What are your opinions on the use of one? Can they be used safely or is it a bad idea?
Steve

 

I used one as a device to verify whether my tranny problems were caused by electrical or hydraulic problems.

I did experience locked shifts when I used it and must say the force of these shifts made me feel bad about what I do to my tranny.(Especially in stock form- I think that the abuse by locked shifting must be taken care of with beefed up parts in the tranny)
I still use mine for goind downhill without an exhaust brake.
But I do have an aftermarket tranny and asked the builder if this was OK. Personally I wouln't use one on a stock tranny since it does not seem to be built for it. Especially when lugging the engine the stock PCM will unlock the converter to allow for higher engine RPM and therefore higher apply pressure to all the clutches and bands. A lockup switch will render this self protection of the tranny useless.
A modified TC-VB combo coming with other stuff makes quite a difference, since every VB mod alters the apply pressures and may help to avoid the problems mentioned above.

I am glad that I have rebuilt my tranny with better stuff in it, and can only suggest that you do the same thing too. The power transfer through the stock TC unlocked is ridiculous (or :'( ). The use of a lockup switch to improve the power transfer will lead to other problems down the road.

IMHO there are two trains of thought on this subject- one like DTT and some others do it says let's improve the fluid coupling so the lockup will not be needed most of the time and make for a good power transfer, the other school says let's modify the tranny so we can lock up in almost every situation and therefore transfer the power better. ( ATS with their triple lock TC and VBs)
I can not comment on which one is better, but want to warn you on the simple use of a lock up switch on a stock tranny. There are good tranny people out there who will have a lot more expertise and experience than me.
Maybe these links will help you a bit

http://www.dieseltrans.com/phpBB/index.php a discussion forum hosted by DTT, where I got my tranny parts.

http://forums.atsdiesel.com/ the board of ATS. Read through both boards and websites and you'll know a lot more about the way a tranny works than before.

Just my 2c, HTH

AlpineRAM

 

I use a lockup switch with my tranny....But its been up graded with a low stall torque converter and a Transgo shift kit....I find the switch is usefull when I tow it gives me a degree of control over how my tranny operates this is helpfull in hilly country that I travel to best use the horsepower and torque of my engine

I would not advise using a lockup switch with a stock tranny and engine if you tow any kind of weight

If you forget to unlock your tranny when comming to a stop it acts like trying to stop a manual tranny truck without disengauging the clutch

 

Don't do it! You will cause harm to the tranny and torque converter.

Doug