Good job making it right!
Why all the issues with the input shafts?
The output shaft problem was known about a long while ago.The issue was that after heat treat the output spline area grew larger than the rest of the shaft because it is the largest densest diameter.We didnt know until 2 or 3 didnt fit.What did we do?We loaded them in the B C hobber and recut them.This shaft was one that we obviously didnt get to .There is no way we intentionally shipped it out,it was a mistake,human error.We actually ran another batch of them a few months ago,and one of them was used by someone in this post with no issue,so is it a widespread problem?Absolutely not.We have positively checked every one from our inventory as well as any installed in any trans recently shipped out .Any trans shipped out goes in a car,every one.If there was input shaft issues we would be aware the minute we install the converter on the trans before the road test.There is no problem with our input shafts ,they are high quality pieces.Are there people telling me they cant get them on?No I am not hearing anything like that.Have I heard of any problems in the past?Yes maybe 5 over the years out of several thousand we have sold.Were there issues with some we purchased from TCS,the company who most everyne else that builds these thing gets them from,when we were out?Yes several with undrilled holes,not enough room for the snap ring etc.How many of these did I buy from them?About 10.How many were defectiiiive?3Oversize splines was the big problem..Do I use them any more?Absolutely not.I just ran a batch of 200 from E4340.The quality of ours verses the others?There is no comparison.The part from us is BEEFED UP IN ALL AREAS WHERE THERE ARE WEAK POINTS.IT IS FINISH GROUND,NOT HARD TURNED.What does this mean?The shaft is dead straight when it is finished because it is ground on centers.Are there issues with turbine splines in the converter fitting the input shaft?This is based on the broach being used cut the splines in the converter turbine.How many are out there?There is the company who broaches my overdrive ring gears and carriers.There is TCS, and Whoever PTC is using.Now if the broach is worn or wearing and you have a brand new input shaft cut on a hob of the exact configuration as stock can there be a tight fit?Of course there can.If the turbine is heat treated after the broach is pulled(standard procedure)can the new input shaft fit tighter than an old one?Of course.Should the shafts be made undersize or loose to guarantee proper fit after heat treat or if the broach is worn or wearing?There is a certain amount material grow during heat treat.Absolutely not in my opinion.We have recorded the amount of growth the material will see during heat treat and use this to calculate the finish size produced on the hob.The areasto look at are:
Keeping the bore of the turbine .0005" + larger than the major outside diameter of the broach.
Controlling growth during heat treat.
Keeping the broach sharp.
Getting a quality input shaft that is test fit on a known goood spec turbine spline before it is sent out to you.
Using a ground input shaft so that all diameters are concentric to each other .
I have not been made aware of 1 problem with my input shafts in the last year that I remeber and if you got one that had an issue call me out right here,I would like to know.
Hopefully once this trans gets straightened out, the driveshaft will be salvageable. If so, I just need to get Cal up here and tune it. Should be a beast once she's all together!
