GL 4 Vs GL5

[V12Bill]

I rebuilt the transmission in my 1950 Ford F1 floor shift. I put in the remains of 2 containers of GL 4 and went to NAPA and Auto Zone to buy more GL 4 or 3. Neither of these stores carried GL 3 or 4. Everything on the shelf was "meets GL 4 and GL 5 specifications". Since GL 5 is not "friendly" to yellow metals, is the new label mean that now GL 5 is friendly to yellow metals or is it the same ole same ole that should not be put in contact with yellow metals. Where do I find a replacement for the GlL 3 and 4 gear oil?

[JSeery]

"meets GL 4 and GL 5 specifications" refers to lubrication specifications and says nothing about yellow metal compatibility. Now, some GL 5 gear oils claim to be yellow metal compatible. I wouldn't go by that, but some folks do! GL 4 is around, just have to find it.

Here are some available on Amazon: https://www.amazon.com/s/?ie=UTF8&ke...l_54avj9qvto_b

Here are the Castrol, Sta Lube & Valvoline versions.

[tubman]

If you have a couple of days, Amazon.com has it readily available at a good price.

[19Fordy]

In hot FL weather I use this.
https://www.ebay.com/i/202082145978?chn=ps&dispItem=1
85-90W is good up north.
https://www.amazon.com/Sta-Lube-SL24.../dp/B000M8RYMC

[qmdv]

I have some GL4 in SAE140. It gets below freezing in winter and up to 100 in summer. I doubt I will be driving an open roadster at anything below 40F. Should it go in the transmission or the rear end.

Tim

[JSeery]

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Originally Posted by qmdv

I have some GL4 in Should it go in the transmission or the rear end.

Tim

GL 4 vs GL 5 is not an issue in regular rear axle gearing, just the transmissions because of brass (yellow metal) parts.

[qmdv]

Originally Posted by JSeery

GL 4 vs GL 5 is not an issue in regular rear axle gearing, just the transmissions because of brass (yellow metal) parts.

My interest is weather or not the 140 wt would be OK in the trans. And how about the 140 in the rear end. I do know that GL4 for trans and GL4 or GL5 for rear end. I have some 140 in stock and would like to use it if OK

Tim

[alanwoodieman]

to answer your question yes--it is good for transmissions, except in very cold weather. I live in upstate sc and run it all year. a little stiff shifting for a bout 2 miles in winter then OK

[Newc]

Hi all: the local , Oregon, NAPA's carry GL-4 newc

[corvette8n]

If you have any tractor stores around they have GL1,3 and 4. I used to buy 5gal pails of GL1 for my Ford 8n.

[JSeery]

Originally Posted by qmdv

My interest is weather or not the 140 wt would be OK in the trans. And how about the 140 in the rear end. I do know that GL4 for trans and GL4 or GL5 for rear end. I have some 140 in stock and would like to use it if OK

Tim

It's somewhat depends on what you like. The different viscosities of gear oil is not a damage issue of the gears, it depends on how you like the driving characteristics. Unless you are wanting to change the gear lube with temperature change, I would suggest a multi-viscosity. Something like 90w-140, or whatever is available. Original Ford specifications were something like SAE 140 Summer & SAE 90 Winter.

[19Fordy]

I use STALUBE GL4 140W in both rear and trans of 40 Ford. JB Welded a tag on transmission and rear to remind me. Also "tagged" gear ratio. Coat tags with clear nail polish from Dollar Store before installing.

[KGS]

Originally Posted by JSeery

GL 4 vs GL 5 is not an issue in regular rear axle gearing, just the transmissions because of brass (yellow metal) parts.

True with the exception of a Colombia rear which has yellow metal components.

[donald1950]

NAPA has Valvoline MTF (manual transmission fluid) and has the letters MTF on the label. also Grainier has it too
https://www.grainger.com/product/VALVOLINE-Transmission-Fluid-46KK52?breadcrumbCatId=27834&s_pp=false&picUrl=//static.grainger.com/rp/s/is/image/Grainger/46KK52_AS01?$smthumb$[IMG]MTF[/IMG]

[JSeery]

Originally Posted by KGS

True with the exception of a Colombia rear which has yellow metal components.

Yep, that was my attempt with the "regular" rear end gears, LOL. As you pointed out, there are exceptions.