For those of you with the np246 which came in 99-06 or later gm vehicles, have you had problems with it? I have a 2500 suburban and it is beginning to complain. After reading up on them, seems to be a common problem, and I am trying to decide whether to rebuild or swap to 241. I use it for towing, mild offroad, and want it to be reliable.
Autotrac Np246 Issues?
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HenryJ
Expedition Leader
What complaints is it giving you?
They have been pretty good in my experience. Are you running the blue autotrac fluid? That is a must. Many got swapped to the Dextron ATF. That is the wrong stuff for this transfercase. Older models can benefit from Autotrac fluid too, so so the TSB said back then.
Check the fluid level. They do not like to be run low, or overfilled by a leaking rear transmission seal.
I have had a couple (fleet rigs) where the locating clip for the pump fell off. The pump then proceeds to chew its way through the tailshaft housing. If you see the little spots leaking, you have a problem. Easy fix and there are more robust answers to that repair now.
The encoder/transfercase shift motor can be a weak point, but it is an easy swap and replacements are around. This is the only issue that I have had with my personal vehicle. It did not make me walk and gave plenty notice that I had a problem.
Other than those issues, the transfercase has been pretty good. If it is bearing, wear or other problems that you have, that is possible in any case you choose. Personally, I would stick with it and fix what you have, unless you want to go hardcore. Inthat case there are way too many options. How deep is your wallet? $$$$$$
They have been pretty good in my experience. Are you running the blue autotrac fluid? That is a must. Many got swapped to the Dextron ATF. That is the wrong stuff for this transfercase. Older models can benefit from Autotrac fluid too, so so the TSB said back then.
Check the fluid level. They do not like to be run low, or overfilled by a leaking rear transmission seal.
I have had a couple (fleet rigs) where the locating clip for the pump fell off. The pump then proceeds to chew its way through the tailshaft housing. If you see the little spots leaking, you have a problem. Easy fix and there are more robust answers to that repair now.
The encoder/transfercase shift motor can be a weak point, but it is an easy swap and replacements are around. This is the only issue that I have had with my personal vehicle. It did not make me walk and gave plenty notice that I had a problem.
Other than those issues, the transfercase has been pretty good. If it is bearing, wear or other problems that you have, that is possible in any case you choose. Personally, I would stick with it and fix what you have, unless you want to go hardcore. Inthat case there are way too many options. How deep is your wallet? $$$$$$
only real issues i really see with them are electrical. the switches in the dash go bad, the control modules have been known to go bad, and a corroded encoder motor (the electronics on the t-case) can cause issues. Hard part issues with them is almost nothing, hardly ever see anything short of an electrical issue, and this is coming from a Chevrolet Technician.
I have had the suburban for 5 months or so, and had never thought about the tcase. I noticed a vibration between 40-60, and checking it out, found that I have a lot of play in the output, along with a crunch/click noise. I pulled fill plug and it was full, so drained it and the fluid is super dark brown, almost black. Tiny bit of metallic in the fluid. Since there is a big magnet inside the case, I imagine there is more metal that I can't see until I split the case.