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Trans and Transfercase

Justin Fleming

Justin Fleming

1/2 ton status
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Aug 24, 2005
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Location
Oxford MI
So I blew the trans out of the 1990 k5 plowing. The sad part is that the trans was three years old but only had 7500 miles on it. Not sure why it failed. Last night I pulled it all out so I could get it rebuilt before the storm. Any how, I noticed the fluid in the transfer case (np208) was as dark and dirty as the trans. That being said that means the trans and transfer case are sharing the same fluid? I know they both took trans fluid but I did not know that it shared it.

Is there a seal that let loose allow this or is this normal?
 
Probably blew trans oil through the seal on the output and pee’d in the t case

Replace that rear seal on rebuild and change the case oil
 
Bent77 said:
Probably blew trans oil through the seal on the output and pee’d in the t case

Replace that rear seal on rebuild and change the case oil
Click to expand...

It's actually the seal in the front of the t-case. There's no seal in the back of the trans but same diff. These seals are famous for failing and will overfill the t-case to the point of puking out the t-case vent.
 
Bent77 said:
Probably blew trans oil through the seal on the output and pee’d in the t case

Replace that rear seal on rebuild and change the case oil
Click to expand...
Is that seal on the trans or t-case, I assume the trans. I dropped the trans at the builders place today.
 
Do we have a part number or a diagram showing the seal that I should replace seems how its apart
 
Did reverse go out ?...usually reverse is the first gear to die on GM automatics...I think the constant shifting from forward to reverse is what kills most plow truck automatics..

I've head TH400's have a habit of braking the reverse band in that type of use..give me reason to be paranoid about mine after plowing with it for 14 years..:eek:..
 
reverse went, I did also notice some issues on the highway towing small trailer like OD as going or slipping. This truck has the 700r4
 
Positive that the TV cable was good, and set correctly?
 
The cable was good, and the way it was set unless I was doing it wrong, was pulling the cable housing through the adjustable ratchet deal, then going in the cab and slowly pressing the throttle cable down until it self adjust

Am I missing anything there? It was actually taken to the tranny shop and they signed off on it after I installed and they did a test drive.
 
Sounds good.. just checking though lol.
 
towing in OD with 3:08s with a 700 R4 is guaranteed to kill it. I have towed many miles on flat ground with 4000 pounds of boat and trailer with 4:56 and 35s no harm. I put it in 3 the minute in down shifted from OD on a hill.
 
yea I know that is for sure these highway gears are no help to the truck plus these old things, the torque converter likes to lock up way to soon.
 
AV8TER said:
Yes. I think it is a 710928.
Click to expand...
The seal did not look bad from the last time it was resealed, but rather be safe than sorry so I thru a new on in it. Now I need to find the adapter gasket and rubber o-ring for the adapter. I know that typically you still throw some silicon on them also for good measure.
 
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