Transmission cooler for the 4l80e

[silver97]

What aftermarket coolers are recomended for the 4l80e. I have a 97 k2500 suburban 5.7liter,4l80e,4.10 gear and towed my 7000lb travel trailer for the first time. The trans warmed up to 210 degrees and would not shift into overdrive. I turned 3000rpms at 60 mph constant. Also I know the engine oil cooler and trans cooler lines are inline through the radiator, maybe bypassing the radiator will help keep everything cool. the engine coolant temp was a little above 210.

 

[Crummins]

210 isn't bad for a towing temperature. I would not recommend bypassing the radiator as in cold months it will actually warm your fluid up (yes, you can overcool transmission fluid). It is weird that it wouldn't shift into overdrive, maybe it is a good thing as with the 5.7 it may search back and forth between OD and 3rd which will kill it. Do you know if it was in lockup? If not, you weren't getting your best cooling.

I think your best bet would be to replace the stock cooler with a larger one and it should help.

Here is a trans temp chart:

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My 96 Suburban has a factory cooler under mounted to the frame in addition to this cooler - again mounted to the frame: http://www.summitracing.com/parts/DER-15850/

While moving down the road, it gets to 170-180, if I stop and idle for a bit it will creep up to 200. Once I get on the road again, it cools back down pretty quick.

When I did the Cummins swap, I couldn't use the radiator cooler since the Dodge trucks didn't use one in the radiator. I live in the Pacific Northwest so it doesn't get too cold here, I don't think I will need to worry about overcooling.

 

[///RAGMC]

In my 99 silverado i had the factory cooler and the trans temp was always 2-3 degrees under the engine temp and sometime with the trailer it would climb over the engine temp. A few months back I replaced the factory cooler with this http://cgi.ebay.com/ebaymotors/Tru-...r_Truck_Parts_Accessories&hash=item4cfa05dc66 and WOW what a diffrence. Around towm the trans temp never goes above 150 and 3 weeks ago in the middle of the Arizona desert in 110 plus weather it never got over 165 I have yet to tow a trailer with it but Im sure its going to be a big improvement over stock.

 

[Fobroader]

My 4L80E in the 06 stays at well below 91C(194F) even when towing my travel trailer. I just have the factory towing package.

 

[454SSguy]

Heres some install pics of my tranny and oil coolers if you need some ideas

Just to start with, all tore apart

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Figuring out where to put it, that looks good.

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Close up of the cooler, with -6 hookups. Would have got the oil cooler too except they only had one.

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My awesome wife, hard at work.

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Gettin em all tied in.

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Finished product, will be much more impressive with a twin on the other side.

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Updates:

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All finished. Cept for the oil cooler thermostat. I gotta make a bracket and then it will fit neatly right by the radiator.

 

[silver97]

Thanks for the replies I ended up putting a tru cool max in series with the stock cooler. I had to relocate the horn. I haven't towed with it yet But I can see a difference in temps already. I also upgraded to the hd radiator which is a 2 row 2 1/4" thick, new severe duty fan clutch, new 16lb. radiator cap and a high performance water pump. Now I just need to figure why it won't shift in OD while towing. Is my trailer that heavy or have that much drag? Or do I need more torque/power?

 

[MOBS]

You don't need to tow with OD enabled anyways. That being said, my 96 won't go into OD until the tranny temps have reached the 190-degree mark, why? I haven't a clue, but that's even when it isn't towing.

Update: Now I know why, the temp sensor plug was not making good contact with the sensor's leads. Pushing down on back of plug would idle engine down, letting go would idle back up. Pulled plug, twisted some aluminum foil and shove into the contact holes, then plugged it back down. Runs perfect and shifts perfect....odd how that fixed what I'd thought for a while was a lemon truck.

 

[narizon]

Back in '0 I purchased one at the local yard for $20.Pulled it out a
'97 Chevy 1 ton Dually with factory HD trans cooler & hard lines in perfect condition.Well if it's good enough for a HD work truck it perfect for my cruiser.It's about the same size as the B&M #70270.Different trans on the 1 ton so I had to slightly bend the lines but other than that,smooth install & keeps it cool at all times.Best of all no lines to cut.Since my trans is out right now I'm going to cut the line to make them fit for the 700r4.While I was add it I also pulled the power steering cooler
and put it in.Figured it wouldn't hurt anything.

http://i608.photobucket.com/albums/tt170/narizon_album/P1030946.jpg

 

[sewlow]

Pix of the P/S cooler?

 

[MOBS]

Most P/S coolers are a 2 or 4 pass cooler.