TCC mod

[Matt Koetting]

Just thought I would share a good mod for those towing heavy loads. I bought a dimmer switch and mounted it to the floor and then wired it in between the TCC lockup. If the switch is on ("auto mode") then it locks the converter when the computer commands it. When it is off it unlocks the converter. Makes it nice to get another 200-300 rpm to pull up a hill. I will say that you should leave it in auto mode unless you are in forth. It threw a code (or something) when I wouldn't let it lock up in third. It wouldn't go to 4th at all. I unhooked the battery for awhile and all was well. BTW, I have a C3500HD, 7.4L, 1996 truck pulling GVW of about 21000lbs. I get between 6.5-7.25mpg usually. Only other mod is 180* thermostat but it has 189 CTS.

Has anyone made or purchased a good or true cold air induction setup ? My IAT in the summer are 100-135*

 

[Christian Steffen]

Its a bit of work and some money, but an 0411 swap would allow you to run a tow/haul switch to take advantage of different transmission tuning tables. Then you could have whoever tunes it set the tcc tables how you wish, plus there would be some power benefits to the tuning.

Do you have the factory airbox with the lid? It honestly is one of the better options, otherwise I've heard volant makes/made a pretty good cai but I've never looked into it myself, maybe someone else has experience with it. Definitely stick with the paper ac delco or wix HD, they perform better than pretty much anything aftermarket.

If you take your time I bet something could be homemade to get more air blowing into the airbox from the grille.

 

[Matt Koetting]

I definitely thought about a 411 swap but quite frankly I'm not sure it is worth it on a otherwise stock truck with 250000 miles. I don't even drive it but a few thousand miles a year so I am hesitant to put very much into it. Good suggestion though.

 

[Christian Steffen]

I definitely thought about a 411 swap but quite frankly I'm not sure it is worth it on a otherwise stock truck with 250000 miles. I don't even drive it but a few thousand miles a year so I am hesitant to put very much into it. Good suggestion though.

Good things to consider. Overall condition of the truck and your plans for when the motor finally gives up would probably help make that choice. Having an oil analysis done would probably point to the bearing condition as well.

As a side note, I'm a little surprised forcing the tcc to unlock like that doesn't throw a code in every gear. What do your ttans temps run at while doing this?

 

[Matt Koetting]

I've got 60psi oil at hot idle. I have always been impressed by that. I did change the timing chain because I thought I should. But it didn't t need it as it had very little slack. It will probably last longer than I want to keep it.

To be clear to those that are interested. My cheap o code reader never saw a code, but I definitely had to unhook the battery to get things set right again after trying to unlock the TCC in 3rd.

My code reader doesn't see the trans temp or I don't have a sensor. The stock converter is pretty tight and it has a huge radiator with integral trans cooler so I'm thinking it is GTG. I do plan to install a gage someday though to satisfy curiosity.

 

[Christian Steffen]

That's pretty impressive for that many miles. I'm not sure if the older trucks had the sensor, but my 2000 does, something like the torque pro app should be able to read it. Any yeah they did a pretty good job with coolers on these.

At any rate, thanks for sharing your mod.