A couple of UD pulley lessons learned!!!!!
I installed UD pulleys on both my 90 XR7 and 94 SC and found that one size does not fit all.
First, the XR7. Your tensioner jumping could be caused by a seizing alternator. Check to be sure the alternator spins freely when the UD pulley is installed. When I put the UD pulley on my XR7 alternator, the alternator would not spin at all. I had to shim it out with a 1/8th" spacer I got at my local hardware store. All is good in XR7 UD pulley land.
Now for the SC. First problem. I did not have the alternator problem as I did on the XR7, however, my belt was tooooooooooooooo close for comfort at the tensioner and the water pump UD. So I got four 1/4'' longer bolts and 1/4" spacers and put the spacers between the air conditioner and the A/C mounting bracket. This made the belt travel longer thus making the belt shorter and eliminating the need for a SPECIAL belt. Second SC problem. The crank UD pulley is a tight fit. The lip on the back of the pulley must fit square in the whole where the crank bolt fits. You might have to take a hammer and tap it in the hole to ensure a good fit. Mine fit OK there but the 4 holes would not line up. I tried all 4 possibilities. I finally drilled the holes out larger and got it to fit. It was not pretty but it does not wobble or come loose. Some blue Loctite made sure of that!
Bleed_Ford_Blue.......you might have cocked the UD crank pulley when you installed it. That could be the reason it wobbles. Your stock pulley probably wobbles because there is now probably a burr inside the balancer that the UD pulley created. I would CAREFULLY run a finger inside the hole and check for the burr.
Hope this helps!
Ed Springer
90 Black XR7 5-speed: 70mm TB, Fresh Air Intake, '94 Supercharger, 5% SC Pulley, Raised SC Top, I/C Fan, Underdrive Pulleys, 190 l/h Fuel Pump, 36# Injectors, Headers, Magnaflow Muffler (no cats) with stock resoantors, 3:27 Gears, Ripper Shifter, 73 CL MAF, Magnacore Wires, NGK Iridium Plugs and Rear Spring Air Bags.
94 Red SC Auto: 70mm TB, Fresh Air Intake, Stock 90 SC Pulley, Raised SC Top, I/C Fan, Underdrive Pulleys, 190 l/h Fuel Pump, 38# Injectors, Headers, Raven Muffler (no cats) with stock resoantors, 3:73 Gears, 73 CL MAF, Magnacore Wires, NGK Iridium Plugs, TRANSGO Shift Kit, ProTorque 2500 Stall TC, Haydon Auxiliary Transmission Cooler, Tokico Struts & Shocks, American Racing 17” Sniper Wheels, Michelin Pilot Sport A/S Tires and 235 RWHP with 315 Lbs.Ft. Torque.
