Trans fluid question

[simplysigns]

I just got my TH400 back from the shop. Totaly fresh rebuild!! And I was wondering if there is a better kind of fluid to use (other than plane old tranny fluid) to keep the trans. cool? I will be running a trans. cooler but what kind of fluid should I use?

 

[4X4HIGH]

The normal fluid is sufficient.

 

[bailey9r]

Amsoil is a bit more money but it will run 40 degrees cooler and last much longer. I've used it for a long long time and it has proven to be better in mho.

Bailey

 

[mrdrinksalil]

I'm curious on this one too. I need a trans cooler cause I dont thinkg the stock cooler in the radiator is suffiecent for wheelin rocks and such. Can you run the power steering through the radiator trans cooler?

 

[Hogback Fabrication]

IMO you should buy a seperate transmission cooler with a dedicated fan and mount the trans cooler away from the radiator. 4 wheeling is hard on transmissions, heat will kill a TH400 just like it will kill any other trans.

I'm curious on this one too. I need a trans cooler cause I dont thinkg the stock cooler in the radiator is sufficient for wheeling rocks and such. Can you run the power steering through the radiator trans cooler?

I don't think that's a good idea, as per the hydraulic steering bible on Pirate you should keep the fluid temp under 200. How warm does your motor get? It probably runs close to that temp and hence won't keep the steering fluid under 200.

I use an automatic transmission cooler from a Saturn (got it for free) for my PS cooler, I have it mounted in front of the radiator. It works well.

I have seen several power steering component failures and many more who have weak steering and/or fluid that's boiling over because the steering is getting hot. Coolers are cheap and easy to install, very cheap insurance if you wheel your truck

 

[Wasatch K5]

Within the last year GM came out with Dexron VI. It is required in new GM automatic transmissions, and is backwards compatible; meaning it can be used in transmissions that originally called for Dexron III. My understanding is that it's better than Dexron III for transmissions, but for transfer cases you should stay with Dexron III.

I need to change the filter and fluid in mine and it's between Amsoil and Dexron VI.

 

[planedr]

I'm really fond of Royal Purple stuff.
I had a 77 GMC 2wd with a built 402 BB and a TH400 and I ran strictly Royal Purple, with great results. The trans shifted better, engine idled better. I even had the gear lube in the rearend, 12 bolt with a Auburn posi, and it was quieter. Better gas mileage too, it went from 5-6 to almost 9 MPG. WOO-HOO!!!

click the picture