What fluid do yall run in your th350s?

[76k5blazerr]

My th350 is being rebuilt as we speak, I'm getting it back tomorrow but I'm going to grab some fluid for it today so I can put it back in and go tomorrow. What do you guys run in your th350? The guy who supposedly rebuilt it last year (2500 miles ago) told me to run type F, which I did. Obviously that was a crap rebuild because the trans barely lasted a year. From what I've read I should either run type F or dextron/mercon 3. I'm going to get the opinion of the guy who's building it this time as well but wanted to hear what you guys thought as well.

 

[AV8TER]

Type F is Ford spec oil. You want Dexron in a GM product.

 

[diesel4me]

Type "F" was sometimes reccomended to improve shift firmness and was known as a "poor man's shift kit" ,but the "F" fluid has different friction charecteristics and isn't what GM intended to be used in their transmissions..it was claimed it wont damage the transmissions,and the B&M "Trick Shift" fluid was nothing but type "F" in their bottles, but who knows..

I'd stick with Dextron/Mercon in whatever the latest version is,"Dextron VI" I think is the newest one..but any of them above Dextron II is suitable..

 

[76k5blazerr]

So I should get dextron 5?

 

[76k5blazerr]

What about dextron 3

 

[livid4dirt]

Someone correct me if i'm wrong, but the fluid is backward compatible. You just cant go forward with fluid choice.

 

[76k5blazerr]

So does that mean I oughta run dextron 3 or 5

 

[livid4dirt]

I think you can use either one, whatever is cheaper.

 

[76k5blazerr]

Geuss I'll be running dextron 3

 

[70jimmy]

Last time I had mine rebuilt my tranny guy gave me some aerosol stuff to spray in the cooler lines and then I blew them out with low pressure air to get all the crud out. He said when your tranny starts going bad it can put a lot of crud in the cooler if you have one and the lines.

When I changed transmissions in my ford explorer the stuff that came out of the lines was nasty.

 

[big-blue]

I would go for Dextron VI - it's synthetic and backwards compat.

 

[Greg Ducato]

I like synthetics in anything that will be stressed beyond daily commuting. There are synthetic variants of all Dexron compatible fluids, pick one that is easy to find in your area and go. And has already been advised, flush the heck out of the cooler and lines before the new trans goes back in.

 

[big dan]

John deere 303 for me. Get 5 gal buckets for $25. Been running it for over a year in my scout with a th350 and my 85 k20 with a th400.

Only issue I have is that its hard to see on the dipstick