It is important to keep the Torque converter locked while towing for cooler trans temps. I have added a led light that tell me when the TC is locked. Then I added a TC lockup switch to use when towing to lock the TC. Just to note; my TC does not lock up until about 50 mph in OD. If I am towing in condition below 50 I can I can Lock the TC with the switch or I can downshift and lock the TC. With the Led light I know when it is locked.

There is more than one way to wire the light. Some like to wire the switch when they turn the switch on but I like it wired so that whenever the TC is locked the light comes on.

To wire the switch to come on when the TC is locked is easy. Tap the # 7 pin on the trans which is ground when the TC lock, and run a positive wire( cig. lighter) to the other side of the light.

 

This is good info, Appreciate it guys!

Any idea on what my temps should be when hauling, and what is too hot? (for both engine and trans)

 

110F Weather last sat:
Freeway w/ Camper (3200lb in truck bed), Engine ran 210-220F, Trans 180-190F
City w/ & W/o camper, Engine ran 210F, Trans 180-190F

If you want to keep the trans cool, try to drive such that the TC stays locked up.

Tony

 

My trans goes over 200 when towing, is this bad?

Also how can I keep the TC locked, just ease the throttle on/off and keep it in tow mode?

 

Much past 220* and bad things start to happen to ATF.




As far as engine temps,towing 11,000lbs in heat up to 90*,I've yet to see the coolant temps go much past 200. On a long hill,they go up to maybe 205,but as soon as you hit the top,they cool right back down.

 

How much weight? Under what driving conditions? What are your ambient temps? How many miles on the trans? Is it regularly serviced?

On an '05, I think if you keep it in tow/haul mode, the TC should be locking up as early as 30-35mph, under light throttle / light load.

I know older trucks can benefit from a TC lockup controller. Some lockup controllers I have seen claim to be able to lockup the TC as early as 18mph. But at ~$500, it may not be worth it.

Tony

 

Whats the weight rating on your 35's? Keep in mind that your tounge wieght will be anywhere from 1500 to 3000 pounds depending how the trailer axles are setup and how the trailers loaded.

 

My tires are the BFG all terrains, will have to check the load rating.

All the weight will be over the axles, so I estimating the tongue weight to be around 1,500.

last time my tranny was over 200 was pulling a boat (5,000lb) and ambient was at 100+.

 

If those are the BFGs in the 315 size, they are D rated. While they are rated for the same weight as an E rated tire, they do not have the sidewall rigidity found in an E rated tire. I would definately take it easy around turns or areas which you roll on the sidewalls, especially with that weight. Many stories of guys having no problems with those tires, but I would still be careful.

 

^^^^ Good to know, last thing I need is a blow out with a 15K trailer...

 

Well just got back from my trip. I was only able to haul one car so the weight was around 12K lbs.

Truck did pretty well overall, engine temps peaked at 215F while tranny temps peaked at 230F on the street, on the highway they stayed between 195-205F.

I think the tranny started to slip a little bit towards the end. From a dead stop the truck cab would shake when I would get on it, but the RPMs do not shoot up. Checked the fluid afterwards and it is still pink and does NOT smell burnt.

I already upgraded my trans pan, what else can I do? The stock tranny cooler is huge, are there any better upgrades?

Will getting a shift kit installed help out with pulling capacity and trans temps? I can only imagine how much worse it would be with another 3,500lbs behind it.

Your advice is appreciated!

 

i have rolled accross the scale many times at 25 to 26k in a 2500 so just hit the road.

 

Is your truck tuned? I am wondering if I should flash it back to stock when towing this kind of weight, I don't know really.

 

^^bump^^ Anyone?

 

a lot of reads, no replies?