TRANSMISSION HOT

[mmayo]

Well today while towing my dads spray machine, "TRANSMISSION HOT" came up on my instrument panel. I was surprised to see it, I had the cruise set on 30 MPH was running around 2000 RPMs and the trans temp was around 200*, which is NOT in the RED. Under normal driving it is around 160*. One thing to note is I didn't have my TOW/HAUL mode on, which I immediately pressed. I drove about 2 miles and slowed to about 25ish and it went off - but the temp gauge didn't budge The weather down here was about 75* so it really wasn't that hot. I looked the spray machine up on the John Deere website and it weighs 11,200 lbs, and it also had around 200 gallons of water/chemical in it. Couple ?s.....Is this normal for the it to say the TRANS is hot when its not even close to the RED, could this be due to my WESTERS HOT TUNE - I went for all out power and light towing, or was it because I didn't have my TRANS in TOW/HAUL mode?

[mmayo]

Heres a pic from my phone.

 

[manytranny]

T/C was probably unlocked, creating heat. Im not sure if T/H mode would do anything going that slow.

 

Does the fluid look burnt? Allison or 4L 80?

 

Going up a hill?

[c5vetteman]

I was reviewing the Wester's info on TBYRNE's web site and it states:

 

" 5) 93 Octane HOT tune (much more aggressive than the Dual octane tune)

(Recommended for performance trucks. No, or very limited, heavy towing or hauling!)"

 

Also, you stated:

...I looked the spray machine up on the John Deere website and it weighs 11,200 lbs, and it also had around 200 gallons of water/chemical in it.

...WESTERS HOT TUNE - I went for all out power and light towing,

 

Considering that the water probably added around another 2000lbs, I would say that you qualified for heavy towing.

 

I would maybe email Tom or call Wester's to see if they have come across this problem before. But, it sure looks like there is a correlation between the two events.

[Butch 02 Denali]

Hey Mike,

 

DEFINATLY use tow/haul mode when towing something heavy. You had two problems, one the engine rpm was a little below the stall speed of the torque converter, so you had some slip there, and your speed was below the converter lock-up speed. Tow/haul probably would have keep the tranny in second gear to keep the revs a little higher. If it wasn't pinging it isn't a problem with the Wester's tune. If your going to tow this kind of weight again, I'd look into a tranny cooler. I'd also highly recommend changing to synthetic tranny fluid!

 

Butch 02 Sierra Denali

[mmayo]

truck wasn't pinging at all.....so i dont think it had anything to do with the westers tune either.....as far as the fluid, i looked at it and it looked fine - like I said, it was only on 3-4 min tops so im not worried anything was messed up.....the thing that i didn't understand was that the trans temp gauge was no where near hot, it was around 200* - only about 40* higher than normal, so why did it come up on the display? Butch, can you explain this further, "You had two problems, one the engine rpm was a little below the stall speed of the torque converter, so you had some slip there, and your speed was below the converter lock-up speed"????

[Butch 02 Denali]

The converters in our trucks have a "stall" speed of around 2000-2200 RPM. That means the torque converter will slip a little till the engine hits that rpm. Even when the stall rpm is reached the torque converter will still not achieve 100% efficiency. That's where the clutch takes over. The torque converter also has a clutch in it, very simular to a clutch in a standard transmission. It is controlled by the computer and will lock at roughly 35 mph. You just happened to be at a rpm and speed that had neither met stall speed or lock-up.

 

Don't forget too, you were at least 25% over the towing capacity of the truck!

 

My guess is the computer saw a FAST rise in temperature and that is why it gave the "Hot" message.

 

Butch 02 Sierra Denali

[mmayo]

one thing i did notice was that when i had it in tow/haul mode the RPMs would increase from 2000 to 2200 but it didn't seem to switch gears........could the computer have increased the RPMs to get into a range where the computer could lock up? also, on the farm, towing these types of loads - and heavier are an every day thing.....

[Butch 02 Denali]

I'm pretty sure tow/haul will hold it in 2nd gear at that speed, getting above the stall speed and elimanating most of the slip and resulting heat. Third gear at 20 mph was probably "slipping" up to that 2000 rpm. I don't know your gear ratio you have but would guess 3rd gear with no load would put you around 1200-1500 rpm?

 

I bet there are many that tow these kinds of loads with no problems. So long as you take it easy you shouldn't hurt anything. The biggest problem with towing loads this heavy is braking ability anyway!

 

Butch 02 Sierra Denali

[mmayo]

im sure thats what it was doing when it was raising the RPMs up to 2200, cause like i said, the message went away shortly after i put it into tow/haul mode, and it didn't change gears, just went to higher RPMs......guess that button is there for a reason!

[c5vetteman]

Butch,

 

For my own knowledge, why does Wester's state that the 93 Hot Tune is for light towing? When would pinging typically occur?

 

Thanks

[Butch 02 Denali]

Every truck/engine is SO different. On some trucks, like Mike's, he can tow 12k pounds with a hot 93 tune and not get a ping. Put that exact tune in an identical truck, and it could ping driving down the street empty. Some trucks ping on the stock factory tuning! The Wester tune list is kind of a starting point to roughly describe the tunes available. They are fine tuned by the choices on the order sheet like towing, light to heavy, and power verses economy. Then, after you get your tune from Wester's, if you are one of the unlucky ones that does get pinging, he will burn a second program for no charge to fine tune it exactly for your truck.

rather than start with a tune that will work with most all trucks, like the Hypertech and others, Wester's starts with a maximum tune and tones it down for your specific needs. The 93 hot tune is really a maxed out program, developed for sport trucks that do little work. I'm amazed how well it works for working trucks too, although sometimes it needs a little tweaking. This really is custom tuning!

 

Butch 02 Sierra Denali

[Butch 02 Denali]

OOps, double post!

[JDahl]

If I remember correctly The guage really wasn't that accurate. Where the red line is located the temp is far over the fluid temp where damage and burnt fluid occurs. The optimum trans temp is 190 degrees. However with the load you were carrying and were you in overdrive? If you plan to tow that much again Please do your trans a favor and tow in manual third.

John