Transfer Case Maintenance

[JJP442]

Hello People,

I've asked this before and didn't receive a response so I'll re-word it and try again.

I have a 99 GMC Sierra ext cab Z71 4x4 with 170k. (NBS)

I picked it up over the summer and it runs awesome.

Today the east coast is getting hammered with snow.

It got me thinking about how, although the truck runs great.

I have no idea what service has been performed or what it might be due for.(save for an oil change)

Which brings me to my question.

As far as transfer case (push button 4x4)

How do you perform a fluid flush and fill?

When or how often should it be done?

What is the recommended things I will need (tools, fluid, etc) to do the job right.

Looking forward to the replies.

 

Big John NYC

[jrod332]

If you dont know how the service records or when it has been changed i would just change it. Its cheap to do it yourself and takes no time at all. Keep an eye on the color of the fluid coming out. Its usually a good indicator of the shape of your gears and if there is anything wrong. Also check for any metal fragments in the fluid or on the magnetic drain plug. As far as fluid your manual should say what is recommended or someone at a parts store can look it up. I know my transfer case in my 05 takes ATF. Not sure how many model/years take it. Synthetic is always a good idea as well. You should only need one or 2 wrenches.

 

And I must add. If you have separate drain and fill plugs ALWAYS pull the fill plug first. you dont want to drain the fluid out and realize the fill plug is seized on there.

 

Im sure others will chime in and add things.

[hockeypro1411]

Invest in one of those fluid pump deals. It'll save you a lot of time/trouble/effort.

[RyanbabZ71]

Transfer case lubricant change

 

(4WD models) (Every 60,000 miles or 48 months)

 

1. This procedure should be performed after the vehicle has been driven so the lubricant will be warm and therefore will flow out of the transfer case more easily.

 

2. Raise the vehicle and support it securely on jackstands. (I Never did this)

 

3. Remove the filler plug from the case (see illustration)

 

4. Remove the drain plug from the lower part of the case and allow the lubricant to drain completely.

 

5. After the case is completely drained, carefully clean and install the drain plug. Tighten the bolt securely.

 

6. Fill the case with the specified lubricant until it is level with the lower edge of the filler hole.

 

7. Install the filler plug and tighten it securely.

 

Drive the vehicle for a short distance and recheck the lubricant level. In some instances a small amount of additional lubricant will have to be added.

 

The T-Case takes just slightly over 2 qts of Autotrac II Fluid (Blue) for the 99-07 classics trucks

[brandon_guzzo]

Invest in one of those fluid pump deals. It'll save you a lot of time/trouble/effort.

 

 

Trust me invest in a pump... i didnt and lets just say allot of 4 letter words left my mouth so i took my suv into town and bought one then finished the job...it was allot easier with the pump..just my 2 cents

[JJP442]

Thanks for the quick responses.

I recently picked up a fluid transfer pump from Harbor Freight (a man can go broke there!)

I'm gonna go to the dealer and pick up the AutoTrakII fluid. (thankfully I got a buddy there)

Wait for the 12+inches of snow to melt and have at it.

Another question.

Would my 2001 Sierra C3 (6.0 AWD) use the same fluid and have the plugs in the same location?

If so, I might as well pick up enough fluid for 2 jobs

 

Big John NYC

[RyanbabZ71]

The AWD system is different than the autotrac system. I have no idea what it takes. Check the manual on that one

[FargoZ71]

depends if that 6.0 has a Auto 4x4 button or not.. if they do there usually Auto-trac2 fluid, if not.. theres this really nice little page in the back of a owners manual( Right side of cabin, in the lil cubby they call a glove box ) that has fluid specs and capacities for anything that requires fluids in the vehicles.

 

Ps.. wth all the snow, i'd pick up some blinker fluid with alcohol so it doesnt freeze

[JJP442]

depends if that 6.0 has a Auto 4x4 button or not.. if they do there usually Auto-trac2 fluid, if not.. theres this really nice little page in the back of a owners manual( Right side of cabin, in the lil cubby they call a glove box ) that has fluid specs and capacities for anything that requires fluids in the vehicles.

 

Ps.. wth all the snow, i'd pick up some blinker fluid with alcohol so it doesnt freeze

 

Well, if I were the original owner the truck, the owners manual would be in the glove box.

Since it's MIA I asked the question here.

I can't tell you how many vehicles I've bought that didn't have that in the glove box.

Why would anyone remove it?

As for the button.

An AWD "All Wheel Drive"means no button.

What's this blinker fluid you speak of?

 

Big John NYC

[rjirvine]

Also, don't forget to put a thin coat of permatex or similar on the lower plugs threads so it doesn't leak.

[BrockwayMT]

Remember in 99-06 NV246/261/263 you have an aluminum plug in a magnesium case. DO NOT OVERTIGHTEN!

 

You do not need smurf oil in a part time transfer case (no auto). Reg dex III is fine. Actually you can use reg dex III in the auto units but you may get some clutch shudder.

[RyanbabZ71]

Remember in 99-06 NV246/261/263 you have an aluminum plug in a magnesium case. DO NOT OVERTIGHTEN!

 

You do not need smurf oil in a part time transfer case (no auto). Reg dex III is fine. Actually you can use reg dex III in the auto units but you may get some clutch shudder.

 

 

Are you out of your mind? Reg Dex III is not fine for the 99-07 GMT-800 models

[JJP442]

 

 

 

 

Remember in 99-06 NV246/261/263 you have an aluminum plug in a magnesium case. DO NOT OVERTIGHTEN!

 

You do not need smurf oil in a part time transfer case (no auto). Reg dex III is fine. Actually you can use reg dex III in the auto units but you may get some clutch shudder.

 

 

Are you out of your mind? Reg Dex III is not fine for the 99-07 GMT-800 models

 

[BrockwayMT]

Remember in 99-06 NV246/261/263 you have an aluminum plug in a magnesium case. DO NOT OVERTIGHTEN!

 

You do not need smurf oil in a part time transfer case (no auto). Reg dex III is fine. Actually you can use reg dex III in the auto units but you may get some clutch shudder.

 

 

Are you out of your mind? Reg Dex III is not fine for the 99-07 GMT-800 models

 

 

For a NV261 or NV263 (IIRC RPO NP2 and NP1, respectively) use regular Dex III as it will be FINE. That's what they came with. For a NV246 (NP8) factory fill is Auto-trak II, which is what you need for factory performance.

 

To rephrase, if you are in a pinch, or cheap, you can put regular Dex III in a 246. The only negative effect will be some 'shudder' or 'bump' when operating in 4AUTO in certain surface conditions.