Hummer Forums by Elcova - Transmission Running Hot

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Re: Transmission Running Hot

Quote:

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.

Re: Transmission Running Hot

Quote:

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.

Re: Transmission Running Hot

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.

Re: Transmission Running Hot

on the dipstick it says check level while parked and ideling. Ok done.

The level while not apparent in the pictures was between the two holes on the stick, the color seams ok. It's not supposed to be clear is it? It doesn't smell burnt.

Re: Transmission Running Hot

I'm pretty sure nothing else is going to fit infront of the radiator.

Re: Transmission Running Hot

dropping the trans pan will not be a problem as the exhaust is well out of the way. There is about 5 inches between the under body protection and the pan

Re: Transmission Running Hot

here are shots of the supply lines for the atf.

Re: Transmission Running Hot

there doesn't appear to be anything leaking and the trans fluid level seams to be ok.

I'm having a new AC unit installed in the house today so will not be able to take the truck to the dealership. I'll get to it and let you know what if anything they have to say or suggest.

The dealership that did the trans service is in Ca not practicle for me to get back to so I'll try my local dealership and see if they'll cover taking a look at the trans under warranty.

Thanks again to all of you for your suggestions.

Re: Transmission Running Hot

Quote:

Originally Posted by PARAGON

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

Re: Transmission Running Hot

The "blotter test" sounds interesting. Now thats a new one on me. Sounds like the sticky lifters and the quart of transmission fluid to unstick the lifters trick. Mabee a check with the amsol and 25 dollars will give more exact information. Not to say it dont work, its just new to me. I would like to know more about that suggestion though. But thanks Phil, I recieved everything! From the looks of the pics I dont see evidence of the pan being removed. Mabee a few pressure checks might reveal something, but again I think a trusted transmission performance shop might shed more light on the situation. FWIW My exhaust is in the same location and you stated the engine temp is normal right? If you cant trust the shop do the show me the money and ask to see it in some form of publication and verify what they are doing. If they dont want to do it then take it eslewhere.

Re: Transmission Running Hot

Quote:

Originally Posted by PhilD

Do the blotter test;

A quick way to test for worn ATF (in the t-case and tranny) is to do a blotter test. Place a couple of drops of ATF on a paper towel and wait 30 seconds. If the spot spreads out widely and is red (or maybe brown), the ATF is likely OK. But if the spot does not spread out and is dark, the ATF is oxidized and should be changed.

That's a good one Phil, I need to keep that one in mind.:)

Re: Transmission Running Hot

Phil, For the cost of transmission fluid I know what I would do! I totally agree with you. I think this problem needs more checks done. pressures and bands and new filter and oil changed. Mabee its worth it if it saves the transmission.

Re: Transmission Running Hot

Quote: H2 Ranger (FWIW My exhaust is in the same location and you stated the engine temp is normal right? )

Yes the engine temp stayed within it's normal range, while the trans displayed "Trans Hot" on the center console. By normal range I mean when the trans was at it's hottest the engine coolant never got more than the width of the needle above 210 however 185 is normal for my truck now with the 160 t-stat, so the engine coolant was affected by the hot trans.

However lets keep in mind my truck is far from "normal or stock" the S/C produces more heat, thats a given, a combination of a larger radiator, new high flow catalytic converters and 160-t-stat seam to have fixed the engine coolant run hot issue.

Depending on who you talk to about my previous run hot condition with the motor most are pointing to the catalytic converters being plugged and a continuing leaning condition being brought on by 1-3 clogged or partially plugged fuel injectors.

After having the passenger side head replaced because a valve guide got sucked into the head due to the motor running too lean and getting too hot on too many occasions, (although I argue the point too many) it was exactly 3 occasions and never driven for long under excessive heat but I guess that was enough to cause the problem. Having replaced the catalytic converts with higher or free flowing ones I probably could have gotten away with not going to the expense of changing the radiator or changing the t-stat, but it's done now and engine wise seams to be working correctly.

I don't think any one thing caused my truck to run hot. I think it's been a lot of things combined.

I'm just hoping the problem with the trans is easier to realize and solve.

Starting with a larger pan which will hold more fluid and a larger trans cooler if a place to locate it can be found I'm hopeful whatever is happening with the trans will be resolved.

The trans shifts fine, the trans operates at normal operating temps with city stop/go driving. There is no apparent slippage so I don't think anything internal is wrong, it's just getting too hot on steep or prolonged hill climbs.

Thanks again guys for all the suggestions:D

Re: Transmission Running Hot

Quote:

Originally Posted by PhilD

I'm not 100% that ATF blotter test is totally accurate, but it does seem to give a good indication. I always work on the basis, when in doubt change it. If ATF is very dark, smelly, or opaque, I change it.

The original dino ATF in my t-case went bad very quickly, and I change it every 10k now, worthy checking if you've never looked at it. same goes for the diffs, which don't ever require a fluid change according to the manual, just a top up. The fluid in them goes bad as well.

I've started using Royal Purple in the diffs and t-case and been very happy with it so far.

Completely accurate. It's a test that's used when evaluating oils and fluids for oxidation and breakdown. The blotter test lets you know that the fluid still flows because it spreads through the paper. If it is oxidized and gunked up, it will sit and not spread very much. They test how long fluids can sit at certain temperatures (mainly engine oil, tranny fluid, gear oil) to make sure it can not break down under extended use at XXX temperature.

Re: Transmission Running Hot

Learn more every day and even more researching. Little more to the story than whats said:

http://www.practicingoilanalysis.com/article_detail.asp?articleid=355&relatedbookgroup= OilAnalysis

Re: Transmission Running Hot

did'nt read the entire post but if your trans is getin hot enough to throw A warning(not just by the gauge) and your not towing you have an issue. New trucks should handle any environment without issue when left stock. Adding A supercharger will not affect trans temp unless you really work it up A steep grade with A lot of added weight as any H-2 will drop to 3rd and no tcc lock up while climbing A long grade. If you are towing and remove the trailer your trans shift adapts take A little while to adapt but should still not cause A heat concern. Have it checked out while under warranty even if it costs A few bucks, at least they have your concern on record if it fails 10k miles out of warranty.