Towing 8,000# TT in Overdrive

[Smokey1]

Wanted more information on towing with auto with 3. 55

I always bring it out of O/D when climbing hills, but how much can I get away with when going straight& level at 65mph???

I have the stock auto trans alarm,( light goes off and transmission shifts out of over drive) but don't know the temps that this happens at? Has anyone installed a gauge and had light turn on, If so what was you temp?? What was the temp when the light went off?

I have been bad all year and santa won't bring the gauge package( pyro,boost, trans. ) until February 01

thanks




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99 2500 QC,LB,Auto,3:55,limited slip. replaced muffler & resonator w 3" pipe and straight-flow muffler.
YTK Komfort TT 24ft w slideout

 

[Fireman Dave]

I'm not any kind of an authority, but I believe you're okay as long as the transmission isn't shifting in and out of OD - like it would be on the hills. Once you're on the flat, putting it in OD should be okay. Once the hills start, OD should be off. Another thing to consider, though - the RPMs would be more in their sweet spot with OD off, thus optimizing power. Higher RPMs (but not too high) may also produce better fuel mileage, according to some on TDR. I'm sure there are many that are more experienced than me that can give a more educated opinion.

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2001 2500; SLT; 4x4; QC; LWB; Auto; 3. 54 LS; 265s; Camper; Tow; Sliding Rear Window; Travel Convenience Group; Cab Clearance Lamps; Forest Green

 

[Big A]

The transmission will shift down automatically,and the transmission temp light will come on, when the transmission temp reaches 250*. These trannies are tougher than you think. Get a gauge on it, you'll be surprized.
Big A

 

[pwr2tow]

I triple trail, pickup 7100lbs, 5th wheel 9500lbs, boat 4000lbs, I tow in OD on the flats and out of OD in hills with no problem. Towing out of OD i get 7MPG and 145-165 trans temps, flats and hills. Towing in OD I get 9MPG and 145-165 trans temps also EGT's are about the same. Just change transmission fluid every 12,000 miles like your owners manual says and you should be O. K. I have 23,000 miles with approximately 15,000 of those towing. Get those gauges and it will put your mind at ease. Another thing about transmission temps is you will see high temps until converter lockup in either 3rd or OD, from srop signs or bringing it up to speed i take it out of OD until i get to 68MPH then take my foot out of the go peddle punch into OD let shift into OD then put my foot back into go peddle to keep my speed at 65MPH, my tach drops from 2700rpm to 1900rpms, better for fuel consumption. Regards, Ron

P. S. there are alot of guys on this board that talked me into doing this when i complained of poor fuel mileage. If my mileage didn't increase i would leave it out of OD as there is a small amount of extra power only due to more RPM's.

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1999, 3500, 6x6, slt, auto, 3. 54, Qd cab, ISB cummins, towing 2001 26RKSS Tahoe 5th wheel, 1999 120hp 1800 bayliner.

 

[Bill Kondolay]

njmech,

Hey i think you got a problem, one of two things to check.

1) If the trans temp sensor is going off, and it normally goes off at 230-250, you are getting extrememly hot. This will force the transmission to shift out of od into drive.
Check to see if the temp sensor is in good operating condition.

2)You have a mechanical problem.
a) Transmission and or tc clutch is slipping and generating a great deal of heat.
b) Cooler flow restriction. An example is that the one way flow valve in the cooler line is damaged and restricting flow.

In either case,the transmission pan should be removed and examined for contaminants.
While the pan is off you can also examine the factory transmission oil temp sensor located on the valve body.

The easiest thing to check so i check first is check your wiring connectors at the transmission for corosion and positive connection.

Bill Kondolay
Diesel Transmission Technology

 

[pwr2tow]

njmech, I should have read your post better. My trans light never comes on and it never shifts out of OD. Like Bill said you might have a problem. get those gauges and install the sending unit in the transmission line from the transmission to the heat exchanger, you will never regret buying those gauges sooooooooooooo much valuable information can be had.
I have the same gauge set-up you want in the A-pilar. Ron

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1999, 3500, 6x6, slt, auto, 3. 54, Qd cab, ISB cummins, towing 2001 26RKSS Tahoe 5th wheel, 1999 120hp 1800 bayliner.

 

[samb]

I run my truck in OD and cruise all the time on the open road. When I get into hills, if the hill are long I will kick it out of od after it downshift so that it will not shift back to od before it gets to the top. Mine will down shift at 59mph and most of the time it will pick up speed and shift back to od before geting to the top if the hill is to long. Most of the time one downshift is all it will do. Temp light has never came on and as for as I know my truck is stock.
SamB

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97, Lamanie SLT, clubcab, driftwood, 3. 5 spicer 70 rear axle
96 Coachmen Royal 285rk 5th wheel, 11,000 #

 

[Big A]

My light has never come on either. And I have a GCWR of about 15000. I tow in Colorado country. Bill, while your here, where should I have my transmission temp sensor.
Thanx
Big A

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'99 3/4 24 valver Quad,auto,KN stock, westin powder black pushbar.

 

[Bill Kondolay]

Big A,
Personally i prefer to have the temp sensor in the transmission out line. (line going from the transmission drivers side up to the passenger side heat exchanger. )

There are lots of ways guys install them, how i suggest is to buy the line from Chrysler 94-95 Dodge Ram, and keep in mind 24 valve guys you MUST REMOVE THE ONE WAY FLOW VALVE from the heat exchanger fitting as the new Chrysler line ALREADY HAS ONE IN IT.

For guys with the 94-95 trucks, you must splice into the line and use a T fitting.
When doing this be careful not to block the cooler flow with the temp sensor.

Lots of guys are also running the temp sensor in the pan. The Mag Hytec pans already have a port set up for this application(1/8th pipe).

DO NOT USE the pressure ports on the passenger side of the transmission as a temp sensor location.

Bill Kondolay
Diesel Transmission Technology

 

[Kodiak]

I’m in the process of trying to install and test a device called Dura-Trans from Intermotive, Inc. (http://www.intermotive.net/). This electronic box has been used successfully by police and cab fleets, and the company is now marketing to the heavy-tow pickup market. The device allows you to set a speed between 50 and 70 for OD activation. Once the OD speed is reached and it is activitated, the box holds the transmission in OD until a low-set speed is reach (15-30mph). This prevents “floating” in and out of OD, holding down trans heat and wear and brake wear. However, if the PCM calls for it, the unit allows a normal downshift.

Before I considered installing this box, I tested the optimum speed for OD upshift in my ‘95, and I found that 50 or 55 seems to keep things in the best power range for acceleration and EGT reduction (the factory-set speed is probably more for reaching EPA and CARB quotas). Also, this shift setup would prevent unnecessary shifts when running between traffic lights. Less OD shifts = less wear.

There has been a little install difficulty to date because of some wire differences on the ‘95 (fleets are usually later models), but Intermotive is researching, and I hope to have it in next week. I’ll report back.

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'95 2500 CC, SLT, LB 2WD, auto 3. 54, 69,000--Westech gauges, Prime-loc, Brite box, Back-off Box, Line X, Flowmaster muffler, Borgeson steering shaft, Geno's Crankcase Breather/Vent Tube Catch-All

[This message has been edited by Kodiak (edited 12-25-2000). ]

 

[Big A]

Bill
Thanx for the advice. I'll do as you explained.
Big A

 

[Smokey1]

Thanks for The info. I have been in Mexico for the past week.

I have never had the light go on and the downshift out of od. Thanks Bill.
Based on this thread the transmission is operating with no problems. I will be adding Egt, Trans temp and boost next month. Maybe I'll save a few $ for the mag
hytec pan #ad

Thanks all