Trans Cooler Question

[Hugh Mongus]

The PO removed the hard lines from the radiator and clamped on some rubber hoses that run through the radiator support to an add on trans cooler.

Any opinions why they would've done this? Is there a way to find out if the trans cooler in the radiator is clogged or not working? Should I just hook them back up and discard the additional stuff they added?

[hugger6933]

So they did away with the one in the rad altogether? That is not the way I normally see them piggy backed on to the factory cooler. You can hook up some ends to you rad and blow some shop air[turned down a bit] through the cooler to make sure it is not clogged or full of metal. Or maybe get a can of that trans flush stuff that goes in to the cooler lines to blow them out for when changing trans. Jim

[Andy4639]

Some people just don't like running the trans through the radiator cooler. Thinking it heats it back up to some degree. I always ran it to it first then the aftermarket cooler then back to transmission. Keeping a transmission as cool as you can is how you keep a transmission for a long time.

[Hugh Mongus]

So, if I blow air through it and everything seems clear, I should be ok hooking the lines back up as they should be?

[Andy4639]

Yes are just run some water through it. Either one will flush it out are tell you if you have a problem. I would use the water myself.

[leddzepp]

Water displaces heat more efficiently than air, the trans lines should go through the radiator and then an aux. Cooler if needed (usually for towing)

[mr48chev]

I don't think I would want to run water through the trans cooler in the bottom of the radiator and don't really think it would do any good as the water isn't going to break down any oil residue in the cooler. You could probably flush it out with brake cleaner though.

The way yours is hooked up is how a lot of guys who tow trailers in hot areas hook theirs up a big part of the time. The theory being that it helps both the engine and trans run cooler. Mine is hooked up that way because I tow a 5500 lb boat and trailer over mountain passes in the middle of the summer with it and don't see any ill effects in cold weather. It may take the trans slightly longer to warm up in cold weather but so far no ill effects.

Good bad or what not the rubber hoses are just the way those axillary trans coolers are normally hooked up.

[mrein3]

Originally Posted by hugger6933

So they did away with the one in the rad altogether? That is not the way I normally see them piggy backed on to the factory cooler. You can hook up some ends to you rad and blow some shop air[turned down a bit] through the cooler to make sure it is not clogged or full of metal. Or maybe get a can of that trans flush stuff that goes in to the cooler lines to blow them out for when changing trans. Jim

Originally Posted by Andy4639

Some people just don't like running the trans through the radiator cooler. Thinking it heats it back up to some degree. I always ran it to it first then the aftermarket cooler then back to transmission. Keeping a transmission as cool as you can is how you keep a transmission for a long time.

Originally Posted by mr48chev

I don't think I would want to run water through the trans cooler in the bottom of the radiator and don't really think it would do any good as the water isn't going to break down any oil residue in the cooler. You could probably flush it out with brake cleaner though.

The way yours is hooked up is how a lot of guys who tow trailers in hot areas hook theirs up a big part of the time. The theory being that it helps both the engine and trans run cooler. Mine is hooked up that way because I tow a 5500 lb boat and trailer over mountain passes in the middle of the summer with it and don't see any ill effects in cold weather. It may take the trans slightly longer to warm up in cold weather but so far no ill effects.

Good bad or what not the rubber hoses are just the way those axillary trans coolers are normally hooked up.

My first TRIPLE quote reply!

When I swapped from a 3-speed manual to a th350 I flushed the radiator tank, installed a temp gauge, and installed an auxilairy cooler. That was 13 years and 24,000 miles ago.

OK. Aux transmission cooler. Up here in the frozen wastelands, where we can and do drive our vehicles in ambient temps below -20F, -30F, my record is -36F, you can get your tranny fluid too cold. Down south the proper way to route tranny fluid is:
hot from trans -> radiator tank -> aux. cooler -> back to transmission.
Up here we plumb them:
hot from trans -> aux. cooler -> radiator tank (to warm it up a bit) -> back to transmission.

Regarding an open tank that you want to re-use, NAPA sells a can of stuff to flush the tank. It was under $10 and after dropping $300 or so at the local rebuilder's I thought it was cheap insurance. Its been a while but I'm sure I just read the directions and followed them.

I pull all kinds of stupid, heavy stuff. I plow snow. I pull stumps. I push docks in the lake in the spring and pull them out in the fall. In the winter my transmission runs 150 degrees. In the summer it never gets over 205.

[LockDoc]

-
If a person is having trouble keeping their engine cool sometimes they will remove the coolant lines and run them to an external cooler. May be what happened.

LockDoc

[Hugh Mongus]

It sounds like regardless of what I do, I will still need the auxiliary cooler. Correct? Even if I just drive it around town and never pull a load with it.

Thanks for all the information too.

[Andy4639]

The life of a automatic is based on how well you keep it under 200 degree's according to GM. I don't pull nothing with mine and my 700r4 had over 100,000 on the transmission. So yes leave the aux cooler on it.

[Hugh Mongus]

Andy, is there much involved with converting from TH350 to 700R4? I have been thinking about this lately. I'm running over 2k RPMs at 55mph. While this is fun at times, it's not much fun filling it up frequently.

[Andy4639]

The hard part is getting the TV cable right to kick down the transmission without burning it up. Mine was simple it came from the same car with the motor and all the brackets so I didn't have to adjust it. Cutting the drive shaft and having it re balanced and move the cross member back and the speedometer gear changed.