I used to have a lockup TC in my 700R4, I recently needed it rebuilt & when it was placed back into vehicle they used a non-lockup converter. Now it seems to run hot, especially at higher speeds & on an incline. Can I install a universal lockup kit (the kind that comes with an oil pressure switch & is hooked up to the side of the transmission housing?) Or do I also need a "lockup" TC?

Here is the kit I want to install: https://www.amazon.com/Superior-K013-High-Gear-Package/dp/B00BZODL5G/ref=sr_1_4?crid=MI2I0TSQI0NO&dchild=1&keywords=700r4+lockup+kit&qid=1592331827&sprefix=700r4+lock+up+kit%2Caps%2C879&sr=8-4

  • You should not have accepted the wrong parts and got them to fit the correct lockup converter.
    – Solar Mike
    Jun 16, 2020 at 19:22
  • Welcome to Motor Vehicle Maintenance & Repair! Jun 16, 2020 at 19:52
  • The 700r4 needs a lockup converter, it will not flow fluid to the trans cooler unless it is in lockup, all you can go is drive it in D for now, then it will flow fluid to the cooler. This is why it is overheating. Other modifications to the valve body needs to be done to make it cool with a non lockup converter.
    – Moab
    Jun 17, 2020 at 17:32
  • So you say that it needs to be in lockup to flow fluid to the cooler but if I drive it in D it it will flow fluid. I do not understand. I have been driving it in D. I am looking at TQ for sale & see that there are alot of different options! I do not know which one I need when I do buy one. Jun 19, 2020 at 18:51

1 Answer 1


Basically, no this wouldn't work because your transmission is already setup for a lockup TC. This would just be adding parts you already have and not what you need. If you want your TC to lockup, you need to have a lockup TC. Replacement with the correct TC is going to be your only way forward.

  • So your saying I should already have what is in this kit currently in my transmission by default? To make it simple, does this kit & a lockup TC work together to make the transmission "lockup"? Sorry for all the questions, just learning here. I did not notice the transmission has a no-lockup TC until over a year or two after the shop did the work. (its a project vehicle & I only recently drove it to a show, that's when I noticed the issue). Jun 16, 2020 at 21:08
  • TBH with you, I have no clue what the kit does. If you want your TC to lock up, you have to have a lockup TC, there's just no two ways about it. It should have been put in there in the first place. Your excess heat doesn't surprise me due to this, either. Your gas mileage is probably suffering as well. Jun 16, 2020 at 21:20

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