Automatic Transmission Tech Talk & Development
Rodney Hudson-Davies posted at 1/29/2013
Hi my name is Rodney Hudson-Davies and I am in charge of the Technical Development and Motorsports department within Wholesale Automatic Transmissions. I have been asked by one of your members if I would put together an article about some items our company has been developing and testing over the past 12-14 years in the hope that at the very least would make for some very interesting reading for all Patrol owners that have an automatic transmission fitted. We have been developing and testing a few items fitted to dozens of 4 wheel drives including Nissan Patrols and Toyota Land Cruisers. Please take the time to read on and feel free contact me about any questions that you might have. Regards: Rodney
Our Extreme Recalibrated change over valve bodies have not only been designed for all V8 conversions but also for all turbo charged, super charged and also for anybody including ourselves that wanted a sharper and more satisfying shift feel. Our valve bodies have been recalibrated to solve other problems such as Soft Shift Feel, Kick Down Flare, Over heating and transmission failure due to heat produced by Lock Up Slippage, Overall Transmission Pressures and Clutch Clamping Force. Our new release Nissan Patrol valve body makes all the difference. Often we hear owners complaining about the quality of their Nissan Automatic Transmission when shifting through the gears, most come from everyday drivers who simply can't stand the slipping and flaring between the gears. We have had dozens of owners contact us about improving the transmission in some way to overcome the problem. We put together a development program and have come up with a cheap and easy way to turn your Nissan Patrol transmission into a firm shifting transmission without having to remove the transmission from the car, Simply remove the valve body and exchange it for one of our Stage II Recalibrated Extreme Nissan Patrol Valve Bodies.
The valve body comes with easy to read instructions for the removal and refitting of the new valve body. The valve body has undergone a tremendous amount of testing including Nissan Patrols that have had turbo chargers, super chargers and even large V8 conversions done and in every single case the customer has been quite overwhelmed about the difference the New Valve Body made to the vehicle.
The transmission once fitted with the new valve body can easily handle more than twice the power and torque with crisp shift points even while towing trailers that are of considerable weight. The New Valve Body has also been tested behind large V8 engines including the 6.5 litre Chevy diesel V8, We simply couldn't fault the new Extreme Recalibrated Stage II Valve Body no matter what we did to it ( At time of print the valve body had been tested to 607Hp = 450Kw without failure to the transmission).
Our New Extreme Stage II Recalibrated Heavy Duty Valve Body
The New Set Of Soleniods Used On Our Extreme Valve Bodies
One Of The Modifications Made Is To This Accumulator
After 2 years of trial and error we have also finally managed to find a way to lower the convertor stall speed of the RE4RO3A Nissan Patrol. We have found that this is a must before any V8 conversion is considered as using the standard convertor behind any V8 engine turns the convertor into an instant high stall. This will generate so much heat when the lock up is not engaged that the life expectancy of the transmission in many cases has been recorded on a regular basis to be as low as 100km with most transmissions lost at 5000km. You simply CAN NOT do a V8 conversion without altering the convertor.
We now have a super low stall torque convertor that we have managed to lower from an average 2400-1200rpm solving the overheating problem caused by stall speed. We have also received A LOT of positive feedback about far greater engine braking and reduced down hill braking by as much as 80%. Increased low to mid range torque helps on never ending hills and highway cruising even while towing. A noticeable reduction in fuel usage has been reported.
All Our Super Low Stall Convertors Come Kiln Bronzed And Micro Balanced
We have found that using fully synthetic transmission oils will lower the overall transmission temperature even further and is also engineered to remain stable under the most severe conditions. We use Olean “Syn Multi-Trans” but have also found that Castrol "Transmax-z" and Allison "TranSynd" are great oils while most other oil companies have their own version of a full synthetic transmission oil. All of these automatic transmission oils mentioned above have one thing in common and that is that they are a True Full Synthetic transmission oil. They will NOT replace the need for a super low stall convertor or Extreme valve body but if you want that added edge on overall reliability then this is it.
We also don't discount a good oil cooler as we always will recommend a suitable cooler in any vehicle that runs a transmission. The transmission life span is mostly measured in heat, the hotter the transmission runs the shorter the life expectancy. A good cooler is the cross flow type as they slow the oil speed down considerably which inturn keeps the oil within the cooler for a much greater length of time while the "S" pipe type oil coolers don't slow the oils speed. Remember that oil coolers are a science in themselves and a greater surface area the greater the cooling.
I DON'T recommend that any of these changes are made while your Nissan is under new car warranty as im sure "without checking" that the wording within your warranty policy would not leave itself open to these changes except for possibly the oil cooler. And don't forget that we are here to help and look forward to hearing from anyone that has a question or maybe some information about an experience or a product, after all we are always looking for new ways to improve our development programs.
Look forward to hearing from you.
Wholesale Automatic Transmissions
Factory 2/4 Melrich Rd
Phone (03) 97628004
Mobile 0415 393755
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