22-06-2019, 04:01 PM
In the throes of installing a new crown wheel and pinion.
I have measured axial run-out on the rear face of the crown wheel with all bolts nipped up = around 0.004".
Arguably acceptable but having already had the mounting face gently skimmed I'm frustrated that it hasn't dropped to nil!
I have tried rotating the two halves of the diff carrier relative to each other but it doesn't materially alter the reading, nor the angular location of the 'high' spot on the carrier (gear side). n.b. It is simple 1st order run-out we are talking about i.e. 1 high spot and 1 low spot per revolution, which are diametrically opposed.
I also tried rotating the crown wheel through 180 degrees relative to the carrier, but the high spot stays in the same position on the carrier, suggesting the gear itself is true.
I'm forced to accept then that the skim has not perfectly trued-up the gear side of the carrier.
I can of course accept this and continue the build, but I'd much rather get it spot on while the opportunity is there.
Can anyone suggest (preferably backed up by experience!) how to get rid of that last 4 thou?
Shimming is of course one option but I'm not entirely sure it's a good idea...
I have measured axial run-out on the rear face of the crown wheel with all bolts nipped up = around 0.004".
Arguably acceptable but having already had the mounting face gently skimmed I'm frustrated that it hasn't dropped to nil!
I have tried rotating the two halves of the diff carrier relative to each other but it doesn't materially alter the reading, nor the angular location of the 'high' spot on the carrier (gear side). n.b. It is simple 1st order run-out we are talking about i.e. 1 high spot and 1 low spot per revolution, which are diametrically opposed.
I also tried rotating the crown wheel through 180 degrees relative to the carrier, but the high spot stays in the same position on the carrier, suggesting the gear itself is true.
I'm forced to accept then that the skim has not perfectly trued-up the gear side of the carrier.
I can of course accept this and continue the build, but I'd much rather get it spot on while the opportunity is there.
Can anyone suggest (preferably backed up by experience!) how to get rid of that last 4 thou?
Shimming is of course one option but I'm not entirely sure it's a good idea...