Correct MTF for my Classic Pickup?

[Jdrum1]

Good evening folks,

Been getting information from this forum for years, and now finally making my first post.

I think I'm on the right track, but just want to make sure;

Time to change the fluids on my '65 Chevy C10 Pickup. When it comes to the transmission (3 speed), the manual (yep, the I have the original manual) states SAE 90.

So, given that it certainly has yellow metal in it, I'm thinking I need to stick with GL4, and not GL5. Correct?

How about Redline MT90? Happens to be what I run in my Honda s2000, and it's been great (only MTF that doesn't give me a 3rd gear grind).

Thanks for the wisdom!

 

[FlyNavyP3]

MT-90 is appropriate for your application. If you want to save money you can search for a GL-4 80w90 or SAE 90. My preference is MT-90 for all of my GL-4 needs.

The original transmission in one of my vehicles just passed 337,900 miles today, you guessed it, it's filled with MT-90.

 

[marc1]

I use this in my old GM muscle car manual boxes (M21, M22 etc.).

http://www.crcindustries.com/products/api-gl-4-multi-purpose-gear-oil-85w90-32-fl-oz-SL24229.html

It is available at NAPA. I also think MT90 from RL would be fine.

 

[mattwithcats]

You might take a look at Mobil 1 Delvac 50, a GL-4 substitute...

Equivalent to 90 weight gear oil...

https://www.mobil.com/English-US/Commerc...ission-Fluid-50

Good price at Summit Racing...

https://www.summitracing.com/parts/mob-122208-1/overview/

 

[dlundblad]

MT-90 or your local NAPA should be able to get you some mineral GL4 80w90 StaLube.

 

[marc1]

Originally Posted By: mattwithcats
You might take a look at Mobil 1 Delvac 50, a GL-4 substitute...

Equivalent to 90 weight gear oil...

https://www.mobil.com/English-US/Commerc...ission-Fluid-50

Good price at Summit Racing...

https://www.summitracing.com/parts/mob-122208-1/overview/



I wasn't aware of this product, thanks for the tip, it looks like a good option.

 

[BigD1]

https://www.napaonline.com/en/p/SLRSL24239

NAPA puts it on sale every now and then for about $32.

Have used the StaLube before in my pickup. Had no problems with it. Have Redline MT-90 in it for over a year now, and I do like the cold weather shifting better. Otherwise, I don't see much of a difference other than that Redline will go for a long time before I have to change it again.

 

[Jdrum1]

I knew I'd get good answers!


While it probably won't make a huge difference, I may go with MT90 just because it's synthetic and I've had great luck with it in my Honda (I'm sure all suggestions would work great). Out of the 4 MTF's I've ran in it, MT90 has BY FAR been the best!

I just did the trans in the Honda, so wish I'd thought ahead a purchased a gallon of MT90.

 

[MolaKule]

Originally Posted By: Jdrum1
I knew I'd get good answers!


While it probably won't make a huge difference, I may go with MT90 just because it's synthetic and I've had great luck with it in my Honda (I'm sure all suggestions would work great). Out of the 4 MTF's I've ran in it, MT90 has BY FAR been the best!

I just did the trans in the Honda, so wish I'd thought ahead a purchased a gallon of MT90.

 

[zeng]

Originally Posted By: Jdrum1
Time to change the fluids on my '65 Chevy C10 Pickup. When it comes to the transmission (3 speed), the manual (yep, the I have the original manual) states SAE 90........

How about Redline MT90?

In 1965, a SAE90 gear oil had a KV40*C varying from 150 cSt upto 320 cSt.
A manual specified monograde 90 then would had been at the upper range of 150-320 cSt KV40*C.
MT 90's KV40*C of 86 cSt is way below then minimum 150 cSt.
Assuming this car wouldn't need to go on for another 100k-200k miles, I guess it makes no significant difference really going for MT 90.

 

[Jdrum1]

Umm....huh? You lost me pretty early on!

 

[zeng]

Brief answer,
Pre-1999 SAE 90 splits into or = Post-1999 SAE 90 AND SAE 110;
Pre-1999 SAE 140 splits into or = Post-1999 SAE 140 AND SAE 190.
....... according to SAE.