Does a trans need to be warmed up at all? Say I could keep my engine running at 180 degrees Farenheit, but I manage to keep my trans running at 40 degrees. Good/bad? I think I remember someone saying something about the fluid needing to be hot enough to evaporate moisture; but how hot is hot enough? 50 degrees? 80 degrees? Know what I mean?

Thanks!


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-Tom P (Hot rodded 1986 Firebird 2.8l) from http://www.f-body.net/mailbag/3rd/3rd_mailbag.html message boards
---Think your car could be pic of the week? Visit http://www.f-body.net for details!

 

First of all, the cooler the tranny, the better.

Second, I think that those numbers are a little bit off. An auto tranny runs pretty hot. So hot that you don't have to worry about evaperation. Assuming that you drive more than one mile. I think like 260 or something.

Third, my tranny would shift harder when I'd first get going.

But to answer your question, no you don't need to warm it up, just make sure that your pump is going. Assuming that it works, when you first start it up, the pump starts pumping.

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'82 Firebird, dead stock, 9 bolt disc rear, over 200,000 miles and still going strong, more to come...
http://www.spinfrenzy.com/stingerssx...easures.html#4

 

It'd be very hard to reach 40 degrees with any fluid application unless the outside temp was at or below 40 degrees. I wouldn't worry so much about going too cold until you find a way to cool it that much

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1984 WS6 Trans Am Hartop
Former L69 Car under restoration
1984 WS6 Trans Am T-tops
4-bolt main 350, headers, Holley 650, T-5, dual elec. fans and 3.23's.
Daily driver and restoration
13.98 @ 101

 

Hehehe, guys, that's why I said "in theory". I have no plans, nor do I have any intent, to cool my trans down to 40 degrees. If I could, I'd be making some big bucks! It was an example.

But thanks for the info! So there's nothing about water vapor to worry about, then? I guess I heard that about something else


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-Tom P (Hot rodded 1986 Firebird 2.8l) from http://www.f-body.net/mailbag/3rd/3rd_mailbag.html message boards
---Think your car could be pic of the week? Visit http://www.f-body.net for details!

 

I'd recommend 120-140 degrees F.

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George P. Lara
1984 "L69" A4
1994 LT1 M6
Member:
SCCA, SCFB, SC3GFB

 

Heh, okay, forget about 40 degrees. Say I wanted to run my tranny at -3902691 degrees Fahrenheit. 120-140 degrees Fahrenheit is better? Why? Is there any reason behind it?


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-Tom P (Hot rodded 1986 Firebird 2.8l) from http://www.f-body.net/mailbag/3rd/3rd_mailbag.html message boards
---Think your car could be pic of the week? Visit http://www.f-body.net for details!

 

I have a tranny cooler and trans temp gauge. I have a stock thermostat so the engine runs around 185 and the tranny barely gets past the 100 mark. Its not that noticable around town, but on the highway when i go down a cog or two, its one hell of a kick (no trans kit either) I really like it and its a preventative toy too!

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• 89 Formula 305 WS6
  SFC's,
  LCA's,
  Air foil
  Flowmaster cat back
  Tranny Cooler
  A/F Ratio Meter, Trans Temp (not a mod but it sure spurs interest)
• 90 Eagle Talon 2.0
  (winter beater)

 

Well, that number seems to be around absolute zero which means the molecules in your transmission would have zero movement and then cease to exist/explode/shatter in "theory" If water evaporation had to happen your tranny fluid would have to be over 220 (boiling point of water) which it rarely is and the only place I could see it hitting that temp while the rest of the tranny was at 140 would be in the torque conv. which is pretty much a sealed unit so the water would be recirculated through the system again and again and again so I wouldn't worry about it. Only possibility is if it was below freezing (damn near impossible!) if there was groups of water that had formed in the fluid it could turn into a small ice chunk in theory.

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1984 WS6 Trans Am Hartop
Former L69 Car under restoration
1984 Trans Am T-tops
4-bolt main 350, headers, Holley 650, T-5, dual elec. fans and 3.23's.
Daily driver and restoration
13.98 @ 101

 

You're confusing boiling with evaporation. Water will begin to evaporate at a lower temperature than its boiling point.

 

Doesn't ATF have detergents in it too? I think that would make the water/oil more misceable (kind of like adding soap to Italian salaad dressing... no more separation of oil and vinegar).

Unless you dumped water down the wrong tube... I wouldn't worry about it. I just installed my tranny temp gauge and the highest I've seen it climb is 180F so far. I don't think that ATF is as susceptable to viscosity as motor oil is.

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1984 z28 w/ a 357 cu in. monster engine which is looking like the posterchild for Edelbrock with the exception of the Holley 750vac... all the suspension stuff... 9-bolt posi disk is in...

-=ICON Motorsports=-

 

I didn't really 'confuse' it. Any amount of moisture would have to reach a point of mass evaporation (boiling) to be a significant enough to hurt the tranny. I'm not an expert on this though.....

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1984 WS6 Trans Am Hartop
Former L69 Car under restoration
1984 Trans Am T-tops
4-bolt main 350, performer intake, headers, Holley 650, T-5, hayes clutch, dual elec. fans and 3.23's.
Daily driver and restoration
13.98 @ 101

 

Tom, transmissions are designed to operate at a temperature that gives the fluid a particular viscosity and puts the internal clearances at optimal values. If you run a transmission colder than that, first you're going to make the fluid harder to pump around, and second the clearance aren't going to be quite right (the former being the bigger problem).

The tranny fluid cooling system is (typically) tied to the engine cooling system, which operates at ~160-195, so the engine and tranny operating temps are about the same. The only reason to keep the fluid cooler is because of the exponential reduction in fluid life as temperature increases above about 200 degrees. Above 250, the life is reduced to minutes. When the fluid oxidizes, it doesn't lubricate properly, clutches/seals/bearings/pump get hotter, fluid oxidizes even more rapidly, and things soon burn/wear out.

Now you'll get my standard sermon about synthetic ATF - extends the servicable temp range from about 160 degrees (lowest to highest temperatures where it performs satisfactorily) to about 300 degrees. Typical petroleum-based fluids will last a long time at 170 degrees - but, our factory thermostats are 195 degrees, and the factory electric fan doesn't come on until 238 degrees. Tranny coolers help, but don't solve the problem.

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82 Berlinetta, orig V-6 car, now w/86 LG4/TH700R. 2.93 limited slip. Cat-back from '91 GTA, Accel HEI SuperCoil. AMSOIL syn lubes bumper-to-bumper. Daily driver, work-in-progress (LG4 w/LB9 block, ZZ3 cam and intake, WP 305 heads ported & polished, TBD headers & hi-flow cat).
57 Bel Air, my 1st car. 0.030 over 396, Weiand Action+, Edelbrock 1901 Q-Jet, Jacobs Omnipack, 1-3/4" headers, TH400 w/TCI Sat Night Special conv & shift kit, 3.08 10-bolt, AMSOIL syn lubes bumper-to-bumper. Best 15.1 @ 5800' Bandimere. Daily driver while Camaro was being put together.

 

I was going to post response, but then I read five7kid's response and ... well, I don't need to anymore. He summed it up perfectly.