Are there any negatives for wiring up a torque converter lockup switch on a 2001 3500 with a pac brake exhast brake system.I've heard it will lead to premature transmission failure. Anyone with some experiences on this?Also what is the correct way to wire this up as i have seen a cople of different diagrams,and will it send any codes to my computer and service engine soon light?

 

If your trans is stock, it will speed the demise of your tranny.
The stock trans is just not built for being locked up like all the time. Also, you'll want to upgrade the valve body and torq convert if you plan on having the trans hold back the truck under exhaust brake usage.

Do a search on this site for "Mystery Switch". There have been some very well illustrated wiring diagrams posted.

Regarding engine codes, I dont know.

Rich.

 

What year truck do you have? if it is a RE unit then you want to tap wire B11 on the center plug on the PCM harness and it will be a orange wire with a black tracer. then install a 33ohm resistor in the wire to connect to B11 on either side of your switch. then connect the switch to a ground, installing the resistor keeps you from having to jump the trans relay which will set a charging circuit code and a trans code. so if you install the relay you will not have any codes set, but if you have a stock tranny say goodnight because it will die a fast death. any other ?'s just PM me.

Chris

 

How Fast of a death? even if you only lock it up when you are going over 60 mph? and leave it unlocked in the city????

 

A number of companies make T/C lockup devices that automatically unlock the T/C to prevent shudder when stopping, etc.
BD has several, including the TowLoc which performs much like the '06 48RE.

Dan

 

i did it on mine when i had factory shafts and i ended up breaking my input shaft

 

It will lead to premature tranny failure with an exhaust brake. How much I don't know...

 

I did it on mine with a stock tranny and have a jacobs exh. brake on it and it worked fine. only problem was it ****** me off cuz on the california trucks it throws a check engine light but other state trucks don't for some reason. I used electrical tape over the light so it doesn't bug you at night but i never noticed any problems with the tranny... and used the brake all the time down to about 40 and then in 3rd with od off it'll pull it down to about 20 mph or so depending on your truck. its very nice and saves on your brakes. what messed up my tranny was later when i had an ez on it full throttle lockup would slip during the engage and well the tc never was very tight. but i got it rebuilt with input shaft and bought the previously mentioned bd tow loc. its a really slick deal you can set it up how you want it with a lap top. you can get it to downshift and lock up again so you can come down to 20 mph from 70 pretty quick without using brakes. However i found it to be a little hard on the downshifts and tc unlocks so i set it up to let off the brake at 35 and unlock at 850 rpm's which is really smooth and slows you down to 35 without brakes. Once you get used to using the exh. brake you'll love it. The other thing is I can manually lock up in every gear except reverse where as with the mystery switch you can only get 3rd and OD. 2nd will lock up and shift into 3rd locked if you have it switched from a stop but you can't manually keep it there.

Sorry its so long but i'd say go for it. I never heard of it being bad for the tranny especially if its just the truck or a light trailer that your slowing down. Wire it with the resistor that sounds like the best way to do it so not to throw a code and just take care not to lock it up unless the tc is already locked or you want it locked it CAN be hard on it if your not carefull but its not hard to use. Hope this helps and if you got any more questions feel free to ask
TNutcher

 

It's because there's not enough driveline pressure when you're not pressing the throttle on declines; thus, slippage could occur.

I hooked up a lock-up switch on my '96 just for fun but I ended up not using it because for 6 months in my particular year, the computer on my truck wouldn't allow such function. I could get it re-flashed from the dealer but I think it costs some money so I said screw it.