Ferret gearbox repair aluminium welding

[ferrettkitt]

I have a gearbox that has been damaged due to it being used as a target. The damage was confined to the casting on one side of the box. As it happens I also had another gearbox with damage on the same side but in a different position. So I decided to use one part of the casting to repair the other. Couldn't see the point of wasting a part if I could have it repaired.

 

I am not saying that the gearbox hasn't been damaged in other areas either, that needs a bit more investigation on my part. I still have another gearbox to attach it to if it is completely U/S.

 

If you need alloy welding a good place to ask is your local motorbike repair shop, think broken cooling fins on an engine casting. If you can find a good metal fabrication shop (notice the if bit) they should be able to do it as well. Anywhere that repairs or supplies outboard motors might be a good place as well to ask.

Edited February 7, 2010 by ferrettkitt

[griff66]

looks like a nice tidy weld, they have done.

[robin craig]

Did they make a full penetration weld ie the complete thickness of the casting or did they just lay a weld over the joint line? Did you see it welded? did they use pre heat at all?

 

R

[ferrettkitt]

looks like a nice tidy weld, they have done.

 

 

It looks like a tidy weld to me as well.

[ferrettkitt]

Did they make a full penetration weld ie the complete thickness of the casting or did they just lay a weld over the joint line? Did you see it welded? did they use pre heat at all?

 

R

 

It looks like a tidy weld to me as well.

 

The person who welded it said he would v the edges of the weld, I'm presuming that knows what hes doing as he welds aluminium as part of his business. No I couldn't stay and watch it being prepared I would have liked to though.

 

I'm not a welder so you can only trust someone with a job, whether they can actually do the job time will tell.

[robin craig]

My concern, as a welder and fabricator, is exactly that, because is the casing bears stress you will likely see cracking in the 90 degree corner first if it was not properly prepped.

 

It good to see a job like that done to keep a vehicle running. You mention the vehicle having been a target, can you explain more? Perhaps pictures before as well?

 

Very interesting and a bold route to go down and hats off for that. Could I be more rude and ask what you had to pay for that work?

 

R

[ferrettkitt]

My concern, as a welder and fabricator, is exactly that, because is the casing bears stress you will likely see cracking in the 90 degree corner first if it was not properly prepped.

 

It good to see a job like that done to keep a vehicle running. You mention the vehicle having been a target, can you explain more? Perhaps pictures before as well?

 

Very interesting and a bold route to go down and hats off for that. Could I be more rude and ask what you had to pay for that work?

 

R

 

It cost forty pounds for the job

 

I'll pm the rest to you

Edited February 3, 2010 by ferrettkitt
adding words

[FoolsHumor]

Hello,

I am certainly no expert on welding in particularbut I have worked metal my entire life and I can tell you that welding cast of any sort, aluminum, steel, iron, magnesium, whatever, is always a crap shoot. There are enough variables and wide tolerances in the material itself, and then an endless number of built in stresses in the way the casting is done. The finest welders in the counrtyside still listen for the depressing "tink" as their handiwork cools. Welding cast consists of doing everything you possibly can and then offering up a quick prayer to the welding gods and Murphy, and just hope for the best. Thanks for listening. Regards, Bob

[ferrettkitt]

Hello,

I am certainly no expert on welding in particularbut I have worked metal my entire life and I can tell you that welding cast of any sort, aluminum, steel, iron, magnesium, whatever, is always a crap shoot. There are enough variables and wide tolerances in the material itself, and then an endless number of built in stresses in the way the casting is done. The finest welders in the counrtyside still listen for the depressing "tink" as their handiwork cools. Welding cast consists of doing everything you possibly can and then offering up a quick prayer to the welding gods and Murphy, and just hope for the best. Thanks for listening. Regards, Bob

 

Hi Bob,

 

Have no fear I'll be praying on this one for a while, it will either work or it won't. At least I'll have tried rather than just scrap it

 

Best regards

[antarmike]

My concern, as a welder and fabricator, is exactly that, because is the casing bears stress you will likely see cracking in the 90 degree corner first if it was not properly prepped.

 

It good to see a job like that done to keep a vehicle running. You mention the vehicle having been a target, can you explain more? Perhaps pictures before as well?

 

Very interesting and a bold route to go down and hats off for that. Could I be more rude and ask what you had to pay for that work?

 

R

 

Aluminiumis usually very ductile. If the welder was unsure of the spec of the original material, (silicon and Magnesium) he probaly used a pure aluminiumfiller rod. That in itself ensures good ductility in the weld, but this is only a cover. The bearing housing is beyond the repair. The original didnot break due to streses in use, but rather impact damage.

 

I cannot see any cause for concern and as an Aluminium welder myself, I would be reasonably certain that will last many many years. Go get a good nights sleep now!

[ferrettkitt]

I've started to take the gearbox apart and have found a fair amount of aluminium particles in the bottom of the box plus the remains of a bearing.

 

The gearbox has been cleaned out and mostly put back together with the exception of the side that had the welding. That needs a new bearing

 

The last thing that I did today was to investigate why I had no pressure on the gear change lever.

 

This is what I found its the busbar spring, its not a recent break as it has rust on the fractures.