probably do it Brent. At least from the "I know I have to be precise with all of this setup stuff" aspect.
I think the main "difficulty" thing with a Dana is the more steps, more repetitions and then doing it again!
You have basically the same concept of gear pattern, it's just getting a bunch of shims just right instead of at least one step being done with adjuster rings like the 9" allows, makes it take longer.
So it might not actually be harder. Just longer...

Then again, sometimes you just get lucky and nail the sucker on the first or second pass!

Good luck.

Paul

 

[DJs74]

I am days away from beginning my Dana 44 gear swap. I have all my parts, just need to dive into it. I did the rear 9" a couple months ago, my first ever R&P swap, plus added a Yukon Grizzly. You all say it is easy, and I guess I would kind of agree, after what I learned. The 9" is still a pile of work, took me forever! The Dana 44 has me nervous, sounds plenty difficult. I like the idea of getting the axle up on the bench. My plan is to powder coat the front axle to match the rear, so hopefully I stick with that plan. The 9" center section being on the bench, that made it much easier. Not breaking your back and knees, light is good, etc., everything is right in front of you..... I have 4.27's going in the front with a Power Lock. I had no choice but to buy a new carrier, 4.27's are not available in thick gears.

Brent

I disassembled mine very carefully and measured everything on the known good setup so I at least had a reference of relationships and function with the gears I changed to. I even measured the pinion depth and pinion preload on the one I replaced to get the experience.
As for the carrier bearings, I took the old ones off very carefully and counted/ measured each shim and thickness, wrote the numbers down and kept the left and right separated with zip ties... again, so I had a benchmark to go by from the guy before me who was probably way better a this than I am - so basically I was checking his work and trying to duplicate the end result backlash and pattern on my work.
I have to say I was pretty happy with my results. My pattern matched the previous installers as well as the factory pattern already on my gear set. The only thing I got off a little on was the backlash... with the setup bearings, I was at 0.008" and then I pressed on the new bearings, I ended up at 0.005" but I let it go because mine is a racer and I only make 300 foot passes at a time so I don't drive it long periods of time and generate a lot of heat.

I was a little nervous too because it was new to me but we got acquainted quickly and it wasn't as bad as I thought it was going to be.


DJs74