Hey Mike, I have had my Superchip installed for about a year and a half. Just started towing a 5K 5th wheel. I had a tranny temp gauge installed in the pan (for now) and have been monitoring the temp. I know that when the TC unlocks it generates more heat. At highway speeds 60-70 the TC will unlock earlier than I would like. On just about any incline that drops the Mph's around 5. My question for you is does my chip change the unlock point from stock? And would a custom burn be advantageous? I do wish I could just give her more gas to make the grade without the TC unlocking.

Thanks

 

Hi IAG,

What's happening is a downshift in response to the higher load of a grade (hill), in addition to the torque converter unlocking just prior to that downshift, so it's a combination, actually. The TQ will unlock first, and if that doesn't provide enough power, then the tranny will downshift as well. What basically happens anytime you're trying to tow a load up a grade is the ECU senses that it cannot maintain speed, whether it's set on cruise control or via your right foot, and so it instructs the transmission to react (as it should) by unlocking the TQ and then downshifting if need be to provide more torque multiplication, thus effectively increasing the amount of actual power being applied to the rear wheels.

WIth regard to altering load tables & other areas to allow any significant increase in load with, in effect, no response from the transmission, meaning either not allowing the TQ to automatically unlock or not allowing an automatic downshift until load is higher than when those things occur right now, this is something you really do not want to do, *especially* for towing.

Under load, the TQ unlocks, and the transmission downshifts as well if need be, in response to the sophisticated algorithms in the powertrain program that are vehicle speed & throttle position versus load dependent.

If we changed parameters to allow for significantly increased load to be tolerated without unlocking the TQ, you would effectively lose power due to no increase in torque multiplication as is required, and that would also adversely affect driveability in other situations as well, not allowing proper TQ action/downshifting in response to increasing load. Bad chu chu.

Unlocking the TQ and downshifting both provide more torque multiplication, in effect, giving you more power. Yes, it does of course increase slippage a bit when unlocked, and so tranny fluid temps will go up when towing something up a hill as compared to driving on level ground, of course. Same thing happens when it downshifts, as now you have internal transmission components turning faster as well as the TQ unlocked, so you have more heat being generated. That's why you need to have an auxiliary transmission fluid cooler on any automatic transmission in any vehicle, whether it tows anything or not, as heat is any automatic transmission's biggest enemy. When towing, we recommend installing another tranny fluid cooler **in addition to** the cooler that comes with the towing package from the factory. For any towing, for any drag racing or other kind of racing, and for aggressive driving on the street, etc., we recommend installing an additional fluid cooler that also has a fan on it with automatic thermostatic control, so that anytime the automatic transmission fluid hits a certain temperature, the fan kicks on and brings that tranny fluid temp right back down to protect the long-term health of that transmission, it's clutches, bands, the TQ itself, etc. That's really the only way to properly address those fluid temperatures, with an active system that is automatic and thermostatically controlled, and that is very easy to do.

Ideally, tranny fluid should never go above 200 degrees, and in normal conditions it should stay around 180 degrees; once you go above 200 degrees, fluid breakdown & seal deterioration is accelerated, and it always goes higher with any factory setups in these F-150's and most other auto-tranny vehicles too. Automatic transmission fluid temperatures can very easily go beyond 240 degrees or higher when driving in traffic without towing, and can hit 260-280 and even higher easily in Summer when towing up a grade, or when drag racing, etc. And with transmission fluid coolers that do not have a fan on them, it takes a long time for the fluid temperature to come back down to normal levels once the load has been reduced or the race is over, so once you heat up that fluid, it's going to be hot for a while unless you have a fan-assisted cooler.

Bottom line, we advise not changing that, just let the transmission do it's job properly as it needs to, and do what is required to keep the tranny fluid temperatures in check. You'll have a longer transmission life and your vehicle will have better driveability & response whether it's under a big load like that or driving unloaded.

Give us a call if you want to go over the details of a proper thermostatically controlled transmission fluid cooler, or to go over any of this in more detail.

Good luck!

 

Mike;

How about just changing the programming to give the computer the ability to lock the converter in 2nd? I have heard that the new diesels will lock up in 2nd. This would be useful for towing long grades.

Ian

 

I've read about a simple 2 wire and a switch mod that will lock the tq converter in 2nd. Search around in the www.ford-diesel.com site. The mod was for the 4R100 but may also work for the 4R70.

 

V10 Man - I read that one too but was looking for something that was more automatic. One thing that is interesting is that the BD torquelock only jumpers the TCC lockup wire not the coast clutch, so I was wondering if the coast clutch jumper is necessary.

BTW, I have the 4r100.

Ian

 

Hi Ian,

Good question, actually!

I still have some of the same concerns expressed above in terms of us trying to do a solution for that in the powertrain program, just because of it potentially happening at times we wouldn't want it to. It would have to be a load-based variable to have any shot of viability, and that may well take some specific R&D.

Most people wanting to do this have done the manual switch type of implementation, that sure is a lot simpler, though maybe not as elegent, perhaps.

If you'd like to give us a call, we can go over your vehicle info, computer code and exactly what you're thinking of in terms of the specific operational aspects, and then take a look to see if that might be viable for us to do for you.

 

I searched briefly on this manual tc lockup mod. I wonder if it will harm my tranny if used properly? Here is the write up. Mine's a 4r70 anyway. Why wouldn't it lock in 3rd gear too? That's what I need.

"basically, you'll find a light blue wire with a yellow tracer at the connector (to the tranny) on the passenger side of the rig...you'll tap into that wire>>route it to a switch, and then run a second wire from the switch to 'ground'...

 

Geeky

My truck does lock up in 3rd no problem but not in second or when decelerating. The manual override would do the trick but as Mike says, it's not elegant.

I looked at the BD torqlock (which is really designed for diesels with exhaust brakes). It has 3 positions - factory, manual lockup and automatic locking under braking. I was thinking that I could use that and set up the automatic to a throttle switch so that when the throttle is closed the lock engages. Any thoughts?

Ian