Can anyone clarify the seals I need on the adapter from a T350 to an NP205 in my 74 K5? Dumped the 203 and got a 205 and adapter from another K5.

Trying to make sure my T350 doesn't dump ATF into the tcase. The adapter does not appear to have a seal on the tranny side, other than the big O-ring. On the case side it has a typical paper figure 8/racetrack pattern where the adapter/case mate.

Are there more than the one seal and O-ring? Thanks for any clarification and part numbers. Something I can get from NAPA?

Maybe this'l help ? quad4x4.com

Input Seals

Input Seal Set for 205 direct mount transfer cases in1976-1993 1 Ton W300 or W350 Dodge trucks with gasoline engines, or Cummins diesel trucks with AUTOMATIC transmissions. Kit includes 2 Seals. Made in U.S.A.

QU10511-2 Small Input Seal Kit $9.98


Input Seal for GM models with the Turbo 400 automatic transmission, most Ford direct mount cases and Dodge 89-93 Diesel 5 SPEED trucks is a double lip, double spring seal. A quality original equipment seal designed to retain fluids from either direction. Made in U.S.A.


QU10517 Double Lip Input Seal $8.99


Input Seal for REMOTE Mount transfer cases: See Rear Output Seals

Input Seal for All Other GM applications: CALL us at 406-446-2427

Just the one seal on the t-case side and the "O" ring on the other

Thanks. Seems like there should be more, but that's all I saw (the O-ring and the regular backside seal) when I removed the adapter.

Used the seal and o ring brand new and still got atf in my t-case. Not a big deal as long as gear oil doesnt make it back into the tranny. What i did was use rtv to seal it up tighter that a witches tit. Well, i had a shop do it. Those things are heavy bastages. Worked great till i sold it. Now i have a 465/205 and i would never go back to an auto.

Where did they RTV?

Issue is that too much ATF obviously causes an overfull condition, which in turn causes the case to vent all over the underside of the truck.
d

Just the one seal on the t-case side and the "O" ring on the other
Actually there are 2 seals inside the adaptor that are turned the away from each other.

???

Of course, my local Napa wasn't able to help. Anyone have a good source these items?

???

Of course, my local Napa wasn't able to help. Anyone have a good source these items?
If you have an O'Reilly's the National part # 471869 have them cross ref it for you. Qty 2 listed as input shaft seal for th350 to np205

You have to take the bearing out to put them in!

I may have misspoken. What I'm really looking for are the o-ring on the front (tranny side) of the adapter and the figure-8/racetrack GASKET (not seal, sorry) on the back (case side) of the adapter.
d

I may have misspoken. What I'm really looking for are the o-ring on the front (tranny side) of the adapter and the figure-8/racetrack GASKET (not seal, sorry) on the back (case side) of the adapter.
d

BUMP

Any part #s for the Gasket and O Ring for the ADAPTOR th400 to np205 racetrack style?

#1
dont yell.
For a th350:
#2,
find a competent transmission shop, they should have all 4 pieces that you need in stock.
#3
Yes, there are 4 peices.

one o-ring on the input shaft that is INSIDE the coupler between the trans and transfer case on the transfer case side.

one square o-ring on the transmission side, seals to the adapter.

two seals that are to be placed inside the adapter, with or without support bearing, that are set in such a way as to keep fluid out from either side. these are to be butted up against each other.

you want part numbers? go to GM.

you want seals? go to a competent shop and pay the 15 bucks.

for a th400:
there is one seal, one gasket. the seal is on the bearing retainer. remove it, get the number, replace it.
the gasket is available at any trans shop or parts store. its the th400 output shaft gasket.

Actually there are 2 seals inside the adaptor that are turned the away from each other.

yes and no.

depends on the year but they are not all designated that way and the early style with the support bearing wont allow the seals to fitted that way.

Yeah, I have a pre 1970 set up in one truck and it always leaks back. Next time I pull it, it's outta there.