Torque Converter Lock Up Kit

[stevemc181]

I went for a trip down to Yeagarup dunes in SW WA this weekend and on the drive down there I had the Torque app running showing Transmission temp.
I can't say I've noticed it before, but this trip I was paying close attention to the revs and tranny temp. The Paj was fully loaded and carrying 3 adults, and I noticed the Transmission getting up to 115°C on just some very minor highway hills.

The revs were around 2450 RPM @ 112kph when the torque converter was slipping, then they would drop to about 2100RPM and the Trans temp would come down to below 80°C. So around a 350RPM difference at the same speed. It didn't make any difference if I left it in Drive or in 5th manual mode.

I don't often tow a trailer, so thought the Torque Converter kit would be a waste of money, now I am rethinking this and may install the lock up kit. Is anyone running one of these in an NW pajero? Any issues I need to be aware of?
I'm not really worried about it locking in first gear, so I don't think I'll need the valve body upgrade as it will be used for highway cruising speeds.

[old Jack]

Hi Steve,

I have done a lot of work on this for the PB PC Challlenger, it has similar issues despite having the Aisin Auto-trans which has electronic lockup torque convertor in 3rd, 4th and 5th and a stall ratio of 1.85:1 so it is much better than the Challengers set up.

Here are a few threads;

http://www2.pajeroclub.com.au/forum/showthread.php?t=30524

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

http://www2.pajeroclub.com.au/forum/showthread.php?t=36892

I found that with the torque convertor lockup indicator I fitted I was able to change my driving style to get the best out of a pretty average setup.

That said I am seriously considering the Gen2 TC Manual Lockup kit with PWM from Wholesale Automatics before the Canning so I can lockup the TC in all gears to save on fuel and keep ATF temps lower.

cheers, old Jack.

[stevemc181]

Cheers Old Jack, I was looking a various threads, but couldn't see anything specific to the NW. I think I'll also be looking into fitting the Kit you mentioned. Once I really began paying attention, it was pretty obvious how often the Torque converter was slipping. I think it would be a great benefit in not only Trans temps but also in Fuel economy, requiring 300-400 less RPM quite often.
There seemed to be no logic at times as to why it was slipping, apparent flat road and the revs were still up there at times. I guess the taller tyres and heavy load have some part to play in this as well.

I'd hate to think what temps the tranny has achieved when I haven't been watching it! Might be time for a fluid change also I think.

[old Jack]

Hi Steve,

ATF of 115C I thought that was high so I looked in the Pajero Service Manual I have (European & Russian online) and found this;

The AT Temp indicator lamp illuminates when the fluid temperature is at approximately 147°C or higher, and goes out at approximately 127°C or lower.

For reference the Challenger is 135C ON - 115C OFF.

In the PB Challenger when the TC is unlocked and under high loads the ATF's climb quickly but once the slip/load is removed the ATF's temp decrease quickly as the ATF cooler catches up. There has been much discussion about replacement ATF coolers and second ATF coolers, those that have fitted second ATF coolers have reported only minor decreases in ATF temps, best results come from changing the way you drive. With my TC meter I can see when the TC unlocks, it is load, speed and accelerator position related, so when I detect the TC unlocking in 5th, I manual change down to 4th and by adjusting the accelerator position I can get the TC to lockup again. When I am touring on the highway I am always at GVM and now days I use "D" to get up to speed and then slip into manual mode and can now judge the sweet spot to downshift from 5th TC locked to 4th TC locked.

Going up a profile in tyre size so your tyre diameter is greater makes the problem worse. Most bulbars, especially ARB reduce the amount of ram air directly into the ATF cooler, also it is very easy for the ATF cooler to become clogged up not only with insects but also from dried up slit, due to driving through dirty water.

cheers, old Jack.

[stevemc181]

Well that is interesting OJ, I thought the point of the transmission oil burning was 120°C, so perhaps I am needlessly worrying. I'll keep an eye on it, and see how hot it gets in various places. I did knock it back to fourth at one stage, but that equated to around 3000RPM at 112KPH.

Still, I can see some fuel saving benefit in the TC lockup kit, so may still be worth having it?

Cheers for the info, puts my mind at ease

[old Jack]

Hi Steve,

At 3000rpm/112kph and in 4th gear the TC could still be unlocked, my guess is with your slightly larger tyres at GPS110kph you would be looking at 2800-2850rpm. We need to remember we are talking about 4 cylinder CRD engines and they prefer like running in the 2,000 to 3,300 rpm range which is the band where max torque is developed.

The ATF in your auto trans is full synthetic and has a flash point of about 210C that said, high ATF temps shorten the life of any ATF and this can usually been seen by the ATF changing colour and going darker. Your problem is there is no ATF dipstick or filler point that you can check the colour of your fluid. I am not sure how often the ATF is recommended for replacement but it is one thing I would certainly do more often than recommended.

The new PWM lockups appear to have solved the issues created by the earlier non-PWM kits, that said you still need to be careful when using them. I am thinking that you should not use them if the engine rpm is under 1800rpm, I wonder how difficult it would be to put in a latched relay control so when engine rpm drops below 1800rpm the lockup kit is disabled.

cheers, old Jack.

[stevemc181]

I've got the NW booked in with Armadale 4wd next Tuesday to have the Lock-up kit installed. Going with the GEN II Lock-up kit with PWM. I thought about going with the Nomad valve body as well, but for the cost I really don't think I need it and am just looking at keeping the converter locked when on longer runs.

I can see a lot of benefit in having the trans run cooler and fuel savings on long runs should be in the order of 10% based on running around 350 revs or so less. I'll be doing a few thousand km's loaded up around Easter time with around 2500km's on the blacktop, so will keep a close eye on temps and fuel consumption when cruising.

[Hatto]

Its funny you mentioned that about transmission temps steve. I noticed the exact same thing on the exact same trip! In went to Yeagarup a week after you went and had transmission temps around 110-115 deg. Once I realised I just dropped it back to 4th manually on pretty much every hill and managed to keep the temps below 95. The reason why 95 deg was the aim was because when I was setting up the torque app I had no idea what transmission temps to expect and so I set an audible alarm to go off at 95 deg. We'll the bloody thing was going off every time I looked at a hill! Even after I reset the "high warning" temp to 120deg it still went off at 95! Fixed it now but at the time it was such a distraction. The point is since having the torque app I reckon I've changed my driving style and saved my tranny from a lot of unnecessary heat. In stock form the tranny/TC is not ideal but just adjusting my driving style helps heaps. What's a lock up kit worth by the way if you don't mind me asking?

[stevemc181]

$792, fitted for the Gen II kit with Pulse width Modulation. Bit dearer than I thought for the fitting and could probably do it myself, but would prefer to have the kit professionally fitted in case of problems.

[Paj People 2009]

Hi,

I thought the alarm in the car came on at 120 degrees?

Most we've had ours up to towing up hills is 107 degrees and it dropped back to the 80s very quickly.

Those temps would scare me! Of course sand driving is harder on the tranny than the towing, Id reckon.

The Torque App is awesome - being able to monitor all these things. I see that wih the SPV Mod our EGT is always zero - hopefully that is what it is meant to show!

There is a lot of discussion on caravanners forums re those torque converter - good feedback, haven't read anything negative as yet.

I'd ring these guys to discuss

http://www.automatictransmission.com.au/release.asp?NewsId=42096

We're thinking of adding this one.

Cheers,
Sally

[stevemc181]

Hi,

I'd ring these guys to discuss

http://www.automatictransmission.com.au/release.asp?NewsId=42096

We're thinking of adding this one.

Cheers,
Sally

The wholesale automatics Gen II unit is the one I am fitting via one of their dealers in Perth

[stevemc181]

I've picked up the Paj today after having the Lock-Up kit installed and have only had the chance for a very brief test. This is in no way a conclusive test as all I did was basically cruise down the hwy and activated the lock up for about 10 km's. I have to say though, that this is the first time in a very long time that I have seen the onboard computer tell me I'm getting 9.8 litres per hundred. It's usually up around the 13lph or higher.

I sat on a GPS indicated 100kph and the revs immediately dropped by 200rpm when I activated the Lock-Up, which obviously indicates the TC was slipping prior to activation, even though I was on a reasonably flat section of Highway.
2150rpm with switch off and 1950rpm with switch on. Tranny temp dropped to 65° which I am very happy with. I dropped from 100kph down to 80kph with the transmission in drive, and it certainly felt more like a manual vehicle without the TC slip when I slowly accelerated again, so I knocked it back to fourth manually and all felt very smooth.
As mentioned though, this was only a very brief test and I'll need to wait until I can get some longer distances in when fully loaded to get a better idea of how effective it is. But initial indications seem great!

[grhyso]

That sounds very interesting Steve. Seems quite expensive but i guess the PWM bumps it up pkus the labour to fit.

I'm very interested to see if your long term fuel consumption drops, depending on your normal routes being highways or freeways

[Pickle]

I've picked up the Paj today after having the Lock-Up kit installed and have only had the chance for a very brief test. This is in no way a conclusive test as all I did was basically cruise down the hwy and activated the lock up for about 10 km's. I have to say though, that this is the first time in a very long time that I have seen the onboard computer tell me I'm getting 9.8 litres per hundred. It's usually up around the 13lph or higher.

I sat on a GPS indicated 100kph and the revs immediately dropped by 200rpm when I activated the Lock-Up, which obviously indicates the TC was slipping prior to activation, even though I was on a reasonably flat section of Highway.
2150rpm with switch off and 1950rpm with switch on. Tranny temp dropped to 65° which I am very happy with. I dropped from 100kph down to 80kph with the transmission in drive, and it certainly felt more like a manual vehicle without the TC slip when I slowly accelerated again, so I knocked it back to fourth manually and all felt very smooth.
As mentioned though, this was only a very brief test and I'll need to wait until I can get some longer distances in when fully loaded to get a better idea of how effective it is. But initial indications seem great!

Watch your temperatures go down as well. I love my lock up
Dave

[Dicko1]

Are these mainly used for towing or would you install one for day to day driving?