Click below to check out the different Stocklock User Guides..

Dual Speed

High Speed (auto)

Auto/High speed locks 5th and 6th gear from 82km/h, and is designed for everyday driving in “Drive”.

It can always stay turned on and being automatic no extra input is required.

Low Speed

Low speed locks from 2nd – 6th gear from 32km/h, and is designed for towing and touring, or working hard in sand/mud etc.

Your gears must be used manually (up and down in “S” mode) or else the gearbox will lug excessively.

If you don’t want to use your gears manually, turn off the low-speed button.


  • When towing, you should always be in “S” mode and change gears manually.
  • You can take off in S2 and then change your gears as required.
  • Low speed lock-up will disengage at 28km/h, allowing for normal operation of the automatic transmission.
  • The Stocklock can be turned on/off on the fly as desired.
  • The Auto (top) button can be left in at all times, and push the Low speed (bottom) button in when you want to activate the low speed lock up. (both buttons can be in at the same time)
  • To get the most out of your Dual Speed lock-up when towing: push both high and low speed buttons in, select “S” mode, and use your gears manually up and down.



With the button on and in drive the lock up will activate automatically from 82km/h and disengage from around 75km/h. It will lock 4th, 5th and 6th gear, depending on your speed. This is designed for every day driving and touring. It can stay turned on all the time. Being automatic, no extra input is required.

Low Speed

To activate low speed, simply move the gear shifter to sports mode. Low speed locks from 2nd gear at 32km/h and is designed for towing. Your gears must be used manually (up and down in “S” mode) or else the gear box will lug excessively. If you don’t want to use the gears manually, turn off the button or move the shifter back to drive.

3rd Speed

To activate the 3rd speed simply select low range and move the shifter to sports mode, you will then have lock up from 8km/h and must use the gears manually.


  • Only one button to turn lockup on/off and can be done on the fly.
  • When towing, you should always be in “S” mode and change gears manually up and down.
  • Low speed lockup will automatically disengage when slowing below 28km/h.
  • If you are driving around 85km/h, in drive and experience a shutter, you may want to turn the lockup off as you are not going fast enough.

DPT Lockup

DPT Lockup

It doesn’t get any easier than this. If you want to engage the transmission lockup, simply move the shifter from drive to sports mode, that’s it.
This will engage lockup from 38km/h, making sure you use all the gears manually (just like a manual gear box), changing up and down as required.
If you want to turn the lockup off, move the shifter back to drive, or push the lockup button off.

2nd Speed

When in low range simply move the shifter to sports mode, this will engage the lockup from 8km/h and the gears must be used manually.

I would like to extend my appreciation and thanks to Matt and everyone at Diesel Performance Tune. After taking my vehicle to another company and was over charged, poorly treated, and my oil leak never got resolved after 1 week and 2 visits.. Brought it to Diesel Performance Tune.. Really great customer service (Matt you rock). Very reasonably priced, honest crew and had my Navara back the next day..I will not be taking my vehicle anywhere else.. Best company in the GC, and not just by a small margin either..
Thank you VERY much guys. New customer here for sure 😀😀

Mcdoogle DutchSTOKED

Went to this place on recommendation from a few blokes. Great experience with these people!! Flexed and accommodated my needs with mods on the new build Toyota 79 series, there was so much unknown about what could and couldn't be done.
I now have a vehicle in my garage that I'm 100% happy with!!


Took my 2021 Hilux down to DPT and the work was amazing. If you have a Hilux and want a little more push or just a remap to remove the dead spot in 2nd you need to call these guys! Every hilux should have this work done and changes it to a different vehicle. Extremely professional work and friendly staff.

Jeremy C

Rick and the team did a fabulous job upgrading my beloved 200 series. I have always loved my vehicle but love it even more now! Rick's professionalism and vast knowledge of the 200 series instilled confidence and trust. I am now a Diesel Performance Tune addict and can't wait for my next mod!

Natalie French

I was asked to contact this business by a third party to try and resolve an issue I had with my car’s suspension. I was somewhat prepared for service that was so-so as I lived on the other side of the country and it was obvious that more than likely I would never cross their doorstep again once I had the problem looked at. That view could not have been further from the truth. Rick fitted me in to initially look at the problem and then spent an hour thoroughly diagnosing what may be the cause. He contacted two separate suppliers, arranged to have the parts delivered ASAP and again fitted me in first thing on the Monday morning to complete the job so I could be on my way. I cannot speak highly enough of this company and it’s staff and it’s approach to customer service. I would have no issue using them for any of the services that they provide and do not hesitate to recommend others to do likewise.

Rick V

When it comes to knowledge and quality workmanship you won't find any better on the GC. We originally took our ranger to these guys to fix something that had been incorrectly installed by another company and no one could correct this. From the first conversation these guys knew their stuff and were honest! And resolved my issue with one visit. We are so lucky we were referred to Diesel Performance Tune and take all our vehicles to these experts now. The staff are great to deal with and are honest good people. Anyone had enough of not getting value with who your using currently don't hesitate give these guys a call!

Jessica Sanders

Very professional outfit. I have a PK Ranger and it is hard to find centres who care about older vehicles these days. Rick, Eddie and the boys treated me like one of their high end Land Cruiser customers. I am mechanically minded and was able to really discuss my issues and findings with the vehicle which did not fall on deaf ears. Not only did they resolve my issues and breathed new life back into my old vehicle, they also repaired smaller less noticeable issues which were very inexpensive now but would have resulted in a lot more costly repairs down the track. These guys will be seeing me again 🙂 Keep up the great work.

Matthew Sonter

The diesel performance team did a great job with my hilux. I have had a reoccurring problem for years with the check engine light, limp mode and the hilux throwing codes that no mechanic was able to diagnose. The team was able to find the hidden broken wire, fix it and tune my hilux. It's been running great ever since. Would highly recommend this business.

Jessy Bloom

Rick, Eddy, and the team did a GVM upgrade on my Landcruiser 200 and were fantastic throughout the process. Thorough and very professional. Would recommend highly.

Joanne Riley

First of all I want to say a big thank you to Eddie and his team, im so impressed on the attention to detail and work they did on my 79 LandCruiser. The staff are very friendly, honest and extremely knowledgeable. Thanks again team and I look forward to getting future upgrades and work done.
Dean from Apollo.

Dean T

Just picked up my turbo diesel iload, being a business owner vehicles off the road cost money, the boys did a professional job, highly informational and job completed in a couple days. Competitive price with excellent workshop and customer service, highly recommended. Thanks

Mark Ansems

What a customer service. So hard to find people willing to help.
Just a phone call, I was able to get an information that saved me wasting my money and time. Thank you so much. Super happy with my experience.

Mark Uzuelli

Have just had my 2012 Land Cruiser worked on by the guys at Diesel Performance & Tune. ECU remap, transmission remap, Stocklock transmission lockup, fuel manager 2 micron post filter, catch can, carbon clean, Scan gauge & transmission service. Ray & Eddy are great guys who patiently explained everything and answered all my questions. Car runs with much more power & torque now. Very professional job. Thoroughly recommend Diesel Performance & Tune.

Colin Price

Great service, Had my 4x4 tuned and some work done. Very knowledgeable bunch. Eti was very friendly and knew what he was talking about. Thanks guys for looking after me. I'll definitely be back if I need more work done. 10/10.

David Mackow

Just had my LC79 in for a bunch of power upgrades from the boys at DPT.
Cannot explain how happy I am with the Ute now, they have woken it up.
Excellent attention to detail, product knowledge and efficiency.
Look forward to the next time fellas.

Jarryd C

Very impressed from start to finish!
Big thanks to Mat & Rick for all their info & experience. Ill certainly be bringing back my cruiser for more upgrades!👍😀

Tara W

Rick and the team at DPT were excellent to work with, and feel they went above and beyond to ensure I was happy with all the modifications. They even had me back the week after to fine tune anything. Have been travelling Oz for 2mths now and very happy with everything they carried out.

Matt B

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