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tranny fluid leaking into 205t-case

k2-k5

k2-k5

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Th350 to a NP205 transfer case. Transfer case fluid is a mixture of 90wt and transmission fluid. Anyone know what seal needs to be replaced to prevent transmission fluid frm getting into the t-case.

Thanks
 
Sounds like the seals in the adapter are bad. Make sure to check the connector as well they will get grooves in them over time.
 
that happened to me as well.I replaced the seal in the trans to T/C adaptor.
I think there is one on each end,Trans side and T/C side.
 
actually, some tranny's and t-cases are ok to do that. I would double check and make sure that your t-case is supposed to have gear lube in it. chevy new that that would happen that's why they made their t-cases to take tranny fluid. find a book or a computer that will tell you waht is supposed to be it your t-case b/c there's a good chance it's supposed to be tranny fluid. mine does the same thing. and if you do choose to keep gear lube in the t-case than you need to find the right seal that is meant to keep them seperate, stock seals won't. /forums/images/graemlins/thumb.gif
 
[ QUOTE ]
actually, some tranny's and t-cases are ok to do that. I would double check and make sure that your t-case is supposed to have gear lube in it. chevy new that that would happen that's why they made their t-cases to take tranny fluid. find a book or a computer that will tell you waht is supposed to be it your t-case b/c there's a good chance it's supposed to be tranny fluid. mine does the same thing. and if you do choose to keep gear lube in the t-case than you need to find the right seal that is meant to keep them seperate, stock seals won't. /forums/images/graemlins/thumb.gif

[/ QUOTE ]

NP 205 t-cases use gear oil and only gear oil.

There is an o-ring on the sleeve inside the adapter that is usually the problem. I went through about 3 or 4 till I found the right one. I think everyone is different and you need to make sure yours has a tight fit before you put it back together. I tried to blow through mine before I put it back together, took a few min. to get the ATF taste out of my mouth but worth not having to replace all the seals in my t-case for sure....
 
Wish you a part number of the right one.

In one of my other blazers the same thing was happening and tranny fluid would keep flowing into the transfer case until it was blowing out the seals. I had to keep draining fluid out of the fill plug on the transfer case until I fixed it.
 
Not sure how many seals are in a 350 to 205 adapter, my 465 to 205 adapter has 1 seal. Gear Fluid only in a 205, 208's can take it as well, they went to atf in 208's for improved mileage i believe, could be wrong.
 
I did mine last weekend with some help...

I have the part # somewhere...let me look for it in the daylight and get back to you. I got them from NAPA. They had 2 in stock. I brought in the old seal and cross ref'd the # on it to get a new one (no books seam to have the right # in them...the ones I bought before I opended it up didn't fit).
 
The part # for the seals in the adapter between my '71's th350 & NP205 is 19760. I got them at NAPA which means it was chicago rawhide brand. They were $6.97 each. One of them was whatever brand they used to cary but with the same part #.
/forums/images/graemlins/peace.gif /forums/images/graemlins/peace.gif

Have fun getting the 205 out! It is one heavy awkward sucker! It took 2 people most of the day just to change those 2 seals out. Be warned there will be about 2 quarts of tranny fluid that won't drain out that will come out (right onto my driveway /forums/images/graemlins/doah.gif) when you crack the adapter off the trans. I didn't have room for a drip pan because the tranny jack was in the way so it just made a huge mess /forums/images/graemlins/mad.gif
 
1 more thing.
NAPA's front output seal sucked. Look for another brand at AutoZone or something. You don't want the CR brand. You might as well replace that seal while you are at it. Mine leaked bad. The t-case being full of ATF about 1foot above the fill plug didn't help /forums/images/graemlins/screwy.gif
 
Awesome. Thanks for looking into that for me.

I managed to take out my transfer case and th350 togther as one unit. Thought that it would be easier to balance that way. Wasn't to bad other then the bellhousing catching on the headers. I hate headers.
 
I found that the easiest way to remove/install the th350/np205 is to leave them together and drop them down from the top with an engine hoist. The tranny hump unbolts and if you wrap a chain around the adapter it will balance with pinky pressure. It leaves you alot more room under the truck to move around.
 
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