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Welding.

Posted: Tue Sep 23, 2008 6:17 pm
by Fmx_Aus
Anyone out there ever welded or had welded a hair line crack in a diff housing before??

Did it hold??

Posted: Tue Sep 23, 2008 6:28 pm
by built2redline
welded my tray up today after chopping it up to the chassis... im sure a weld would hold on a diff housing if its just a hairline.

Posted: Tue Sep 23, 2008 7:00 pm
by Struth
I am not sure but I reckon a diff housing would be cast, so a particular type of welding rod might be required.

But you could always give it a little grind and hit it with a ferrocraft or the MIG.

Cheers

Posted: Tue Sep 23, 2008 7:02 pm
by Shadow
Struth wrote:I am not sure but I reckon a diff housing would be cast, so a particular type of welding rod might be required.

But you could always give it a little grind and hit it with a ferrocraft or the MIG.

Cheers
most are cast steel.

Special rods i believe, good preparation to remove any grease, and also using heat blankets to make it cool slowly.

Posted: Tue Sep 23, 2008 7:04 pm
by joeblow
think he is talking housing, not third member. most housings are mild steel, all third members are cast.

Posted: Tue Sep 23, 2008 7:09 pm
by sloshy
If its the housing just up it with the mig, people weld brackets and stuff to them all the time. My ladder bar and shock mounts haven't broken off yet and they have been on there for about 4-5 years. Not bad for a chippie :lol:

Posted: Tue Sep 23, 2008 7:32 pm
by v840
Don't lay a bead longer than an inch or so at a time as it may warp the housing.

Depending on the location of the crack it may also be a good idea to grind it out a bit to ensure you get sufficient penetration.

Posted: Tue Sep 23, 2008 7:33 pm
by Fmx_Aus
Yeh fellers its the housing. One of the seem welds on the left of where the diff gears ect are.

Was readin a few things saying a mig wont hold it as mig welds are more porus then stick welds.

Might go ok with a plate or something over it :?

If ya wanna give it a go Sloshy let me know. And what ya drink ;)

Posted: Tue Sep 23, 2008 7:35 pm
by Fmx_Aus
v840 wrote:Don't lay a bead longer than an inch or so at a time as it may warp the housing.

Depending on the location of the crack it may also be a good idea to grind it out a bit to ensure you get sufficient penetration.
Thanks mate. Might have to grind it out a little then drill each end of the crack to stop it spreading. (No I dont know what Im talking about, nor do I know how to weld :oops: )

Posted: Tue Sep 23, 2008 7:50 pm
by Fmx_Aus
Here is a couple of pics.

Its on the seem weld, I have put two little red dots on each end of the crack.

Image

Image

Posted: Tue Sep 23, 2008 7:52 pm
by chunderlicious
GQ by any chance? they are prone to cracking on the V shape welds between the pumpkin and long side diff tube.

just mig it up. then when you have it properly sealed again, add a truss to the diff to make sure it doesnt happen again

Posted: Tue Sep 23, 2008 7:56 pm
by Fmx_Aus
Yeh bud its a GQ. Thanks for the info, really appreciate it.

Truss?? Sorry mate :oops:

Posted: Tue Sep 23, 2008 8:18 pm
by Big_GQ
He means brace it,seen heaps of these crack at work just turn the wire speed and heat up and clean the paint off before you weld it dont even bother about draining oil it will be fine.

Posted: Tue Sep 23, 2008 8:22 pm
by juzzydykes75
Had to weld the long side of my rear housing - used a mig then bent a 2mm plate around the area the migged that at all sides to strengthen it - going to put bracing on it soon though

Posted: Tue Sep 23, 2008 8:47 pm
by Fmx_Aus
Thanks fellers. Where abouts does the brace go?? Anyone draw something on one of those pics and Tonka??

Thanks a heap everyone for the info and advice, greatly appreciated.

Posted: Tue Sep 23, 2008 9:07 pm
by chunderlicious
Image

this is the first diff i did, ive got it down to an art now...lol. but it gives you an idea of how i brace diffs. i also put a bit of half pipe on the bottom of the diff and bits of plate everywhere

Posted: Tue Sep 23, 2008 9:15 pm
by Fmx_Aus
Thanks a heap bud. That looks bloody great.

If there is anyone around my area Ripley/Ipswich that can weld let me know.

If not, I will duck down to the welder at Yamanto and see what they can do. Just worried as to what they will charge :?:

Thanks again ;)

Posted: Tue Sep 23, 2008 9:22 pm
by phil94delica
Im at Redland Bay. Bit far maybe?? But give it a good clean and weld it at a fairly low heat so the inside coating doesnt flake off. If your really keen its not a bad idea to change the oil after you weld it to get out any flaky bits.

Also the idea of drilling the crack ends is cos it stops the crack spreading because the load is not focused at the point of the crack. Probably not needed but if you want to be safe it cant hurt.

Posted: Tue Sep 23, 2008 11:04 pm
by highwaychook
Fmx_Aus wrote:
v840 wrote:Don't lay a bead longer than an inch or so at a time as it may warp the housing.

Depending on the location of the crack it may also be a good idea to grind it out a bit to ensure you get sufficient penetration.
Thanks mate. Might have to grind it out a little then drill each end of the crack to stop it spreading. (No I dont know what Im talking about, nor do I know how to weld :oops: )
Nooo don't drill holes. Grind it right out, use metho etc to clean the grind, then run a nice hot bead, grind out again slightly and then weld over that.... ;)

Posted: Tue Sep 23, 2008 11:53 pm
by sloshy
PM sent ;)

Posted: Wed Sep 24, 2008 12:27 am
by zagan
metal fatigue.

it'll keep cracking, even with welding over the crack, the bracing will/may stop the cracking of the metal next to the welds.

I wouldn't bother grinding it out as it'll just crack somewhere else.

shouldn't push it so hard, lol.

Posted: Wed Sep 24, 2008 7:37 am
by Fmx_Aus
Thanks a heap fellers.

Sloshy, I will give you a call today sometime.

Thanks once again everyone ;)

Posted: Wed Sep 24, 2008 12:11 pm
by KiwiBacon
highwaychook wrote:
Fmx_Aus wrote:
v840 wrote:Don't lay a bead longer than an inch or so at a time as it may warp the housing.

Depending on the location of the crack it may also be a good idea to grind it out a bit to ensure you get sufficient penetration.
Thanks mate. Might have to grind it out a little then drill each end of the crack to stop it spreading. (No I dont know what Im talking about, nor do I know how to weld :oops: )
Nooo don't drill holes. Grind it right out, use metho etc to clean the grind, then run a nice hot bead, grind out again slightly and then weld over that.... ;)
If you don't drill it, then you'll never fuse the end of the cracks together and it'll continue to grow.
It'll probabaly still last several years, but drill it past the end and it'll be good for a lot longer.

welding

Posted: Thu Sep 25, 2008 6:47 am
by hollywood
exactly kiwibacon you must drill the ends of the crack before you weld and warm the area to about 150c and just let air cool it will be fine. Mig welding is not porous and will be fine, christ knows who told you that story, i own an engineering business and beleive me they are fine. Mig wire is rated at about 70,000 lbs per square inch and is equivalent to low hydrogen. godd luck cheers ;)

Re: welding

Posted: Thu Sep 25, 2008 6:55 am
by KiwiBacon
hollywood wrote:Mig welding is not porous and will be fine, christ knows who told you that story,
Probably someone who left the gas turned off. :lol:

Re: welding

Posted: Thu Sep 25, 2008 7:54 am
by lump_a_charcoal
KiwiBacon wrote:
Probably someone who left the gas turned off. :lol:
Been there, done that!

Re: welding

Posted: Thu Sep 25, 2008 8:41 am
by KiwiBacon
lump_a_charcoal wrote:
KiwiBacon wrote:
Probably someone who left the gas turned off. :lol:
Been there, done that!
Me too.
Lightweight welding I call it. Honeycomb. :D

Re: welding

Posted: Thu Sep 25, 2008 9:50 am
by v840
KiwiBacon wrote:
lump_a_charcoal wrote:
KiwiBacon wrote:
Probably someone who left the gas turned off. :lol:
Been there, done that!
Me too.

:rofl:
Me three. :oops:

Posted: Thu Sep 25, 2008 5:13 pm
by ian1974
Fmx_Aus wrote:Thanks a heap bud. That looks bloody great.

If there is anyone around my area Ripley/Ipswich that can weld let me know.

If not, I will duck down to the welder at Yamanto and see what they can do. Just worried as to what they will charge :?:

Thanks again ;)
mate make shore you get somone that knows what they are doing.. it is very easy to warp your housing whem welding on a truss. weld it slowly, small runs of weld, stop and let it cool..weld again and then let it cool.. so it does not heat up to much.

Posted: Thu Sep 25, 2008 7:58 pm
by Fmx_Aus
Thanks fellers, Sloshy sorted me out. Thanks mate ;)