June 23, 2018, 08:58:07 PM

Author Topic: Transmission and differential lubrication.  (Read 1520 times)

Offline Gordie Allen

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Transmission and differential lubrication.
« on: July 29, 2013, 05:29:45 PM »
I want to  change out the transmission and differential lube.  My manual was printed in 1958.  Are there better lubricants than those recommended in this 55 year old manual?  It recommends S.A.E 50 engine oil for the Spicer 4 speed transmission and S.A.E. 140 MIL-L-2105 for the differential.  I doubt that that the differential gear lube is even a current S.A.E standard.  What's the best product for each?
Augusta, MI
1956 4104
DD 671

Offline luvrbus

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Re: Transmission and differential lubrication.
« Reply #1 on: July 29, 2013, 06:14:01 PM »
The military spec MIL-L-2105 is still a good spec those specs have worked for 55 years why change the old girl may not like change lol I found out the hard way some old seals don't care for the synthetic stuff
Life is short drink the good wine first

Offline Gordie Allen

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Re: Transmission and differential lubrication.
« Reply #2 on: July 29, 2013, 06:32:24 PM »
Since I have NO LEAKS, I'm not opposed to sticking to what works - if there's nothing better.
Augusta, MI
1956 4104
DD 671

Offline robertglines1

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Re: Transmission and differential lubrication.
« Reply #3 on: July 29, 2013, 06:45:14 PM »
FWIW  I changed one to SYN and could hear a hum I never had before.  Bob
Bob@Judy  98 XLE prevost with 3 slides --Home done---last one! SW INdiana

Offline RJ

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Re: Transmission and differential lubrication.
« Reply #4 on: July 29, 2013, 09:19:24 PM »
Gordie -

If it ain't broke, don't fix it?

 :o
RJ Long
PD4106-2784 No More
S13406 1978 MC-5C Converted
6V71/MT-644
S14947 1980 MC-5C Shell
6V92/HT-740
Cheney WA

Offline bevans6

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Re: Transmission and differential lubrication.
« Reply #5 on: July 30, 2013, 02:51:02 AM »
Just remember that the spicer gearbox wants a non-hypoid oil while the differential wants a hypoid oil.  I use a SAE 50 synthetic transmission oil in my spicer but I'm sure it would be equally happy on normal SAE 50 engine oil.  I top up the differential with normal 85 -W140 diff oil.

Brian
1980 MCI MC-5C, 8V-71T from a M-110 self propelled howitzer
Spicer 8844 4 speed Zen meditation device
Tatamagouche, Nova Scotia

Offline gus

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Re: Transmission and differential lubrication.
« Reply #6 on: July 30, 2013, 09:52:25 AM »
The oil specified for the Spicer is actually Aviation grade mineral oil, more commonly known as "break-in oil" because it has no additives or detergents. I use it in my trans even though it leaks a bit because I happen to have some I bought for an airplane by mistake. You can find this oil at any small airport. You have to be careful with older trans because modern additives can destroy brass and other type metal bushings.

The rear uses GL-4 non-extreme pressure, most modern vehicles use XP so GL4 is not easy to find.

This link will answer your questions; http://www.mobiloil.com/USA-English/MotorOil/Car_Care/AskMobil/GL-5_and_GL-4_Gear_Oil.aspx
PD4107-152
PD4104-1274
Ash Flat, AR