manual torque lockup switch

[jcclures]

Has anyone made there own manual lockup for a Toyota Crown Gearbox, as I am using this in a 4X4. This would be good, as it would give me engine braking as well to help when towing.

I have been looking on this site and other sites for information on locking up the torque converter for my Nissan conversion, as I am using the 4-speed auto that came with my half cut Toyota Crown.

I found on a 4X4 site, which had a circuit, which I thought with a few changes I could use on my Toyota gearbox.

By the wiring diagram I do have for the gearbox, it looks as if the ECM earths out the converter lockup solenoid on pin 14 (slu - ) plug e10 to lock the converter. I think this happens once the system decides that it is OK, but I would like to override the system.

Has any one got any thoughts on this, as any ideas would be helpful?

John

 

[Zuffen]

The Toyota t/c is designed to drop out on very slight hills.

The t/c clutch can't handle much torque. Once you kill the cluth the t/c is a throwaway item.

The cltch only engages to remove the slip in the t/c so it's essentially a direct 1:1 drive. The o/d effect comes from the 3rd gear ratio in the box, that once the slip is gone (by engaging the clutch, or as people would say, changing up to 4th) effectively gives o/d.

You will get engine braking by manually downchanging into a lower gear.

 

[krayn]

Rod,
My torque conv lockup is not yet hooked up, planning to connect it up to one of the aux outputs from the stand alone ecu, and it definitly still has the 4 speed ratio working. There is a seperate solinoid to lock up the torque converter. Im only using sol 1 and 2 in the auto to get all 4 forward ratios. Not sure if this helps???? Kris

 

[Toysrme]

If the clutch lock-up is not strong enough (What you guys appear to be saying).
Then the best application of it would be for making dyno runs. Even then... A relay plus a button to trigger it is cheap & very fun.

I would suggest, on a Toyota torque convertor (stock, OR modified/rebuilt), to get your hands on it's associated A/T FSM. That way you can get your hands on the exact conditions Toyota uses it for.

(In general active only in 3rd + O/D gear<s>, and is unlocked by the stop-light, and IDL switches.)

 

[jcclures]

The way I understand it is that as I have fitted the engine & gearbox into my Nissan the ecm (computer) might never decide it has the right parameters to switch on the t/c lockup clutch, as I think it looks at speed, throttle and gearbox line pressure.
This is why I am looking at this now as when I get it on the road I would like to have some idea.
From my understanding the third solenoid only drives the converter lockup, and should not affect the operation of the gear box including O/D if anything is should help reduce the oil temp as a consequence of less slip in the T/C.

 

[edz]

auto and torque converter lockup

That's my understanding too, it only engages under light throttle to improve fuel economy and reduce slip=less heat in the oil. Can't handle heavy loads, and disengages at zero throttle to allow car to coast. If you switched it manually you would have to be careful you didn't work it too hard and it would stall the motor if you forgot to turn it off and stopped.

With the cheapness of discs and pads, I'd rather wear them out than kill the lockup (and probably the box as they use the same oil).

 

[sideshow]

like others have said

my lock up clutch only comes on say over 60 or 70 kms

and at about 4 to 10 % throttle any more throttle and it drops out

it is a waste of time if u drive the car hard

so i would not worry about it cause if u have to think about turnin it on and of

u will be pushing switches all the time and one time u will forget and accelerate alittle bit and stuff the clutch when u forget to turn it off

best bet would be to either run it of a vacuum switch or of the throttle

so it only comes on in top gear and when just touching the throttle

but its easier to not connect it

 

[jcclures]

This week I emailed Rodney at Wholesale Automatic Transmissions, in Bayswater Victoria.
He emailed me back this is what he said.
---------------------------------------------------------------------------
Hi John it's Rodney here from Wholesale Automatics.

In short yes it can be done but I believe there is a much better way then
just hard wiring the lock-up. I have looked at your wiring and for the most
part it is just hard wired with a brake release.

I feel there is a far better way and forget about the brake release, you
simply don't need it. We have used a fully automated system that simply
pulls the lock-up on at a certain road speed. Nowhere as cheap but much
better in the long run.

It would easier if you contacted me so I can explain as I also have
questions.
-----------------------------------------------------------------------------

I then rang him and what he told me was that the T/C could handle the lock up clutch being on, having very little affect on the life of the clutch may be even extending the life of the auto as it reduces the heat developed by the T/C slipping.
This was as long as I don’t tow very heavy trailers in OD, but he thought my camper would give me no trouble.
Rodney suggested that I wire in a hardwire system either my system, if I want the brake override or one he could sell, he also said there is a system that is speedo driven so at 90km per hour it would loch the clutch, I would need a speed sender to do this as my speedo is cable.
So to try it out, what I now need to know am I wiring of the correct solenoid and do I just earth pin no 14 Plug E10 – B (slu-).
I have the single ECM for both engine and gearbox, I have been using the wiring diagram for a 1993 Lexus SC400, most of the colors are wrong but the wiring seems to be the same.

 

[Zuffen]

A simple way to engage the O/d at a set road speed would be a frequency switch (the kit is available from Jaycar for under $50.00) and sense the pulses fom the speed sensor in the transmission.

Once you had worked out the number pf pulses per minute you needed, a little trial and error would do that, you adjust the swich (it has a wide range of screw adjustment) and away you go.

You would still need to make it drop out under load but a pressure or vacuum switch could handle that.

 

[edz]

lockup clutch

A simple way to engage the O/d at a set road speed would be a frequency switch (the kit is available from Jaycar for under $50.00) and sense the pulses fom the speed sensor in the transmission.

Once you had worked out the number pf pulses per minute you needed, a little trial and error would do that, you adjust the swich (it has a wide range of screw adjustment) and away you go.

You would still need to make it drop out under load but a pressure or vacuum switch could handle that.

You could also setup a simple micro switch on your throttle plate or pedal that went open circuit at more than light throttle and even a second one that opened at zero throttle so it rolls when you back off.

Good aftermarket computers can handle this with ease taking inputs from gears (so it could only come on in top), sending numerous outputs to relays at light load, no load etc, certain speed etc.