Differential Service

We have an 05 3500 chev dually bought new and now has 113K miles on the truck. I have changed the rear fluid 13 times because it was an easy job for me to do. Kinda overkilled all maintenance but the truck feels and drives like new.

chevman

valhalla360 wrote:

klutchdust wrote:

PartyOf Five wrote:
He said when the particulate matter in existing fluid will, when replaced, make the seals/ gaskets the "weakest link" & they may fail more readily. Let a sleeping dog lay.

That's a new one. I do know this. A transmission "flush" is the worst thing you can do to your transmission.
Jerry was in business over 30 years, replaced many a trans just after a flush. Want piece of mind, don't flush.....your tranny that is....

I think there is confusion with the transmission.

In a transmission, the fluid does other thing including creating specific levels of friction...and the common response is don't fix it if it's not broken.

The rear diff is a much different animal. It certainly shouldn't cause leaks.

I responded to the comment made that 'If you were to change the fluid it would make the seals the weakest link" At least that is what iIunderstand the OP to be saying.

Having spent my career wrenching on just about everything, i can say that I have not seen a seal leak in a differential after the fluid has been changed.

What I have come across is the fact that transmission flushes have a direct link to transmission failures. Drop the pan, replace the filter, clean the magnet and refill.I referenced my buddy who ran a shop for 30+ years.

What many non mechanic type folks are lead to believe is that your car/truck RV needs flushing. Flush the radiator, brake lines, transmission.

Has anyone ever had a brake failure because their brake fluid failed? I cannot find any mechanic that I know that has seen that happen. Yet go into a jiffy type place and they swear you are in danger if you do not get it done.
So, I tell my family that regular maintenance using quality products on a consistent basis is the best warranty out there.
It's interesting that a differential failed with less than 20K miles on it. That is a rare occurrence. Maybe an outside bearing but the differential, that's odd.
Safe travels folks and change your oil.

klutchdust wrote:

PartyOf Five wrote:
He said when the particulate matter in existing fluid will, when replaced, make the seals/ gaskets the "weakest link" & they may fail more readily. Let a sleeping dog lay.

That's a new one. I do know this. A transmission "flush" is the worst thing you can do to your transmission.
Jerry was in business over 30 years, replaced many a trans just after a flush. Want piece of mind, don't flush.....your tranny that is....

I think there is confusion with the transmission.

In a transmission, the fluid does other thing including creating specific levels of friction...and the common response is don't fix it if it's not broken.

The rear diff is a much different animal. It certainly shouldn't cause leaks.

Recommended differential service is between 50,000 and 60,000 miles. So it was time. They just replaced the gasket and the fluid. Because it was just service the warranty does not cover it. Didn’t hurt to ask. I still don’t have the RV though because they were not happy with the alignment so sending it back for a rear axle alignment. These look like they are relatively uncommon. But if the steering wheel is off center or there is pull one way or the other I guess it’s possible the rear axle can be adjusted. Can’t find much on it on Google. So the shop that does alignment for them can’t get to it until next week. It’s drivable they say but I didn’t want to experience a problem after all the work I’ve had done so I won’t get it until 2022!

Had a complete differential failure on my 2006 E450 at 17,200 miles. Replaced with a new differential. At 72,000 miles noticed some leakage at the differential pinion seal. Had the seal replaced and changed the fluid.

I remembered that most differentials have a vent. If it is clogged pressure can build up and blow fluid through seals while it is hot.

Seems strange to have lost fluid with no evidence.

I didn’t notice a leak. Still waiting to pick it up but the shop said it was ok and just performed regular maintenance. They did not mention a leak either just that fluid was low. I have since read that metal shavings are common and not a problem. They should have been cleaned out with the fluid change.

OP: you didn't say whether there was any signs of a leak?

Grease Monkey does a 16 point inspection and I’ve found that should include the differential but I can’t find the details on the GM inspection points. The paperwork is in the RV. I’ll have to see what it says.

Edit:
I found this online for Grease Monkey.
Its 16-point inspection consists of the following checks and maintenance procedures: wash exterior windows, vacuum interior, check/fill battery fluid, check air filter, check windshield wiper blades, check breather element and PCV valve, check/fill windshield washer fluid, check all exterior lights, check/fill transmission or trans-axle fluid, check radiator level and test coolant, check/fill power steering fluid, install new oil filter, change oil (up to 5 quarts), lubricate chassis, check/fill differential fluid, and check and set tire pressure. Grease Monkey technicians also visually inspect hoses and belts.