Just curious if anyone here has ever actually worn out a differential or transfer case. I would never do it, but it almost seems like a differential or transfer case will outlast the rest of a vehicle even if you never bother to change the fluid. Just seems like engine oil and trans fluid are far more important maintenance items.
Differentials and transfer cases
- Thread starter CheezWhiz
- Start date
Being a professional youtube trained mechanic, i have not personally seen one. South Main Auto, Rainman Rays, and Wrenching with Kenny on youtube have showcased several. All seemed to be due to lack of maintenance.
Only a few were notable like the first gen Nissan Titan with a faulty breather, even then haven't seen a video on a busted one.
Only a few were notable like the first gen Nissan Titan with a faulty breather, even then haven't seen a video on a busted one.
The posi unit in my old 68 Vette was pretty blown. The car may have been drag raced before I got it because it had a real Mickey Mouse cam in it. My brother set up an Auburn 3:36 ratio set. The carrier was cracked when we took it apart.
yeah i have blown a few diffs but those were not lubrication-related failures 
4WD
$50 site donor 2024
Yes - 2002 Dodge 1500 - changed at Shell Rapid Lube @ 30k
Started to hear it at 62k - opened up and oil dumped fast - still smelled like gear oil … Looked like WD40 …
Ring, pinion, spiders, pins - 100% of parts = worn …
Bought a used rear end and filled with Bob’s brand …
Started to hear it at 62k - opened up and oil dumped fast - still smelled like gear oil … Looked like WD40 …
Ring, pinion, spiders, pins - 100% of parts = worn …
Bought a used rear end and filled with Bob’s brand …
It depends on how long you keep the vehicle. doing an early oil change to get out most of the wear particles greatly increases the life of the component.
Are we talking wearing out the ring and pinion or a bearing that sends metal fragments through the whole unit causing its demise?
Plenty of 1500 series GM trucks and suvs outlived their 10 bolt differentials. Same can be said for Ford Explorers with the 8.8 independent rear suspension setup.
Plenty of 1500 series GM trucks and suvs outlived their 10 bolt differentials. Same can be said for Ford Explorers with the 8.8 independent rear suspension setup.
i've just never seen it ... not saying it doesn't happen ...
For rear ends it's quite often pinion bearings if there is a failure. My neighbor has a TJ he purchased new, now at 200k.
He said the pinion bearings first went around 100k and I just did them again for him at 200k. Bone stock, not lifted, not wheeled, OEM alloys and tiny rubber and automatic trans. But D35s are marginal on their best day....
Transfer cases fail largely on design flaws. BW1356 and many GM New Processes have trouble locating the oil pump long term. Both failures are incredibly similar although they were used in Ford and GM (in GM they call it pump rub)
Others like early NP241D's (Dodge) used a single row input bearing that eventually spits rollers into the planetary. Later years were revised with a double row bearing to better handle the load.
There were also examples with roller bearings with a plastic cage (NP246) and snap rings of questionable design (NP231 and 241). The aftermarket addresses pretty much all of this.
The thing is it's a fine line between "worn out" and failed after some use due to poor design. The line between the two isn't clear -- I mean arguably the entire D35 is just one big engineering flaw.....or not depending upon perspective
He said the pinion bearings first went around 100k and I just did them again for him at 200k. Bone stock, not lifted, not wheeled, OEM alloys and tiny rubber and automatic trans. But D35s are marginal on their best day....
Transfer cases fail largely on design flaws. BW1356 and many GM New Processes have trouble locating the oil pump long term. Both failures are incredibly similar although they were used in Ford and GM (in GM they call it pump rub)
Others like early NP241D's (Dodge) used a single row input bearing that eventually spits rollers into the planetary. Later years were revised with a double row bearing to better handle the load.
There were also examples with roller bearings with a plastic cage (NP246) and snap rings of questionable design (NP231 and 241). The aftermarket addresses pretty much all of this.
The thing is it's a fine line between "worn out" and failed after some use due to poor design. The line between the two isn't clear -- I mean arguably the entire D35 is just one big engineering flaw.....or not depending upon perspective
ford’s PTU has entered the chat
It's a matter of statistics. Gears and bearing will last a very, very long time if the operating conditions are as-assumed by the manufacturer, meaning absolutely perfect. With an ideal oil film mechanical parts can last nearly forever. But if you compromise those conditions in any way you will get a shorter life. But more importantly, along with that shorter life you will also get a lower confidence level (or higher variation) that it can be reached. That is the reason why things seem to randomly "break" and that lack of understanding is why forums such as this evolve.
You know how much load those diff gears have! It's crazy how people cheap out and skip the diff fluid change that will prob run them less than $50.
2016 BMW 528i xdrive. Replaced rear diff due to failure at 157k miles.
1st svc was with BG fluid at dealer-100k miles.
I thought tire noise at 80k to 90k but may have likely been the rear diff.
The new (used) diff was silent.
1st svc was with BG fluid at dealer-100k miles.
I thought tire noise at 80k to 90k but may have likely been the rear diff.
The new (used) diff was silent.
I have 240,000 miles on my diff and transfer case of my 2008 3/4 ton Chevy Suburban. I change the diff every 5 years ( about 50,000 miles) and the transfer case fluid every two years. Both have magnets and I find a significant amount on them that I clean off. If I didn’t clean them I would think filings could come loose from the magnet and damage the equipment. I’m not interested in finding out.
Speaking of transfer cases, I came across this one. I was actually surprised how light it was. Any experts out there who can identify it?
Looking at the code sticker, the transfer case looks GM.
A friend was having transfer case issues on an almost new (at the time) '91 Syclone; I don't recall what the problems were; ignorant repair techs and incorrect lube use is my guess. There's rumblings that it may be for sale. Paylod of 500lbs; totally impractical but loads of throttle fun.
A friend was having transfer case issues on an almost new (at the time) '91 Syclone; I don't recall what the problems were; ignorant repair techs and incorrect lube use is my guess. There's rumblings that it may be for sale. Paylod of 500lbs; totally impractical but loads of throttle fun.