Manual Transmission Recommendation - 64 Chevy 4 speed

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Nov 5, 2022
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My C10 pickup has 4 on the floor. I don't know if it is the original transmission or not (I think it is). It is attached to a 283 V8.

Can someone help me figure out what transmission fluid would be best for this?
 
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Dec 19, 2013
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The only 4 speed offered in a '64 C10 would be a Muncie SM420 "Granny Gear", They called for SAE 90 mineral oil gear lubricant.

If the unit has a PTO Cover....It's either a SM420 or a later SM465.

An SAE 50 motor oil would work......Though many run 80W90 GL-4 & GL-5 gear oils in them though I would caution against GL-5 oils.
 
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Amsoil MTG or Redline MT90
The local Napa still had stalube gl4 85w90

Ford GM Mopar also have some good GL4 manual transmission fluids

Preferred back then is obsolete today.



If you're stuck on SAE-50, consider using any of the fleet Mack TO-A Plus gear oils. Mobil for example:

And, the GO-J Plus 75w90's don't have LS additives. Mobil for example:
 
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MolaKule

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As @clinebarger stated the 4 in the floor of that era was usually a Muncie design that required a 90'ish grade gear oil.

With much better dedicated MT gear oils today you have a choice of modern MTF's.

Those in the list below in BOLD would be my choice picks in no particular order.

MTFs in the 14-15 cSt (SAE 75W90) range would be:

1. Amsoil MTG
2. Redline MT-90

3. Castrol Syntrans Multivehicle 75W-90
4. Castrol Syntrans Transaxle 75w-90
5. Ford XT-75W90-QGT (Carries a GL-5 rating as well)
6. Ford MOTORCRAFT® Full Synthetic Manual Transmission Fluid XT-M5-QS
7. ACDelco 10-4059 GL-4 75W-90 Manual Transmission Fluid

8. RAVENOL TSG SAE 75W-90
9. LIQUIMOLY 75W-90 GL4
10. PENNZOIL 75W90 GL-4
11. MOTUL GEAR 300 GL-4/GL-5 (PRODUCT NUMBER 100118)
 
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HondOtaChOrd

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The 4 in the floor was usually a Muncie that required a 90'ish grade gear oil.

With much better dedicated MT gear oils today you have a choice of modern MTF's.

Those in the list below in BOLD would be my choice picks.

MTLs in the 14-15 cSt (SAE 75W90) range would be:

1. Amsoil MTG
2. Redline MT-90

3. Castrol Syntrans Multivehicle 75W-90
4. Castrol Syntrans Transaxle 75w-90
5. Ford XT-75W90-QGT (Carries a GL-5 rating as well)
6. Ford MOTORCRAFT® Full Synthetic Manual Transmission Fluid XT-M5-QS
7. ACDelco 10-4059 GL-4 75W-90 Manual Transmission Fluid

8. RAVENOL TSG SAE 75W-90
9. LIQUIMOLY 75W-90 GL4
10. PENNZOIL 75W90 GL-4
11. MOTUL GEAR 300 GL-4/GL-5 (PRODUCT NUMBER 100118)
Thanks for the list! Any idea on the capacity for this transmission?

I am going to try Redline MT-90 GL4.
 
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Sounds like a perfect application for a high quality API GL-4 gear oil.
JD HyGard (or Low Vis HyGard) is an excellent choice and you don't have to pay the premium of Red Line or Amsoil.

Hy-Gard transmission / hydraulic oil

I can personally confirm that HyGard LV works exceptionally well in manual transmissions that utilize brass synchros in my climate (-30C to +30C).


`
JD HyGard.jpg
 

HondOtaChOrd

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Tomorrow Ford Motorcraft Transmission fluid arrives!

Anything I need to be aware of or is it just drain and fill?
 
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And he might have a Muncie M20/21 or a Borg Warner T10 for all I know, Just no trucks ever came with light duty 4 speeds from the factory except some early 80's 1/2 tons with the optional 4 speed (3 speed w/ Overdrive) which is actually a New Process A-833/NP-440 most notably used by Chrysler.
 
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California
The only 4 speed offered in a '64 C10 would be a Muncie SM420 "Granny Gear", They called for SAE 90 mineral oil gear lubricant.

If the unit has a PTO Cover....It's either a SM420 or a later SM465.

An SAE 50 motor oil would work......Though many run 80W90 GL-4 & GL-5 gear oils in them though I would caution against GL-5 oils.
If there's any brass in there yes stay away from GL-5
 
Joined
Feb 12, 2018
Messages
556
Location
California
Sounds like a perfect application for a high quality API GL-4 gear oil.
JD HyGard (or Low Vis HyGard) is an excellent choice and you don't have to pay the premium of Red Line or Amsoil.

Hy-Gard transmission / hydraulic oil

I can personally confirm that HyGard LV works exceptionally well in manual transmissions that utilize brass synchros in my climate (-30C to +30C).


` View attachment 127148
Redline makes everything shift like a hot knife and butter
 
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