H3 Couple questions about trans coolers

[Simplelife]

Well as the title says , I'm a bit confused , I live in south Florida where the lowest temps are 45 and that's only couple days out of the year.... Do I have to run a bypass or can I hook the tranny lines straight to the cooler and cap off the oem rad cooler... ? That's were I'm confused at, some one please clarify this ! Thanks buds

 

[woodwardsh3]

if you use a plate style cooler you do not need to run it threw the radiator. If it is a cheaper tube style then I think it would be a good idea,

 

[Simplelife]

So, what you are saying is I can go buy a cooler from Napa and cut the tranny lines and connect the hoses from tranny lines to new cooler and cap off old oem cooler .. Correct ?

 

[alrock]

Correct. I do not run a bypass here in AZ. Some of the coolers have thermal bypasses that will help for the cooler days in Florida, or if you travel north. That should be sufficient for your needs.

Go large when sizing that cooler. Most of those online sizing charts are for when you add on the cooler to an existing one. I'd go up a couple of sizes if using the plate cooler standalone from the integrated cooler.

 

[Simplelife]

Alrock, that sounds great.. In May I plan a trip from Naples fl to Laredo in the h3... So just trying to do some mods before I go.. We usually take the Cummins .. This will be the first time we take something other than a Cummins.. So just trying to get things done.. Napa as a great selection of coolers I'm going to pick one up Friday , to install Saturday.. I just feel so new to this hummer world . Next will be an airdoc, it's quickly becoming an addiction! And I bought it for my wife lol

 

[Graham2990]

I used this cooler from Jegs to do a complete bypass of my OEM Radiator. http://www.jegs.com/i/JEGS+Performance+Products/555/60382/10002/-1

My average trans temps on my Scangauge ranged from about 180-200 with ambient temps being around 70 degrees in traffic.

I've yet to break 175 while sitting in stop and go traffic since installing.

For what it's worth, I also own the equivalent B&M cooler on another vehicle and can't tell a difference between them physically, or performance wise.

 

[H3nightrod]

Make sure you have your hoses sized up correctly with the line.
I have a H3 alpha and my hose were blown off due to pressure build up. If you blow the hose you wI'll toast your trains.

In my opinion go with a aluminum radiator with a built in cooler. Sorry just my opinion.

 

[amrg]

I ran the 30K trans cooler from trucool. Its rated for 34K btu and is meant to bypass the radiator, never got over 185 and thats with 35s and heavy offroad +110* weather. Just upsized it to a 40K GVW cooler and the temps with my stall are at 150!!! I still need to drive the truck with the new setup more often to give better numbers.
The trucool can be bought with a thermal bypass.

www.transmissioncoolers.us/category/trucool-MAX-cooler.html

You can never be wrong with a big cooler.

 

[Simplelife]

Great info, I was just scared my tranny wouldn't shift right due to over cooling.. But I'm not worried anymore.. I'll pick 1 up tomorrow ! Thanks guys !

 

[4speedfunk]

I'm with Nightrod...just get an aluminum radiator with the built in cooler. It's cheap, quick, easy, looks great, and solves the cross-contamination issue.
I've not heard of any cooler failures on aluminum radiators. However I have heard of tranny issues after installing outboard coolers.

 

[Simplelife]

Well, I've searched for hours . I think I'm going to buy a cooler from Napa and cap off my oem .. I'll do that this weekend and get back with you guys for my results

 

[digglesworth]

i put a fan on mine. plate/fin is definitely the way to go. ive had 3 different setups and this is the winner by far. im running an 'improved racing' 165deg thermal bypass here in the midwest since it gets pretty cold here. i completely bypassed my radiator. in fact, ive replaced my radiator since then with a manual trans version w/out the internal cooler. normal operating temps are 172-174 on my scangauge. i think ive seen temps rise to the low 180s like twice.... but never any higher than that. I put the fan on a switch instead of a thermostat so I have full control. Automatic fans can be very bad in water crossings so the switch makes sure I can turn it on/off whenever I want to.

 

[H322]

What are some available options for aluminum rads with built in tranny cooler? I have done some research and was just about to pull the trigger on an aluminum rad and electric fan but will hold off till I find the best option for a trans cooler I am new to all this so please bare with me if I ask dumb questions. Thanks for the help


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[Simplelife]

i put a fan on mine. plate/fin is definitely the way to go. ive had 3 different setups and this is the winner by far. im running an 'improved racing' 165deg thermal bypass here in the midwest since it gets pretty cold here. i completely bypassed my radiator. in fact, ive replaced my radiator since then with a manual trans version w/out the internal cooler. normal operating temps are 172-174 on my scangauge. i think ive seen temps rise to the low 180s like twice.... but never any higher than that. I put the fan on a switch instead of a thermostat so I have full control. Automatic fans can be very bad in water crossings so the switch makes sure I can turn it on/off whenever I want to.

That's awesome , Im going to completely bypass the oem and cap off as well ,, I might not do the fan yet maybe that will be the Next mod ... Another question is which line is the in and out on the tranny ? I read you want to feed the cooler from the bottom and exit out of the top.. Correct?

 

[Babyjohn460]

^^^ What h322 said. May have to look into separating the rad from the tranny cooler. I'm assuming most of the aluminum radiators are direct swap?


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[woodwardsh3]

Make sure you have your hoses sized up correctly with the line.
I have a H3 alpha and my hose were blown off due to pressure build up. If you blow the hose you wI'll toast your trains.

In my opinion go with a aluminum radiator with a built in cooler. Sorry just my opinion.

Did you double flair the tube ends before putting on the hose, so the clamp an hose cannot slide off the tube?
If you clamp the hose on to straight tubing without a double flair it will come off at the worst time.
Just my 2 cents.

 

[Simplelife]

http://www.napaonline.com/napa/en/p/ATP17508

im looking at this cooler .. What do you guys think ? There is also a bigger one for 10 bucks more

 

[woodwardsh3]

That looks like the one I have. If it has the worm style hose clamps, Spend the extra money on the high pressure clamps like they use on high pressure fuel lines. If you cut the trans tube's make sure you double flair the ends so the clamped hose can not slip off.

 

[Simplelife]

Ok 10 4 , I'll buy a flare tool

 

[Simplelife]

Ok I'm back to square one.. My transmission guy said not to spend money on a cooler and just buy an aluminum radiator .. Now where can I buy one for a 2008 h3 ?

 

[alrock]

Question: it's been posed that an aluminum radiator is better than a plastic one in terms of preventing transmission cooler failure. Help me understand that idea. Isn't the trans cooler simply a cooler placed within the radiator, essentially independent of the engine coolant tank whether that's aluminum or plastic? I don't think the plastic tank failures correlate to the transmission cooler failures. Am I incorrect?

 

[Simplelife]

That's what I thought ... I thought aluminum or plastic the inner cooler will still be there ? I was reading that the oem cooler is held by 2 o rings and aftermarket are by 2 nuts .. Figuring the only way perhaps maybe a oem cooler can fail is from using straight water and it some how corrodes ? And cracks ? I'm so lost by figuring out this .. Every other radiator has the same set up ??? We need a transmission guru

 

[4speedfunk]

I think you guys are over-thinking it. Just buy an aluminum radiator...slap it in...drive it.

 

[Simplelife]

I think you guys are over-thinking it. Just buy an aluminum radiator...slap it in...drive it.

I'm with you on that one .. Where did you buy yours ?

 

[4speedfunk]

I'm running a stock plastic radiator but, here's the ebay link:

http://www.ebay.com/itm/262005228616?_trksid=p2055119.m1438.l2649&ssPageName=STRK:MEBIDX:IT