transmission Temperature

[cwsoules]

I have a system which allows me to monitor the temperature of the ATF in the transmission sump. When in heavy traffic pulling a 10K 5th wheel moving slowly or not at all my transmission temperature has approached 190 degrees F. On one occasion I pulled off the highway and shut down the truck to allow it to cool before proceeding. As soon as my speed went up the temperature woould drop to aboput 160 to 170.
Then when pulling a 10K 5th wheel West on Nevada 160 out of Las Vegas enroute Pahrump (6% grade several miles long) my speed dropped to 40 mph in second and the transmission reached 195 degrees.
Is my transmission failing? I only have 20K on the truck? Any ideas on how to manage the temperature better?

If I make the Bill K mods to the transmission will that solve my problem?

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Chuck
2000 Quad Cab 2500 Auto w/4:10 rear end.
Rigged to tow a 5th wheel.

 

[RobbyRam]

On DTT's site, I think I read that the 'super worry' temp is 250 degrees.

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Y2K Awesome Black LB 3500 QC SLT, 24Valve ETC ISB, 4x4, 4:10 LSD, DTT Custom prepared Auto transmission VB, Power Edge 'EZ', DD2's, K&N, Polished Stull Billet Grill/Fog inserts, Chrome Smitty-Built Step Rails, Mopar Chrome-Tipped Mud Flaps, A-Pillar mounted West-Tach Turbo/Pyro/Trans Temp gauges, Rancho 9000's, Diamond Plated Tool Box, + a bunch of other stuff. Fact:The First Fords' had 'DODGE' Engines! The new PSD's need them!

 

[Dieselnerd]

I pull a 14K fifth wheel and seldom exceed 150 and that is out of the hot line going to the cooler. I suspect something is slipping badly or your gauge is not reading the right temperature. Normal temps while towing are about 140. I can get up to 200 or 230 while parking and going back and forth.

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Ron

'96 Club Cab 2500 4x4, 4:10LS, Camper/Tow package, Auto, BD Pressure Loc, Mystery Switch, TST 230/605, Cat Test Pipe, Cummins Chrome, Mag-Hytec rear and trans covers, Boost, Pyro and trans gauges, Optima Red Tops, All black. Tow 14k HitchHiker triple glide 5th Wheel. Also use 9. 5' Lance camper. NRA Life Member.

 

[WyoJim]

I copied a post of Bill K's to my word processor. I hope he don't mind me using it.

As a basic guideline i tell my customers
275 degrees is getting on the high side, when reading your trans temp from the front
cooler line, ( the line that goes from the transmission to the heat exchanger)
Keep in mind if you see temps going above that you should consider a secondary cooler
for your application.

When reading trans temps in the pan, Chrysler has their panic level between 230-240
degrees.

I usually consider 210-220 high in the pan.
If you are seeing temps above that you should consider a cooler for your application.

Normal operating temps between 180-190 out of lock up in the cooler lines , heavy traffic, (stop and go)

In the pan, normal operating temps should be 140-150. Bill K.

I can't imagine your truck slowing down to 40 in second gear on a 6% grade with 410 gears in the rear end. I would guess it would pull it in 3rd with the TC locked up. You will get no over heating as long as you can keep it locked. Mine won't unlock untill I get below 25 miles per hour with 3. 54's.

Are you attacking the hill? If you let it lug down too far in a higher gear it won't pull it in the next lower gear either.

Same in town. If you are not moving at all, put it in park.

The real danger to your TC is on the highway, cruising on the cruise control with your 5th behind you. When it is just trying to maintain its speed, it don't have enough line pressure to keep the TC from shuddering. It will feel like the wind is hitting you, but there is no wind. Bill K's Valve Body will fix that and help the temperature.

My transmission guy put mine in no charge when he serviced the transmission.


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98. 5 24 valve auto, QC, LB, EZ, DTT vb 9 1/2ft 3500# slide in S&S Camper

 

[B.G. Smith]

CW, I would say that 195 on a hard pull in 2nd gear is normal. The torque converter is un-locked and the heat is being generated there. bg

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White 99 3500, QC, 3:55, auto. most options except leather, Line-X bed liner, fiberglass running boards Rancho 9000s, bug shield and window vents, black vented 5th wheel tailgate, 110 gal. aux. fuel tank.

 

[cwsoules]

I do not tow in OD and usually tow in cruise control at about 62 mph.

I was in cruise control at 62 mph when I hit the hill enroute Pahrump. It is one long, long grade. When the speed dropped to 40 mph and the transmission shifted to 2nd I selected 2nd until I got closee to the top when the grade eased. As soon as the grade eased and I was back in 3rd the temperature dropped down to about 160.

I too have trouble with the sump temperature raising when I have to back the 5er up or jocky the rig back and forth. 200 degrees is my limit. When I get there I will shut down the rig and let it cool before trying for more backing.

I'll try cooling the transmission in Park, I did try in Neutral when stopped at a construction site on a Saturday on I-65 in Nashville with no noticable lowering of the temperature.

I appreciate the comments.

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Chuck
2000 Quad Cab 2500 Auto w/4:10 rear end.
Rigged to tow a 5th wheel.

 

[K_Arts]

Well, this probably doesn't help out your situation. . but here is what has been going on with me.

I have a DTT TC and VB, along with the Chrysler transmission line that has the port in it to plug in a transmission sender. Running empty around town, I can see up to 210 degrees. One day when there was a bad accident going home, I saw 250 degrees. After talking with Bill K about this, he has given me some tests to run. But overall we believe that my heating problem is a bad checkball in the transmission line (I am most likely going to take that thing out).

Normal operating temps for my truck seem to be anywhere from 165* to about 180*

Hope this helps out.

Kev

 

[Dieselnerd]

Chuck, why don't you tow in overdrive? With 4:10's your engine is really revving. As long as you are towing over 2000 rpm or so there is no harm in using OD. This subject has been tossed around on this forum many times. If you have the 3:54's and are towing at lower speeds that might be different. I think you'll find that most of us tow in OD with no problems whatever.

 

[MCummings]

My Dad's 2001 Chebby Duramax/Allison Pulls 19,000Lbs-30,000Lbs and has never gotten above 200*F on the transmission Temp Gauge.
The transmission Gauge is IN the instrument panel, if ya weren't in the know.

MerrickNJr

P. S.
As of right now he has about 7-7. 5K Miles on the truck. His LOWEST Mileage has been 14MPG
and He gets about 18 Unloaded w/Mixed City/Highway/OFF-Road

 

[WyoJim]

Chuck,
Thats what I meant by attacking the hill. Your cruise control cannot see the hill, and only tries to maintain 62 as it slowly applies the fuel and lugs its self down to shift at 40. When it shifted it went from 3rd with the TC locked to second with the TC unlocked. Thats a wicked gear change and the TC is heat shearing oil now. Or it might have already unlocked in 3rd. mine does if I get on it too hard.

Take it out of cruise control just before the bottom of the hill and at the bottom open her up, but not enough to unlock the TC. Watch the tacometer. At around 2500 open it up so it unlocks the TC. It should pull 10 thousand pounds up a tree in straight third.

Try a zero to 60 run against a stop watch without spooling the transmission up. Just one foot, Brake to the foot feed and at the same time hit the clock. When the speedo touches 60, stop the clock. It should say 13 or less. If it don't, then take it in to be reflashed.

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98. 5 24 valve auto, QC, LB, EZ, DTT vb 9 1/2ft 3500# slide in S&S Camper

 

[WyoJim]

Oh, I forgot to mention to do the zero to sixty stuff empty

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98. 5 24 valve auto, QC, LB, EZ, DTT vb 9 1/2ft 3500# slide in S&S Camper

 

[Big-D]

My understanding of cooling a high temperature transmission is to fast idle (1500 rpm)in neutral, not in park. Although I haven't had to do this myself, I was told by a transimission specialist that neutral allows the fluid to circulate and the fast idle provides fan cooling to the oil cooler.

Like to hear what the experts on this forum have say regarding the best means of cooling alongside the road.
Dave

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[amsoilman]

BIG-D,
Your right on the money! Cooling is best when the transmission is in nuetral. Synthetic ATF will also help to keep temperatures in check, as the fluid will help cooling.

Wayne

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94'SLT 4X4 AT/White in color. Factory Tow Hooks & Running Boards. Amsoil By-Pass filter, Amsoil Air cleaner,and all fluids are Amsoil. Optima "Red Top" batteries.
BD exhaust Brake, BD Torque Lock, BD Torque Converter, Dr. Performance Stage II Injection Pump. Mag-Hytec Diff Cover,Mag-Hytec Transmission Pan, Isspro Pyro, Boost,Oil temp Gauges mounted in 3 Gauge post mount. One gauge monitors Engine Oil, Trans, Diff. Temps.
Wayne Owen