Does a 99 Z71 come with a factory Tranny cooler?

Matt99Z71 · May 12, 2005

Starting to do some hauling and wanna put a tranny cooler in my truck if it doesn't have one. If it does, anyone know the rating on it? Probably pretty small. I actually saw one the other day that was a tranny and oil cooler built in one, kinda cool.

redvett · May 12, 2005

Starting to do some hauling and wanna put a tranny cooler in my truck if it doesn't have one. If it does, anyone know the rating on it? Probably pretty small. I actually saw one the other day that was a tranny and oil cooler built in one, kinda cool.

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Do you have Z82 on your option sticker? If so you have HD towing PKG. If not i suggest you look at this cooler. The best on the market. Go to http://www.jcwhitney.com/autoparts/Product...trans%20coolers.

This is the same design that GM uses and works best.

DougsTJ2 · May 13, 2005

I like the mounting system that GM uses. I would go to the dealer and get one that it comes with. Air will definately pass through it but the heat won't transfer to the AC or Radiater by contact. There is about 4 to 5 inches between the two. If you don't go with a factory unit, I would rig it up so it will mount in the same fashion.

WhiteyZ71 · May 13, 2005

My '98 (OBS) has no towing package, but it does indeed have a tranny cooler from the factory

Turbine Doc · May 13, 2005

there is a full listing of RPO codes(what equip your truck camer with) in the 6.5 section FAQs at this site www.thedieselplace.com Depends what you are needing to haul I run a 25K rated cooler under my bed with a thermostat controlled electric fan that does not come on unless >170F.

Also get a deep pan, more fluid = less heat as more fluid to heat up www.yourcovers.com makes an excellent aftermarket deep trans pan

Cool Zr2 · May 13, 2005

All auto trucks have a cooler, its in the rad, it may not be the best unit but its a cooler.

99-2door · May 13, 2005

My '98 (OBS) has no towing package, but it does indeed have a tranny cooler from the factory

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That's true, but it doesn't have the aux. tranny cooler. I think that is what they are referring to.

Bish · May 13, 2005

All auto trucks have a cooler, its in the rad, it may not be the best unit but its a cooler.

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You're right but would anybody REALLY call that a cooler. WIth the radiator style tranny cooler, the in radiator cooler is better at bringing the temp up in cold weather than it is at cooling anything.

Temp is the biggest cause of failure in an auto. I would not drive any truck for any significant distance without a cooler ESPECIALLY if you ever tow anything. The 4L60E's in out 1500 trucks is really too small for the weight of the truck IMO. Every little bit helps for reliability of these things.

Matt99Z71 · May 13, 2005

Thanks for the replies, yea I have the Tow/Haul package, that was dumb of me. Whats the factory unit rated at? 20k? I suppose the factory one should be fine, all i'm towing is two four-wheelers and the trailer, which is for a Bobcat though.

Norseman · May 16, 2005

I have a 1999 1/2 Z71 5.3L . It has the AUX trannie cooler.

WhiteyZ71 · May 17, 2005

My '98 (OBS) has no towing package, but it does indeed have a tranny cooler from the factory

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That's true, but it doesn't have the aux. tranny cooler. I think that is what they are referring to.

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Well I just went a double checked, and sure enough, i saw the 3 letters KNP in my glovebox....

KNP Transmission, Heavy Duty Cooling System

and if i'm not mistaken, thats the aux. tranny cooler

496 CUBIC INCHES · May 17, 2005

Thanks for the replies, yea I have the Tow/Haul package, that was dumb of me. Whats the factory unit rated at? 20k? I suppose the factory one should be fine, all i'm towing is two four-wheelers and the trailer, which is for a Bobcat though.

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The factory aux. cooler on my 98' Z-71 was rated at 15K. IIRC the GCWR of my Z-71 was about 13K,so the 15K left a bit of extra capacity.