700R4 input shaft question
Thread Starter
Pro
Joined: Apr 2003
Posts: 517
Likes: 0
From: South Lyon Michigan
700R4 input shaft question
27 spline to 30 spline swap question
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I was hoping one of you guys could answer this question about a 700R4 trans. When I built my trans I used all good parts except I didn't have a 30 spline so I used a 27 spline input shaft that I had, now I want to swap to a 30 spline input shaft and I am not sure if there is anything else I would need to change other than just getting a new input shaft. If anyone knows of anything else that needs to be changed please let me know.
Thanks,
John
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I was hoping one of you guys could answer this question about a 700R4 trans. When I built my trans I used all good parts except I didn't have a 30 spline so I used a 27 spline input shaft that I had, now I want to swap to a 30 spline input shaft and I am not sure if there is anything else I would need to change other than just getting a new input shaft. If anyone knows of anything else that needs to be changed please let me know.
Thanks,
John
Melting Slicks
Joined: Oct 2002
Posts: 3,193
Likes: 1
From: Cincinnati Oh
you will also need the correct 30-splint torque converter to match the 30-spline input shaft. But I really know zilch about transmissions - that's just what I had to do when I had mine rebuilt.
Thread Starter
Pro
Joined: Apr 2003
Posts: 517
Likes: 0
From: South Lyon Michigan
Thanks for the info. Can you clarify what you mean by the pistons in the trans? I know I need a new torque converter, I want to get a bigger stall which is why I am upgrading to a 30 spline. I also need a new pump stator but I'm not sure what else I will need.
Thanks for any input.
Thanks for any input.
Race Director
Joined: Feb 2004
Posts: 12,518
Likes: 19
The input shaft is press fit into the aluminum input drum. You will be swapping the shaft/drum assembly not the shaft only. The aluminum drum contains apply pistons for the clutch packs. If you tranny builder is robbing a drum assembly (as most do) from a parts trans you have no worries. All the parts inside will match. The press fit of the shaft to drum is a somewhat weak point in the 700 r4.They rarely fail in mild horsepower/ torque applications. For the high output stuff they make a reinforcing sleeve that adds rigidity to the spot where shaft and drum meet. Long story short: do not swap shaft only. Be sure to swap drum/shaft assembly.
Advanced
Joined: Oct 2004
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If I were changing the input drum, I would go with a 1988 & up drum, as these will hold an additional clutch & steel in the 3-4 clutch pack. The 1987's used the same part number, but they will not accept the extra clutch.
