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Output shaft question 66-68

Posted: Tue 16. Mar 2010, 09:48
by buddy67lincoln
The Lincoln C6 has a 3 spline or triangular output in the tailshaft that the slip yoke slides onto. What kind of abuse can this 3 spline take? I heard they were only good for 300-400 hp? How someone would know, I have no idea, but I wanted to look into it. Are there better 31 spline outputs I can get? I tried looking these things up but I might have the terminology incorrect. Again its 3 (triangular) splines that the slip yoke slides onto. I don't think I will have a problem with I have in mind for my 462 but the hp will be around or just over 400hp. Just so it will not kill those 3 splines. Thanks for any help.

Re: Output shaft question 66-68

Posted: Wed 17. Mar 2010, 09:01
by Treinarts
I can promise you failure within a short period of time.
The output shaft on the Lincolns was intended to soften the impact of shifts for a smoother ride.
Simple truth is the more splines the merrier. And stronger.
A tranny shop could rebuild your 462 case with FE or truck shafts that would be much stronger. TJR

Re: Output shaft question 66-68

Posted: Wed 17. Mar 2010, 09:14
by buddy67lincoln
Treinarts wrote:I can promise you failure within a short period of time.
The output shaft on the Lincolns was intended to soften the impact of shifts for a smoother ride.
Simple truth is the more splines the merrier. And stronger.
A tranny shop could rebuild your 462 case with FE or truck shafts that would be much stronger. TJR
Just what I wanted to hear! I appreciate it. Thanks

Re: Output shaft question 66-68

Posted: Mon 22. Mar 2010, 04:35
by 66Lincoupe
John - Just to add some more info. The C-6 is a C-6. All of the C-6's (that I am aware of) used the 31 spline output shaft - except ours (lucky us, huh?)

If you are not comfortable removing the transmission and disassembling it you can have a shop replace the output shaft housing and output shaft with one from any other C-6 - They interchange. You can buy a 31 spline yoke from Jeg's or Summit or use the one from the donor car.

I am doing this to mine. I didn't have the parts when I had my trans rebuilt - I got the output shaft, the housing and the yoke from a donor car cheaper than I bought just the correct output shaft bushing for the 3 bearing from the Usual Suspects.

There is someone on the other forum that has done this as well...

Re: Output shaft question 66-68

Posted: Mon 22. Mar 2010, 05:46
by buddy67lincoln
66Lincoupe wrote:John - Just to add some more info. The C-6 is a C-6. All of the C-6's (that I am aware of) used the 31 spline output shaft - except ours (lucky us, huh?)

If you are not comfortable removing the transmission and disassembling it you can have a shop replace the output shaft housing and output shaft with one from any other C-6 - They interchange. You can buy a 31 spline yoke from Jeg's or Summit or use the one from the donor car.

I am doing this to mine. I didn't have the parts when I had my trans rebuilt - I got the output shaft, the housing and the yoke from a donor car cheaper than I bought just the correct output shaft bushing for the 3 bearing from the Usual Suspects.

There is someone on the other forum that has done this as well...
Thanks a lot! I appreciate the help. I didn't want to learn the hard way! Easy fix.

Re: Output shaft question 66-68

Posted: Mon 22. Mar 2010, 09:55
by buddy67lincoln
A transmission shop told a friend (with a 462 in an Isuzu Mighty Max!) that all he needs is a 2500 stall converter and that will handle the power fine so he can keep the original output shaft...any advice? I still think it would hurt that 3 spline eventually but I am not trans shop. Thanks again for any further advice

Re: Output shaft question 66-68

Posted: Mon 22. Mar 2010, 13:56
by 66Lincoupe
You build the drivetrain to match the vehicle or its intended use. Seeing as a stock MEL makes the most torque and horsepower at a very low RPM a stock stall converter or a little higher RPM is fine. Gearing would be my concern, but a Mighty Max is so light any gear ratio would probably be okay.

Also since the vehicle is so light there may not be a concern with the 3 spline Lincoln stuff... But I would be afraid of side-loading those bearings in an abusive environment (I'm sure a 462 in a Mighty Max wasn't installed to putt around the subdivision delivering newspapers...) That's just me though!

Re: Output shaft question 66-68

Posted: Tue 23. Mar 2010, 05:45
by buddy67lincoln
66Lincoupe wrote:You build the drivetrain to match the vehicle or its intended use. Seeing as a stock MEL makes the most torque and horsepower at a very low RPM a stock stall converter or a little higher RPM is fine. Gearing would be my concern, but a Mighty Max is so light any gear ratio would probably be okay.

Also since the vehicle is so light there may not be a concern with the 3 spline Lincoln stuff... But I would be afraid of side-loading those bearings in an abusive environment (I'm sure a 462 in a Mighty Max wasn't installed to putt around the subdivision delivering newspapers...) That's just me though!
Yeah he just putts around with it right now on weekends, no daily driving or drag racing, but he wants to run it a few times to see what it can do. I guess he realizes how expensive it can be to rebuild on these MELs. I believe its all stock from what I know, might have a cam in it. He is looking for the tri power so he is not trying to up the power so if he does, I'd think about the 31 spline output swap. That's just me. Thanks for the help again

If gas gets back to $4.00 a gallon I might want to spend the extra loot and put OverDrive on it. I wanted 3.50 gears too