Removing Stubborn Locating Dowel Pins?

Since I am having trouble with mainshaft alignment in my GB rebuild as the inner cover encounters the dowel pins, it was suggested that I remove the dowel pins to see if that relieved the misalignment issue.

I heated the case in the area of the pins but could not get them to budge. In fact one of the pins broke leaving about 1/8" of pin protruding. It still locates the inner cover but I would like to replace it.

How hot can I safely heat the aluminum in the area surrounding the pin? I am thinking of having someone TIG weld a nut onto what's left of the pin and using that to turn it out while it is still hot.

350F

I recall heating cases for bearing replacement to 200 degrees C (Gas Mark 6), which equates to 400 F.

But of course that is uniform heating, to apply 'localised' may well cause problems?

The TIG idea is fine except wait until it cools. You want the aluminum hotter than the steel, not the other way round.

Plain AL melts at about 1220F. Not sure the melting point of the alloy in the gearbox case. For safety I would not go over 500F but you don't normally need to go over boiling water 212F for any operation.

Try to heat only the aluminum and pull/twist gently.

If that doesn't work use KD tool square easy outs these are not twisted and are awesome drill it to size use extractor .....or drill it right out There is also a proper dowel removing tool for un broken ones it has a split chuck which goes over dowel its tapered on the outside , you then tap down the outer sleeve , and slide the weight up up , and it's really a shock puller style remover .

I think I have found a sure fire solution.

This stuff chills to - 60F




1 TIG weld nuts to the stuck studs with some clearance under the nut.
2 Heat the case in the vicinity of the stuck pin.
3 Place a carboard shield under the nut to isolate aluminum from the chilling of the nut/pin
4 Spray the nut/pin with freeze spray
5 Grasp the nut with Vise Grips to gently pull/twist the pins free of the case.