Cheap torque converter lockup kit project

[jimsutt]

I'd think very carefully before you did that. I'm not a tech expert but seeing the amount of testing MM did in conjunction with OJ to produce his kit, it's not something which you can just build and plug in.

I would think very carefully also.
In my opinion, I would not fiddle with the lock up as you may cause expensive repairs. I nearly burnt out my lock up clutch in my Patrol.
These clutches are small and not made to be used to transmit much power and only switch in when under light loads while cruising.
I will probably be told I don't know what I am talking about as I quite often do but after 50 years of 4wdriving I have gained a huge amount of experience.
Cheers
Jim

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[pharb]

Is the NS box same as the NM?

If yes, a mate gave me an instruction sheet with resistors and all to fit a TC lock up kit. I did it on my NM and it worked flawlessly.

Not derived from here? -

https://www.4x4community.co.za/forum/showthread.php/116501-Pajero-3-2-Di-D-Torque-Converter-Lock-Up-Override/page3

[nj swb]

These clutches are small and not made to be used to transmit much power and only switch in when under light loads while cruising.

I was concerned about precisely this when I was building mine - I wanted to find the load / throttle levels that would cause it to unlock.

Factory programming only unlocks under load at low revs. Above about 2000 rpm it stays locked. Up Adelaide's South East Freeway, at 90 km/h plus, full throttle up the hill wouldn't unlock the torque converter. The factory programming isn't concerned about the diesel's peak torque in the Aisin.

[jimsutt]

I was concerned about precisely this when I was building mine - I wanted to find the load / throttle levels that would cause it to unlock.



Factory programming only unlocks under load at low revs. Above about 2000 rpm it stays locked. Up Adelaide's South East Freeway, at 90 km/h plus, full throttle up the hill wouldn't unlock the torque converter. The factory programming isn't concerned about the diesel's peak torque in the Aisin.

If you load up with say towing you will find it will unlock when you hot a hill or put your foot down.
It normally engages around 80 in 5th gear and will stay locked until it detects an increase in load.

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[nj swb]

If you load up with say towing you will find it will unlock when you hot a hill or put your foot down.
It normally engages around 80 in 5th gear and will stay locked until it detects an increase in load.

At 80km/h in 5th the engine is around 1500 rpm, the torque converter is unlocking to reduce vibration. At lower engine speeds vibration will increase with load - the lower the revs, the lower the load at which vibration becomes noticeable. Above about 2000 rpm this vibration is no longer noticeable at any load.

In 4th gear, above about 2000 rpm, the Aisin transmission in the Pajero does not unlock the torque converter under load.

[geopaj]

At 80km/h in 5th the engine is around 1500 rpm, the torque converter is unlocking to reduce vibration. At lower engine speeds vibration will increase with load - the lower the revs, the lower the load at which vibration becomes noticeable. Above about 2000 rpm this vibration is no longer noticeable at any load.

In 4th gear, above about 2000 rpm, the Aisin transmission in the Pajero does not unlock the torque converter under load.

This has been my findings too (including when towing).

[chrisfarru]

Sorry for the late reply. This is what I was forwarded

[Kingmarz]

Sorry for the late reply. This is what I was forwarded

Thank you very much.

I’ve seen a few diagrams but yours is easiest one to read.
I’m going to attempt this one day when I’ve done enough research and gained enough courage.

[dclinton]

Sorry for the late reply. This is what I was forwarded

Thanks mate! The trouble with this type of setup is it causes the solenoid to prematurely fail. The factory ECU only runs the solenoid at about 50% duty cycle to keep the converter locked, that equates to about 5-6v. The coil in the solenoid burns out if it’s fed 13-14v constantly.

I’ve got my setup functioning properly after a few days of troubleshooting once I installed it in the car. Turned out that I needed a diode to stop feedback from the solenoid interfering with the operation of the mosfet. That bloody 35c part had me scratching my head and going mad trying to figure out why it was working on the bench, but not in the car!

[old Jack]

You may find information in the following post useful.

https://www2.pajeroclub.com.au/forum/showthread.php?t=35928

OJ.

[dclinton]

For anyone that’s interested the Jatco box runs a 2.9khz PWM frequency and when the ECU locks the converter, it starts at roughly 65-70% duty cycle before dropping to 50-52% within a couple of seconds. Obviously it engages it fairly firmly to make sure it doesn’t slip and then backs off once it’s properly locked.

The setup that I’ve built cost about $100 all up to throw together and at this stage is just a basic lock/unlock setup. I’ll keep playing with it now it’s functioning in the car and aim to have it unlock automatically when coming to a stop and then lock again once it reaches a certain speed. Could also use throttle position etc to influence its behaviour. Just a matter of getting the time to tinker with it.

I’m also starting to work on an arduino based boost controller for the VNT turbo setup. ��

[dclinton]

This is what it turned out looking like all put together. I did away with the potentiometer and stuck with a fixed duty cycle.

[jimsutt]

This has been my findings too (including when towing).

I have never noticed any vibration. I understood that the lock up was to reduce fuel consumption while cruising under light loads.

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[jimsutt]

I have never noticed any vibration. I understood that the lock up was to reduce fuel consumption while cruising under light loads.

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Exactly...

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