Transmission/ Transfer Case Help

[arrigo106]

Great forums!! I have a 93 GMC 3500HD 6.5TD. This truck from the factory was 2wd and a company converted it to 4wd. It has a dana 60 straight axle front end with the pumpkin being on the pass. side. The transmission is a 5 speed with low. I don't know which t-case i have but i do know that it is cast iron and has the emergency brake built in the back of it. My question is what would cause 5th gear to keep going out? I've had it fixed 3 times now by 2 different people in less than a year!! They both say 5th gear pack keeps moving backwards under a load which i believe becuz every time i accelorate in 5th the speedometer drops in speed until i let off and or coast. They also seem to believe that it has something to do with the t-case not being the right one for that trans (they say it's not holding the gear where it should be). Is there a fix for this? Any help is appreciated!!! Thanks, Mike

[Grumpy_old_fart]

Originally Posted by arrigo106

Great forums!! I have a 93 GMC 3500HD 6.5TD. This truck from the factory was 2wd and a company converted it to 4wd. It has a dana 60 straight axle front end with the pumpkin being on the pass. side. The transmission is a 5 speed with low. I don't know which t-case i have but i do know that it is cast iron and has the emergency brake built in the back of it. My question is what would cause 5th gear to keep going out? I've had it fixed 3 times now by 2 different people in less than a year!! They both say 5th gear pack keeps moving backwards under a load which i believe becuz every time i accelorate in 5th the speedometer drops in speed until i let off and or coast. They also seem to believe that it has something to do with the t-case not being the right one for that trans (they say it's not holding the gear where it should be). Is there a fix for this? Any help is appreciated!!! Thanks, Mike

so you have the NV4500.

not a bad trans.

need to fix the retainer nut on the output shaft by replacing it. Generally, you have to replace the gear too.

The transfer case isnt the problem.

search "NV4500 OD Gear" on Google.

[MuddyDiesel]

Originally Posted by Grumpy_old_fart

so you have the NV4500.

not a bad trans.

need to fix the retainer nut on the output shaft by replacing it. Generally, you have to replace the gear too.

The transfer case isnt the problem.

search "NV4500 OD Gear" on Google.

I thought the Dodge NV4500 only had this problem. The trans that dodge had minor differences then the GM NV4500, and one of the differences was that dodge did not have spines all the way back on the countershaft (or mainshaft) and the retaining nut on the end would loosen over time by towing alot in 5th gear.

[arrigo106]

Thanks grumpy! Found all the info i need! Heres one for u guys. I'm going to take the manual out and replace it with an auto. From the factory it would have came with a 4l80e, i'm thinking more on the lines of a turbo 400? Does anyone have any suggestions or problems i may incure?

[Grumpy_old_fart]

the th400/np205 is reasonably straightforward as a swap.

[Grumpy_old_fart]

Originally Posted by MuddyDiesel

I thought the Dodge NV4500 only had this problem. The trans that dodge had minor differences then the GM NV4500, and one of the differences was that dodge did not have spines all the way back on the countershaft (or mainshaft) and the retaining nut on the end would loosen over time by towing alot in 5th gear.

and thats what happened to his.

[arrigo106]

Grumpy, do u no what transfer case i have from what i described?

[Grumpy_old_fart]

hard to say. if its aluminum, it could be a 241c. if its cast iron, you have an Np205. the 205 is a rarity behind the NV4500. Im not even sure they came from the factory with one, but i understand its doable.

you could use the same transfer case that it has behind the manual behind a th400. the only major adjustments would be driveshafts.

you will, of course, have to have an adapter. if you have a th400 setup for np208/np241, you can use the stock 2 1/2" thick adapter and bolt your current case to the th400.

Im thinking you will have a 241c. look for a tag on the case.

[arrigo106]

It's cast iron with the emergency brake built in to the back of it. So unless i find a turbo 400 that had the 205 (assuming thats what i got) behind it i'll have to use an adapter? The 400 uses no electronics, correct? Shortning and lengthing driveshafts and moving, making new crossmembers isn't a problem i just want to make sure i have the combo of parts before i start.

[Grumpy_old_fart]

Originally Posted by arrigo106

It's cast iron with the emergency brake built in to the back of it. So unless i find a turbo 400 that had the 205 (assuming thats what i got) behind it i'll have to use an adapter? The 400 uses no electronics, correct? Shortning and lengthing driveshafts and moving, making new crossmembers isn't a problem i just want to make sure i have the combo of parts before i start.

sounds like you have a 205. can you get photo of it? Im interested to see this one.

you can change adapters and bolt a th400 directly up to it.

the adapter you want is available through one of our members on this board, and you might be able to search this thread: http://pirate4x4.com/forum/showthread.php?t=645564 for more information.

[Red Chevy]

Just a thought here, but that t-case wouldn't happen to be divorced would it. Being that the truck was a 2-wheel drive and all.

[myojunk]

id like to see a pic myself. please post one if its in your means

[arrigo106]

I'll try and post a couple of pics but i've never did it before so might need some assistance! I believe divorced means not together and married means together? If thats the case it's married.

[Grumpy_old_fart]

Originally Posted by arrigo106

I'll try and post a couple of pics but i've never did it before so might need some assistance! I believe divorced means not together and married means together? If thats the case it's married.

you can go to photobucket and post the photo there, then add a link here.

[j20m715]

Originally Posted by arrigo106

Thanks grumpy! Found all the info i need! Heres one for u guys. I'm going to take the manual out and replace it with an auto. From the factory it would have came with a 4l80e, i'm thinking more on the lines of a turbo 400? Does anyone have any suggestions or problems i may incure?

Check the gear ratio 1st.
You might not like the top speed with only a 3speed trans.
I have the same truck you have.
It has a bw t-case & 5.13 gears. Its screaming at 60mph.

[j20m715]

I just noticed you mentioned the diff on the PASS side.
My truck has the dif on the drivers side.

Do you have 10 lug, 19.5 wheels ?

[junkyardjunkie]

could it possibly be a NP200. I have 4 of those and they all have the emergency brake on the back of the transfer case. 3 are in army 3/4 ton dodge m37 trucks and I have one sitting on the floor of my shop. I am planing on using a model 42 brown lipe in front of it and mating it to a a granny low 4speed.

[Red Chevy]

Could be the 200, but he said he thinks it is married. Also I have seen the rockwell 221 cases with an e-brake, but it was divorced also.

[Grumpy_old_fart]

im very interested in a picture of this setup, so, if you can, please post one up for us.