Building a Track Car – Drive Shaft

Yes, in a previous entry I talked about a road trip to pick up a replacement drive shaft for the Miata track car and then left you  hanging.  Well, here is the tale.

I had found out that the Driveshaft Shop in Salisbury, NC, made aluminum drive shafts for Miatas.  Salisbury is only a couple of hours away and I can always use a break by going on a short road trip.

I called them up and put in an order for the new drive shaft.  They told me that it would take a few days.  Sure enough, a few days later they called to let me know it was done.  It was time to hit the road.

On the drive out I kept to the Interstate to save some time, but told myself to be sure to take some back roads on the return trip.

It wasn’t a bad drive out to Salisbury.  The weather was sunny and mild.  Since I was not driving during commute times the traffic was not bad either.

My GPS worked well enough to get me to the Driveshaft Shop’s front door and there was a NASCAR car out front just to make sure you didn’t miss the place.

Once inside there were many drive shafts, axles, and other driveline components on display.  I made my way to the counter.

I let them know that Jim’s Garage had arrived to pick up the Miata drive shaft and I also brought my old one so I could do a quick visual comparison.   The new one looked great and was the perfect replacement.

It weighs a bit less than the stocker, about two pounds, but the really nice thing was that its u-joints are replaceable.  The stock Miata drive shaft u-joints are not.

I paid my bill and packed the new shaft in to the passenger side of my Toyota pickup truck.  Then I hit the road heading back to the shop.

It was a nice ride back and I’ve already shared the main event in my previous post.  The Miata was ready and waiting when I returned to the shop. 

I had the exhaust all loose so it was easy to slip the new drive shaft into place.  Its diameter was just a little larger than the stock shaft, but that didn’t make it hard to slide into place. 

I checked the interference by rotating the shaft by hand and discovered that there was some by the Power Plant Frame (PPF) near the tail shaft of the transmission.  I pulled the drive shaft out and put some white-out on the aluminum yoke, reinstalled the shaft and rotated it again.  I could tell by where the white-out had been scuffed just where things were tight. 

I pulled out the shaft one more time and wrapped a red rag over the tail shaft so I could use a cut-off tool to provide clearance on the PPF.  It only needed about .020 to .030 of an inch more clearance.  Once that was shaved off the drive shaft went back in and a test rotation showed that all was well.  Not bad.