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955L Timing case can it be brazed?

xmongo96

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I have this timing cover on a 3304 out of 955l, question I have is does anyone know if i can safely weld/braze up this surface with out having to care too much about heating entire part or do i need to find a shop to fix it? Does anyone know if it is a cast steel or cast iron? I have tried looking for another case but haven't had much luck.
IMG_2775.jpegIMG_2774.jpegView attachment IMG_2777.jpegView attachment IMG_2778.jpeg
 

Welder Dave

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I'd guess it's cast iron if it's part of the engine. You could confirm with a spark test. What caused it to be worn like that and what does that part of the casting do? I'm wondering how critical it is. Maybe a good epoxy could work depending on what that area does. Brazing requires high preheat and slow cooling. Possibly could be welded using nickel rods and a cold weld process or minimal preheat where you only weld about 3/4" at a time, peen it and let it cool before the next weld. Contacting someone like Castolin Eutectic they would likely have a repair process. You need to be concerned with it cracking if you attempt to weld it.
 

xmongo96

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I'd guess it's cast iron if it's part of the engine. You could confirm with a spark test. What caused it to be worn like that and what does that part of the casting do? I'm wondering how critical it is. Maybe a good epoxy could work depending on what that area does. Brazing requires high preheat and slow cooling. Possibly could be welded using nickel rods and a cold weld process or minimal preheat where you only weld about 3/4" at a time, peen it and let it cool before the next weld. Contacting someone like Castolin Eutectic they would likely have a repair process. You need to be concerned with it cracking if you attempt to weld it.
I'm not sure exactly what caused it but that is where the idler gear rides off of the oil pump to tie the balance shafts together and I am in process of rebuilding engine for customer for second time in the past 2 years due to previous builder not having a clue what he was doing and glazed over the fact that one of the used balance shaft gears had sheared key and spun on shaft after throwing #3 rod through both sides of block among many other glaring issues that a fresh rebuild shouldn't have. So long story short i believe the excessive wear is due to the engine being severely out of balance.
 

Welder Dave

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If something came loose or wasn't assembled correctly and caused the damage then I think a good epoxy could be used to repair it. Devcon should have something if you can't find Belzona. You can use an ice cube or even some water on your fingers to help smooth out epoxy. After 24 hours you can file, sand or grind it to the proper profile. Rough up all the surface's where the epoxy will go and push the epoxy into the surface when spreading it.
 

HarleyHappy

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By the looks of the edges of the worn area, I would believe that is cast steel and not cast iron. Therefore, I would build it up with MiG passes and machine back to spec.
 

tctractors

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Yes the cover is cast steel and could be hit with a Mig to build up this area and buffed flat, the bush in the gear is something I always change and the mounting peg comes free with a new oil pump, you will need to time up the complete gear train including the injector pump, the idler gear to the injection pump has no marks and is set off the pegged flywheel, the con rods are marked for front also, I always fit new bushings in the block for the Lanchester balance shafts also for the camshaft as they are always worn, the balance shafts are handed as the drive teeth angle is opposite cut, the rear crank seal is a hydro dynamic type with the steel sleeve that fits in 6 mm from the back case the sleeve on the crank has to be on around 4 mm past the end of the crank to match the pot depth of the flywheel, the front crank seal can be just a rubber job or again a hydro dynamic type with the steel sleeve that has to be set home in one like the rear.
 

Welder Dave

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If it is cast steel makes welding it much easier but you still need to be concerned with it warping. I'd preheat the whole piece to about 300F and not let it get too hot by continuous welding. Weld some then let it cool off for 30 seconds to a minute and then weld some more. Peening each weld would help relieve stress. You don't want to get the repaired area red hot as that would surely cause some distortion. Slow cooling by wrapping it in a welding blanket or insulation would be a good idea too.
 

HarleyHappy

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Meh, as big and heavy as that cover is, I wouldn’t want it to get hot.
Just preheat where you are welding, put some filler metal in there. Jig up on a knee mill and fly cut away, then use an end mill for the side.
 

tctractors

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Better still just hit it with a Mig or MMA an inch at a time letting it cool an amount so three hits in total, and grind off flat with a flap disc, this will restore it good enough for the work it does, the gear face will be damaged I expect and will need replacing as it only fits in the one way, any distortion will not be an issue if you tackle it with care, when I have done this weld repair I start by welding nearest to the sump face, it's not hard to return the metal area to as it should be and to make a reasonable surface finish with a disc pad. p.s. or just buy a new cover.
 

Coaldust

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Big trucks is what I know. HAZMAT is what I tow.
Welding, heating, grinding and all that fuss.
I would still Belzone it, like we did at the dealer in the old days.

Unless, there was an extra cover laying around. We even Belzoned trust bearing wear on the back of the block. And warrantied it under Caterpillar certified warranty programs.

I’d have it fixed, Assembled and ready for the dyno, faster than this conversation. Pidder Padder, let’s get at er’.
 

Welder Dave

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Better still just hit it with a Mig or MMA an inch at a time letting it cool an amount so three hits in total, and grind off flat with a flap disc, this will restore it good enough for the work it does, the gear face will be damaged I expect and will need replacing as it only fits in the one way, any distortion will not be an issue if you tackle it with care, when I have done this weld repair I start by welding nearest to the sump face, it's not hard to return the metal area to as it should be and to make a reasonable surface finish with a disc pad. p.s. or just buy a new cover.
This is basically treating it like cast iron which isn't bad idea but I think a little preheat would help eliminate stress in the area around the repair. It's a pretty heavy chunk of steel. If the repaired area isn't a sealing surface grinding and finishing with a flap disc would suffice.
 

chidog

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So Cat used cast steel for engine parts? I know things like some final housings and the final housings that are welded to the main frame are cast steel, but did not know a front cover would be made of cast steel?

I wish all industrial engine castings were made from steel and not iron.
 
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