ATF Specifications

P

Pat Callaghan

Hi,

The owners manual says that Dexron II is to be used in my 92 Legacy's
automatic transmission. Is Dexron III/Mercon a acceptable substitute? I
have five unopened quarts left over from when I changed the tranny on my 87
GL and would like to use it if safe. Thanks.


Pat Callaghan
92 Legacy L AWD Wagon
 
Check with a parts store if you want to be sure, but Dex 3 is an upgrade of
Dex 2, so perfectly useable in Dex 2 applications.
 
Just a clarification here. You _didn't_ say that an upgrade of a
previous specification means it is an acceptable substitute, but some might
still infer that from your wording, so I thought I might add a bit. I cannot
speak to the transmission fluid concern, but in another fluid, brake fluid
specifically, the upgrade to DOT 5 from DOT 4 involved a totally different
base substance (5 is silicone-based, previous were glycol-based, and 5.1 is
glycol based again), and in some cases this is NOT acceptable to an earlier
spec vehicle or brake system.
I'm no expert in this area, and others may correct me or add
understanding here. I only found out about this because the disc brakes on
my mountain bike use DOT 3, DOT 4, _OR_ DOT 5.1, but NOT DOT 5 because the
silicone base will not absorb and thus suspend (dispel?) water. If water is
not absorbed and suspended, it can lead to localized rust more quickly,
particularly in low areas. Collected water can also cause boiling in the
calipers in heavy braking, leading to pedal fade.
A link to a short article on this is found at
http://batauto.com//articles/brkfld.shtml
I apologize if this rather off-thread-topic was discussed here already.
I can't remember if I got my info via this group or my biking newsgroup. So
much for upgrades of specifications.
 
Just a clarification here. You _didn't_ say that an upgrade of a
previous specification means it is an acceptable substitute, but some might
still infer that from your wording, so I thought I might add a bit. I cannot
speak to the transmission fluid concern, but in another fluid, brake fluid
specifically, the upgrade to DOT 5 from DOT 4 involved a totally different
base substance (5 is silicone-based, previous were glycol-based, and 5.1 is
glycol based again), and in some cases this is NOT acceptable to an earlier
spec vehicle or brake system.
I'm no expert in this area, and others may correct me or add
understanding here. I only found out about this because the disc brakes on
my mountain bike use DOT 3, DOT 4, _OR_ DOT 5.1, but NOT DOT 5 because the
silicone base will not absorb and thus suspend (dispel?) water. If water is
not absorbed and suspended, it can lead to localized rust more quickly,
particularly in low areas. Collected water can also cause boiling in the
calipers in heavy braking, leading to pedal fade.
A link to a short article on this is found at
http://batauto.com//articles/brkfld.shtml
I apologize if this rather off-thread-topic was discussed here already.
I can't remember if I got my info via this group or my biking newsgroup. So
much for upgrades of specifications.
 

Ask a Question

Want to reply to this thread or ask your own question?

You'll need to choose a username for the site, which only take a couple of moments. After that, you can post your question and our members will help you out.

Ask a Question

Members online

No members online now.

Forum statistics

Threads
13,889
Messages
67,365
Members
7,364
Latest member
Cimarron49

Latest Threads

Back
Top