GEN 2 Pinion Bearing Failure - New Part From Ford

[FordTechOne]

Truck recently developed a mildly audible hum/whine from the back that was tied exactly to wheel speed, so I assumed it was a diff issue. Sure enough, service diagnosed pinion bearing failure.

What was interesting was a bird then informed me that there has been a recent uptick of Raptors coming in for this, and that Ford has recently released a new updated part (bird did not specify but it’s the bearing or a shim etc obviously) included in the repair service.

Don’t listen to service advisors, you’re better off consulting a magic 8 ball. Raptors use the same 9.75” axle as other F-150 models, so any “uptick in Raptors” specifically would be attributed to the use case, meaning lifts or fluid contamination from off road use.

Consulting the parts catalog, there is no new part number for pinion bearings, oil slinger, flange, or seal. They’ve all been the same since 2014.

Said bird also informed me that it’s their prediction that there may be a recall or TSB at minimum coming down the pipe for this.

So yeah, at any rate, if you hear said diff whine and take your truck in, make sure they know about or are ordering the updated hardware.

Recalls are for safety issues, not a bearing noise concern. If there was a widespread issue, which there is no evidence of, at best it would extended coverage. Asking about updated hardware will only cause confusion, because there are no updated parts to order.

 

[FordTechOne]

I just noticed that I have a pinion seal leak. When i changed my diff fluid i noticed some oil. I reached aster the fluid change and now see clean oil under the diff. This would just require the seal to be swapped out? If the bearing is still fine no need to change that too?

The seal can be replaced without pinion bearing disassembly or replacement.

 

[typecase]

Mileage & mods?

78K and stock from the factory with no mods.

 

[TwizzleStix]

78K and stock from the factory with no mods.

No mods!? That’s unusual, but ok. Most likely a “use case” issue as nothing else seems relevant. You live in the frozen north?

I’ve only had 1 pinion seal fail in all my range of vehicles, but I lived in South Dakota near I-90 for a short time. I had a very short, low speed drive to the on-ramp and then up to 70+mph in seriously minus deg F. The engine/trans was slightly warmed, but the rear axle is/was cold soaked to stupid cold with a 4.10 posi axle in my 1989 Ford Aerostar van. 100+k miles on it. I’m thinking the seal failed with little to no lube on the pinion, then run at relatively high speed such that the pinion speed damaged the seal. Note this was long before new super-lubes and seals.

 

[typecase]

No mods!? That’s unusual, but ok. Most likely a “use case” issue as nothing else seems relevant. You live in the frozen north?

I’ve only had 1 pinion seal fail in all my range of vehicles, but I lived in South Dakota near I-90 for a short time. I had a very short, low speed drive to the on-ramp and then up to 70+mph in seriously minus deg F. The engine/trans was slightly warmed, but the rear axle is/was cold soaked to stupid cold with a 4.10 posi axle in my 1989 Ford Aerostar van. 100+k miles on it. I’m thinking the seal failed with little to no lube on the pinion, then run at relatively high speed such that the pinion speed damaged the seal. Note this was long before new super-lubes and seals.

Yeah I live in Michigan so its winter here for what feels like 9 months.

 

[Zeusmotorworks]

Yeah I live in Michigan so its winter here for what feels like 9 months.

Try summer (100+ WITH humidity) for 9 mos... you will want your shovel back!

 

[smurfslayer]

Try summer (100+ WITH humidity) for 9 mos... you will want your shovel back!

Yeah... no. I’ll take 9 months of summer and no snow blower !
#FTS

 

[downforce137]

pinion angle does not in anyway affect the pinion bearings. there might be some increased u joint wear, and there might be some vibrations that arise from incorrectly setting up the driveshaft angle, but please do not believe adding 1 or even 2 inchs to the rear of your truck caused the pinion bearing to fail. You'd know there was an issue way before with vibrations..

i'd lay money the bearing surfaces are pitted out, from a poor casting or some oil problems. back when i was a gold certified master ASE technician for Chrysler, we were changing carrier and pinion bearings in just about every jeep grand cherokee, and when the bearings were removed, there was noticeable pitting in the races below the fluid level. i doubt this is the case here, but just saying.

 

[FordTechOne]

pinion angle does not in anyway affect the pinion bearings. there might be some increased u joint wear, and there might be some vibrations that arise from incorrectly setting up the driveshaft angle, but please do not believe adding 1 or even 2 inchs to the rear of your truck caused the pinion bearing to fail. You'd know there was an issue way before with vibrations..

That is simply not true. Increasing pinion angle results in higher radial load on the pinion bearings. A lift changes the pinion angle significantly, especially with leaf springs. That change in pinion angle will easily put the working angles way outside of specifications, resulting in wear and damage.

i'd lay money the bearing surfaces are pitted out, from a poor casting or some oil problems. back when i was a gold certified master ASE technician for Chrysler, we were changing carrier and pinion bearings in just about every jeep grand cherokee, and when the bearings were removed, there was noticeable pitting in the races below the fluid level. i doubt this is the case here, but just saying.

Spalling, which is similar to pitting, can be caused by an overloading of the pinion bearings. Which goes back to my response above. Pitting is caused by contamination, such as dirt, debris, etc.

 

[downforce137]

That is simply not true. Increasing pinion angle results in higher radial load on the pinion bearings. A lift changes the pinion angle significantly, especially with leaf springs. That change in pinion angle will easily put the working angles way outside of specifications, resulting in wear and damage.

Spalling, which is similar to pitting, can be caused by an overloading of the pinion bearings. Which goes back to my response above. Pitting is caused by contamination, such as dirt, debris, etc.

but it does not. i dont believe we are talking about 6" lift blocks with +4" springs here. the truck in question is stock even...

as long as the pinion angle and transfer case output shaft angles are relative, the driveline is happy.

otherwise there'd be hundreds of trucks with worn out pinion bearings. this is going to be a preload, or oil contamination issue.

a spalled up pinion bearing would definitely be caused in rear end setup.. very highly unlikely to be caused by pinion angle.

on my second raptor, with +3 deaver springs, 100K miles total, with towing, long highway stints, drifting, off roading and i had one pinion seal start leaking from sand getting behind that plastic shield behind the pinion yoke.