Engine/Transmission (1998.5 - 2002) 1999 Truck, DTT - OK to use ATF+4?

[Joe Mc]

DTT done in 04, trans builder used Dex/Merc III, said I could use ATF 3 if I wanted to no big deal? This was before ATF+4 hit the streets.



The first fluid change / band adj I went with ATF 3. The next one I went back to Dex/Merc III as I couldn't find ATF 3 anywhere. I've continued with the Dex/Merc III since, the last change I didn't notice till after finished the Dex/Merc III was "for high mileage" transmissions. So far (changed Spring 08) the high mileage fluid has been fine. I'm hoping it's use will not be detrimental to the life of the trans - any thought on this topic?



So I'm wondering what's the best fluid to use?

 

[Regcabguy]

DTT done in 04, trans builder used Dex/Merc III, said I could use ATF 3 if I wanted to no big deal? This was before ATF+4 hit the streets.



The first fluid change / band adj I went with ATF 3. The next one I went back to Dex/Merc III as I couldn't find ATF 3 anywhere. I've continued with the Dex/Merc III since, the last change I didn't notice till after finished the Dex/Merc III was "for high mileage" transmissions. So far (changed Spring 08) the high mileage fluid has been fine. I'm hoping it's use will not be detrimental to the life of the trans - any thought on this topic?



So I'm wondering what's the best fluid to use?

ATF+4 wasn't recommended when I had the DTT on my '99. The Dex-Merc III was recommended if you couldn't find ATF+3. Call DTT for the current skinny. They're very helpful.

 

[24V-DSL]

I've used Mopar ATF+4 in my DTT since 4-01 when Bill built and installed it. He knows it and has never told me not to use it when I've been back for upgrades. I change every 15K, and now have 194K on the truck.

Walmart sells Mopar in quarts for ~$4. 50, so it's now competitive with other synthetics.

 

[BDaugherty]

My local WalMart also sells Moper ATF+4. I've been using that in my Dad's '97 auto truck.

I would call DTT and ask them what to use. My old SunCoast trans specified DexIII/Merc. I'm guessing that it doesn't really matter which one you use, but for me personally, I like to run one type and brand of oil and stick with it.

 

[Joe Mc]

My local WalMart also sells Moper ATF+4. I've been using that in my Dad's '97 auto truck.

I would call DTT and ask them what to use. My old SunCoast trans specified DexIII/Merc. I'm guessing that it doesn't really matter which one you use, but for me personally, I like to run one type and brand of oil and stick with it.

I'd prefer use of same fluid as well. That's why I'm trying to figure this out.



As suggested the best thing to do is check with Bill.



Thanks, I'll update when I hear back from DTT.

 

[DavidC]

When my trans was built ATF+3 was what Fred Swanson put in. I use ATF+4 now. I thought DTT recommended the +4 on their site.



Dave

 

[raychem]

I run Dex 3 on all the trannies. Its cheaper and like with all built trannies 15k to 20k is the recommend service interval. Bottom line is that with regular service intervals you should not have a problem.





Richard

 

[Joe Mc]

Rich, Thanks for clearing that up for me/us.