So here's a thought I've been having: Can you top off one brand of ATF with another?

Recently I dropped my AW-4's pan, did a complete flush (not a pressure flush) and put in some Valvoline max life d/m but ended coming up short. So I went to buy some more but they ran out and bought some Castrol d/m to not leave empty handed. Also have some Castrol transmax lying around for when I changed the transfer case. It sounds like a bad idea mixing all three, but I want your opinions.

 

You should be using a fluid that is compatible with the Dexron III/Mercon specification. It may say something like Dex/Merc on the bottle.

If it's Dex III/Merc, you're good. If it's not, you're not. Get it out of there!

Do NOT listen to auto parts store people tell you that you need ATF+4 in there. They think because it's a Chrysler that it runs what other Chryslers run. Not so. It's actually a Japanese transmission, used in Toyotas and a lot of other vehicles.

You might want to read this.

 

Agreed with only running Dexron/Mercon fluid.

 

Oh I believe you. Had one of them tell me it needed ATF+4 just because it's a chrysler haha.

Thing is, and i dunno if this will make sense, but the castrol d/m says not to use in trannys calling for m/V, LV or SP which is what the valvoline stuff is compatible with also. Making me think both atf won't get along. The transmax stuff just says it's recommended for anything atf+3 and prior and anything else as long as it doesn' call for dex VI

 

Strongly agree and the same brand/kind if you can, in an emergency you may not have a choice but change when you get home.


The AW4 trans is a very good one and a match for the 4.0 engine as far as durability goes.

 

It's the same kind, but not the same brand which is what's making me have doubts.

 

I'm thinking that any "Name Brand", quality ATF will be compatible with each other. As long as they are the same "type", I really don't see a problem. If it really concerns you, pick up a few 2 gallon tubs and go crazy draining and filling.

I have better things to do.

 

I'm sure it's fine to mix brands. If it's DEXRON III, you are fine. 4 may be OK in the transfer case, but why complicate it.

Yes, never power flush an AW-4. Just change whatever fluid will drain more often till it's nice and pink.