Trans fluid

[Mike Sammons]

I want to replace the trans filter in my TH400, how much and what kind of fluid will I need. Thank you

 

[Jrgunn5150]

About 4 quarts of anything Dex III rated. I use Valvoline Max Life.

 

[Mike Sammons]

Thank you!

 

[Matt69olds]

If you have a deep pan, better double that amount. Sometimes AutoZone have the Valvoline synthetic on sale, about 20 bucks a gallon. Any modern fluid would be better than what the truck had originally.

 

[MrMarty51]

I have heard a lot of horror stories about using the synthetic transmission fluid, enough so that I will not use it in My 4L80E in the 2000 K3500.

 

[Matt69olds]

I’d be willing to bet the 4l80 came factory filled with synthetic, I think every OEM trans today does. With the EPA cracking down with more and more mileage requirements, automakers are doing everything possible to squeeze every little advantage.

 

[Matt69olds]

I’d be willing to bet the 4l80 came factory filled with synthetic, I think every OEM trans today does. With the EPA cracking down with more and more mileage requirements, automakers are doing everything possible to squeeze every little advantage.

 

[Jrgunn5150]

I’d be willing to bet the 4l80 came factory filled with synthetic, I think every OEM trans today does. With the EPA cracking down with more and more mileage requirements, automakers are doing everything possible to squeeze every little advantage.

It 91 it would have had Dex III, Dino Base stock, in 06 it had Dex VI, synthetic. Nothing significant changed in between.

I use whatever, but usually as I said, Valvoline Max LIfe.

 

[Matt69olds]

Valvoline max life is good stuff, especially considering the price.

Pretty sure synthetic fluid was used in everything by the mid to late 90s. And even if it wasn’t, there is nothing wrong with using synthetic after using old school fluids. I personally have never seen contamination issues after making the switch. I suppose it could happen, but the risk would be negligible with quality fluids.