[64speed]

I did exactly what I was told 3 times and came up with the same measurements. I went to install the shaft today and it was 1 1/4 too long approximately. I called Carolina driveline and they basically gave me the same instructions. They told me not to measure the shaft and subtract but to start over like I was starting from scratch and then come and have it shortened. How do I measure for the driveshaft the easiest way? You guys with early A bodies with TKO transmissions how long is yours

[grivera]

Make sure the suspension is loaded like on ground or a drive on lift. Measure from tail shaft seal to the bolt flange surface of the pinion yoke (this is center point of u-joint). Also measure the distance from tail shaft seal surface to tip of tail shaft.

[Tom Vaught]

When I did mine I put the front wheels on a pair of car ramps about 8 inches tall.
Then I used a quality floor jack and raised the rear axle until the frame was basically the same height front to rear,
(measured behind the wheel wells on the front and in front of the rear tires. I then installed my constructed wooded
2X6 "Boxes" under the rear tires at that height. So now the tires were all at the same height and the chassis was loaded to the proper weight on the suspension. Then I went under the car and measured the distance from the yoke (pulled out 1 inch) to the Rear Axle Pinion Flange.

Then they built the drive shaft one time. EASY

Tom V.

[tom s]

When I did 5 speed swaps I used my stock shaft and just shortened as needed.Tom

[Brian Baker]

You measure from the butt of the tailshaft on the transmission...not the housing, but the end of the shaft itself...to the flat face of the U-joint saddle on the rear yoke. This will give you the measurement from the butt of the tailshaft to the centerline of the rear U-joint This is the only measurement I've ever had to provide and a competent driveshaft shop should be able to make it right the first time.

[OCMDGTO]

Strange did mine and they had a fill in the blank blueprint you get off their site. It came in the mail in a week and fit perfect. I would imagine your people do too

[FrankieT/A]

I think the best you can do is ask whomever is going to shorten your DS as to how they want it measured.

I always put the front yoke in the trans as far as it will go in, pull it out an inch. With the suspension loaded measure from centerline of front yoke U joint bearing bore to flat of the rear yoke. The flat of the rear yoke is the centerline of rear U joint bearing.

[Skip Fix]

Mark Williams I got for the Camaro/IA using their measurements AND their trans yoke was perfect but using the other factory type yoke would have been too long-as it was the same length as that for the ST-10/12 bolt that would not fit the TH400.

The trans yokes all have different depths.

[67Fbird]

The front is where things get "different". The rear is easy...flat part of YOKE = U-Joint centerline. CHECK. Now the front all depends on YOUR YOKE. There anr at least 2 different th400 yokes and IIRC 3 different th350 yokes. THEY will need the YOKE you are going to use. Either install yoke in your tranny till it bottoms out then measure from u-joint center to rear AND SUBTRACT 3/4" (it's gotta be able to move in and out some)

OR

as stated measure from the rear to the END OF THE OUTPUT SHAFT.....and carry your front yoke to the shop so they know EXACTLY which yoke and THEY will adjust your measurement per YOUR parts.

[grivera]

All good points as as Chris indicated best to follow instructions provided by the driveline shop. I’ve dealt with 3 different shops and all require different points of measurements. Maybe instructions weren’t followed correctly?

[theamcguy]

Excellent video on taking the measurements for a new driveshaft. Shows the differnce between loaded and unloaded measurements. Can't go wrong if you follow this video.

https://www.youtube.com/watch?v=vwHU-AxX4uI

[grivera]

64 - did you figure it out?

[64speed]

Originally Posted by grivera

64 - did you figure it out?

I measured again and was off by an inch this time I am gonna measure again and again just to be sure THEN take pictures of the tape measure placement AND take my yoke. If that ain’t right then I guess I’m an idiot

[grivera]

Gotcha - was the suspension loaded first time around?

[64speed]

I measured from housing face to rear yoke like I was told by tech from American Powertrain. I have to admit I am not really impressed with the “tech support” 24 hours my ass and they don’t seem to have a consensus among them.

[SRR]

Originally Posted by theamcguy

Excellent video on taking the measurements for a new driveshaft. Shows the differnce between loaded and unloaded measurements. Can't go wrong if you follow this video.

https://www.youtube.com/watch?v=vwHU-AxX4uI

That was awesome.

[67Fbird]

Originally Posted by 64speed

I measured from housing face to rear yoke like I was told by tech from American Powertrain. I have to admit I am not really impressed with the “tech support” 24 hours my ass and they don’t seem to have a consensus among them.

If that is what you measured...then you MAY only need a different YOKE!! instead of cutting the drive shaft. Might ask them to compare YOUR yoke to the "numbers" THEY are using.

[grivera]

Originally Posted by 64speed

I measured from housing face to rear yoke like I was told by tech from American Powertrain. I have to admit I am not really impressed with the “tech support” 24 hours my ass and they don’t seem to have a consensus among them.

Was suspension loaded for original measurements?

The video posted is good to illustrate the change from loaded to unloaded but doesn't indicate how far to pull slip yoke out for measurement. Always best to follow specific instructions from driveline shop.