Toasted my rear M220 axle...40s, towing, heavy foot 😋

[Dorf2point0]

Using Ford:

D60 (F250) = about 2.9QTs
D80 (F350) = about 4.2QTs

Thank you

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[flip]

since you can look it up maybe find it, whats the pinion/gear backlash on a D44 from Ford just curious has to do with shock loads.

205-02A Rear Drive Axle/Differential	2022 - 2023 Bronco​
Specifications	Procedure revision date: 05/19/2021​

Specifications


Materials

Name	Specification
Motorcraft® SAE 75W-85 Premium Synthetic Hypoid Gear Lubricant / XY-75W85-QL	WSS-M2C942-A
Motorcraft® Thread Sealant with PTFE TA-24-B	WSK-M2G350-A2
Motorcraft Electrical Grease XG-12	WSB-M1C239-A
Motorcraft® Premium Long-Life Grease XG-1-E1	ESA-M1C75-B
Motorcraft® Metal Surface Prep Wipes	ZC-31-B
Motorcraft® Threadlock and Sealer	TA-25-B

Capacities

Item	Type of Axle	Type of Drive	Liters
Material: Motorcraft® SAE 75W-85 Premium Synthetic Hypoid Gear Lubricant / XY-75W85-QL (WSS-M2C942-A)	Conventional	4WD	1.93L (4.07 pts) (Fill to the bottom of the filler hole)
ELD	4WD	1.88L (3.97 pts) (Fill to the bottom of the filler hole)

General Specifications

Item	Specification
Maximum pinion flange runout	0.127 mm (0.005 in)
Pinion bearing rotational preload	1.7 - 3.1 Nm (15 - 27 lb-in)
Ring gear backlash	0.076 - 0.15 mm (0.003-0.006 in)

Pinion Bearing Shim Adjustment Table

mm	In	mm	In
1.48	0.0583	1.24	0.0488
1.46	0.0579	1.22	0.0480
1.44	0.0567	1.20	0.0472
1.42	0.0559	1.18	0.0465
1.40	0.0551	1.16	0.0457
1.38	0.0543	1.14	0.0448
1.36	0.0535	1.12	0.0441
1.34	0.0527	1.10	0.0433
1.32	0.0520	1.08	0.0425
1.30	0.0512	1.06	0.0417
1.28	0.0504	1.04	0.0409
1.26	0.0496	1.03	0.0406

Rear Axle Backlash Shim Adjustment Table - LH (Differential Flange Bearing Shim)

mm	In	mm	In
3.423	0.1348	2.923	0.1151
3.373	0.1328	2.873	0.1131
3.323	0.1308	2.823	0.1111
3.273	0.1289	2.773	0.1091
3.223	0.1269	2.723	0.1072
3.173	0.1249	2.673	0.1052
3.123	0.1230	2.623	0.1033
3.073	0.1210	2.573	0.1013
3.023	0.1190	2.523	0.0993
2.973	0.1170	2.498	0.0983

Rear Axle Backlash Shim Adjustment Table - RH (Differential Button Bearing Shim)

mm	In	mm	In
2.62	0.1031	2.152	0.0847
2.581	0.1016	2.113	0.0832
2.542	0.1001	2.074	0.0817
2.503	0.0985	2.035	0.0801
2.464	0.0970	1.996	0.0786
2.425	0.0955	1.957	0.0770
2.386	0.0939	1.918	0.0755
2.347	0.0924	1.879	0.0740
2.308	0.0909	1.84	0.0724
2.269	0.0893	1.801	0.0709
2.230	0.0878	1.762	0.0694
2.191	0.0863	1.723	0.0678

 

[AttackGuy64]

because I like em and I drive on logging roads and skidder trails for work.

You had me at "because I like them." I feel similarly about guns.

 

[AttackGuy64]

I would love to be able to measure the actual tooth deflection to see where the point of failure is.

You sir, are a gear nerd. I mean that in the most complimentary way. Kudos to you sir!

 

[vrtical]

205-02A Rear Drive Axle/Differential	2022 - 2023 Bronco​
Specifications	​

General Specifications

Item	Specification
Maximum pinion flange runout	0.127 mm (0.005 in)
Pinion bearing rotational preload	1.7 - 3.1 Nm (15 - 27 lb-in)
Ring gear backlash	0.076 - 0.15 mm (0.003-0.006 in)

figured it be in the .08-.12 range like other Ford stuff. I would run it closer to .07 for sure specially the higher you go on the gear with smaller pinion. higher than .10 definitely adds more risk to shearing the teeth.

 

[flip]

figured it be in the .08-.12 range like other Ford stuff. I would run it closer to .07 for sure specially the higher you go on the gear with smaller pinion. higher than .10 definitely adds more risk to shearing the teeth.

My guess is a lot of the "OE" specs, especially r&Ps, are set with NVH as the primary consideration. Never hardness tested an OE gearset compared to a HD aftermarket but would assume original is made for "normal" use. Aftermarket is probably going to care less about noise and more about strength.

Regardless of brand, a good drive and coast pattern is still what you're shooting for.

 

[Mikerider]

Has anyone found a Bronco specific M220 Truss? easy enough to modify a Jeep one but would be nice to not have to change a truss and know its not going to hit anything on full bump.

 

[Dorf2point0]

Heat treat, alloy type, etc probably all feed into that as well. We've replaced gears, set perfect drive and coast patterns and the damn things make noise. Next set we put in may not pattern as well but run out perfect. Haven't had any with a catastrophic failure out of the box but I'm sure there have been. Shit, Dana just had issues with heat treat on '23 model super duty axle shafts. How in the hell, in 2023, are manufacturers having issues with things they've been doing for well over 100 years?

Something in the process “broke down”. People get distracted, bad day in the “office”, etc etc.. Ford Store still hasn’t figured out why they shipped me 1 rear cover in a big box when it was supposed to be 3 covers in the big box..

 

[flip]

Something in the process “broke down”. People get distracted, bad day in the “office”, etc etc.. Ford Store still hasn’t figured out why they shipped me 1 rear cover in a big box when it was supposed to be 3 covers in the big box..

Some of the PDC folks give absolutely no f's and are union so basically no accountability. FedEx has an equally horrible habit of destroying stuff. Not sure if you're a dealer but if not, there's a lengthy thread on the dealer message boards chronicling the destruction.

 

[87-Z28]

@flip sorry. Not trying to be an ass. Just trying to point out some factors that many folks reading this thread may miss (except probably those on this thread).

my gearhead mechanic buddy that does ring and pinion for a living, assured me this is the main issue the cast center section is NOT very stiff and flexes under load and twists also. he's seen the cases spread so far apart the housing is junk on many occasions.

I think this is the most important observation for those that don’t really understand the mechanics. The weight and leverage from larger tires can result in loads causing excessive deflections of the housing/pumpkin. This can not be fixed by strengthening, it is a stiffness issue. The D44 housing has given section properties (diameter and thickness) that dictate its flex (not related to strength). This of course also includes the pumpkin stiffness.

The only real fix for D44 housing is to add external braces to stiffen response and reduce flex. As @Snacktime pointed out. The D60 housing has increased section properties that will reduce flex.

I am curious, if someone has the info, what are diameter and wall thickness for these axle housing’s. D44 vs D60? @CarbonSteel. I would like to see how much additional stiffness the D60 provides.

 

[CarbonSteel]

I think this is the most important observation for those that don’t really understand the mechanics. The weight and leverage from larger tires can result in loads causing excessive deflections of the housing/pumpkin. This can not be fixed by strengthening, it is a stiffness issue. The D44 housing has given section properties (diameter and thickness) that dictate its flex (not related to strength). This of course also includes the pumpkin stiffness.

The only real fix for D44 housing is to add external braces to stiffen response and reduce flex. As @Snacktime pointed out. The D60 housing has increased section properties that will reduce flex.

I am curious, if someone has the info, what are diameter and wall thickness for these axle housing’s. D44 vs D60? @CarbonSteel. I would like to see how much additional stiffness the D60 provides.

The part that you posted in bold is absolutely true and is why there is a D50 under the rear of a BRaptor with 37" tires. I ran 37" tires on my Jeep Wrangler with a D44, but I added a truss, chrome moly axle shafts, a 5/16" thick with 3/8" steel flanged axle cover, AND I never put it in a situation where the tires could not rotate. Even with all of these precautions, I knew that I was past the design limits, and it was up to the skinny pedal to prevent breakage.

I will see what I can find on the axle sizes, but I can say off the cuff, the difference in the housing is pretty substantial given there is 1.55" difference in the ring gear diameter alone:

8.2" = D44/M220
9.75" = D60/Ford 9.75

In conjunction with that, consider the load carrying capacity of the D44 versus the D60; e.g. Bronco versus F150. The rear axle ring gear in a D44 Advantek (8.2") is smaller than that found in a 1980's Ford Mustang which was 8.8" and is the 8.8" is the same as the front axle of many F150 4x4 trucks.

 

[Snacktime]

I was going to say something but Spicer Dana 60 is 11/32" tubing and that is sissy shit. I will not be buying one since the tube thickness
is to close to bracket thickness.

 

[BigMeatsBronco]

I was going to say something but Spicer Dana 60 is 11/32" tubing and that is sissy shit. I will not be buying one since the tube thickness
is to close to bracket thickness.

Actually that's not entirely true most OEM Dana 60s come with a 3.25 diameter tube and it is only a quarter inch thick from the factory. The extreme Duty Spicer unit that you have pictured above has a tube diameter of 3.5", and .400 thick.... that's almost a half inch thick tubing! comparison both the camberg and spidertrax fabricated 9 in housing uses 3.5 diameter tubing with only a quarter inch wall. for racers like Healy, a 4" diameter version is available too, but still not .400 thick.

Nobody uses half inch wall thickness tubing on the Rears anywhere! The half inch thick tubes are always used on the FRONT Dana 60s mostly because they have a smaller diameter tubing.

The center section cast portion of the Dana 60 has been produced through the years in numerous castings, originally they had less webbing and the case was not as thick back in the 60s and 70s, at some point ford used a 60 that was known as the h60 or heavy 60 and that heavy duty casting became the new standard...I imagine this is similar for th d44/m220

 

[Dorf2point0]

Some of the PDC folks give absolutely no f's and are union so basically no accountability. FedEx has an equally horrible habit of destroying stuff. Not sure if you're a dealer but if not, there's a lengthy thread on the dealer message boards chronicling the destruction.

Do you have a link to the Dealer Message board?
It would be helpful.. Thanks

 

[BigMeatsBronco]

I spent several hours each evening for the last month researching every freaking axle from every side of the country and the prices and options and decided that the Spicer was by far the easiest and best fit for me and my truck. If I had unlimited time and if only a few more dollars I probably would have gone the spidertrax or camburg, but either of those axles would approach $10,000 and do not come with prefabricated pre-attached bracketry only one company offered to attach the bracketry for me. For those that are interested in a fabricated Rear axle based on the 9-inch rear end, you can have one built for around $8,000 to $10,000 that is comparable

the biggest difference is time, you could wait 6 months to get the fabricated rear completed... but then you still need to add things like wheel sensors speed sensors in the axle shafts, change your wheel ends to accept your Bronco brakes if you intend to keep the features like Trail turn assist and the electric e brake?

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