The Stovebolt Site Forums The Shop Area Driveline 1950 4spd floor shift: fluid type and capacity?

My 50 has the 4 on the floor. Its a torque tube driveline.

What is the fluid capacity of this trans (want to do a change) and what should I run? Does the rear end have its own reservour or are they linked through the torque tube?

Trans is very noisy in 1-3 then gets real quiet in 4th. Want to start with the fluid.

Do you have an Operator's Manual and a Shop Manual? They are on-line (see links below).

http://chevy.oldcarmanualproject.com/chevyowner/52tom77.htm

http://chevy.oldcarmanualproject.com/shop/1948_51truck/51ctsm0005.htm

http://chevy.oldcarmanualproject.com/shop/1948_51truck/51ctsm0730.htm

6 pints of 90 weight gear oil in transmission (same oil is used in the rear end).

The rear end is filled through a plug in the rear cover.
http://chevy.oldcarmanualproject.com/shop/1948_51truck/51ctsm0410.htm

The transmission fluid also lubricates the enclosed u-joint (see last link above). If you empty the u-joint housing, you should put about a 1/2 pint of oil in the plug-hole near the rear of the transmission case.

I found that using 85W140 in my 4 speed helps the synchros work a little faster. My gears all are quite vocal with the "Chevy whine" until I get into forth. Forth gear of course is just a straight through connection.

for filling a drained tranny i like to fight with removing the stick and pouring it down the hole rather than fight trying to get it in the fill hole one quart at a time and not all over me. i found over time im getting good at stick removal and installation. for just adding a little bit i use a little pump oil can to top it off. it takes a while but is not messy.

Mike,

Be gentle with the stick/shifter retainer and it will oblige. It's all in the motion.

When I installed the SM420 in my Suburban last year (4 times, emptying it three times), I also figured out that filling through the stick/shifter hole was much easier, quicker, and cleaner.

tim, the dump and the 40 are easy. it's the ashton that's hard. i think its the amount of spring it has compared to the other two.

i also find that if you remove the vent on the rear and fill until it comes out the filler plug is simpler and also cleaner and in the mean time maintenance can be preformed on the vent.

Any else have recomendations on what weight to run in the trans and rear end? I'm seeing 90 weight and 80W140 listed so far.

Planning on buying some after work today.

Thanks

This topic has been kicked around a lot do a search to find some. There is a well-known rebuilder that has good info check out novak.com

I put 3 quarts of 80W90 (because that is what they had the store) and it has not overfilled out of the side fill hole. Is it supposed to spill out when full?

Also, the rear "u-joint housing" has a grease zerk on top of it, I assume I grease it not put oil in it?

No, you do not put grease into the u-joint housing via the Zerk fitting. Transmission lubticant goes in there (and it eventually will be fed/filled from the transmission). Rumor has it that the Zerk fitting was used by the factory (and maybe dealers) to fill (or top up) the u-joint housing with transmission lubticant.

tim is right, no grease. my 40 has a 1/8th npt plug. either way its a real pain to add oil there.