Transfer case issue

I posted in the drivetrain section, but haven’t received any advice yet, so thought maybe I posted in the wrong place...

My tcase shelled out on my 99 Tahoe. Replaced it with a reman. Everything hooked up nice, plugged in all connections, vacuum line, and checked fluid levels. I replaced the electronic gear switch on the side of the tcase as well.

I did pull the Tahoe into my garage under its own power. Transmission seemed fine and have had no issues with it.

Now that I replaced the tcase the Tahoe will not move under its own power. Does not matter what gear I put it in. When I put it back into park after switching to any other gear it makes a short grinding noise.

One other thing.... in park I can roll the Tahoe. Actually in any gear it will roll when I push it.

Any help would be appreciated as I’m about to push this thing into the river.

Thanks in advance.

Try the old gear switch?

your transfer case seems like its in neutral or you forgot to put the driveshaft back in lol. at minimum you could pull the shifter motor off and manually put it into gear

I had tried manually switching the tcase before. No luck.

I ended up taking the Tahoe to a mechanic. He pulled the case this week. I got the wrong case or at least the wrong input shaft on the tcase!

The output shaft of the transmission is a lot smaller than the tcase and is basically just free spinning inside the input shaft of the tcase! I thought it went together awfully easy!

Calling the tcase company on Monday... the case model #’s match up, so I’m guessing they made a mistake during assembly? Not sure why the same model of tcase would have 2 different input shafts?

Sounds like there was an info disconnect between your old TC and the reman info. Without knowing which brand of TC you had originally, know that there are several varieties of transfer cases with the same model number but different inputs: 27- and 32-spline versions, for example.

I'm guessing you got a transfer case made to mate up to the 4l80e transmission. The input shaft is bigger to accommodate the larger diameter of the 4l80e output shaft. Both versions of the transfer case were outfitted on many 1500 and 2500 series trucks. Its possible that the transfer case was used on other truck brands but I dont have any specific knowledge of that.

Fless you are correct. The input shaft is supposed to be 27 spline, but they sent me the 32 spline. Now I just have to figure out if I want to battle them over the cost of taking it to a mechanic. Not sure if it’s my fault or theirs that I received the wrong one, but I provided them all the information they requested. They asked for the vin# this time.

The TC is a NP246

turk said:

Fless you are correct. The input shaft is supposed to be 27 spline, but they sent me the 32 spline. Now I just have to figure out if I want to battle them over the cost of taking it to a mechanic. Not sure if it’s my fault or theirs that I received the wrong one, but I provided them all the information they requested. They asked for the vin# this time.

The TC is a NP246

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Well, you should have looked it over but you didn't know what you didn't know.

Swath exactly.

I should have checked it closer when I received it. Hopefully someone will learn from this mistake and it will show up in “googles searches”.

I had no clue there were 2 variations of the NP246, so in my haste once I saw it had the right NP246 badge on the back of the TC I just immediately installed it without thinking there was a different spline.

I remember when ordering asking the guy if he was sure if I gave them all they needed because I was nervous ordering online. He said if it had NP246 on the back it’s the right one... I think he learned from this as well.

Embarrassing to hear from the mechanic I installed the incorrect unit and even worse I’m out a few extra hundred dollars because of this mistake.

turk said:

Swath exactly.

I should have checked it closer when I received it. Hopefully someone will learn from this mistake and it will show up in “googles searches”.

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Live and learn Ray, there's a cost to learnin'! These forums are helpful and have helped me learn a ton and save a bundle; but they are not shop manuals. However, I need them both!