Transmission Running Hot

[Fubar]

Hi all; if it's not one problem it's another At least it seams that way for me lately.

Here's my current concern; while climbing long grades or steep mountain passes my trans gets hot to the point where "Transmission Hot" appears on the center console.

I know simply pulling over and leaving it in park and letting the motor run for 10-15 minutes brings everything back to normal. It's just a pain..

But considering I'm not towing anything and the trans is reaching this "Too Hot" condition, I'm wondering if getting a larger trans pan, one that will hold an additional 3 quarts if this would solve this problem?

I guess a larger trans cooler might also help but with my recent past engine running hot issue, which I can happily say has been solved, anyway with this past trouble in mind I don't really want to stack something else in front of the new radiator.

So would something like this work? It say it supports up to yr 02 and the list of trans that it says it will fit doesn't list the one in the Hummer (Hydra-Matic 4L65-E).

http://www.xtremediesel.com/index.as...PROD&ProdID=29

Thanks in advance for any suggestions

[H2 Ranger]

Check some of the racing parts suppliers, they have many configurations as it pertains to Transmission coolers. Some offer remote cooling fans and alternate mounting locations, additonal remote filters, larger oil supply lines, etc. Anything that give addition oil supply and cooling area mass will help. Hope you get it resolved.

[MarineHawk]

Is this normal? Or is something wrong with the tranny? Also, do you have the two/haul mode thingy? Would it help? Mine shifts higher and more sharply in the tow haul mode.

[Fubar]

Thanks guys.
Adding a larger radiator that holds 2-3 extra gallons along with adding a couple additional rows of cooling fins solved my run hot issue with the motor/supercharger. Even though the trans got hot the engine coolant remained at or below 210 which is normal for the H2.

So I was just hoping that by adding a larger pan to the trans that the same would hold true for that system.

I'll continue looking at options.

Just running around town there's never any problem with the trans getting hot but it seams that when its under any prolonged stress/load and the temp continues to climb. I would expect the temps to climb if I was towing anything but I wasn't.

The trans was just serviced in April. I'm guessing they pulled the pan changed the filter and re-filled it with oil. I'll check to make sure they actually filled it.

As for the tow/haul button, good question. I don't know I've never used it, it is there. The trans was not hunting or shifting as I was going up the grade. 2000rpm's 60-70-mph I wouldn't think that would be too much for the truck.

On the my trip to Big Bear 8200 feet up and doing 20-mph up windy roads I kind of expected to see the trans temp raise just not as high as they did.

What concerned me most was on the way home from Ca there are two 5000-ft passes spanning 25 miles 16 miles on one and 9 miles of climb on the second or may it's reversed either way near the top of the second pass the trans got to the point where I needed to pull over. Outside air temps were 80-85 not what I would consider a problem.

I'm rambling... Thanks again for the suggestions.

I see an F250-F350 in my future (possibly)

[Fubar]

Phil,
wouldn't adding an additional tranny cooler possibly make the trans run too cool most of the time under normal day to day driving and possibly cause a problem of its own?

I've been told that if you make the front part or one part of the trans too cool the back end or other part has to work extra hard to make up the temp difference. I don't know anything about trans or how they work so this may be complete b/s..

Adding a trans cooler seams like it would be the lesser complicated or cheaper way to go.

Thanks

[Fubar]

Phil,
looking at your pictures of your install of the Hayden Ultra Cool I can't install the unit in the same place due to the fact that the innner cooler for the S/C is currently there. I have no doubts that installing a trans cooler where you have it would reslut in much cooler trans temps.

The other possibility might be to place the additional trans cooler in front of the radiator and put a fan on it to make up for the lack of air coming threw the front grill.

[H2 Ranger]

Has the overheating been since the vehicle was new? or has it started since service?

If its been that way since service:
1. Maybe the bands were adjusted too tight thus causing excessive friction.
2. Is the pick-up filter properly installed?
3. Is there any line restriction including bent or twisted lines?


Seems like you might have noticed it earlier if its been overheating. Additional cooling and or fluid capasity is always a good route to go.

[H2 Ranger]

Heres one for you and there are others..

[Fubar]

H2Ranger, ya I was looking at those on-line last night. I'm just a little leary of anything made by flex-a-lite because of the troubles I've had in the past with there fans. In all fareness the fans were probably just fine it was just a crapy job of installing the control module that I believe caused my past problems with the fans.

Thanks though I will continue to look that option and others.

Originally Posted by H2 Ranger

Heres one for you and there are others..

[Fubar]

question; does the truck need to be in drive when the trans fluid level is being checked? I mean do I need to tackel a neighbor and ask for help with checking the fluid level or will placing the truck in park and letting it get up to operating temp work?

[H2 Ranger]

Originally Posted by Fubar

question; does the truck need to be in drive when the trans fluid level is being checked? I mean do I need to tackel a neighbor and ask for help with checking the fluid level or will placing the truck in park and letting it get up to operating temp work?

dont ask me to help, but no just operating temp., and check in park.

[H2 Ranger]

Originally Posted by Fubar

H2Ranger, ya I was looking at those on-line last night. I'm just a little leary of anything made by flex-a-lite because of the troubles I've had in the past with there fans. In all fareness the fans were probably just fine it was just a crapy job of installing the control module that I believe caused my past problems with the fans.

Thanks though I will continue to look that option and others.

you can attach any fan to the cooler (pusher or Puller)depending on mounting and location conditions.

[PARAGON]

I would fashion a heat shield over the exhaust crossover first, before I did anything else. The radiant heat could simply be cooking the bottom of the tranny pan when working hard as your exhaust temps would be running higher than a stock rig would and that would show up on an extended grade climb. Cheap and easy that might just help.

[Fubar]

Originally Posted by PARAGON

I would fashion a heat shield over the exhaust crossover first, before I did anything else. The radiant heat could simply be cooking the bottom of the tranny pan when working hard as your exhaust temps would be running higher than a stock rig would and that would show up on an extended grade climb. Cheap and easy that might just help.

Paragon, thanks. I can see in this pic exactly what you mean. The exhaust is pretty close to the pan.

[KenP]

Originally Posted by PhilD

Not sure how much difference a bigger tranny pan will make, but a fonned pan will help a little. You'll have to remove the exhaust to replace it, and some of the deeper ones will not fit because of the exhaust location, so make sure you measure first. That seems pretty expensive also.

I added an additional tranny cooler it made a quite a difference;

http://www.*******club.com/tech/tranny_cooler.html

If you are concerned about redicing flow to the main rad, you could mount one somewhere else and have a fan for it. I think someone else did that ?

Great write-up Phil. I thought of your problem when I read Fubar's post.

[KenP]

Fubar, FWIW, our old truck NEVER got hot. Even during the VA Beach to Moab run. Heck, our new truck doesn't get hot either. Somethin's rong, brotha.

Find a place to mount a 4 pass trans cooler in front. Look hard, I know there's space. That'll solve your problem.

Keep us updated, buddy.

[Fubar]

Ken thanks.
mount a trans cooler up front, where?

there are 3 coolers stacked (4) if you count the inncooler for the s/c in front of the radiator.

The 3rd in line or 2nd largest I'm guessing is the current trans cooler, don't know what the other two are.

Perhaps if the front most one bracketed by the black braces can be relocated a new or additional trans cooler could go in it's place. ?

[H2 Ranger]

Check out this article talking about xsmn cooling;

http://www.carcraft.com/techarticles/116_0308_cool/


Also consider the following mods:

Shiftplus electronic Improver kit

Shift improver kit (for valve body)

both from B&M

Both of these kit reduce slippage and heat buildup

[Fubar]

Originally Posted by H2 Ranger

Check out this article talking about xsmn cooling;

http://www.carcraft.com/techarticles/116_0308_cool/


Also consider the following mods:

Shiftplus electronic Improver kit

Shift improver kit (for valve body)

both from B&M

Both of these kit reduce slippage and heat buildup

Ranger thanks for the info and the suggestions. The article was informative and I'm seeing that there are options out there. I just need to find a quality repair shop here in town. Thanks again.