ITS BEEN A LONG TIME COMING. SORRY FOR THE WAIT.
THIS IS FOR THOSE WITH THE 4SPD AW340E(30-40LS).
Sorry for the long wait. I have been very busy with on the job training and training seminars.
Well if you are still interested here is the secret.
I AM NOT RESPONSIBLE FOR ANY DAMAGE CAUSED TO YOUR VEHICLE. THIS IS SIMPLY FOR INFORMATIONAL PURPOSES.
Your results may be slightly different from mine but this upgrade is not and will not make the tires break loose after every shift. It will remove most or all of the clutch slip from the transmission and increase part longevity while bettering acceleration due to a faster and firmer shift.
In the transmission there are 3 total shift accumulators 2 large and one small. The larger of the 2 if memory serves me right is the B-2 and C-2 accumulators.
In the older AW340E the accumulator spring had a metal rod inserted to limit spring travel to create a faster and firmer shift. On our trucks this component was deleted for a comfort shift.
I do not have a photo so i will try to be as descriptive as possible.
On the top of the 2 accumulators you will add a spacer 21mm diameter and aprox 6-10mm thick. It will be placed in the accumulator bore between the spring and the transmission case. These accumulators are located behind the valve body of the transmission and if memory serves me right uses 3 different size bolts.
(NOTE...USE CAUTION DO NOT DAMAGE THE GASKET ON THE VALVE BODY, THERE IS NO REPLACEMENT UNLESS YOU BUY A NEW VALVE BODY) ALSO WHEN REMOVING THE VALVE BODY YOU WILL HAVE A PLASTIC CHECK VALVE WITH A METAL BALL ON ATTACHED AND SPRING EXIT RAPIDLY BE CAUTIOUS AND SLOW AND YOU WILL BE ABLE TO SEE WHERE IT IS ON THE VALVE BODY AND HOW AND WHERE TO REINSTALL IT.
This will increase the spring rate but will hydraulically compensate the accumulator which will create no movement of the accumulator this is NOT what you want to do because that passage needs to be clear for lubrication.
The trick is to drill a small diameter hole slightly off center and on one side of the spacer create a dished area to prevent the passage from being blocked. The diameter of the hole does not need to be very large because this is not a high pressure passage it is just a drain port to allow transmission fluid to bypass the valve and lubricate that portion of the accumulator. A hole approx. 1/8" (.125") diameter is fine but you do not want to be at or near 1/4"(.250). Mine is just over (.130") yes it is not a common size.
After you have built the shims(spacers) you will position them above the spring in the accumulator bore on both accumulators as I stated earlier and an extra set of hands is a major help to reinstall the valve body while keeping the components in check.
A little TIP: when reinstalling the check valve it will try to fall out you can use petroleum jelly to help hold it in place. It will not affect transmission performance in any way.
After everything is reinstalled its a good idea to have a min of 7 quarts of Type T-4 Toyota ATF on hand and the gasket sealer. You do not have to buy a new filter because it is a metal mesh filter all that is required is gently back-flushing the filter with clean ATF or low pressure air(30PSI at MAX).
Reinstall your pan using the Toyota sealer and let it set for about 3 to 4 hours minimum. The sealer tube is made just for this application and can be used to seal up to a little over to transmission pans.
Here is where it gets a little tricky. Fill the transmission with ATF use about 4 Quarts then start the truck. DO NOT PUT IT INTO GEAR!! Let the engine run for about 5-10min allowing it to warm up and while the engine is running check the ATF level.
It should show low. Next shift the transmission into all of the gear positions allowing it to remain at that position for a few seconds between shift points(from P-L). Keeping the engine running check the oil level again this will give you the accurate level. Adding ATF to the transmission must be done while the engine is running.
Continue adding ATF until it registers on the dipstick just below the hot mark and not in it. Once you see this shift through the gears and and recheck the ATF level. If it remains just below the hot mark close the hood and go for a short steady drive a 5-10min drive is enough do NOT run it hard yet.
After the little drive park the truck and check the level again it should be close. Add oil slowly to just enter the hot mark on the dipstick and shut the hood.
Now you can drive it hard. You should and will notice the shifts will be shorter and firmer.