tranny fluid

[4404spdcharger]

I live in Northern Colorado so cold is a fact of life.  Shifting the tranny is noticeably stiff at first but loosens up after 30 minutes of driving so I'm thinking maybe a lighter fluid is better.  I've been told by some (Passon) that synthetic fluid is a NO NO.  The manual says 140 wt but OK to use Multigear 80 or 90 wt in cold weather but doesn't mention synthetic since it didn't exist in 1968.  OReilly's says MasterPro 75w-90 synthetic is good stuff.  Any suggestions??

[A383Wing]

I assume we are talking about a manual trans here

Service manual says 140w in my 66....then starting in 67, it says 80-90w for same trans, nothing was changed....then in the 70's it also states that ATF can be used in the same 4spd trans...

I have a 94 Dakota, it says to use 80-90w in manual trans...it was so hard to shift it when I used regular gear oil..I had to change it out, so I used 75-90w synthetic now....shifts smooth now and not hard at all

we use Oriellys 75-90w at our shop with no issues

I say use it...you will be OK with it

Bryan

[4404spdcharger]

Yes, I'm talking about the 4 speed in my 68 Charger R/T.  If there's no problem, I too would like to change over so the shifting is smoother.  Just wanted to see if anyone had similar problems with an 833 4 speed and used a synthetic wihout any isses.  Thanks.

[matrout76]

Read my old post here:

http://www.dodgecharger.com/forum/index.php/topic,69014.0.html

since then, i've found that most Napa stores carry the Royal Purple Synchromax for about $15 a quart: http://www.royalpurple.com/product-categories/automotive/#!synchromax-manual-transmission-fluid

[Chryco Psycho]

75-90 would be the first choice , Redline MTL would be the second choice