AZ455

Anyone here use Dexron VI? I hear it's supposed to be better and backward compatible, but is it worth the money?

I was just going to use Napa's Dex/Merc DexIII equivalent until I got to wondering about the VI.

jaunty75

Hey, it's me again. When I changed the fluid on my '73's transmission last weekend, I bought whatever the house brand of transmission fluid was at Autozone. It meets all the specs required for the car.

Unless you're planning to use your '74 as a daily driver, I don't see the need to spend more and get a transmission fluid that is more than is called for by the manufacturer. In fact, even if you were going to use the car as a daily driver, I'm not really sure what you gain by spending the extra money. The "base" fluid is meant to be used in any car that calls for it for regular driving.

Again, like I said in my post in the other thread, I've changed transmission fluid on several different cars over the last few decades, and just like I always bought whatever transmission pan gasket they had on the shelf and never had a problem, I always bought whatever the house brand of transmission fluid they had, as long as it met all the specs, and put that in and never had a problem.

AZ455

Hey again! I was just seeing if anyone may have noticed a difference using the VI in a TH400 or other trans. I actually use VI in my Toyota truck (2 times now) that calls for Dexron II, it's been around 40,000 miles with it and the trans seems to love it. The fluid is more expensive but the I drive the truck at least 6 days out of the week.

I'll likely stick with the Napa brand (Ashland, like Valvoline) DexIII/Merc fluid. The price is good too...

jaunty75

How do you tell that the transmission "loves" one fluid and not another? A transmission is a transmission. It just shifts! If it doesn't shift when it's supposed to, it's usually because the transmission itself has problems or because it's low on fluid. I've never heard anyone claim that a poor-performing transmission was due to the choice of fluid.

AZ455

I know it loves it because I haven't had any problems with the stock tranny and the truck has about 200,000 miles on it...

I didn't mean to sound like I'm claiming Dex VI is some miracle fluid. Simply saying I've used it in a Dex II tranny for many miles without issue. I'm sure this is not due to the fluid I used, it is more due to the fact that I have regularly changed it the time I have had the truck, which is about 10 years and it only had about 70k on it when I got it. Sorry if I made it sound like the Dex VI is why the transmission performs as it should. I'm sure it'd shift the same with Dex II like Toyota asks for.

I will be using standard Napa Dexron/Mercon in the TH400.

jaunty75

There's lots of reasons that your transmission can last that long besides the choice of fluid. The way you drive (jackrabbit starts versus slow acceleration), freeway versus city driving, etc. all figure into it.

I think you're second paragraph says it all. Your transmission's long life is more likely due to the regular maintenance that you've done to it more than any particular fluid you've put in it.

oldcutlass

And sheer good luck! Come ere, I want to rub yer belly before I buy a lottery ticket.