Transmission oil???

[mobigly73]

I know this has been covered but I am still confused about one thing. The Haynes manual says to use 20w50 motor oil in the trans case but on this site everyone seems to be saying something else. Who is right ? I know that everyone here has extensive experience with Fiats but I would think that Haynes does too. I do have an older print of the manual and it reads like a Castrol add and my car is a 78' 5spd.

[ventura ace]

There is no single exclusive 'Right Oil'. This topic will be debated left and right from here to eternity, and many people have had ongoing great experiences with different oils. That makes sense, since the oil companies have experimented and come up with many changes in oil formulations since the Fiat Manuals were printed back in the 60's, 70's and 80's. The Fiat manual calls for non-EP GL-1 gear oil (85 or 90 weight). An equivalent viscosity oil is 50 weight engine oil, which is what I use (Valvoline 50 wt racing oil) and I've been much happier with it than the GL-1 (though I understand that many people are very happy with GL-1). I don't know why the Haynes suggest a multiviscosity (20w50), but I think a straight 50 is better than the multiviscosity.

What you don't want to put in there are oils that will attack the brass synchro rings, such as GL-5 gear oils.

Alvon

[mobigly73]

So in your opinion will the 20w50 weight oil do any damage or should I drain it out and start over?

[red107]

Not the first time a Haynes Manual was wrong.

[So Cal Mark]

I'd leave the 20/50 in

[mobigly73]

Awesome!! I will probably change it in a couple hundred miles because its been sitting for a while and it can use a good flushing but that's cool that I can leave it in there for now. Thanks for the advice.

[courtenay]

On a slightly different topic, but still transmission oil...does anyone have an easy trick for getting the new oil into the transmission. I used a very small squeeze bottle with a 2 inch snout to get the stuff in - but it took forever and was quite messy!

[narfire]

With an assistant and a long tube, one can pour from the engine bay into the fill hole. Just have a method to stop the flow when the oil comes out of the trans. A wine store should sell tube and the plastic stopper/clip that works.
Others have neat ways as well.

[mobigly73]

You can buy a hand transfer pump that fits on top of a gallon container for cheap (like 7 bucks) Its great has a nice long hose and a fitting on the end of the hose that holds it in the hole so its one hand operation and lets air out as you pump fluid in. Plus it works with pretty much any material. I just keep a half gallon milk jug in my garage for fluids that I don't need to buy a gallon. Just make sure you purge the pump when you change to a different fluid or it comes apart to clean. Here's one from ACE
http://www.acehardwareoutlet.com/produc ... GoogleBase

[brunorahl]

Go ahead and run that 20/50. By saving a couple bucks over getting the GL1 that you need, you can look forward to a transmission rebuild within the next two years. Even sooner if you drive the car regularly.