Auto locker

[GQtdauto]

Finally decided to do the cheap arse version of the torque converter lock , mate of mine gave me a stepped relay which made the job a bit easier , I can't believe the difference it's made when locked .
Had a good try out up and down Taminick gap and I now have to slow down going up the hill instead of I think I can I think I can .
Down hill it has fantastic engine braking and didn't need the stop pedal at all .
Just one question I have to anyone who has done this mod is apart from stalling the motor if you forget to turn it off , will it damage the tranny?

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[the evil twin]

Never hurt the tranny any of my vehicles or AFAIK other vehicles I mod'd for their owners.
Did 200,000 K's or more in my TB42e with no issues FWIW
It is important not to lock it up under a massive load tho... like full metal and the vehicle is just about to bog down on a dune or whatever and reaching over to flick the switch is not encouraged.

If I was 4Xing I used to often lock mine and drive it like a manual... gnarly hill descents I would lock it at the top... and if I was towing I would lock it and leave it until the next town or steep hill

[GQtdauto]

Never hurt the tranny any of my vehicles or AFAIK other vehicles I mod'd for their owners.
Did 200,000 K's or more in my TB42e with no issues FWIW
It is important not to lock it up under a massive load tho... like full metal and the vehicle is just about to bog down on a dune or whatever and reaching over to flick the switch is not encouraged.

If I was 4Xing I used to often lock mine and drive it like a manual... gnarly hill descents I would lock it at the top... and if I was towing I would lock it and leave it until the next town or steep hill

So towing up hills you'd turn it off is that right ? Thanks for that ET I was worried but feel much better about it now .

[the evil twin]

So towing up hills you'd turn it off is that right ? Thanks for that ET I was worried but feel much better about it now .

Yeah, easier grades I would leave it locked up until it felt like everything was loading up then just lift the throttle a tad to lighten the drive torque, disengage the lock and then roll the throttle back on.
Steeper hills I would just flick it off at the bottom 'cause you know you will be going back thru the gears.

I usually would leave it engaged between top and overdrive but you can kinda use it as an electric split gear between 3rd (or Drive if you prefer), 3rd locked, (3rd being 1:1) and overdrive and overdrive locked if you have the series 2 gearbox

It doesn't take long to get a good feel for what works best as it depends on trailer weight, gradient etc.

[Chubba]

I don't ever use it off road, not for any reason other than I don't find a need for it. The extra torque generated from the TC comes in handy and decents are a pleasure with the reduction gears. .
On the highway I do worry about putting too much load on the locked converter (warranted or not, I don't know) and use it sparingly. The way I drive is to have the OD on and when I feel the TC unlock and I can see it will be for a while I'll just turn OD off. This lower gear normally will lock up the TC again untill I go back into OD again. For me the heat in the trans is what I'm trying to avoid. I'm not overly concerned about the fuel economy. Rather spend a couple of extra dollars on juce than comprises the trans IMHO. So this mod is one I've made but don't really use.

[GQtdauto]

Going by trannie temps the torque converter only locks up in OD , OD off temps get way up there but as soon as it slips into OD the temp needle drops like a rock .
Will only use for towing and engine braking and maybe small inclines , thanks again ET that gear just before it hits OD is definitely the best gear for towing on mine and now I can lock it not only cooler temps but should reduce fuel consumption from 24 litres per 100 .

Chubba , fuel economy is secondary to heat I agree and found on my last trip to Birdsville if I could get to OD the temps were lower and fuel economy was the best under 20 litres per hundred .

[the evil twin]

Yep, totally agree, a locked TC reduces tranny temps by heaps and yes the Tranny ECU only locks the TC in Overdrive.

After the mod the ability to lock the TC in 3rd or D and also prevent the Lock Up cycling in OD when rolling on and off the throttle when towing is one of the best things to do for the Tranny IMHO.

I noticed a worthwhile change in fuel economy (mine was a dual fueller) of an extra 50 K's or so on LPG but it would depend on terrain etc an WA tends to be open and flat.
The big difference was the much lower tranny temps when towing my Camper on its generally 1500 to 3000 K round trips

[GQtdauto]

Mines a td4.2 auto so when it gets wound up all good except for trans temps but now not a problem and looking forward to towing the camper to see the difference , probably should do the GU as well but it's getting an upgrade so not worth it .

[the evil twin]

Yours will be a series 1 won't it?
I think they dropped the auto for the TD's when the series 2 was released in '94.
The tranny programming and control is a bit different between 1 & 2 but shouldn't matter one bit for the TC lockup mod.

[GQtdauto]

Yours will be a series 1 won't it?
I think they dropped the auto for the TD's when the series 2 was released in '94.
The tranny programming and control is a bit different between 1 & 2 but shouldn't matter one bit for the TC lockup mod.

Mine is a 94 factory auto td4.2 , not many of them around and no idea if it's series 1 or 2 , I'm sure the GU trans lock up in first gear and reverse when fitted with this mod .

[Chubba]

Yep, totally agree, a locked TC reduces tranny temps by heaps and yes the Tranny ECU only locks the TC in Overdrive.

After the mod the ability to lock the TC in 3rd or D and also prevent the Lock Up cycling in OD when rolling on and off the throttle when towing is one of the best things to do for the Tranny IMHO.

I noticed a worthwhile change in fuel economy (mine was a dual fueller) of an extra 50 K's or so on LPG but it would depend on terrain etc an WA tends to be open and flat.
The big difference was the much lower tranny temps when towing my Camper on its generally 1500 to 3000 K round trips

I only know the series l GU auto as that is what I have and the Maverick was a manual. But the GU locks the TC in 2nd, 3rd(D) and OD. An improvement from the GQ I guess.

[GQtdauto]

No idea what's in our 2002 GU either Chubba but I do know it only locks in OD same as the GQ .
If I was keeping the GQ I would go for a wholesale auto nomad valve body and have the whole box upgraded because I believe you can even get them to lock in first gear .

[the evil twin]

I only know the series l GU auto as that is what I have and the Maverick was a manual. But the GU locks the TC in 2nd, 3rd(D) and OD. An improvement from the GQ I guess.

Yep, GQ Autos in the factory configuration only lock the TC in O'drive above 80 KPH which is why the mod is so popular with them esp if running 33's.

So GU is different then?

Must admit I have never driven a 4.5 tho so don't know that much about them.
Those and the 2.8TD are the only two variants of MQ, GQ, GU I haven't had as either a private or fleet vehicle over the years.

[Chubba]

I don't know but GQtdauto said his 2002 GU only locks in OD. Mine is a Ti. So maybe something to do with that.

[GQtdauto]

I don't know but GQtdauto said his 2002 GU only locks in OD. Mine is a Ti. So maybe something to do with that.

I'm sure I read somewhere that the earlier GU and 94 < were the same box basically just slightly different wiring or tcu .
Towed the same camper in both nissans and bugger all difference in the way the box works or engine heats up when the going gets tough , having just put the temp gauge on the tranny back in May for the Birdsville trip I'm still amazed at how high temps can get when the converter isn't locked .