Questions about 2 pc driveshaft.
Hello, I have a 89 Ranger 4X4 super cab so it has the 2 piece driveshaft. The truck has 168k miles and it was starting to get a slight driveline vibration at moderate speeds. I inspected the drive shaft assembly and found a couple of the u-joints had a small amount of play and the rubber bushing that holds the center bearing was really loose.
My game plan was to replace the bearing and all 3 u-joints. I got the parts from NAPA and was carefull to follow the fsm. I marked all of the parts so they would go back together the same way and mount to the transmission and differential flange the same way. I used a vise and socket to remove the u-joints and did not clamp either driveshaft in a vise.
I bolted every thing back together and went for a test drive. The mighty Ranger was smoother and quiter than I can rember up to about 40mph where it started to develope a very noticiable vibration. The vibration happens under load and coast and is unaffected by what gear the transmission is in.
When I took the small foward drive shaft apart I used a permanent marker to mark the alignment, and lined it up the best I could, but the center bearing was in the way and it was an eyeball alignment. When it came time to put it back together the splines did not line up with my mark. I tried the splines on both sides of the mark and in each case it was off by the same amount!
Well I picked the spline that made the front and rear u-joint be matched or if you will lined up when looking down the shaft. I wonder if the proper alignment was suposed to be off one tooth from being lined up? Could this cause the vibration problem? Like I said I followed the fsm and didn't rush the job. What do you all think the problem could be? If you happen to be doing work under your truck please look at that front driveshaft and see if the front and rear u-joints are lined up.
1989 Ford Ranger STX supercab. 2.9L 5spd 4X4 with 167K miles. Bone stock!