Will it ever end?
Posted: Thu Dec 22, 2016 7:04 am
Hi all I have an issue with removing the pinion from my AD 102 gearbox . I have tried repeatedly with lots of heat constant pressure and impact force but it will not budge even a little bit. I must let you know first I only have basic backyard shed tools to use (vice, clamp, butane blowtorch and 8 lb hammer) .
I was wondering if the problem is the composition of metals in the 102 gearboxes? In a forty gearbox, you have a brass bush inside an aluminium casing, aluminium expands at a lower temperature than brass therefore the external pressure becomes less during the heating process where the aluminium expands in size before the brass allowing for less external pressure and you strike with force the pinion and bush move, job done.
But what (I) think is my problem is that with the AD 102 gearboxes you have the bushes encased in a ¼ inch or approx. 8mm wall thickness aluminium tube like the one in the picture. When you heat the gearbox housing attempting to remove the pinion and bushes which are encased in the aluminium sleeve you are actually heating both the housing and sleeve at same rate, aluminium sleeve and housing expand at same “thermal expansion rate” ( got that from google) so I am not achieving anything during the heating process because both aluminium surfaces are still bonding together the same, because at say, 500 degrees for example, they are the comparatively the same size?
This is just my thoughts as I have no experience with this type of stuff and am trying to figure out why I cannot get the bugger out!
Any feedback would be greatly appreciated.
Cheers
Bob
I am using the same method I have before with a 40 gearbox and it worked easily at that time.I was wondering if the problem is the composition of metals in the 102 gearboxes? In a forty gearbox, you have a brass bush inside an aluminium casing, aluminium expands at a lower temperature than brass therefore the external pressure becomes less during the heating process where the aluminium expands in size before the brass allowing for less external pressure and you strike with force the pinion and bush move, job done.
But what (I) think is my problem is that with the AD 102 gearboxes you have the bushes encased in a ¼ inch or approx. 8mm wall thickness aluminium tube like the one in the picture. When you heat the gearbox housing attempting to remove the pinion and bushes which are encased in the aluminium sleeve you are actually heating both the housing and sleeve at same rate, aluminium sleeve and housing expand at same “thermal expansion rate” ( got that from google) so I am not achieving anything during the heating process because both aluminium surfaces are still bonding together the same, because at say, 500 degrees for example, they are the comparatively the same size?
This is just my thoughts as I have no experience with this type of stuff and am trying to figure out why I cannot get the bugger out!
Any feedback would be greatly appreciated.
Cheers
Bob