NEK5
3/4 ton status
I need to double check the spline on my tranny, to make sure I order the right converter. Is the innermost spline section the splines I should be looking at?
TIA!
TIA!
CK5
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spline check
- Thread starter NEK5
- Start date
Get a 31 spline torque converter... if for some reason you have a 27 spline input you should replace it with a 31. There is no way I could count splines on that pic. Paint a line on one of the splines and start counting all the way around.
NEK5
3/4 ton status
if that is the section, then yeah, its 27 spline. Any reason to swap it out, didn`t really figure that into the build, nor do I have the slightest idea how to do it
If your already going to have it torn down to rebuild, you simply change that shaft for a 31 spline version. You can get a used one from a tranny shop by itself for $10-25 give or take.
NEK5
3/4 ton status
well, the tranny was already built by a shop in RI, so I`d like to keep it the way it is, if possible. Will I have any issues running the 27 spline?
Nothing wrong with the 27 spline. Of course the 30 spline is a bit stronger and was used in the later model tranny's.
The 27 spline shaft was a common failure point in the early transmissions. It may make it, it may fail. I doubt anyone could predict that. Its going to depend on how you drive it. But at this point if you just had it rebuilt, run it as is and buy the converter to match. Worst thing that could happen is you have to pull it back out later.
NEK5
3/4 ton status
I sure hope it doesn`t happen. I bought this tranny from a guy on a local board, who had it built by a local race shop. It was super built w/ extra clutches, hardened sprag, kevlar bands, and corvette servo,deep finned pan with drain plug,and a brand new "K" case.
I`m going to be running it behind a mild SBC, I`d say around 350-400 HP, 400-450 ft/lbs of torque. Got me all worried now
I'd really be worried about any shop that did that much to upgrade it and overlooked the 27 spline input shaft myself.
NEK5
3/4 ton status
i`m couting the right splines right? the ones inner most from the end of the shaft?
NEK5
3/4 ton status
Should I just stick with the tranny thats in the truck, the 90 700r4? I didn`t notice anything wrong with it, no hard shifts really, sometimes it would slip, then bang into reverse, but it only did that a few times a year ago. Maybe just replace the TC and put the pan thats on the built 700r4 onto it?
Why not have your local tranny shop swap the input from your tranny into the rebuilt trans then buy the correct convertor (never use an old convertor with a new trans).
NEK5
3/4 ton status
Is that the only weak spot in these year 700r4s, though? Is it more than just the 27 spline input? Any idea what that would run me?
Yes, its the center shaft splines closest to the end.
I would recommend doing this... if not doing it yourself. Its not a complicated task.
That is not the only weak spot, but it is a major one.
NEK5
3/4 ton status
The end, being closest most to the tranny, or furthest?
Really? Any tips...have to do a little research....
Well, after being built up, what else would be left?
There is only one end of the input shaft sticking out of the tranny...
It's been a few years since I tore into a 700R4, but at the worst you will need to pull the pump to get the input shaft out. Hopefully someone with a little more recent experience can give more info.
It's been a few years since I tore into a 700R4, but at the worst you will need to pull the pump to get the input shaft out. Hopefully someone with a little more recent experience can give more info.
NEK5
3/4 ton status
Alright, before I confuse myself even more than I am, is it the splines at the green arrow, or the orange arrow? 
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NEK5
3/4 ton status
Is it 31, or 30 spline?
If its 30 spline, I counted 30 on the end of the shaft.
Also, check out TCI, they list 27, and 30 spline for the torque converters....
http://www.tciauto.com/Products/GM/gm_4L60E.asp
EDIT: I`m going to assume that 31 spline was a typo, kenny, as Scott also says it a 30 spline, and everywhere lists 30 spline converters.
So that means it IS 30 spline. PHEW!
Thanks for helping me sort that out guys!
If its 30 spline, I counted 30 on the end of the shaft.
Also, check out TCI, they list 27, and 30 spline for the torque converters....
http://www.tciauto.com/Products/GM/gm_4L60E.asp
EDIT: I`m going to assume that 31 spline was a typo, kenny, as Scott also says it a 30 spline, and everywhere lists 30 spline converters.
So that means it IS 30 spline. PHEW!
Thanks for helping me sort that out guys!
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