Oh boy..
The problem with your transfercase is internal. The 4.70:1 gear set that you purchased through Advanced Adapters is using our old discontinued 4.70:1 gear set made by their gear cutter. I know this because he was our gear cutter for about 3 years and as soon as we left him to make better gears, A/A immediately began retailing 4.70:1 gear sets (both A/A and Marlin used the same gear cutter). The problem is that his machinery lacks the ability to cut those old gear sets (originally designed in 1997) the way the manufacture Toyota did --
And this is one of the reasons why we left him.Our new 4.70:1 Gear Sets are cut by none other then Toyota©'s Gear Cutter in Japan. We went straight to the source and our New Gears are manufactured by the same company that made the gears in everyone's pickup on this board.
The above picture is a shot of the shift hub teeth on the Input gear. The factory 2.28:1 gear sets used a 2° taper that was tapered into the gear - forcing the shift hub to stay in place. Our old discontinued gear sets (now A/A's) does not have this 2° taper and therefore the shift hub can "float" up or down those teeth depending on coast, drive, and load.
This was a HUGE problem with our gears when we used to sale those. Customers all over the place would complain about it popping out of gear, it would even happen to Marlin. So to counter this problem, the only thing we could do was try to strengthen the detent ball spring pressure and hope that the fork could keep the shift hub in place, but we found that this was only a 50/50 chance of working. Some units would stay in gear while others would still pop out. It may have been due to some shift hubs with higher mileage that had wear on them but we were unsure.
So we demanded for our gears to have the same 2° taper as the factory gears but our old gear cutter lacked the ability to cut any taper to those teeth. So we were left with no choice but to leave him and find a better gear cutter and that's when we hired Toyota's gear cutter. Now Marlin could design his gears the way he had wanted to - including his new Total Spline™ technology......
The left gear is our Total Spline™ Input and the right gear is our old gears (now A/A). The TS prevents couplers from stripping out and also prevents inputs from breaking at the "fuse" (this is another story
)
There are a couple other important changes that improve gear strength and design but these are the main two changes.
Now about your gear set popping out, Marlin and I both agree that after installing the bud built, there are two reasons for those old gears popping out.
1) The BudBuilt crossmember raises the drivetrain up about .5 - 1 inch. This puts more torque-stress on the rear output shaft because of the increased driveline angle. And since the output shaft holds the low speed gear, when it moves around, it effects the shift hub and walks it off of the gear.
2) In addition to the increased backflow of torque, also remember that the BudBuilt uses two crossmember mounts that hold the drivetrain more solid. This means that as you accelerate or coast, instead of the change of momentum being absorbed with some drivetrain flex/wrap, now more of the energy is conserved which puts more energy through the drivetrain which walks that hub off of the input gear.
shheww.
That's alot to think about. I may have gotten carried away but I am best when I write like this....So If I'm running around in circles, please let me know what recommendations or advise you are looking for.
The only thing I could say to try right now is to find a shift detent spring that is stronger than a stock spring and replace it. This may or may not solve the problem but it's sure easier than pulling the whole unit apart.
Regards,
BigMike
