Diff and x-fer case service interval

[redhat]

Trying to get a reasonable handle on my service intervals for a vehicle such as my Suburban.

We bought it used with 203k in January of 2021 and it has been in service a little over 2 years now. At that time, I changed all fluids.

I am coming up on having 20k on the front differential fluid, transfer case and transmission. I have a drain on the trans. pan and 20k on tranny fluid is good to me.

More so questioning the diffs and the transfer case. Maybe 30, 40, 50k?

Thoughts?

 

[userfriendly]

100,000 kms or 62,000 miles, which ever comes first.

 

[D60]

Front diff? Honestly I'd say every 100k amuhreecan miles even though some BITOGers just had a mini stroke reading that.

T-case....WHICH ONE? What year Burb is this?

 

[redhat]

Front diff? Honestly I'd say every 100k amuhreecan miles even though some BITOGers just had a mini stroke reading that.

T-case....WHICH ONE? What year Burb is this?

2005 Suburban NP 246 takes AutoTrak II.

 

[andreigbs]

I've done 60Kish-mile interval on the driveline fluids in the MB in my sig and it's happily trucking along still.

I think more often than that and you're likely wasting good fluid.

Although some cars, like VWs with the DSG transmission, require a fluid change every 40K.

 

[D60]

2005 Suburban NP 246 takes AutoTrak II.

Then I'd do 50k amuhreecan miles. If you never use the stupid Auto position you could likely go longer. In Auto it slips the clutches just like an automatic trans and you wind up with friction material in the fluid.

Also if you care Valvoline makes a t-case fluid which should meet Autocrap II standards and NAPA appears to have it on monthly special ATM with a very competitive price of $8 per amuhreecan quart:

https://www.napaonline.com/en/p/VAL855459

 

[redhat]

I've done 60Kish-mile interval on the driveline fluids in the MB in my sig and it's happily trucking along still.

I think more often than that and you're likely wasting good fluid.

Although some cars, like VWs with the DSG transmission, require a fluid change every 40K

You said it best, wasting good fluid. I'd hate to drain it, have it look clear as day then think how I wasted it. That sounds reasonable.

 

[redhat]

Then I'd do 50k amuhreecan miles. If you never use the stupid Auto position you could likely go longer. In Auto it slips the clutches just like an automatic trans and you wind up with friction material in the fluid.

Also if you care Valvoline makes a t-case fluid which should meet Autocrap II standards and NAPA appears to have it on monthly special ATM with a very competitive price of $8 per amuhreecan quart:

https://www.napaonline.com/en/p/VAL855459

That sounds good, and I never use the Auto position, only 2wd or 4high usually. Thanks on the Valvoline recommendation, I did buy a some AutoTrak II for $10/quart when I saw rockauto had some. Good to know.

 

[D60]

That sounds good, and I never use the Auto position, only 2wd or 4high usually. Thanks on the Valvoline recommendation, I did buy a some AutoTrak II for $10/quart when I saw rockauto had some. Good to know.

At your mileage if anything I'd be worried about pump rub but there's just NO way to know without opening it up. Some seem to suffer from it and others are pristine.

 

[redhat]

At your mileage if anything I'd be worried about pump rub but there's just NO way to know without opening it up. Some seem to suffer from it and others are pristine.

Ooo forgot to mention this, when we got the Suburban around 203k, it had a newer tranny in it, but my assumption was that the shop who did the trans never filled the x-fer case. It was howling and very dry. So I put a rebuilt transfer case in it around 204-205k. The rebuilt one had a case saver put in it.

 

[The Critic]

If the auto position is avoided and the truck is not used for towing, is there even a need to replace the diff/xfer case fluids more often than the OE interval?

 

[Kira]

Is "pump rub" when the oil pump in the t-case is run dry?

What is a "case saver"?

 

[redhat]

Is "pump rub" when the oil pump in the t-case is run dry?

What is a "case saver"?

The pumps in these NP246 transfer case have a tang/clip that keeps the pump positioned one way. When that clip breaks, the pump starts to contact a part of the case. The pump is made of aluminum and the case is magnesium and the pump ends up wearing a hose in the magnesium case. A case saver is a beefed-up bracket/retainer/guard to not allow the pump to rub through the case.

 

[redhat]

If the auto position is avoided and the truck is not used for towing, is there even a need to replace the diff/xfer case fluids more often than the OE interval?

that is very possible.

 

[Passport1]

Just had the transfer case lube in my 2018 Edge changed today @36K miles. Ford says no change is necessary yada yada. These PTUs are a known failure point w/o grear oil change ~every 30-40K miles. Not worth ignoring this service.

 

[repairman54]

210k on a '99 AutoTrak case and 150k on a '11 T case with zero issues with year 'round towing duty on both. Fluid is way cheaper than the hard parts. Use the severe maintenance schedule. Front diff will stay cleaner longer than the rear.

 

[Snagglefoot]

Here is the 2005 owners manual. I’d use severe service intervals for the auto transmission which is 50,000 miles. I use 50,000 miles for my rear diff on my 2008 Burb. I’d use 50,000 miles for the transfer case and front diff as well, but since they are so easy to change you could do them more often such as every 2nd year. This works for me and I have 240,000 miles on everything - all original.

 

[nthach]

Really depends on the use case. If you’re off roading or using your 4x4 a lot, like say to make up the mountains for a ski trip/chain control then 30K unless you’re fording water or using 4x4-lo, then every 15K.

 

[GMBoy]

At your mileage if anything I'd be worried about pump rub but there's just NO way to know without opening it up. Some seem to suffer from it and others are pristine.

The pump rub eventually shows up as a hole in the case and you'll know because you will have a leak on the top right side. I had it happen on my Denali with the 149 t-case leaked but never any mechanical issues.

 

[GMBoy]

One common theme being said in this post that is wrong is basing the oil change interval of the transfer case on how much he is using 4WD. That makes no difference because the T-CASE is running the same no matter what range it's operating in. It is always transferring power.