Front spindles & torque

[Peter Pleitner]

Hi Whitworth Heads, I noted the traffic discussion wheel bearings, spindles and torque. Nice to read that my tech article is still useful. My spindle replacement tooling is in Texas at the moment to make another TC live up to Abingdon's motto. I enjoyed reading Jim Case's back of the envelope analysis. That 150 ft/lbs torque spec came from Bob Grunau, my source for my replacement spindles. He has described the material numerous times on our LIST (probably 12 - 24 months ago). Stock spindles should be torqued to 70 or 80 ft/lbs as stated by Terry Sanders and Jim Case. All of you, please only run your T-ABCs with inner race spacers shimmed to the proper distance. Yes, ball bearings are a little less forgiving with respect to spacer dimension (but not much because you still want the balls to run near the center of the races without side load). Safety Fast! Peter PS: Jim - I have an old original spindle stub possibly around here, but certainly in the tooling kit, in case you want to test it's tensile strength.

[Robert Grunau]

Hi All, I've been away for a few days and found all this talk about front wheel bearings, spindles and torques. My comments are: 1-Wheel bearings: Tapered roller bearings are far superior to ball bearings. There is no reason not to use tapered roller bearings, as long as the bearing spacer is retained and shimmed to allow very slight slackness in the bearings when the stub axle nut is fully tightened. Ball bearings are easier to use but give a false sense of security. Unless you measure exactly the spacer length and the distance between the outer races in the hub you don't know if the ball bearings have seated properly in the hub. Use of tapered rollers with a loose outer cup allows any descrepancy in the assembly to be compensated by the shimming process. Also, bearing mount Loctite, or equivalent, can be used to mount the outer cups/races of tapered roller bearings to ensure a tight fit in the hub. Whatever you do, DO NOT LEAVE OUT the bearing spacer, that will weaken the assembly and may result in a broken stub axle.. 2-Spindles: I have supplied many replacement spindle inserts ( ref. TCs Forever, Sherrell page 103 ). These are made of 4140 Heat Treated and Stress Relieved steel and have a mill test report of 129,433 psi tensile strength. I use a 3/4" NF thread on the stub axle spindle insert instead of the much weaker 5/8" BSF thread on the original spindles. Therefore the two assemblies have different torque values. 3-Torques: I agree 60 to 80- ft-lbs torque is probably correct for the old original stub axle nuts with 5/8" BSF threads and unknown history or metallurgy. However I use 120 to 150 ft-lbs torque on my replacement spindle inserts for several reasons; a-The thread is 3/4" NF and the steel is known to be 129,433 psi tensile strength. b-A grade 5, 120,000 psi bolt with 3/4" NF thread can be torqued to 180 ft-lbs when lubricated and up to 300 ft-lbs when assembled dry. Therefore my figure of 120 to 150 ft-lbs is conservative. I would not slacken the nut to get the split pin installed, the torque range should allow you to find the split pin hole. c-The stub axle nut is doing dual duty when used with a stub axle insert, obviously to hold the bearings on the axle but also to ensure the spindle is held securely in the steering knuckle. The whole assembly becomes stronger when the effective diameter is increased by locking the assembly together. Bob Grunau Hi Whitworth Heads, I noted the traffic discussion wheel bearings, spindles and torque. Nice to read that my tech article is still useful. My spindle replacement tooling is in Texas at the moment to make another TC live up to Abingdon's motto. I enjoyed reading Jim Case's back of the envelope analysis. That 150 ft/lbs torque spec came from Bob Grunau, my source for my replacement spindles. He has described the material numerous times on our LIST (probably 12 - 24 months ago). Stock spindles should be torqued to 70 or 80 ft/lbs as stated by Terry Sanders and Jim Case. All of you, please only run your T-ABCs with inner race spacers shimmed to the proper distance. Yes, ball bearings are a little less forgiving with respect to spacer dimension (but not much because you still want the balls to run near the center of the races without side load). Safety Fast! Peter PS: Jim - I have an old original spindle stub possibly around here, but certainly in the tooling kit, in case you want to test it's tensile strength.