The Stovebolt Site Forums The Shop Area Engine Shop tranny oil

Hi I have a 58 3600 4 on the floor. I went to top up my differential oil and it was down an entire container about a litre. Dont know when it was done last. So I thought I better check the tranny as well. I just wanted to check with you guys before I do anything. Drain plug seems obvious - back of tranny at the bottom. Is the fill plug on the passenger side about 2 - 3" higher than the drain plug. both are 4 sided bolts.
Thanks Rick

Hy rickyt, I can't remember which side of the case the filler plug is on, but yes it is up on the side of the case, a little less than half way up, hope that helps.

Fill plug is in the upper right hand corner of this picture:
http://www.pbase.com/dennygraham/image/137678406/large
Don't over fill when cold, check your manual for the proper level.
DG

Thanks very much guys I should have also asked how much it holds?

A little trick fill these 4 speeds is to remove the gear shift and pour it down the hole. Have the plug out on the side so you can tell when it is full. I always fill it until level with the plug opening, but some say to stop a little shot of the plug.

Kurt

Somewhere in the shop manual it tells to fill it to 1/2" below the hole when it is cold. The earlier four speeds had a tendency to dribble a bit out the front shaft but in the later years they used a seal instead of slinger on the front. I think the 58 would have a seal.

Which mine can attest to very well. Drip...Drip..

It holds 6-6.25 pints (depending on which manual you look at). Fill it as described above.

1954 was the first year of no "weep hole" in the SM420 4-speeed transmission.

Fill to 1/2" below fill-plug hole if transmission and lubricant is "cold"; but, if transmission and lubricant is warm and you are topping it up, the 1954 Shop Manual says to fill to the bottom of the plug hole.

Thanks guys

DENNY- Why are you supposed to use Delvac 50 in your trans? I remember an old post when you were looking all over the place for it.

If you look at the note at the bottom of the picture it says, "What NOT to use In your SM420". Ken uses it in his newer transmissions so I thought I'd try a synthetic when I rebuilt it last fall. The syncros didn't have enough grab with the synthetic oil and it would clash the gears going into forth every time. Switched back to the old standard 85w-140 Mystic and all is well now.
Denny G

Sorry Denny, I meant,
why are you not suppose to use Delvac 50?

Just a brain fart.

I find it interesting that some of the old service manuals recommend SAE 40 and 50 motor oil for 3 and 4 speed trannys. From what you've said, it's not good.