I am having a bit of a nightmare rebuilding my 1956 Dominator 500 Laydown gearbox. The gear teeth hardening had worn and I managed to get a NOS gear N8041 (Layshaft 2nd gear sliding pinion). The problem is that whilst it has the same part number as the original worn pinion, it will not fit onto the splined shaft - looks like the dimensions across the recess where the spline slide on the pinion are slightly smaller (by roughly about 5 thou). Has anyone else come across this issue? Mick Hemmings gearbox rebuild video notes that some layshafts can be slightly oversize resulting in some free pinion bushes being too tight and he suggests using emery paper presumeably on the shaft? As that is hardened I can't see what that would do or am I being thick!! I have tried another layshaft but with the same result. Any help would be appreciated.
Emery paper will cut a…
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John, Thanks for the quick…
John,
Thanks for the quick reply. I did not want to destroy any case hardening (like the wear on the pinion teeth shown on Mick's video and on my gears) by filing too much - I will give it a go. Regards
Gavin
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Case hardening is normally…
Case hardening is normally 60 thou deep, looks like you will only be removing 5 to 6 thou so no risk of removing it completely.
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I had to do a bit of…
I had to do a bit of judicious sanding on mine too
dan
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Emery paper will cut a hardened steel surface, not as well as a soft steel but the emery coating is hard enough to still cut the hardened steel as long as its the proper stuff. As you have 2 layshafts and one gear then wrap some emery around a file thin enough to enter the spline groove and start filing. Check for fit often so you do not go too far.