Can you install a 2 speed transfer case in to a vehicle with a single speed?

[Brad Sponsel]

The modules are the same when both have Magna transfer cases. It does appear that programming would be the difference. Notice that Charles used the TCCM from a donor vehicle, probably the same PN# but obviously different programming and likely not VIN dependent.

Thanks for the reply! I'm going to try to keep the existing TCCM and will report back if it works or not.

 

[Tozan]

Thanks for the reply! I'm going to try to keep the existing TCCM and will report back if it works or not.

The reason I replaced mine is because the guy I got the information from told me too... Plus the salvage yard I got the parts from pulled it from the same unit so it wasn't a big deal for me... I would be interested in knowing how it works for you..

 

[Brad Sponsel]

The reason I replaced mine is because the guy I got the information from told me too... Plus the salvage yard I got the parts from pulled it from the same unit so it wasn't a big deal for me... I would be interested in knowing how it works for you..

I had a shop install the Transfer case and the shift motor. they had a lot of problems. First: when they first got it all put together they TC was stuck in neutral! They tried the old shift motor and it still was stuck in neutral. They checked the wiring and downloaded new software (twice because it didn't work the 1st time??) for the TC motor and they said that fixed it (but I kind of wonder if that was really what was wrong and it was really a matter of not being wires not seated in properly.)
I picked up the truck today and when I got home I tried Auto, 4HI, and when I switched to 4LO I got a "service four wheel drive" notification. So now I don't know what the hells going on!

 

[Brad Sponsel]

[QUOTE="Brad Sponsel, post: 1418305,
I'm really beginning to think that the TCCM replacement is necessary!

 

[Tozan]

[QUOTE="Brad Sponsel, post: 1418305,
I'm really beginning to think that the TCCM replacement is necessary!

Maybe, I installed the shift motor, TCCM and transfer from the same vehicle. Everything worked perfectly for me. Of course I also installed the new dash switch too.

If it is telling you to "service 4 wheel drive" my guess is, it is not be shifting correctly, a bad connection, the TCCM or a shift motor. If you are near Reno we could swap parts and narrow it down...

You probably know this but, I will say it just in case..

When shifting the transfer from High to Lo or Lo to High or Neutral to High. The transmission should be in N and it should be moving at less than 3 mph or stopped. (Transfer in N you can shift right into High 2 or 4 high)

When I do my shifts most of the time I just stop, put transmission in N then shift transfer and wait a few seconds. When light stops blinking I shift the transmission into drive and go on..

Shifting from 2-High > Auto > 4-High > 2High can be done on the fly at any speed with the transmission in gear.

 

[swathdiver]

I had a shop install the Transfer case and the shift motor. they had a lot of problems. First: when they first got it all put together they TC was stuck in neutral! They tried the old shift motor and it still was stuck in neutral. They checked the wiring and downloaded new software (twice because it didn't work the 1st time??) for the TC motor and they said that fixed it (but I kind of wonder if that was really what was wrong and it was really a matter of not being wires not seated in properly.)
I picked up the truck today and when I got home I tried Auto, 4HI, and when I switched to 4LO I got a "service four wheel drive" notification. So now I don't know what the hells going on!

Got to know the codes so you're not guessing.

 

[Brad Sponsel]

Maybe, I installed the shift motor, TCCM and transfer from the same vehicle. Everything worked perfectly for me. Of course I also installed the new dash switch too.

If it is telling you to "service 4 wheel drive" my guess is, it is not be shifting correctly, a bad connection, the TCCM or a shift motor. If you are near Reno we could swap parts and narrow it down...

You probably know this but, I will say it just in case..

When shifting the transfer from High to Lo or Lo to High or Neutral to High. The transmission should be in N and it should be moving at less than 3 mph or stopped. (Transfer in N you can shift right into High 2 or 4 high)

When I do my shifts most of the time I just stop, put transmission in N then shift transfer and wait a few seconds. When light stops blinking I shift the transmission into drive and go on..

Shifting from 2-High > Auto > 4-High > 2High can be done on the fly at any speed with the transmission in gear.

Tozan, I do appreciate all the help. I'm going to try to find the TCCM out of a same year tahoe that has the 4wd low.
I did put the vehicle in neutral to switch to and off of 4 low, doesn't work.
Thanks again for all of your help!!

 

[Brad Sponsel]

Got to know the codes so you're not guessing.

For my code reader to read the codes I have to switch the key to the "start" position but the vehicle is not supposed to be running.. as soon as I turn the vehicle off the error codes disappear. Only when the vehicle is running do the error codes show up. I use a Diablo Intune.

 

[Brad Sponsel]

GOOD NEWS! I finally got the 4LO working! you DO need to replace the TCCM. The TCCM is flashed with the 4LO option. I ordered the TCCM from Advanced auto (it was indicated that it was flashed for the NQH (MP3024) Transfer Case, just install it and follow the included "relearn" instructions.
To sum it up, you'll need the following to swap out to the 2 speed:
1) 2 speed transfer case
2) Transfer case motor
3) TCCM (Transfer Case Control module) that has the 4LO flashed on it.

When I was trying to find the TCCM at Advance Auto, they only had the one option, which was for NQH.. could not find any TCCM for the NPO option.
(please keep in mind, this is for the 2007-2014.. you'll need to know your RPO codes if you have a different year)

Thanks again for everybody's help!!! you guys are great!

 

[swathdiver]

GOOD NEWS! I finally got the 4LO working! you DO need to replace the TCCM. The TCCM is flashed with the 4LO option. I ordered the TCCM from Advanced auto (it was indicated that it was flashed for the NQH (MP3024) Transfer Case, just install it and follow the included "relearn" instructions.
To sum it up, you'll need the following to swap out to the 2 speed:
1) 2 speed transfer case
2) Transfer case motor
3) TCCM (Transfer Case Control module) that has the 4LO flashed on it.

When I was trying to find the TCCM at Advance Auto, they only had the one option, which was for NQH.. could not find any TCCM for the NPO option.
(please keep in mind, this is for the 2007-2014.. you'll need to know your RPO codes if you have a different year)

Thanks again for everybody's help!!! you guys are great!

NP0 is the MP3010, single speed TC. This was introduced in 2010. 2007-2008 got the NVG246 (NP8) and the 2009s got the MP3023 (NQH). Curiously, there are two TCs for RPO NQH, the other is the MP3024 used in the 3/4-Ton trucks from 2008-2013. Function is the same, just a stronger unit which later rebuild kits for the 3023 include many parts from it standard now.