Transmission fluid 1980 spider

[sigkadetm]

I recently changed my manual transmission fluid using the GL-1 Traveller 90w transmission oil from tractor supply. Now my transmission is a little hard to shift from first gear to second gear. Has anyone had this problem? Can't remember what fluid I had in it before I changed it.

[baltobernie]

Previous lube may have been Redline or even motor oil. GL-1 is more vicious than those, and you can feel it in the shifter, particularly when the car is cold.

[aevansgatech]

I'm having a similar debate, and I've seen some people reference GL1 manual trans fluid. My 1982 manual does actually specify 80W/90 (not EP) oil. I don't see GL1 referenced in the Fiat manual at all, so is there a problem with using 80W/90 (redline for example) that's technically a GL4 rating?

[PhillySpider]

What's the right fluid available today for a 1980? I was just thinking I should check/change it the other day. I don't know it was ever done, and am a little affraid as my car is currently running perfectly. Don't fix what's not broken as they say...but preventative maintenance should keep her going. How do you check/change it?

[TX82FIAT]

I switched from redline 90 back to GL1 from Napa. I would stick with the GL1.

I would not use GL4 or GL5 in a FIAT Spider Transmission- A long time ago trans oils began to be replaced by gear oils with a phosphorous additive (in itself a decent anti-wear additive) with active sulfur to grip hold of the gears and create a very solid sacrificial layer of material that could be worn off, thereby protecting the gear surface. Eventually it was discovered that the active sulfur was causing corrosion of brass and other soft metals used in differentials and transmissions. As the gears turn, instead of wearing, the sacrificial coating of additives is peeled off or worn off. This is normal and acceptable in all steel gears. But when one or more of the surfaces is brass or another soft metal like in our Spiders, the sacrificial coating is stronger than the base metal, and instead of just peeling off, it takes with it a few microns of brass that it is bound to. I switched back to GL1 after finding a gold rush of brass in my transmission oil. I had a period of time where shifting into first was difficult. While not cured, and the shifting is a little notchy. The transmission is preforming better.

I really advice sticking with the design Non EP GL1. Thicker than Honey but it works. I'm sure there are other 90 weight non EP classic car oils you can buy and pay a lot more.

[aevansgatech]

Is it correct to say that the factory (or dealer prep?) would've delivered new cars with GL1?

[TX82FIAT]

I have older Fiat documentation that says GL1 non EP. In many conversations over the years I am told that is manufacturer spec of what came from the factory. I don't have anything that states factory is GL1 Non EP.