What are we supposed to be running in the spicer 4 speed manual tranny? MC-5.
Thanks,
Fred
Engine oil
I think 90Wt gear lube is what was used in the MC8 I had.
Again
Step one: Buy a Bus
Step two: buy the manual for it.
Or listen to the folks who've been there, Doug. ;)
Fred, I've mentioned this in earlier posts but will be happy to do it again. My MC5A must not have had the transmission oil changed in eons and that was on my mind when I pulled the engine to do the clutch and install the Jake Brakes. Da Book calls for the same oil as in the engine, SAE 40. Having driven the bus home from IL I wasn't a happy camper with the shifting and it appeared to me that it was a bit more difficult the more highway I saw behind me.
For the record, I'm an 'Old' double clutcher from back in the late 40's when I learned to drive the farm trucks. Too, I had to replace the transmission input shaft (it was too sloppy where it mated to the next shaft) so I opted for an oil I felt would be a bit heavier and more lubricity than standard engine oil. I put in Valvoline 50# Racing oil (available at Advance Auto) and haven't had a squawk since. Granted we only run the warmer climates so that might make a difference in your decision...but for my tastes...it wouldn't make a shadow of a difference. ::)
Your choice...just my experience.
NCbob
Fred,
On my last trans. oil change I of used 40 wt engine oil with a 30% mixture of Lucas oil treatment and it seemed to make trans shift a little easier and stopped real seal leak.
I am using Delo 40wt.
But on the next change I am going to try out the 50wt like NCBob has done.
Bob has had positive results with his own actual driving tests by going to a heavier wt oil.
And nothing like real world results vs theoretical results.
Cliff
I use the same 40 wt oil as described in the manual.
Ncbob brings up a good point using 50 wt.
Another good point is using Lucas. I use that in the engine, guess it sure couldn't hurt using it in the transmission. Anybody used that with the 50 wt?
Paul
Thanks guys. By the way I have the manual; I'm just wondering what really works. I don't always go with what the manual says.
Fred
Fred,
Just curious. What does the MCI manual say to use? I assume both buses use the same trans since the drive lines are so similar.
My 4104 manual says to use 50W aircraft grade mineral oil. I just happen to have some 50W aircraft engine break-in oil which is mineral oil so I use that.
This Spicer 4-sp is not supposed to use 90W because it has an oil pump, it is not the usual type trans used in later years. GMC used these same trans on their heavy trucks in the '50s, I have four of them.
Fred -
Some folk have used straight 40wt synthetic oil in their manual transmissions, with reportedly good results.
FWIW & HTH. . .
;)
problem is with synthetic is that if you have a leak synthetic will leak at a higher rate
Out of curiosity, what's the oil capacity of this transmission? A transmission oil change is on my fall / winter to-do list and I'd like to know how much to have on hand and how much to expect to have to contain when I drain it. I haven't been able to find this in my manuals. I'll probably go with the 50 wt to see if it helps it shift a bit smoother. When it's cold, it shifts no nicely. After a few miles, it (or I) have problems with those damned gear crunches.
David
Quote from: DavidInWilmNC on October 10, 2007, 06:17:59 AM
Out of curiosity, what's the oil capacity of this transmission? A transmission oil change is on my fall / winter to-do list and I'd like to know how much to have on hand and how much to expect to have to contain when I drain it. I haven't been able to find this in my manuals. I'll probably go with the 50 wt to see if it helps it shift a bit smoother. When it's cold, it shifts no nicely. After a few miles, it (or I) have problems with those damned gear crunches.
David
David,
I'm not sure how much your transmission holds, but to help with the shifting problem after the transmission warms up try letting your rpm's drop longer than you think they should.
It takes quite a while for a Detroit to lose 500-600 rpm.
Instead of counting 1-2-3 like you would with a car or truck, count 1-2-3, 4-5-6 before pulling your shifter back into gear.
IHTH
Dallas
That's the one bad thing about converting this thing; I can't just go out for a spin in it! There are so many tools and parts lying about. At some point, farther down the road, I'll get to practice more, which is exactly what I need. I'll try giving it a bit more time, especially the 1-2 (and the 2-3 and the 3-4 ;) ) shifts.
David
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
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
Me not know, Fred...but as I indicated earlier when I saw that the transmission had 3 shafts...a light bulb went on. ;)
Bob
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??
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