Slip Yoke Question for Th400
Thread Starter
Joined: Dec 2001
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From: Central Indiana Honors: 4th grade spelling bee contestant
Slip Yoke Question for Th400 It seams the more I research the subject, the more confused I get 
I have a 1989 TH400 long tail that came out of a Chevy Van.
I have a Spohn driveshaft already cut to fit, but the barrel on the 1350 series yoke that was provided isn't correct. It won't even begin to slip into the transmission case. That is totally my fault for not knowing any better when I placed the order.
Since I read in the sticky that the long tail uses a 27 spline output shaft, I am under the impression that I need to buy a 1350 Series 27 Spline Slip Yoke for a TH400. Is that correct? If so, I am having trouble locating one online for a TH400 or a 4L80E.
Thanks for the help!
Scott
I have a 1989 TH400 long tail that came out of a Chevy Van.
I have a Spohn driveshaft already cut to fit, but the barrel on the 1350 series yoke that was provided isn't correct. It won't even begin to slip into the transmission case. That is totally my fault for not knowing any better when I placed the order.
Since I read in the sticky that the long tail uses a 27 spline output shaft, I am under the impression that I need to buy a 1350 Series 27 Spline Slip Yoke for a TH400. Is that correct? If so, I am having trouble locating one online for a TH400 or a 4L80E.
Thanks for the help!
Scott
FWIW that tail housing length was also used with 32 spline output shafts, it looks like you do have a 27 spline though.
You need to remove the tail housing and find out if the yoke doesn't fit the output or the tail housing.
There aren't many variables here, a 27 spline yoke should fit every 27 spline GM transmission.
edit: you don't need a 27 spline yoke specifically for a th400. FWIW (again) I have factory a 27 spline 1350 yoke, it came off a early 90's 3/4 ton long wheel base truck with a 27 spline th400.
You need to remove the tail housing and find out if the yoke doesn't fit the output or the tail housing.
There aren't many variables here, a 27 spline yoke should fit every 27 spline GM transmission.
edit: you don't need a 27 spline yoke specifically for a th400. FWIW (again) I have factory a 27 spline 1350 yoke, it came off a early 90's 3/4 ton long wheel base truck with a 27 spline th400.
Last edited by Jays_SSZ28; Aug 25, 2010 at 12:52 PM.
Thread Starter
Joined: Dec 2001
Posts: 12,829
Likes: 30
From: Central Indiana Honors: 4th grade spelling bee contestant
FWIW that tail housing length was also used with 32 spline output shafts, it looks like you do have a 27 spline though.
You need to remove the tail housing and find out if the yoke doesn't fit the output or the tail housing.
There aren't many variables here, a 27 spline yoke should fit every 27 spline GM transmission.
edit: you don't need a 27 spline yoke specifically for a th400. FWIW (again) I have factory a 27 spline 1350 yoke, it came off a early 90's 3/4 ton long wheel base truck with a 27 spline th400.
You need to remove the tail housing and find out if the yoke doesn't fit the output or the tail housing.
There aren't many variables here, a 27 spline yoke should fit every 27 spline GM transmission.
edit: you don't need a 27 spline yoke specifically for a th400. FWIW (again) I have factory a 27 spline 1350 yoke, it came off a early 90's 3/4 ton long wheel base truck with a 27 spline th400.
we have billet yokes for 1350 joints and a 27 spline shaft. The trans you prolly have is a 375 which is the same as a 400 onh the inside but with a 350 diameter output 9" long.
Greg
Greg
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FTI COMPETITION CONVERTERS AND TRANSMISSIONS
"IT'S NOT CHEATING, IT'S THE COMPETITIVE EDGE."
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info@ftiperformance.com
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FTI Converter build sheet
You don't really have a th375. Those were used for a short time in the 70's as a light duty th400. They actually did have less clutches and taller apply pistons.
The last of the th400's are in late 80's and 90's trucks and vans and look like the 375's but internally are identical to any other th400. The 375 tailhousings had thm-375 cast into the bottom and a different trans mount location.
The last of the th400's are in late 80's and 90's trucks and vans and look like the 375's but internally are identical to any other th400. The 375 tailhousings had thm-375 cast into the bottom and a different trans mount location.
