tonyinsandiego 37 Report post Posted April 22, 2014 (edited) Hello all, I'm in the middle of an AOD swap and I am having issues with installing the drive shaft. The extra length of the AOD is causing problems with the original drive-shaft (so I believe) install. It's looking like I need to shorten my drive-shaft about 1". Does this sound right for the guys with the AOD swap? If so, how much did you shorten the drive shaft and how much play did the yoke have to slide on the splined shaft? I have a 351W that had the FMX transmission and now it's got an AOD in there. It's currently up just need the linkage done and the drive-shaft installed. Any help or tips is appreciated. Edited April 22, 2014 by tonyinsandiego spelling Quote Share this post Link to post Share on other sites
j69302 11 Report post Posted April 22, 2014 Not un common to have to have the shaft shortened. However, if you have the original 2 piece shaft, most shops won't shorten it, as there is rubber in between the two shafts that slip inside each other. Instead they will build you a new one piece shaft. If I remember right, cost me a couple hundred to have a new drive shaft made. Find a local drive shaft shop, they will tell you what to measure and how to measure it. You will also need to take the proper transmission and rear end yoke to them. Quote Share this post Link to post Share on other sites
Trinitys 134 Report post Posted April 22, 2014 Drive Line Service of San Diego Inc. 1090 Morena Blvd San Diego, CA 92110 this shop did mine.... balanced and ujoints. You can also cut some off of the front of the yoke too. any shop with a chop saw can do that. Quote Share this post Link to post Share on other sites
j69302 11 Report post Posted April 22, 2014 I would never cut the yoke. The length needs to be there so the splines can stay engaged with the splines in the transmission as it slips in and out. Quote Share this post Link to post Share on other sites
sportsroof69 13 Report post Posted April 22, 2014 (edited) I don't see how shortening the yoke would help anyways. It bottoms out in the back of the yoke, not the front where you'd be cutting it off. Make you sure get the length right. You should have 3/4"-1" of travel between the driveshaft being bolted up, and the slip yoke bottoming out on the output shaft. If the shaft is too long, it will damage the trans, and even worse, it'll knock the thrust bearing out in the engine. If it's too short, you'll have a vibration. Edited April 22, 2014 by sportsroof69 Quote Share this post Link to post Share on other sites
j69302 11 Report post Posted April 22, 2014 Also, Make sure to take you measurements with the rear suspension loaded at ride height. Jack stand under the axle tubes will accomplish this. Quote Share this post Link to post Share on other sites
Trinitys 134 Report post Posted April 22, 2014 I had cut the yoke on a C4 but its been years, never had a problem but maybe I was just lucky. Soooo.....don't listen to me on this one :) I did have Drive Line Service in San Diego balance the one in my car right now with my AOD. I'd recommend them. Quote Share this post Link to post Share on other sites
tonyinsandiego 37 Report post Posted April 22, 2014 Thanks guys. It looks like sideline services is the place to go. Do you guys know about how much shorter your drive shaft turned out in the end. Just trying to get a ball park figure just in case I get a bad tape measure or my measuring is way off. I'm thinking about an inch shorter. Also sounds like I might need another drive shaft if it's original. Quote Share this post Link to post Share on other sites
miketyler 15 Report post Posted April 23, 2014 Not that it means anything but my original drive shaft fit perfect in my 70 Mach 1 with 351c and FMX. My AOD came out of a 90 model Mustang so maybe shorter unit than the one you have? Quote Share this post Link to post Share on other sites
chillininnh 21 Report post Posted April 23, 2014 http://www.streetortrack.com/Custom-length-aluminum-driveshaft-pr-16159.html Knowing what others ended up with is really not important. Stick the yoke in the transmission and pull it out an inch. Now measure from the flat face of the rear pinion yoke to the center of the slip yoke opening where the u joint cups go.. Be sure the car is on its suspension, a 4 post lift is ideal. This measurement is the length of your new driveshaft. Quote Share this post Link to post Share on other sites
LindenBruce 27 Report post Posted April 23, 2014 Tony, Are you trying to use the FMX yoke? Because it won't work, to big. You must use a C4/AOD yoke. I didn't see any mention of this so I thought I would ask. B. Quote Share this post Link to post Share on other sites
tonyinsandiego 37 Report post Posted April 23, 2014 I'm using an AOD yoke from two different vehicles. I have one from a LTD and the time does fit but binds inside. I see the AOD yoke is not hollow like the fmx yoke. I thought about boring out the aod yoke to match the fmx yoke but worry about strength and leaking from the tail shaft. Now I know exactly what to measure and it looks like I need up to an inch of travel. Looks like I can order on line if I supply the measurement and that sounds pretty straight forward. Quote Share this post Link to post Share on other sites
Grabber70Mach 108 Report post Posted April 24, 2014 http://www.rosehillperformanceparts.com/ I bought my yoke from here. Quote Share this post Link to post Share on other sites
