Broke Locking Diff Pin in Rear Axle

[KaiserM715]

As a side note, it is interesting that the dealer included the limited slip lubricant additive, which is not needed (to the best of my knowledge) with the elocker. It certainly won't hurt anything, though.

 

[dkfc13]

Wiz--you are good troops for helping out the OP. Just make sure he does it right. Lot of metal was getting ground up from what I could see! Bummer---one reason I don't buy used vehicles. Never know what the previous guy or gal did to the vehicle or did NOT do to the vehicle..

Wiz is getting me fixed up. Just waiting on info from the dealer(s).

---------- Post added at 09:30 AM ---------- Previous post was at 09:30 AM ----------

As a side note, it is interesting that the dealer included the limited slip lubricant additive, which is not needed (to the best of my knowledge) with the elocker. It certainly won't hurt anything, though.

Agree. No need for friction modifiers on a locker. Wiz pointed this out as well.

 

[Hockster]

Wiz is getting me fixed up. Just waiting on info from the dealer(s).

---------- Post added at 09:30 AM ---------- Previous post was at 09:30 AM ----------


Agree. No need for friction modifiers on a locker. Wiz pointed this out as well.

Good ole wiz mizzer!!!










Ok thats enough

 

[dkfc13]

Okay here is an update. But some quick background info first.

I am an application engineer for a drivetrain company who manufactures commercial truck axles however; I have previously worked for a few of the largest axle/transmission manufactures. My specialty has been off-highway vehicle applications but I have worked in light vehicle and commercial truck as well.

I sent the pictures and info over to our chief engineer of carrier design to get input on the situation. He sent me a list of questions. I have attached his questions and the answers provided by the SMT at my dealer below:


1) In what condition were the diff nest components (diff pinions and side gears)?

Upon removal of the rear cover, one of the differential pinion gears (#3) along with its thrust washer and the right side axle c clip and a pile of metal debris, were lying in the bottom of the housing.
One of the differential pinion gears shows signs of galling in its bore for the differential pinion shaft (#8)
The teeth of the differential pinion gears are chipped from contacting metal debris.
The differential side gears look almost undamaged at a quick inspection. (they are included with a replacement differential case (#9) anyway.

2) Is the pinion damage limited to the three teeth in the pictures?

Primarily yes.

3) Is the ring gear damage limited to the chips at the toe end and only adjacent to the spider pin hole in the diff case?


No, there are other damaged teeth in various areas.


4) Is there only one set screw retaining the spider pin and was there evidence of the set screw contact on the spider pin or evidence of contact with the spider pin on the inboard end of the set screw?

I am not certain what you are asking here. The differential pinion shaft lock bolt (#7) is broken into at least three pieces. The hex head and threaded portion are still in place, and do not appear to have contacted anything. The portion that is supposed to be inside the Differential pinion shaft (#8) is missing, and presumed to be part of the debris field in the bottom of the housing. The end of the Differential pinion shaft lock bolt (#7) that extends past the differential pinion shaft into the differential case is still in place.
The root cause of this failure, in my opinion, is either the differential pinion shaft lock bolt fractured, or else galling of the differential pinion gear forced the differential pinion shaft to rotate, and sheared the lock bolt.
There was no evidence of the vehicle being stuck, and since the vehicle is equipped with an electronic differential lock, it seems unlikely that the vehicle should have been in a situation where excessive speed differential was encountered.

If you have further questions, feel free to call, or stop by, and I will be happy to review things with you.

XXXXXX XXXXXXXX
Senior Master Technician


1 — Differential side gears (part of kit 4880)
2 — Differential side gear thrust washers (part of kit 4880)
3 — Differential pinion gears (part of kit 4880)
4 — Differential pinion thrust washers (part of kit 4880)
5 — Differential pinion spring (part of kit 4880)
6 4209
Differential ring gear
7 — Differential pinion shaft lock bolt (part of kit 4880)
8 4211
Differential pinion shaft
9 4204
Differential case
10 4216
Differential ring gear bolt (12 required)
11 4221
Differential bearing
12 — Cam-ring (part of kit 4880)
13 — Plunger (part of kit 4880)
14 — Coil (part of kit 4880)
15 — Coil bolt (part of kit 4880) (6 required)
16 — Stopper (part of kit 4880) (3 required

 

[dkfc13]

Sorry the diagram didn't go though on my last post. Here is the rear diff exploded view.

 

[G & P Racing]

Nice write up.

 

[dkfc13]

Okay, here is an update.

The repairs to the existing axle will be covered under warranty (I will believe it when I take delivery of the truck). This truck was sold as a "Ford Certified Used" vehicle back in 2012 so the power-train is covered for 7yrs/100K miles. That is the good news.

The bad news is that due to weather on Monday and Tues, I still dont have the truck back yet (will be 2 weeks this Sunday). I called the servicing dealer and they said they received parts yesterday but they were incorrect. I was told unfortunately they dont know why the parts that were sent were not the parts in the truck (they are trying to figure it out now). I guess the parts need to be ordered though Paco (dont know the spelling) - which is an email ordering system for SVT parts?? Anyway there is no one they can call and talk to regarding this.

So for the time being I am sitting and waiting...

 

[PropDr]

In my opinion:
Tires don't have the traction to brake anything during a slow turn with the locker engaged, it would take the wild spinning of one rear wheel and the sudden engagement of the locker.
Damage to ring and pinion look secondary.
The twisted case indicates that failure started in the spider gear assembly.
Also with that twisted case and the side loads created with debris going through the ring and pinion I would demand proof that the axle housing is not tweaked and the tubes are still in alignment.

 

[dkfc13]

Spoke with the servicing dealer today. I couldn't be more upset. They told me they dont think it is a Raptor axle in the truck.

Not sure how that can be since the Raptor axle is 7" longer than the F150 but whatever. I guess the bearings that were sent are not the ones that are in the truck. She is telling me it could be another week. They cant get Ford to call them with any answers as to why the parts that should be in that truck are not. What a disaster.

 

[Squatting Dog]

They are morons... The service guy is looked up parts for 2010-2011 Raptor. They changed the diff in 2012 that is why there are not a lot of options for regearing 2012 and up the last time I checked.. This is from Yukon gear December 9th 2013:
" At this time there is nothing available for the 2012 and newer ford rear differentials. we are in the development process and I will add you to the list for an update when I have one available."

-Greg (aka Squatting Dog)