transmission fluid question

[btoran]

i've read on the forum that redline mtl should be used for manual transmission fluid. i think they make several different fluids. which is the correct one and where can it be purchased? thanks.

[RRoller123]

I used their MT-90, and bought it online. Great stuff, smooth as silk.

[btoran]

the MT-90 says it's GL-4. i thought i read we don't want to use gl-4.

[BEEK]

just be sure what you get is gl-1 this is a non ep (extreme pressure) lubricant, this is what the fiat box needs to survive. Having said that, i have used Redline MTL in my race cars with no issues

[81SPIDERMATT]

make sure you get the fill plug loose before draining the tranny

[4uall]

this may help

http://wwwe.fiatspider.com/f08/viewtopi ... ansmission

Immediate difference.

Good luck.

BE SURE TO GET THE FILL PLUG OFF BEFORE THE DRAIN PLUG JUST IN CASE

[TX82FIAT]

This is from an old mirafiori site post.

" Mobil makes a synthetic gear and bearing oil called SHC-630. It is non-EP and contains no additives. It will NOT attack yellow metals. It is fully synthetic and although it is weighted in ISO format, I was told that it was equivelent to 75W-90. It also has anti-foaming properties. It is NOT GL-5 like MT-90 may be."

The user said they had great luck with the product saying it even silenced a noisy bearing using GL1. You may need to call an industrial suppier like MSC or Grainger to get it ordered if your interested in it.

I'm running GL1 non-ep that I picked up over the counter by the gallon at NAPA. I have mixed emotions on the many synthetics offered. GL1 is basically mineral oil. Redline makes a 90 wt non-ep.

I would caution the following. These gear boxes need a little friction to work properly. Going a step further these gears are supposed to have a certain amount of coating. The design is from the 60's and my concern is that oils today are not designed with this friction and coating in mind. Many newer oils are very slippery even at the same weight. If you depart from GL1 non ep I would look around for a mineral oil that is 90 weight non ep designed for older cars.

[Emersonfiat1977]

I am going to attempt tomorrow.

1st get fill plug loose

The Car Quest

Ask for GL1 non ep(SL-SGLX) correct?

75W - 90 correct?



When adding measure or like a differential add until it starts leaking out?

Any help is much appreciated

Thank you

[18Fiatsandcounting]

GL-1 is correct for the older Fiat transmission, but it's pretty much not available in stores. So, you have to order it online. I have heard people can find it as older tractor oil, but I've not gone down that path myself.

75W-90 sounds correct, but keep in mind that the viscosity ratings for gear oil are different than engine oil. In other words, 75W-90 is not twice (or more) as thick as 10W-40 motor oil. Different oils, different viscosity ratings.

As for how much to add, I just drain the old oil, put the drain plug back in, then fill the transmission up to the level of the fill plug with new oil. When it starts to drip out of the fill plug, stop and put the fill plug back in.

-Bryan

[RRoller123]

My local NAPA has gallon size GL-1 on the shelf.

[18Fiatsandcounting]

My local NAPA has gallon size GL-1 on the shelf.

That's very handy! I checked with NAPA out here, and they looked at me like I was a wingnut. No GL-1. Just curious: How much $$$ does your NAPA want for a gallon of GL-1?

-Bryan

[rridge]

https://www.tractorsupply.com/tsc/produ ... _vc=-10005

[manoa matt]

If I can get the NAPA GL-1 in Hawaii, you should be able to get it anywhere on the mainland. A gallon of it will do 2 trans oil changes.

https://www.napaonline.com/en/p/FCA65201

[RRoller123]

I don't remember how much they charged for it, but that probably means it wasn't out of the normal expectation.

The folks behind the counter may know of it more generally as "Mineral Oil", as GL-1 is obviously a very old designation!

[tima01864]

NAPA has the GL-1 branded with their name on the container. #1 Mineral oil