Boat power steering: Dexron II (?)

Joined
Dec 16, 2006
Messages
970
Location
Sweden
My manual says Dexron II for my GM 5.0 1999 Volvo penta engine. I just bought Dexron III as I never even heard of DexII. Are those backwards compatible fluids?
 
Joined
Oct 14, 2008
Messages
110
Location
Maryland
Yes. My 76 Chevy Truck called for Dex II in the transmission, but I've been using Dex III since I got it 20 some years ago.
 

lars11

Thread starter
Joined
Dec 16, 2006
Messages
970
Location
Sweden
Ok, thanks. Strange to put DexII in a manual for a 1999 engine. But that GM iron slab is probably from some earlier day...
 

lars11

Thread starter
Joined
Dec 16, 2006
Messages
970
Location
Sweden
ok. I will use it in the power steering(dex2), the power trim (dex3) and the Bennet trim tabs.
 
Joined
Mar 21, 2004
Messages
26,409
Location
Upstate NY
Check the requirements for your power trim pump and Bennett trim tabs. My 87 Merc power trim wants 30 weight non detergent oil. Other pumps may want different fluid.
 
Joined
May 25, 2005
Messages
3,559
Location
SE Pa
 Originally Posted By: lars11
My manual says Dexron II for my GM 5.0 1999 Volvo penta engine. I just bought Dexron III as I never even heard of DexII. Are those backwards compatible fluids?
Dex III is fine. You can even use Dex VI. I've used M1 ATF and it's held up just fine over many years. It's not a very rigorous hydraulic system. Fluid spec is not ubercritical.
 
Joined
Mar 21, 2004
Messages
26,409
Location
Upstate NY
 Originally Posted By: lars11
ok Donald, the Bennett manual says "any ATF". Now Dex3 is an ATF, right?
Yes, DEX III is an ATF, although officially GM withdrew licensing for the DeEX III spec so no one can claim they are DEX III anymore, but many still do. The current GM spec is for DEX VI. I would use any DEX III or above ATF except maybe some real cheap stuff from the dollar store. The trim tab application is no where as tough as the transmission application.
 
Joined
Dec 2, 2002
Messages
6,388
Location
Washington St.
Dexron-II (and Dexron-IIE) are long obsolete automatic transmisson fluid specs. They were replaced with the Dexron-III spec, which is almost 100% compatible (older Hondas are the only transmissions I know of that need Honda's own ATF to replace Dex-II rather than using Dex-III). Dexron-III is now an obsolete spec replaced only in GM Hydramatic transmissions by Dexron-VI. Yes, most ATF blenders still produce a product to the Dex-III spec under a somewhat similar name, maybe Mer-Dex or D-M or something. GM still licenses the same ATF formula under different names...Allison TES-389 and some GM manual transmission fluid name.
 
Top