99 Tahoe T-case

[CrewCab59]

Can anybody tell me what t-case was in a 99 chevy Tahoe 4x4 old body style 88-99? It has push buttons on the dash ,I found so many different anwsers.

Thanks
CrewCab59

[bggrnchvy]

Do the buttons say 2hi, 4hi and 4lo or do they say 2hi, 4hi, 4lo and auto?

The 2hi, 4hi, 4lo case is an NP243.

The 2hi, 4hi, 4lo and auto case is an auto-trac NP246.

[CrewCab59]

Originally Posted by bggrnchvy

Do the buttons say 2hi, 4hi and 4lo or do they say 2hi, 4hi, 4lo and auto?

The 2hi, 4hi, 4lo case is an NP243.

The 2hi, 4hi, 4lo and auto case is an auto-trac NP246.

I will have to go back and look at the buttons again,it has a auto trans 4l60E?

Which t case is better or are the same,I was told that if you have a auto trac you can't lift them without changing the t-case?Does that sound right?

CrewCab59

[bggrnchvy]

Your going to need a CV shaft for the front driveshaft if you have the 246 and want to lift it as the front shaft spins all the time. I really don't like the clutch packs and the required autotrac fluid for the 246, not to mention the front slip yoke.

You DO NOT have to switch cases if you want to lift, unless you got to a solid front axle without CAD.

[CrewCab59]

Originally Posted by bggrnchvy

Your going to need a CV shaft for the front driveshaft if you have the 246 and want to lift it as the front shaft spins all the time. I really don't like the clutch packs and the required autotrac fluid for the 246, not to mention the front slip yoke.

You DO NOT have to switch cases if you want to lift, unless you got to a solid front axle without CAD.

Well I was going to a soild axle swap, HP 60 and a Cummins at the same time,So the t-case has to be removed then?
Is it because the shaft turns all the time or what? so I just need to get a older t-case from what year of truck,burb,tahoe .

This is going to be my wifes DD .

Thanks
CrewCab59

[CrewCab59]

I went back and took a look at the buttons 2Hi with auto,4HI ,4low.
So I have to swap out the Case ,now what year of t-case to get and still use the push buttons ? What year used the 243 ?96-97

Thanks for the help

[bggrnchvy]

My 97 had the 243, I believe it was an option in 96-99 but Im not sure.

Yes its because the front shaft turns all the time and without a CAD front axle the extra rotating mass will burn up the front clutch that allows the auto function on the 246 to operate.