Transmission: Maually Locking And Coolers

Godti · July 7, 2009

I have some questions in regards to my truck and towing. I want to ensure I do not harm the transmission. So Im going to install a tranny temp gauge first to monitor the transmission temperature. There is a factory cooler already installed.

My questions are:

Should I replace the factory cooler, or keep the factory and install an auxiary cooler?

I have been reading up on installing a switch that manually locks the converter. Im not sure I understand the advantages of this? If I understand this, basically when you get to cruising speed you would flip the switch and this would ensure that the tranny is not "hunting".

I have only towed my RV once and have done in 3rd. But I was told if you monitor the temperature and ensure that the tranny is not constantly shifting gears you can tow in OD (on flat level grounds).

Cheers

AD

txab · July 7, 2009

Replace the factory cooler with a stacked plate cooler. I'd go with a 11" x 11" x 3/4" model. How much weight are you towing?

texx · July 7, 2009

I have some questions in regards to my truck and towing. I want to ensure I do not harm the transmission. So Im going to install a tranny temp gauge first to monitor the transmission temperature. There is a factory cooler already installed.

My questions are:

Should I replace the factory cooler, or keep the factory and install an auxiary cooler?

I have been reading up on installing a switch that manually locks the converter. Im not sure I understand the advantages of this? If I understand this, basically when you get to cruising speed you would flip the switch and this would ensure that the tranny is not "hunting".

I have only towed my RV once and have done in 3rd. But I was told if you monitor the temperature and ensure that the tranny is not constantly shifting gears you can tow in OD (on flat level grounds).

Cheers

AD

Do you have a trailering pkg with the truck? If you do it may already have an aux cooler on it. If it does you may look into replacing it with a larger one.

texx · July 7, 2009

Replace the factory cooler with a stacked plate cooler. I'd go with a 11" x 11" x 3/4" model. How much weight are you towing?

The stacked would be approx 2in thick. Factory is 3/4in.

www.derale.com/

Godti · July 8, 2009

Well the trailer dry is around 4400lbs, the GVWR on the trailer is 5600lbs.

It does have the trailering package.

So I should look into upgrading my cooler then. I live in Alberta so the weather gets cold here in the winter, I would need to install a bypass, correct?

redvett · July 8, 2009

If you have "KNP" RPO you already have at aux. cooler and nothing needs to be done. As for manual lock up you cannot do this on PWM transmissions without a SES light and doing harm to the transmission. Just take it easy with your towing and all will be good.

Well the trailer dry is around 4400lbs, the GVWR on the trailer is 5600lbs.

It does have the trailering package.

So I should look into upgrading my cooler then. I live in Alberta so the weather gets cold here in the winter, I would need to install a bypass, correct?

Godti · July 8, 2009

If you have "KNP" RPO you already have at aux. cooler and nothing needs to be done. As for manual lock up you cannot do this on PWM transmissions without a SES light and doing harm to the transmission. Just take it easy with your towing and all will be good.

Well the trailer dry is around 4400lbs, the GVWR on the trailer is 5600lbs.

It does have the trailering package.

So I should look into upgrading my cooler then. I live in Alberta so the weather gets cold here in the winter, I would need to install a bypass, correct?

Thanks.

Ill just add the Tranny temp gauge then.

Cheers

Wires · July 10, 2009

I
I have been reading up on installing a switch that manually locks the converter. Im not sure I understand the advantages of this? If I understand this, basically when you get to cruising speed you would flip the switch and this would ensure that the tranny is not "hunting".

The torque converter is typically 90% efficient. So for every 10 turns at the engine side, the tranny input shaft only spins 9 times. So, you're losing power/efficiency with that.

What the lockup does is lock the converter to give a true 1:1 output. Good for fuel economy. Locking it up won't change the transmission hunting. You can feel the converter lock/unlock if you're under load though. Techincally, when it unlocks, you get an extra 10% torque to the ground, so it's better when it unlocks for towing power.