Okay. What do I do now?

You're 1500 can't tow a 5000 lbs trailer? I towed my 7000lb trailer with my RAM 1500 and it was perfect. I am pretty sure other than the ratio, our trucks would be pretty equal with you getting the edge on payload...

get a 3:73 gear in it you will be fine

Did it stabilize at 200? Or did it continue to climb? Were you towing in 3rd/D or 4th/OD?

Are you locking out overdrive? Watch your tachometer and see what is happening. First, take note of what RPM the engine runs at normally on the flats at your towing speed, without the trailer. Then, monitor the RPMs with the trailer. If they frequently climb about 500, that is a sign that the unlocked torque converter is letting slippage take place, and this generates a ton of heat. Or if you see that the RPMs climb about 800-1000 to help the truck gain speed, then drops down (and the truck loses some speed), then the RPMs climb again, this tells you that the transmission is shifting back and forth too frequently and this generates a lot of heat also. Solution: lock out overdrive while towing, and see if this solves your heat problem.

The other question is, how fast are you towing? 65? Maybe faster than that? If so, you may just need to keep it down to 60 mph. Wind resistance increases exponentially with speed, so 5 mph reduction can make a big difference.

If you already have an aux tranny cooler you should not need another one. But check these things:
1. Are the cooler's fins dirty?
2. Did they route the tranny fluid lines correctly? They should go to the normal cooler AND to the aux cooler (first one, then the other), not just the latter. I have heard of screwups where they routed the lines wrong. Rare, but possible.

I really don't think that 200* trans temp is anything to worry about. Mine was up over 210* towing through the mountains last week.

200* isn't anything to worry about.

You need to keep engine RPM over 2500. I recommend gear swap to 4.10 ratio.
200 might well be normal and reflects also the increased coolant temperature because the thermostat is open.

All seems to be normal. 200 ain't nothing to worry about.

On edit, In your last post on this subject you kept talking about upgrading the TV.

You want a new truck, you are not satisfied with the current truck.

Upgrade my friend, that's what you want to do.

Thanks!

Jeremiah

Okay. To answer some questions. I had overdrive locked out and was running mostly in 4th. When my trans temp hit 190, I shifted down to 3rd. I never got over 55 MPH. My trans temp was climbing very fast and I pulled over and let it cool down to 170 before heading home. There was no wind today, so that was not an issue. It was 100 degree and I am sure the temp on the asphalt was super hot and that was making it hard for the trans cooler to keep the trans oil temp down. My tow/haul system is stock from GM, so I am sure it is installed correctly.

Okay, I just took a 30 mile round trip test drive tonight to Denny's. It is a slight downgrade all the way there and I did 60MPH. My trans temp started at 110 got to 168 on the way there. It took us about an hour to eat. On the way back my trans temp started at 150 and got to 179.6. It stayed at 60MPH and it is a slow climb almost all the way. The outside temp was 85 degrees during this test.


So the problem appears to be that my transmission cooling system cannot compete with Texas summer heat while towing a trailer.

So now I have to weigh my options. Here are my options

1. I can either restrict my towing to early morning and nighttime only, which will limit my daily travel distance significantly.

2. I can spend money to change the rear gears to a much lower ratio and maybe add an additional trans cooler, which will significantly reduce my empty fuel economy and slightly increase my towing economy.

3. Trade up to a larger TV.

Can you put a bigger tranny cooler on. Like one for an RV. Way cheaper than a new truck or gears.