Switch Transfercase to Synthetic? Help?

Maxed Ambition said:

Hi, I pulled my transfercase to re-seal the seam, and wanted to change to synthetic, just not sure what to put back in. It's an NP1 with electronic shift, gm only recommends Manual transmision and transfercase fluid, but what do the rest of you run for synthetic? Thanks.

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You could run synthetic 5W-30 in it. A lot of guys have done that and are having quite a bit of success with it. Personally when I did my transmission I put AMSOIL Torque Drive in both.

Take care,

I did Torque Drive in mine also. Due to the pump inside of it, I am a tad skittish on the 5-30 oil switch. I will moniter the threads to see how those who have switched are doing. If turns out to be a good thing, I may consider it, but I'm gonna give it time.

i always just put ATF in them Others will overfill it with 3 quarts of 5w30 through the speed sensor hole.

I only run GM auto trak in mine because thats what my transmission shop said was the best as far as preventing wear and also what GM recommends

I ran TD in both of mine, and I have had zero issues.

Well, went to three different shops to get them to cross reference the manual transmission and tranfer case fluid to synthetic, not one could do it, or suggest which was safe to use. So, as the internals of the transfer case looked to be in fantastic condition, I put the GM manual transmission and transfer case fluid back in, till I get confirmation on the propper synthetic to use. Thanks any ways!

audioworks04 said:

I only run GM auto trak in mine because thats what my transmission shop said was the best as far as preventing wear and also what GM recommends

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I would find a new transmission shop, cause you do not have the Auto-Trac behind your Dmax/Alli. And Gm recommends Dexron III in the 02's.:drink

audioworks04 said:

I only run GM auto trak in mine because thats what my transmission shop said was the best as far as preventing wear and also what GM recommends

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GM recommends Dex III
Not necessary to run auto trac fluid and the expense that goes with it, you don't have auto trac in the truck..
I run Dex III but some friends run Mobile 1 syn and swear by it. Not sure about the 5-30

what is a NP1?????
ALL the transfer cases behind Duramax /Allisons.....are in fact 263XHD units......It hard to phuck up a transfer case by putting incorrect oil,they just like to have oil in them at all times

daddysLBZ said:

what is a NP1?????
ALL the transfer cases behind Duramax /Allisons.....are in fact 263XHD units......It hard to phuck up a transfer case by putting incorrect oil,they just like to have oil in them at all times

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Two SHD (Super Heavy Duty) transfer cases used in the 2500/3500 series
NVG 263-RPO-NP1 electronic shift transfer case used w/Allison
NVG 261-RPO-NP2 manual shift transfer case used w/ZF & Allison

Both have a capacity of 2.0 qts. Dex III

The difference between HD and SHD is: SHD uses double row input bearing, larger output shaft, larger rear seal and the case halves are machined different from HD, not interchangable with 4L80E or 4L60E LD or HD units

gotcha.......

BIOTEC said:

Two SHD (Super Heavy Duty) transfer cases used in the 2500/3500 series
NVG 263-RPO-NP1 electronic shift transfer case used w/Allison
NVG 261-RPO-NP2 manual shift transfer case used w/ZF & Allison

Both have a capacity of 2.0 qts. Dex III

The difference between HD and SHD is: SHD uses double row input bearing, larger output shaft, larger rear seal and the case halves are machined different from HD, not interchangable with 4L80E or 4L60E LD or HD units

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Thank you for this !

i run 90w in mine tired of tranny fliud leakin out the seal is that bad?:rof

WVRigRat05 said:

i run 90w in mine tired of tranny fliud leakin out the seal is that bad?:rof

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yes it is

WVRigRat05 said:

i run 90w in mine tired of tranny fliud leakin out the seal is that bad?:rof

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90 wt is too thick and lacks the viscosity index of Dex III.

Incorrect fluid, overfilling, blocked vent, steel drain plug (should be aluminum) or worn rear output bushing can cause a leak with these transfer cases. Most of the seals along with the rear output bushing can be replaced without pulling the unit.
Dex III is what is specified for the internal pump in the transfercase along with the seals and "O"rings in most of these units.

I used dexron 6 is that ok?

Yes Dexron VI is ok to run in your T-case:drink

for the hell of it and cause i like lubes i always add some lube gard as an additiveit has special goop that helps make things slippery

just put 3 quarts of 5w 30 synthetic in mine last weekend, running like a champ