Stuck Transmission Plug PART DEUX

Aug 11, 2011
O'day 30 313 Georgetown MD
The manual states to use type A or Dexron ll grade automatic transmission oil. Neither are available in any of the automotive stores. The closest I've been able to find is Napa Premium ATF Dexron lll. Its the next generation but not synthetic. Anyone know the answer
May 24, 2004
CC 30 South Florida
Oils and fluids are much better today than they were a few years ago. As far as I'm concerned I sort transmissions by whether they use "engine oil" or automatic transmission fluid" and I use whatever corresponding premium lubricant is available today. For the transmission I would go for a synthetic product.
Jan 22, 2008
Oday 30 Stamford CT
twodzusfitting....Attached is the correspondence I received from Mack Boring regarding the the transmission fluid for the Hurth transmission in my 1983 O'Day with the 5416 Universal engine.

Hello George,
Most major brands still offer Dextron III. Dextron III is available and is more commonly known as ATF fluid. In regards to Dextron IV this is a synthetic based fluid and is not recommended by ZF as viable fluid to use in their transmissions. ZF DOES NOT recommend the use of a synthetic based fluid in the transmission.

Thank you for contacting Mack Boring and Parts Company.
Happy Boating

Hello George,
I searched on AutoZone’s website. I am very surprised you could not find it at your local AutoZone. Here is a picture of the bottle they commonly carry and a link to their website. Most major companies are switching to different names for DEX III this is the way AutoZone has it listed DEX/MERC .This is a Dextron Mercon blend and will work fine for your application most DEX III fluids are a multi-blend with Mercon.
I also searched NAPA auto. They have the same DEX/MERC blend and commonly known as ATF fluid for NAPA it’s the same fluid named differently. I hope this helps you

I hope you find these fluids in your local auto parts retail outlets if you have any problems please feel free to contact us at anytime and we will do our best to answer your questions.

AutoZone - System Error
Aug 11, 2011
O'day 30 313 Georgetown MD
The big deal here is that the ATF to be used in our old Hurth Transmissions must be mineral and NOT synthetic. The tolerances of the seams will leak if synthetic is used. There are both synthetic and mineral ATF's out there under the dexron lll standards

George thanks for confirming this with your contact.