Oil for 3-speed?

-
Aaron65

Aaron65

Well-Known Member
Joined
Nov 16, 2013
Messages
625
Reaction score
226
Location
Michigan
I just read (after filling it with 80W-90 and driving 50 miles) that non-synchro 3-speeds take automatic transmission fluid! Anyone know if that's true? If it is, I have to get that gear oil out of there ASAP! This is in a '65 Dart with a Slant.
 
When my '62 Dart Service Manual comes in, I'll let you know. I have the same question on the same trannie (A903).
 
I double checked the service manual and did some online research, and it all said that trans. uses ATF. I just changed to Dexron III...It's easy to change with the filler plug on the bottom. I don't notice any difference in shifting or noise. I think gear oil would be equally acceptable.

My other problem is that it's forcing oil from somewhere when the car's moving. The vent makes sense, but it seems dry up there. There's a chance it could be blowing it back so it doesn't land on the top of the trans, but leaks down the side. It's definitely coming from up high. My local trans guy put front and rear seals in it and used RTV for the top cover. It could be coming from the tailshaft to main body gasket. Who knows, but finding parts for this thing is a bummer! Good luck with yours!
 
My 63 manual says type A suffix A (ie) dextron , but in the maintainance section It does say in hot climates you may use SAE 90 or 140.

Brian
 
GEO said:
You old 3spd takes just regular gear oil , if you want to go hog wild use synthetic
Click to expand...
I may indeed go with the lightest weight Mobil 1 synthetic.

My A903 is hard to shift OUT of 1st so the rear bearing may be going and allowing misalignment with the fork, or the shifter shaft is hanging.

For parts, I found what looks like a basic A903 rebuild kit:
http://www.onlinetransmissionparts.com/servlet/the-407/Rebuild-Kit-for-1962-dsh-72/Detail

Probably does not needle bearings and such tiny stuff, but looks to at least have the basic overhaul parts.
 
Aaron65 said:
My other problem is that it's forcing oil from somewhere when the car's moving. The vent makes sense, but it seems dry up there. There's a chance it could be blowing it back so it doesn't land on the top of the trans, but leaks down the side. It's definitely coming from up high. My local trans guy put front and rear seals in it and used RTV for the top cover. It could be coming from the tailshaft to main body gasket. Who knows, but finding parts for this thing is a bummer! Good luck with yours!
Click to expand...
For the top cover and tailpiece gaskets, just get some gasket paper and cut out a new one! Easy-peasy....RTV just ain't gonna hold for long.
 
I checked the 65 and 67 books. The way I read it the 3 speeds specify type A ATF, 4 speeds 140, 80-90, or ATF depending on climate
 
Changed out the 3-speed non-synchro-1st trannie fluid today (A903). The old fluid was clean and appeared to be a 75W90 wt gear oil; not too heavy. Put in Mobile 1 synthetic ATF, compatible with Dexron, DexronII, DexronIII, Mercon etc. Seems to run fine and as quiet, perhaps it shifts a little better. The shift out of 1st gear when moving is not hanging quite as hard now.
 
You must log in or register to reply here.
-

Back
Top