Mokume
Well-Known Member
- First Name
- Jeff
- Joined
- Aug 18, 2019
- Threads
- 44
- Messages
- 1,753
- Reaction score
- 2,740
- Location
- Honolulu, Hawaii
- Vehicle(s)
- 2000 Ranger Supercab (sold 12/19) , 2002 Honda CR-V
- Occupation
- Retired Firefighter III, Honolulu Fire Department
Phil,Hi Big D,
Castellated Nuts and Cotter pins are a PITA on the assembly line. Run the nut on to torque and the hole and castellations do not align, so manually rotate the nut in the tightening direction until achieving alignment and then insert the cotter pin and bend. Do not know what kind of nut the 5G Ranger uses but I can think this is a real boon for the assembly plant I do know that torque prevailing nuts are supposed to be good for 5 on - offs. Do not recall any use of one time nuts in my days at Ford, but there may have been some...
Here is a Castellated Nut/Cotter Pin back story. The E450 Econoline stripped chassis has been favored by RV Class C and ambulance manufactures. We kept having occasional problems on Airzona durability where the tie rod would disconnect from the steering arm on the left front wheel spindle. Since there was ample caster steering was not totally lost and the noise and tire smoke from tie rod resulted in warning signs for a driver. We never had any field complaints ever, but on durability we had this issue. Having Chassis Design Analysis, I decided to see if I could figure out what was going on with this issue that was only durability course and only the Silver creek portion where all the failures occurred. Since there was no castellated nut or cotter pin to analyze, we decided to drag the durability course with strong magnets and collect a castellated nut for examination...unfortunately we could never find a castellated nut, so the mystery continued. I had all the E450 cotter pins tethered with safety wire and had one of my engineers set up a lab test to duplicate and this test ran for 6 months with no incidents. Still majorly puzzled by this I had my engineer compare the tie rod steering arm joint for F450 through F150, which did not have any issues. What the engineer found was that the E450 steering arm had the least taper engagement with the tie rod taper. Ah Ha! we had a lead so the engineer brought me a Econoline steering knuckle and I noticed that there was a very agressive machined surface on the steering arm...a very deep cut to achieve a flat surface for the castellated nut. So we headed up to the design engineer and asked if this cut could be lessened to give us more taper engagement. The design engineer when to the supplier who indicated that this could be done. We got parts for the durability E450s and the revised spindle when in to production. We never had another tie rod disconnect, so the tape engage improvement was the fix. Even though we never had any field complaints, I still felt relieved we had identified the root cause and had a fix that worked.
Best,
Phil Schilke
Ranger Vehicle Engineering
Ford Motor Co. Retired
You always amaze me with your engineering experiences while with Ford, have you considered writing a book, or is one in the making?
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