Driveshaft yoke comparison between 4L60E and TH400

[Frank Enstein]

I have the B&M Star Shifter on my list, granted I would be getting rid of the chrome on the plate, but it has a reverse light switch built in, so it would be easy enough to wire that in.

B&M 80675 B&M Automatic Shifter - StarShifter

The B&M StarShifter is our 3-speed shifter with a split personality of performance, function, and that classic muscle car styling. The first personality is as a straight-line detent shifter, meaning you can move between gears without a positive stop, like an OEM shifter. The racing personality...

www.holley.com

This is the one you're talking about though right? I'd have to sand the cover down and paint it black.

www.holley.com/products/drivetrain/shifters_components_and_accessories/automatic_shifters/pro_ratchet/parts/80843

Yes, as well as the 80842, and if you want a pistol grip either of these will work;

https://www.summitracing.com/search...et&N=knob-style:round_magnum-grip_pistol-grip

The 80842 and 80843 use 3/8-16 threads for the knob. The pistol grip ones have different side panel with buttons available for a line lock but the main part of the "knob" cannot be changed.

 

[MrPink]

So for those wondering. I flipped the measurements around lmao, the 4L60E shaft is ~3.1" longer, than the TH400 Shaft, but the real differences are in the lengths of the transmissions. The 60E is 30.75 OAL from Bell to Tail, and the TH400 is 33.85" OAL from Bell to Tail. The mounting locations are 22.5" for the 60E from bell to mount holes and 24.3125" from bell to mount for the TH400.

 

[stutaeng]

So you'll just have to shift your transmission crossmember back a bit? Drill new holes on the frame?

 

[Frank Enstein]

So for those wondering. I flipped the measurements around lmao, the 4L60E shaft is ~3.1" longer, than the TH400 Shaft, but the real differences are in the lengths of the transmissions. The 60E is 30.75 OAL from Bell to Tail, and the TH400 is 33.85" OAL from Bell to Tail. The mounting locations are 22.5" for the 60E from bell to mount holes and 24.3125" from bell to mount for the TH400.

That's not a 4" tailhousing TH400 then. Prolly an 9". There are 13" tailhousing TH400's too.

 

[MrPink]

So you'll just have to shift your transmission crossmember back a bit? Drill new holes on the frame?

Yep just a smidge.

That's not a 4" tailhousing TH400 then. Prolly an 8".

The 4" one is 28.75" OAL, the 9" is the one I went with as far as orig measurement. The 13" long is 37.875"

 

[unruhjonny]

Gm uses the 27 spline on Powerglide, TH200,250,350, 375, 2004R, 700R4, 4l60, 4l60E,4l65E,4l70E, T5, T10 (except Super),Muncie (except M22),Saginaw, and prolly 37 others I forgot.
32 Spline on the on the 400 and 4l80E as well as Super T10 and Muncie M22.

just a small correction on the highlighted;
The 1963-1970 Muncie transmissions all used the smaller output - BUT(!) the 1970 M22 placed in Chevelles(?) had the larger output (and corresponding revised tail housing);
The 1971-1976 Muncie three speed (common in 73-76 square bodies) kept using the smaller output, while 1971-1973 Muncie four speeds all went to the larger output design.
The Muncie four speed (M20 & M22; no M21 after 1970) was replaced during the 1973 model year with the BW-ST10 and this design retained the same larger (TH400) style output.
To the best of my knowledge, the Saginaw kept the smaller output because it was a transmission with a lower torque rating (the four speed was essentially a modified three speed);
GM decided to leave ALL three speeds with the smaller output.

 

[stutaeng]

Why did they have those long tailshaft version in the 70s anyways? They look goofy.

 

[Frank Enstein]

Why did they have those long tailshaft version in the 70s anyways? They look goofy.

To eliminate the cost of a 2 piece driveshaft on Giant cars and trucks. Larger diameter driveshaft tubing costs more so a shorter, cheaper driveshaft could be fitted.

 

[Queso Del Rio]

Here's the one I bought for mine. I initially bought another yoke, but it was too long. This is the shorter version (I think they actually made like 4 or 5 different output shaft versions, including the RV drum brake set-up for those transmissions?)

T-400, 4L80, 4L85, 6L80 Transmission Slip yoke GM 3R Series 32 spline w/threaded hole in output shaft

GM 3R Series 32 spline T-400, 4L80, 4L85, 6L80 Transmission Slip yoke specifically designed to be used on a T-400, 4L80, 4L85, 6L80 with the Threaded Hole in the Output shaft. This design will replace the truck style bolt on yoke with a car style slip yoke and allow for proper slip travel and...

www.dennysdriveshaft.com

Beware of ones with the infamous "vent hole." I had one dump out 2 qts., luckily just sitting in the driveway. After my motor's 500-mile oil change, it somehow decided to mark its spot overnight! Had to go "Dr. Pimple Popper" on the junkyard rescue of a non-vented one. I did a search here and found a couple of goofy fixes beyond proper welding (JB Weld, Silicone, etc.). Living in the desert, $10 for a solid one was a no-brainer! 2k miles+ later and no issues.

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[454cid]

Beware of ones with the infamous "vent hole." I had one dump out 2 qts., luckily just sitting in the driveway. After my motor's 500-mile oil change, it somehow decided to mark its spot overnight! Had to go "Dr. Pimple Popper" on the junkyard rescue of a non-vented one. I did a search here and found a couple of goofy fixes beyond proper welding (JB Weld, Silicone, etc.). Living in the desert, $10 for a solid one was a no-brainer! 2k miles+ later and no issues.

Running the wrong slip yoke is not the proper fix. You've got a blown seal in the back of the transmission. The vent is supposed to be there, and the vented slip yokes are the ones that actually get greased from the factory.