700r4 lockup. How many ways?
 

Hey

The title says it all. 700r4 lockup. How many ways are there to achieve this. I have heard about the TCI switch and changing a brake light switch, are there other ways?

Thanks everyone!!

Re: 700r4 lockup. How many ways?
 

I have mine through a toggle switch. Currently cruise around town most often, not needing to lock it up. When it was rebuilt had my mechanic put in the toggle switch.

Re: 700r4 lockup. How many ways?
 

Here's what I used, https://www.classicindustries.com/pr...B&gclsrc=aw.ds

Re: 700r4 lockup. How many ways?
 

I just did one for my buddies Chevelle. I put an early 80's VB into a '90 case, with other required mods. No control needed, lockup is completely automatic by means of a hydraulic valve that IS NOT in later valve bodies.

Re: 700r4 lockup. How many ways?
 

Does it unlock with the brake switch?

Re: 700r4 lockup. How many ways?
 

If I recall correctly on my '83 K20 it had ignition power to a vacuum switch and then through a brake switch to the converter lockup + side. The ground is provided by a 4th gear switch on the transmission valve body. So if you are in 4th you get a ground. Then if you are not on the brake and have sufficient manifold vacuum it will lock up. Lose any of that and it unlocks the converter.

Re: 700r4 lockup. How many ways?
 

I used the B&M lock up kit. Wired through the converted brake switch. It automatically locks up at a speed that you set. Then unlocks when you touch the brakes or drop below set speed. What I don't like is that it wont unlock when passing. When I get it back on the road I am going to also run it through a vacuum switch. So that when you accelerate hard and vacuum pressure drops it will unlock as well.
https://www.summitracing.com/parts/b...+5b9ad3715b1a7

Re: 700r4 lockup. How many ways?
 

If you still want it wired in for safety or panic stops then you certainly can wire the TCC in. Otherwise the hydraulic valve is ONLY inline after there is pressure signal from 4th gear and likewise causes an UNlock when there is no 4th gear pressure signal.

Re: 700r4 lockup. How many ways?
 

.

I've got the updated brake switch (a second circuit) wired to UNlock with brake application. It's not great exactly but it does get the job done. The TC locks immediately after shift into 4th and stays that way unless I give enough throttle to downshift to 3rd or 2nd. I can hold steady OD acceleration and tap the brake pedal and see the RPM go up maybe 200 and then right back down.

Not ideal...I've read on here of at least one member using a vacuum switch and delay circuitry to add some more smarts into it though so as vacuum goes toward zero, some threshold is reached were the TC will UNlock and stay that way for a short period...maybe 10 seconds or something.

The kit above seems to also be reasonable IMO.

-Kevin

Re: 700r4 lockup. How many ways?
 

b&m lockup switch

https://www.summitracing.com/parts/b...YaAlYmEALw_wcB

Re: 700r4 lockup. How many ways?
 

I went like Smitty, a switch and mine knocks off with the brake. Depending on your gearing and tire size, I found I really only want lockup out on highway driving. If I have my push button switch engaged, I have a green LED that comes on also. The brake switch will kill the LED also.

Your situation may be different. I drive sometimes in D and not using the OD at all. This also prevents lockup.