Driveshaft Question

[cmsu]

Hi, I am at the stage where I'm ready to cut the driveshaft and the shop that is cutting, re-welding and balancing the driveshaft asked me to measure and compare and contrast the measurements in the manual VS the actual measurements, and of course they don't appear to match. Any tips or tricks or been there did this would be helpful thanks:

FFR Manual shows 11" from what looks like the rear end flange to the yoke flange and almost looks like it includes the thickness of the rear end flange in that measurement.

Actual measurement from the front of the rear end flange to the tip of the trans output shaft is 11.5" so if I include the thickness of the rear end flange that distance will increase by the thickness of the flange.

Actual measurement from the front of the rear end flange to the edge of the transmission tail is 12.125" so if I include the thickness of the rear end flange that distance will increase by the thickness of the flange.

I have a Ford 306 crate engine with E cam, T5 and the rear end out of an 87 Mustang GT donor.

Thanks in advance for your help!!

[canuck1]

Mine were exactly as per drawing. I didn't measure, I just supplied the Mustang driveshaft and drawing from the manual to the driveshaft shop, they did the rest. Are you looking at the correct model year drawing and/or using the correct model year parts?

The 94-95 era T5 used a 5/8" longer input shaft and so this pushes the trans back an additional 5/8" or so. Any chance you have a mixed bag of components in your car? Is the the trans and bellhousing definitely from an 87-93 donor or supplied from another source? Even if it was in an 87 car, it's possible to fit a 94-95 trans in there as a replacement with some work (I know, not likely). I would check the tag on the trans to confirm.

Sean

[cmsu]

I took the trans, driveshaft and rear end out of the donor myself, but of course I purchased the donor as a used vehicle so I dont know the history of it. The engine is a new 1990's vintage) ford 306 crate engine, if the old owner of the donor car changed the trans to a SN 94-95 era T5 he would have had to have done something with the driveshaft to compensate for the 5/8" I would imagine?? I'm happy for you that you didnt have any issues with your build, that is awesome, my experience so far is well not very awesome, but I digress .......

[edwardb]

I don't know how much this helps, but I've ordered both of my driveshafts from Denny's Driveshaft. They provide a very nice product just for our kind of builds. This is the diagram they use to collect the required information.

http://www.dennysdriveshaft.com/img/File/how_to_measure_diagrams/k.html

It would seem the measurement may not include the pinion flange, but can't say for sure. Several points though. As pointed out on this worksheet, you should be roughly at ride height while taking the measurements. Your pinion angle should be in the ball part as well. Also keep in mind the final driveshaft won't be exactly the measurement you provide. It has to be slightly shorter in order to install, but long enough that the slip yoke has as much engagement as possible. Denny's obviously knows what to do. Both mine just barely tipped in. HTH.

[cmsu]

Thanks Edward B, your post and link were very helpful, I dont believe we set the pinion angle as yet so maybe just maybe I will loose a 1/2 " from that, she was sitting on her own weight at the time but the ride height is not set as yet, so I'm hoping ................I'm trying to be optimistic!!

[cmsu]

OK so I adjusted the rear end up and down, side ways and back to front and my measurements are still 12.25" from rear end flange to T5 flange and believe it or not, no matter how many times I read the manual the measurement look like it should be 11" so I'm providing my measurements to the driveshaft shop. I give up, I'm calling "Uncle" thank you all for all of your help.