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F-450 Broken Transmission Housing.

Posted: Mon Mar 14, 2016 11:22 pm
by GFab70
1989 F-450 housing was damaged during removal. Something about bolts with the heads broken off and corroded to the aluminum. Then they attached a come a long to the tailshaft housing and pulled until it broke.Image
Housing view to give you an idea on how much actually broke off.

Re: F-450 Broken Transmission Housing.

Posted: Mon Mar 14, 2016 11:27 pm
by GFab70
ImageThis is a Crack around the starter snout area. I drilled the end of the crack.

Curtis

Re: F-450 Broken Transmission Housing.

Posted: Mon Mar 14, 2016 11:29 pm
by GFab70
ImageAnother view of the starter snout area, you can see the drilled hole better here.

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Re: F-450 Broken Transmission Housing.

Posted: Mon Mar 14, 2016 11:31 pm
by GFab70
ImageBroken piece after bead blasting.

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Re: F-450 Broken Transmission Housing.

Posted: Mon Mar 14, 2016 11:34 pm
by GFab70
ImageKinda tacked up, man is this some NASTY cast.

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Re: F-450 Broken Transmission Housing.

Posted: Mon Mar 14, 2016 11:40 pm
by GFab70
ImageOK guys, go easy on me. This is some of the dirtiest cast I have welded.

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Re: F-450 Broken Transmission Housing.

Posted: Mon Mar 14, 2016 11:42 pm
by GFab70
ImageThis grove was about 3/4 the way thru to help get full penetration.

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Re: F-450 Broken Transmission Housing.

Posted: Tue Mar 15, 2016 12:10 am
by Sandow
GFab70 wrote:ImageAnother view of the starter snout area, you can see the drilled hole better here.

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Epic repair!

This looks like a spider web of stress fractures though. If that is isolated to this area, I wonder if running a bead across them would keep it from shattering down the line.

-Sandow

Re: F-450 Broken Transmission Housing.

Posted: Tue Mar 15, 2016 1:01 am
by GFab70
Thank you Sandow, only if it holds will it be epic. I haven't noticed stress cracks in any welds or I would have stopped immediately. I am going to build up and smooth out the factory ribs to help prevent failure. I will say the thing that helps the most is its huge heatsink and it allows for me to weld as much and as fast as I can. My FlexLoc uses the time I'm on the carbide burr to cool down.

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Re: F-450 Broken Transmission Housing.

Posted: Tue Mar 15, 2016 12:28 pm
by Sandow
I was thinking more of these:
stress fractures?
stress fractures?
IMG_1237.PNG (420.38 KiB) Viewed 1745 times
My experience repairing castings is limited to fixing crap around the track so maybe I've just never come across it before but these look like partial thickness stress fractures. No idea if they really matter or if they are just a common casting imperfection. Wondered if it might have been hit by a rock there or something like that.

-Sandow

Re: F-450 Broken Transmission Housing.

Posted: Wed Mar 16, 2016 9:18 am
by GFab70
The bellhousing bolts were seized in the aluminum with corrosion and he pulled straight back with a come a long until it broke/came out. What you see in that picture is the only area to have broke in 2 directions.

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Re: F-450 Broken Transmission Housing.

Posted: Thu Mar 24, 2016 6:01 pm
by Nick1947
Sandow wrote:
GFab70 wrote:ImageAnother view of the starter snout area, you can see the drilled hole better here.

Curtis
Epic repair!

This looks like a spider web of stress fractures though. If that is isolated to this area, I wonder if running a bead across them would keep it from shattering down the line.

-Sandow
Howdy Nick here .Aussie . Just viewing fotos re housing I noticed tacking parts together etc. You probably know that it has to be properly aligned . But have had experience with a lot of these over time. The rejoining as you may know has to be ' V'd " both sides . A very important note also is to make sure the housing and ALL PARTS has to be contaminate FREE !! Over time oil etc DOES penetrate into the aluminium and when one goes to weld there becomes all sorts of problems. I used to generally start with heat all parts over an old bbQ unit and let it simmer ha ha . It did work without any damage to housing parts. It did eventually get rid of ant contaminates.. Just thought I would pass on a bit of info .Maybe of some help in future then may get some do's and dont's but been in the game for 50yrs ..retired now .Good luck ................

Re: F-450 Broken Transmission Housing.

Posted: Thu Mar 24, 2016 9:58 pm
by GFab70
Nick I bead blasted the smaller pieces and used aluminum acid on the rest of the case. I did the cleanest prep work possible, no other way to weld cast. As you know it's very dirty on its own. I did fuse the inside and then ground down to clean metal, then welded a small root bead followed by a cap. Then groved the inside down to clean metal and only had to do a single pass since I got 75% penetration from the outside. It has been back in service for several days. Owner said the alignment was correct and all is well. This was a 10 hour job.

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Re: F-450 Broken Transmission Housing.

Posted: Tue Mar 29, 2016 12:47 am
by TamJeff
Any high torque applications, I'll weld the cracks, grind them flush other than leaving the zipper bead on the inside provided there is clearance, and then fit and weld plates on the exterior, such as in between those fins. Adding extra fins made of plate works as well in some situations also. Either way, you made a nice repair on an otherwise trashed part.

Here was a thin part that was spider cracked in a bunch of different directions over that uppermost bore, so I annealed a section of 3/16 plate and formed it well past the damage being that one of the main pivot tubes was going to load this area. Often times, an exterior treatment like this will change the direction of the added weld stresses to where it will not distort the part in a critical direction. If I had welded that crack with a full penetration weld, it would have shrunken the bore and I did not want to have to grind it by hand and keep test fitting it.
Image

Image

These reinforcement repairs work on cast more often than not. Especially those that have absorbed contaminants. As trained welders, we are often naturally inclined to fill instead of patch. Some annealed sheet or flat stock, a ball peen hammer and some patience, and one can make some really artful (which the above photos are not!) repairs on cast parts. All the different stops at the corners are because I cross alternated the welds and let them draw a bit before continuing on to avoid hearing that dreaded *tink*.