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G56 gear oil?

cj3a

Well-known member
Joined
Jun 3, 2020
Member Number
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What is the recommended secret sauce now for these transmission?
 
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Never had a G56, but big trucks use the same oil in Eaton Fuller trans, this stuff seems to be pretty good, way better than the OTR dark shit from Fleet Pride. We get it by the 55 gallon drum at our shop.
 
I used some stuff from Shaffers in mine. anything is better than the ATF they use from the factory
 
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Never had a G56, but big trucks use the same oil in Eaton Fuller trans, this stuff seems to be pretty good, way better than the OTR dark shit from Fleet Pride. We get it by the 55 gallon drum at our shop.
They make it in 75w90 as well which is thinner when cold.

50wt is around an ISO220
75wt gear is around an ISO 45, 90 wt around iso 220.

I haven't figured up what the point of Meropa is yet. It's for gear boxes as well.
 
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This is what I run in mine. Shifts like new hot or cold. And quiets down the gear rollover noise better than the atf that comes in them.

I think ya supposed to overfill them by 1 quart also. This is just what the fella that custom builds them says to do. YMMV


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I also over filled mine by 1 quart. I put like 50k miles on that truck after that with no issues.
 
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