tc lock up

[diesel4life]

Anybody ever do their own tc lock up switch? Tst products has a write up t install one for the cost of a toggle switch and a little wire. They tell you to splice into the orange and brown wire coming out of the middle plug at the ecm, run a wire to a toggle switch and then come out of the other leg to ground. Then they tell you to pull the trans relay and jump 2 specific terminals to give the tc lock selonoid constant power. The problem im having is when i jump these 2 terminals the selonoid (im assuming) starts to click rapidly in the trans. This does not seem right and i unplugged it as soon as i located the source of the noise. Anybody have this issue?according to theyre diagram ive got the right terminals and it seems as though alot of other people have done this with no issues...????

[98whitelightnin]

I have one in my 98 and couldnt drive it without it lately. Mine never clicked and never had any problems, its actually the only part od my truck that works 100% of the time.

[diesel4life]

Its about as straight forward as it gets ive rechecked to make sure ive got the right terminals so many times im beginning to feel like im ocd. Soon as i jumper the relay and turn the key to on, the selonoid in the trans starts goin nuts. Im going to try to talk to someone from tst to see if they have any suggestions this afternoon

[98whitelightnin]

Try is without the jumper, mine worked with it out sometimes.

[diesel4life]

I was testing my switch to make sure i was getting power to it and for some odd reason i was getting 12 volts regardless of the position of the toggle. So i threw another one in (yes another brand new one) and it works like a ding dong now. So basically i had a brand new junk toggle switch. Such is life these days......anyhow, im surprised/disapointed at the difference in shifting. I guess i assumed i would retain the same shift points i normally have but boy oh boy thats not the case! It dumps the gears one after the other until im in 4th.. the reason i did this mod was number 1 ive heard you can slightly increase your mileage with it bieng in lock up and number 2 i plan on getting an exhaust brake in the near future. Hey 98, does yours dump the gears super quick too when your accelerating?

[98whitelightnin]

Are you starting in 1st with it locked? Mine shifts normal but I lock it in when I want it locked but only in 3rd or 4th gear. If you have the od off then lock it whenever you want in 3rd, if you are driving in od you can lock it whenever you want in 4th.

[diesel4life]

If i start out in 1st with the tc locked, it will dump the gears quickly. itll shift into od before im even up to 35. The only way i can get it to up shift normally is with the tc unlocked.

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So what your doing is accelerating like you normally would with the tc unlocked and then throwing the switch once you get into od? Ive read where other people throw their switch from the start and this helps their mileage at lower speeds and city driving because the converter is locked instead of slipping but im not seeing it bieng it just rifles through the gears until you get to od. I could always keep it out of overdrive i suppose that would help some. I suppose ill just have to drive it and play with it a little to see what works best

[98whitelightnin]

Ya, its not meant to be drivin like that. I use mine when the motor ir cold so it doesnt get up to 1800 rpms before it lockups. I usually turn od off when its cold or the speed limit is under 45 and then lockup 3rd gear. When you hit 3rd, hit the lockup switch and use it the same way in 4th. Dont flip the switch whiel your setting still.

[Eforbes]

Im hearing from others we shouldnt use this feature unless we have a input shaft and a valvebody that can take it, but if i am wrong, i will be glad to be wrong. I had one on my 97 crew cab powerstroke, worked like a champ, but diesel power mag says on the doge we can shatter stuff by locking it. But to me if you only lock it in third or fourth it should be fine. I would want one to be able to keep it locked when on a downhill, in stock form it unlocks when foot is removed from pedal, that builds trans heat coasting like that. Let me know, i already bought the switch, but backed out of it when i saw the article, and some threads in the cummins forum. I am ready.

[98whitelightnin]

I have been using mine for several years with stock input shaft but I do have shift kit/valvebody upgrades. I dont flip the switch untill im in a lockup gear and I let out if im gonna let it shift locked. I dont imagine its the easiest on parts but neither is sled pulling with the throttle pinned to the floor.