im working on my 4WD and....
#16
03-25-2006, 11:10 AM
Originally Posted by DAVE K.
Dennis- The stange thing is, I did ask the tech if I could keep the old shift-fork. As I expected, he said no because they are required to send the old parts back to FORD because the parts were covered under warranty. If I did still have the kit, I would ship it out to you. To answer your other question, I don't know the exact price of the kit (the shift-fork, a few gears and what looked to be some kind of metal sleeve), due to the fact that it was warranty work. However, I was told that if my truck was out of warranty it would have been around $1,000 big ones for the parts and labor. Dave
-Joe
#18
03-29-2006, 09:43 PM
yes the system is designed to be engaged on the fly, but in realality due to the small differences in tire size and the splines on both shafts not being lined up everytime, the shift fork will try to slide the coupler from one shaft to the other locking the front end in. the diaphram will continue to hold pressure on the collar until it slides from one shaft to the other putting pressure on the nylon tips. the faster the shafts are rotating, the longer it takes for the collar to slide causing more wear on the nylon tips. now start spinning wheels or braking when trying to engage and the stress level goes up. i only engage at low speed with all the wheels turning at the same speed. even from a stop when engaging i sometimes get a noise out of mine
#19
03-30-2006, 07:07 AM
Originally Posted by dwsf150
yes the system is designed to be engaged on the fly, but in realality due to the small differences in tire size and the splines on both shafts not being lined up everytime, the shift fork will try to slide the coupler from one shaft to the other locking the front end in. the diaphram will continue to hold pressure on the collar until it slides from one shaft to the other putting pressure on the nylon tips. the faster the shafts are rotating, the longer it takes for the collar to slide causing more wear on the nylon tips. now start spinning wheels or braking when trying to engage and the stress level goes up. i only engage at low speed with all the wheels turning at the same speed. even from a stop when engaging i sometimes get a noise out of mine
Here's another calculation.... figure a 32" tire, 16" radius. The circumference is just over 100 inches. (100.531 to be exact). Assume that measurement is the true rolling circumference. In order for one wheel to travel 6.42 degrees farther than the other, that means that one tire has to travel about 6.5" farther than the other one. Is that going to happen sooner when driving slow or driving fast?
Not trying for an argument, just trying to process the logic, that's all... it's the engineer in me.
-Joe
#20
03-30-2006, 11:11 PM
wow joe thats some fancy figuring, you lost me, but it sounds good to me. i do know that i've replaced a lot of fork assemblies, even one right outer axle shaft and collar(end of splines were ground up). most of the customers always stated they were turning the 4x4 on and off at highway speeds when they thought there was ice on the road. do you think it was just wheel slip or loss of traction that caused a difference in axle speed allowing the fork to break when the collar was bouncing off the end of the right axle when it was trying to engage or is the fork just the weak link. i'm not sure what to think now.
but it sounds good to me. i do know that i've replaced a lot of fork assemblies, even one right outer axle shaft and collar(end of splines were ground up). most of the customers always stated they were turning the 4x4 on and off at highway speeds when they thought there was ice on the road. do you think it was just wheel slip or loss of traction that caused a difference in axle speed allowing the fork to break when the collar was bouncing off the end of the right axle when it was trying to engage or is the fork just the weak link. i'm not sure what to think now.