MTFCA Forum

Reading the 1927 owners manual I saw
Lubricating the Differential
"Do not put too much grease in the differential housing. The housing should not be more than one-third full. The differential is supplied with the required amount of lubricant when the car leaves the factory.
The oil plug should be removed about every 1,000 miles and more grease added if necessary. If a fluid grease is used the level should be approximately one and one-half inches below the oil hole."
What is fluid grease.

One of the most frequently asked questions with multiple responses. You likely to get confused - oil vs grease and related viscosity
Just buy this https://www.modeltford.com/item/600W.aspx

On a standard differential use 600W but if you have Ruckstell use sae90. On the early cars the fluid should be 1 1/2 inches below the oil hole but on your 1927 the oil filler hole is lower and it should be filled just till it reaches the oil hole.
Norm

I do use 600W oil, I am not trying to find out what to use I am just curious what "Fluid Grease" was back in 1927

Here is the original recommendation http://www.cimorelli.com/mtdl/1923/1923fordlube.pdf

TRDxB2 wrote: ↑

Fri Mar 17, 2023 4:07 pm

One of the most frequently asked questions with multiple responses. You likely to get confused - oil vs grease and related viscosity
Just buy this https://www.modeltford.com/item/600W.aspx

I agree. Another area that's way over-thunk! It's made specifically for this purpose, I use it with no issues. I keep a bottle on hand for the infrequen "top-offs".