Cast Iron Gearbox repair

[Shox Dr]

Rear bearing cover from a 1950 Muncie SM420 gearbox.

cleaned up further after this picture was taken, despite a thorough preclean it was oil soaked, causing fun and games welding up. No preheat, no peening, no post heat. On the pedal so not sure on amps, around 60-90amps.


Initially cleaned up on the mill, but after a trial fit it became apparent why it had broken. The bearing had been replaced with the circlip in the wrong place, so it sat 1.9mm higher. The muppets just nipped it up, breaking the lugs. You can just see the difference in height of the bearings


It would have taken ages to rebate it further on the mill using a boring head, and equally long to centre on the lathe, so back in the mill, to centre drill. Once in the lathe a dead centre was used to hold somewhere near while it was fixed to the faceplate. Luck must have been on my side as it was bang on.


Found a suitable lump to counter balance it out, again luck was on my side as it was also spot on.

Machined OKish the welded area was like glass at first.

I'll tap the centre hole and fit a bolt.

 

[Parm]

Shox if you don't mind me asking, do you do stuff like this for a living or just a hobby ?

 

[Shox Dr]

Shox if you don't mind me asking, do you do stuff like this for a living or just a hobby ?

Both, this is off my pickup

 

[wookie]

Shox, you've got some nice kit there, seriously jealous.

 

[Richard.]

Really nice job there shox. What method was your choice to join it back together. Looks brazed from the pics. Was it tig/OA

 

[Screwdriver]

Looks like TiG brazing to me....

 

[Richard.]

Looks like TiG brazing to me....

Me too.

 

[brightspark]

Really nice job there shox. What method was your choice to join it back together. Looks brazed from the pics. Was it tig/OA

wont be oxy acet using a pedal

 

[Screwdriver]

Did a bit more "repair" to my stove baffle plate today. TIG brazing.

The baffle appears to be made from pot metal and melts at about the same temp as the brazing rod!

When will this ever end??

Video to follow...

 

[Shox Dr]

Sorry thought I'd put the heat source

DC TIG. 2.4mm multistrike

 

[Parm]

Both, this is off my pickup

Top quality work. No compromise

 

[Shox Dr]

Really nice job there shox. What method was your choice to join it back together. Looks brazed from the pics. Was it tig/OA

It was a pain to weld, loads of contaminants, you can see on the inside the porosity, although is not deep. The outside is like a ploughed field, but there was no sense in tarting it up putting even more heat into it

 

[Shox Dr]

Top quality work. No compromise

Cheers

More like no choice, though, I only found the damage as the engine is out for a rebuild, I thought I'd have a look inside the box, just to make sure it was OK. As least it stops a leak

 

[Richard.]

It was a pain to weld, loads of contaminants, you can see on the inside the porosity, although is not deep. The outside is like a ploughed field, but there was no sense in tarting it up putting even more heat into it

Porosity is inevitable in something like that. The unknown material is one thing but the fact it's spent it's whole live covered in oil doesn't help either.
I'd say the real sucsess there was simply down to the time you spent on the prep getting the part as clean and well prepped as possible. Something that goes overlooked more often than not. Nice spot with the circlip.

 

[Shox Dr]

Ey. Prep, prep, prep and then some more prep

 

[octo0072000]

how is the truck refurb coming along Dave did you get all the engine bits sorted

 

[Shox Dr]

how is the truck refurb coming along Dave did you get all the engine bits sorted

I have now, thanks