mixing types of ATF

[kikkegek]

hi guys,

I used to put regular ATF in my TH400, but after the last service the shop put ATF III in it and told me that is just fine.

I want to change the radiator tomorrow. I need to unhook the rad-cooler and I am afraid I will loose ATF in the proces.

I only have ATF in stock. two questions:

1. will I loose any ATF when I onhook the tranny cooler from the rad? or is it ampty when not running? because it is above the tranny?

2. can I put ATF in the tranny that is holding ATF III?

[hatzie]

You won't loose more than a few ounces of fluid changing the radiator.

Dexron I, II, III, & VI ATF can be mixed with no problems.

[COBALT]

Correct - just have a couple of little plastic bags and some rubber bands handy when you unhook them, throw the bag over it and secure it with the rubber band. Pretty much just like you do with the brake lines when you have those disconnected.

[kikkegek]

thanks guys! you really helped me with this.

IF it can be mixed, what is the big difference in them then?

[hatzie]

Originally Posted by kikkegek

thanks guys! you really helped me with this.

IF it can be mixed, what is the big difference in them then?

The additive pack and viscosity differs slightly. The later generation Dexron fluids are backward compatible for use in earlier transmissions. The opposite is not true. Don't use Dexron III in a 2011 vehicle that calls for Dexron VI. According to GM using Dexron VI in a 1987 TH700R4 that calls for Dexron II is OK.

Compatibility is only guaranteed in automatic transmissions.
Manual transmissions that call for Dexron III should only be filled with Dexron III.