Everyone knows the topic of what lubricant to use in what part of your rig comes up on a regular basis around here. Unfortunately there are a few things you can do wrong in that regard and a few gray areas where choice really comes down to a matter of personal preference. For anyone considering what to run in their 727/A518, here's what Dex VI looked like in one of my 727s after 1k miles:

http://stuff.is-a-geek.net/PhotoAlbu...d_betsy_29.jpg

I was impressed with the way it seemed to run with the Dex VI, but was amazed at what the fluid actually looked like after getting some miles on it. This particular trans has almost 100k miles, never rebuilt. I put a Transgo TF2 kit in the VB a few years ago and it gets beat on hard behind a '71 440HP. I installed the deep pan from the '07 Ram last spring in the process of routine servicing after it became available when the Ram got a Mag-hytec.

Yesterday I remembered it still needed a spacer to drop the filter further into the deep pan, so I pulled the pan and fabbed one up. I never looked at the ATF like this after only 1k miles before, but thought the absolutely translucent clarity of this fluid was remarkable. The tranny looks healthy, but I'm going to have another look after 10k miles just to follow up on this fluid situation anyway.

 

I thought you had to run special fluid in mopar trannies? ATF +4 or something, it even says "designed for chrysler transmissions" on it.

G2K you can run Dexron/M in them ...or so far at least

 

The 727s/A518s came from the factory with Dex III in them. Look on the dipstick. Ma Mopar decided to standardize on ATF+4 at some point in the mid-to-late 90s IIRC, due strictly as cost savings measure as far as the older gearboxes were concerned. The "cost" was not due to the fluid itself, but the cost of burnt trannies when techs at dealerships and tranny shops all over the country were still putting Dex III or Dex III with some bogus additive in the newer boxes. It's alot easier for a grease monkey to remember just one thing: If it's a Chrysler product, it gets +4. There are a few exceptions, but generally speaking that's the rule. It's in a TSB somewhere. Played a big part in the Chrysler transmission reputation saga/myth.

There are issues with the clutch material after that, requiring the "+" fluid. The older boxes like Dex better.

 

Is it uncommon for the fluid to look that good after only 1000 miles? I have never attempted to pull the pan after only 1000 miles, ATF is too expensive.

 

Don't know. I never saw fluid come out of a tranny looking that good before. I guess I just expected to see maybe a slight tint or cloud to it. All but the half quart or so I spilled went right back in.

 

Ace, how does the DEX VI compare price wise to the (sadistic raping priced) ATF4+?

I've been puttering around since Sept. with *mostly* DEXIII... after the cooler line blew off the hardline in Mooresville and dumped the majority of the (new) ATF4+ on the ground!
It's (DEX3) done fine for around town & the single time I've towed (9K towed). To me it feels like the shifts are a bit crisper...

 

Absolutely. That's what those boxes are designed for - a more aggressive fluid. The + fluids are a much more highly friction modified blend to be compatible with the clutch materials in the newer transmissions. I believe the + fluid will actually run hotter in the old transmissions because of this. As for price, the Superttech Dex VI is like $4.70 a qt. at Walleyworld. Not much difference in price. But I believe it should serve better and longer than +4 in a 727-based trans, so worth it in my book. Dex III won't be around much longer, so if you are pinching pennies it might be a good idea to stock up and just keep using that. Still better for the tranny than +4 as long as you change it on time and don't run it hot.