I have a repair on my hands.
A ring gear attached to a cast iron differential housing.
The 10 M8 X 1.25 x 20 retention cap screws loosened and allowed the ring gear to rotate several degrees with load reversals. Both the threaded holes and the cap screws are truly snookered!
All in an oil bath, so the ring gear fit to the housing appears to have fared well. ;-)
I've considered Time-sert thread repair. But have no experience with them in "damaged" cast iron, only aluminum. The threaded hole damage may exceed the the clean up offered by the time-sert. The housing wall thickness is but 24 mm , and likely does not allow other types of solid thread repair inserts..
But really, my question is, what benefit is offered by "high strength" cap screws onto cast iron in these proportions?
150ksi is a lot of tensile strength. If I consider "torque to yield" methods, Wouldn't grade 8.8 (110ksi) be a match to the cast iron female thread component?
N.B. Loctite will be applied what ever the repair ;-)
A ring gear attached to a cast iron differential housing.
The 10 M8 X 1.25 x 20 retention cap screws loosened and allowed the ring gear to rotate several degrees with load reversals. Both the threaded holes and the cap screws are truly snookered!
All in an oil bath, so the ring gear fit to the housing appears to have fared well. ;-)
I've considered Time-sert thread repair. But have no experience with them in "damaged" cast iron, only aluminum. The threaded hole damage may exceed the the clean up offered by the time-sert. The housing wall thickness is but 24 mm , and likely does not allow other types of solid thread repair inserts..
But really, my question is, what benefit is offered by "high strength" cap screws onto cast iron in these proportions?
150ksi is a lot of tensile strength. If I consider "torque to yield" methods, Wouldn't grade 8.8 (110ksi) be a match to the cast iron female thread component?
N.B. Loctite will be applied what ever the repair ;-)