Turning Steel into Aluminum: DIY Driveshaft Swap
by Jason Giacchino
In a world of optimizing performance, it's a sad reality that the drive shaft is often overlooked. Why is it sad? Because there are certainly more costlier modifications which result in a lot less discernible gains.
In the case of the Ford Mustang, the stock steel unit is heavy, clunky and not designed to handle top speeds the engine is capable of producing. Fortunately, swapping to an aluminum aftermarket unit is a fairly simple modification which can be performed in an afternoon. For this swap, I located a complete aluminum drive shaft assembly for $299, and no special tools were required.
The benefits of making such a swap are plenty. Reducing the rotating mass of the drivetrain reduces stress on the chassis, and less weight, of course, means more efficient power transfer. The fact that it's a fairly painless project really exemplifies the benefits of putting in the effort.
That said, it doesn't hurt to have a shop manual on hand, and you should always follow the instructions for your kit precisely. If you're feeling sketchy during the process, it's better to stop and get some help than plunge ahead and risk breaking something. Got it? Then here we go.
Step 1: Up in the Air
Having a lift sure makes the whole process that much easier, but these are tough times. Jack up the rear of the car, chalk the front wheels, use jack stands for extra safety and get on under there. Also, make sure the car is in neutral.
Step 2: Locate the Yoke
The drive shaft, as you will surely discover on your own, is connected to the yoke at the differential via four 12-mm bolts. These have to be removed and wedging a ratchet in there could have been a feat even for Houdini. I had success with a box wrench, some PB Blaster and a bit of elbow grease.
Step 3: Turn and Repeat
Rather than frustrating yourself with the impossible task of working around the shaft, spin one of the wheels to rotate the shaft so that the bolt is in the proper position for removal. This has to take place for all 4 of the bolts.
Step 4: Remove Das Shaft
Once you've removed all four bolts, the drive shaft should slide out of the transmission extension housing. You're half way there!
Step 5: Crossroads
Okay, we'll be honest. You could slide your shiny aluminum drive shaft right back into place, tighten the four bolts and be on your way at this phase, but this is the perfect opportunity to take a look at the seal on the extension housing holding the drive shaft in place. Resist the urge to finish up and make a sandwich. Odds are very good that it will look more like hand grenade shrapnel than a seal. Grab the puller and get a fresh seal situated at this phase (the new seal can be purchased through your local Ford dealer, ordered from the performance shop where you purchased the shaft, and some kits actually come with the replacement seal).
Step 6: Position the New Shaft
Slide the new aluminum shaft back into the extension housing and gently engage the teeth. Don't force it! It should slide into place and engage smoothly when you have it positioned properly.
Step 7: Again with the Bolts
Time to reinstall the four 12mm bolts again using the process of installing, rotating the wheel/ shaft then installing the next. It's a good idea to apply Loctite to the threads, as having these bad boys come loose at 110mph could be quite troublesome. Additionally, in the off chance that these bolts look pretty rough, don't hesitate to replace them.
Step 8: Go get that Sandwich
Congratulations, you have just completely a successful drive shaft swap, if that doesn't warrant an extra slab of turkey on your Dagwood, a trip to the drive-thru with your new aluminum drive shaft may be just may be in the cards.