New trans but unsure about fluid

[Bones Jackson]

Hey guys, just picked up a near fresh 727 w/brake for cheap, $250 no converter. Guy had it built this winter was racing it this spring, made 9 passes and blew the motor. He's going with a richmond 5 speed and a small block now. Anyway, to my question, how do I know what fluid he used? I use Type F in the current 727. I was going to drain it anyway but theres always a little fluid in there afterward. Can they mix?

 

[Greg Ducato]

Yes, they can mix, type F to Dexron, synthetic to regular, no problem

 

[moparpoor]

Use dexron/mercon 5 it is the replacement for almost all ford type fluids.I run it in all my 727's.Some guys claim it lowers operating tempature,I haven't noticed any.

 

[Endangered Species]

I think you can mix Dextron and Type F. If you talk to Rick Allison he'll tell you to run Type F. But with that being said I don't think it really matters. Type F is suppose to have a higher friction coefficient. But I think Dextron runs cooler.

 

[Al K]

Bones;you stated that he blew the motor. Any damage to the over-running clutch? Better check that before getting on it hard.

I use Valvoline "+4" in mine without problems-so far!

 

[Bones Jackson]

Bones;you stated that he blew the motor. Any damage to the over-running clutch? Better check that before getting on it hard.

I use Valvoline "+4" in mine without problems-so far!

He spun a rod bearing, I didnt really dig for details.

Thanks fella's I'll use my reg Type F. This is just a spare trans I got for a good price.

 

[Slantsixdan]

You will get lots of guesses and folk wisdom and old info whenever and wherever you ask about transmission fluid.

See this post for discussion with support for the assertions made.

 

[Budnicks]

If I remember correctly the Chrysler ATF+3 & +4 have a better heat control & an anti-foaming agent, that the old style Dextron & Type-F fluids don't have, I use the Chrysler Type+3 or +4, in all my Trucks & Cars, I have a friend that takes apart stuff after abussing/testing it, for research, at Cheveron Researh in Richmond Ca. he stated the fact that the Chrysler Type+3 or +4 showed less wear on hard parts & was superior in heat resistance, that sold me, I use to always use B&M trick shift {Dextron}, pryor to that, with no real problems except after hot-lapping, 4 or 5 passes testing, the trans would get very hot {Dextron}, with the newer Chrysler Type+4, I had a 15*-20* difference in trans temp on my gauge, after the same amount of hot lap passes... I'm sold now & it saves a few bucks too...

 

[Slantsixdan]

If I remember correctly

Almost, but not quite. ATF+3 is a relatively poor fluid. ATF+4 is an excellent fluid. Read the linked research paper in my previous post in this thread.

 

[Bones Jackson]

You will get lots of guesses and folk wisdom and old info whenever and wherever you ask about transmission fluid.

See this post for discussion with support for the assertions made.

Thanks for the info but, this doesnt answer the question. If the converter and trans is drained can I run any fluid I want? Or if there is some still old ATF left in the trans will mixing cause a problem?

 

[67 coronet]

Thanks for the info but, this doesnt answer the question. If the converter and trans is drained can I run any fluid I want? Or if there is some still old ATF left in the trans will mixing cause a problem?

small amounts or"residual"fluids will mix just fine.only minor vicosity and addative differences from atf to atf,small amounts will mix together just fine.

 

[Slantsixdan]

Yup, 67 coronet is right.

 

[Bones Jackson]

small amounts or"residual"fluids will mix just fine.only minor vicosity and addative differences from atf to atf,small amounts will mix together just fine.

Solid, thanks