transmission temps to high

[Slim]

Hello



I've got some concerns about my transmission temps (stuppid auto :{ ) being to high, I pull a trailer every day ranging from 12,000Lbs to 22,000Lbs CGVW and up to 13% grades with no problems. I only run my truck empty about 5% of the time, but on my last trip out to the bush (no trailer) my transmission temps hit 210deg. F (wich is very uncommon as the temps never go above 150) , and considering my transmission gauge is on the pan how hot would my presure line be? I don't have a deep pan and I only have two coolers. Should I get another cooler and a deep pan? or should I just bite the bullet and get a 5or6 speed . Oo.



P. S.

I hit those temps at less than 5lbs boost and only a couple miles an hour while going down logging roads.

 

[1stgen4evr]

high temps

As I read your comments, what comes to my mind is that you are begining to have slippage in a clutch pack or the torque converter is begining to make more heat than it has in the past. I was invloved with a heat problem on a crawler tractor application that had an automatic transmission. The design was adequate for about 500 hours but the charge pump would begin to deliver inadequate pressure which resulted in clutch packs slipping and if not tended to in short order the result was a burned out clutch pack. Doubling the charge pump size eliminated the problem.



From your description, you have something developing that an extra cooler won't solve. I can tell you from my experience that the manual will give you better mileage and basicly there is no heating problem with a manual, but from all the post here on TDR regarding the 4x4 application, you will not be completely free from transmission problems with any of the manual choices that are available.



I have both manual and automatic with my trucks and I like them both for different reasons. With the heat of this summer, I have cooked the torque converter seal in the automatic and am as of now only using the manual. I and I stress I have had very good result with the Getrag but my manual truck is not 4x4 and I don't load quite as heavy as you mention. I don't have any HP mods either to increase the load on the transmission. What is your axle ratio? If you have 3. 75 or 4. 10 that would take some load from a manual (or automatic for that matter and probably lower the temps).



Keep us posted.



James

 

[bmoeller]

How slow were you going? Were you holding the brakes a lot? What were the road conditions like?



If there were a lot of potholes, and you were riding the brakes, that was probably the problem. Low engine RPMs mean low oil flow through the cooler, and most likely, the fan wasn't running either. Flow through the transmission isn't that good on a stock trans, without any VB mods to improve it. The tighter convertor would only aggrevate the situation.



Going through looking at stuff at consignment auctions would heat up my old stock transmission very quickly. 200-220* was normal. Had to stop once in a while to let it cool off. The GB transmission won't go over 190-195*. This is even with a tighter convertor, too.



When you are towing, there is plenty of oil moving, more air getting the cooles working better, if your truck has a lock-up clutch in the convertor, that is helping out also. The oil heats up a lot quicker with it un-locked.



Just a thought.

 

[Slim]

Thanks for the feed back guy's



To answer some of your questions, I have a new transmission from BD and as far as I can tell there's no slipping do to the fact that I can lite up both back tires with my stock trailer on. I've got 3. 54 gears, I was going about as fast as you can go on 25% grades cut by a skidder (mild articulation only about 24inches, no air time). In regardes to the manual does anyone know if there is a bolt in aplication for an NV4500 for my truck or do I have to use adapters etc. if so then mabye I'll just get a NV5600. I don't really care about the extra gear in the NV5600 as I am not lackin in power, I just want a tough transmission in my truck.

 

[1stgen4evr]

Too Hot

I logged and cut pulp for 4 and 1/2 years so I have a visceral understanding of your application. You probably need an Allison transmission and even that may not be good enough. The 4500 is more or less a bolt in conversion but be advised that there are a 'lot of bolts'. The Getrag is in the same sense a bolt in conversion but for your job isn't likely tough enough. Either way you will have to change the column and pedals to go manual. Read up on the problems associated with the 5600 before you go that route.



Before you shoot the big gun on anything, get a can of Enginkool which is a CRC product that NAPA sells. A good many farmers around here use that product with some (10 to 30 degrees) success. Next to logging, farmers are pretty hard on their trucks. This is a 'water wetter' product that enhances the ability of the cooling system to dissapate more heat. I had already cook the converter seal on my automatic before finding that this product was available. The stuff is cheap and it just might do the job for you. Also, while you need to have some product to stop corrosion in the cooling system, you will get better cooling with no antifreeze solution. I used to run a very heavy solution of antifreeze but now only run enough to feel protected from freezing.



Is it possible that you have a leaking head gasket? Any bubbles in the radiator? You indicate that this is a recent problem and that it might have been ok previously.



Good luck with what you find, and keep us posted with the end result.



James

 

[TKingsbury]

Was your trans in "D", or did you manually select a lower gear? When you are going slow, below the stall speed of your converter, you will be generating lots of heat. Put it in low and get the RPM above the stall speed and your temps should go down. Sounds normal for an auto to me.

Travis. .

 

[Slim]

sounds like I was running the engine at to low of an RPM, yes I was in D and the rad fluid looks good. I think next time I will stick it in 4low just to keep the rev's up. I'm heading back up there in about a week but this time loaded (about 20,000lbs) so I'll see how it does in four low, Thanks again for the input. I think I'll look at doing the transmission this next winter, then I'll start using an exhaust brake and save on brakes.