Spicer Four Speed Lubricant

[Ncbob]

FWIW the count I use with mine is 1-2-3-4 from 1st to 2nd...1-2-3 from 2nd to 3rd and from 3rd to 4th...
MOVE IT!  That one goes real fast!

Bob

[Fredward]

Gus,
The MC-5 Manual says to use SAE 50. I must confess I have no idea what's in mine so I guess I'll dump it out. The manual also states that this transmission is splash lubricated and the oil change interval is 15,000 highway miles. I cannot locate the capacity. It just says to fill it until oil runs out of the plug.

It sounds like everybody that has tried heavier oil has liked it. I suspect mine has 30 or 40wt in it which is maybe why it takes so long to spin down when initially shifting from neutral to First.

Bob,
It also says not to energize the reverse solenoid in any of the forward gears. (Strangely written; wouldn't you think they'd just say "shift into reverse from Neutral"?)
Fred

Fred

[Ncbob]

Me not know, Fred...but as I indicated earlier when I saw that the transmission had 3 shafts...a light bulb went on.

Bob

[gus]

Fred,

I don't think we have the same trans even though they use the same weight oil. My Spicer is pressure lubed (Pump) and yours is splash?? My trans also has a dipstick at the top rear which is nice, but that just confuses me more about the differences in the two.

I would guess that a splash lube trans can handle heavier weight oil and am surprised that the manual says 50W. That 50W aircraft oil is expensive stuff but I just happened to have some I couldn't use in my airplane, at least not right now.

Look closely at the cutaway drawing parts list in the trans section of your manual to make sure there is no pump listed.

As I remember mine holds 12.5 Qts.

If you have a reverse solenoid you probably can't get into reverse from neutral, otherwise there would be no need for a solenoid. At a full stop GMs have to go to first, hold solenoid switch on, move lever to second gear position and then release switch.

Maybe the book means not to energize the reverse solenoid while moving in any forward gear??

[TomC]

All new trucks I order are equipped with synthetic transmission oil.  On Allisons, in order to get additional warranty, you have to also use synthetic transmission oil.

For what it's worth- synthetic is normal engine oil that is refined at a closer tolerance so the molecules, or ball bearing lubricators per say of the oil are more uniform.  This is why it is more slippery and that it has a tendency to find its' way out of small holes that regular oil won't go.  Good Luck, TomC