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cracked weld on diff

Posted: Wed Jun 16, 2004 1:36 pm
by grumpy221
Hey guys went wheelin last weekend and just noticed oil leaking from rear diff cleaned it up and saw a crack along the horizontal weld Question is will I be able to just get it rewelded or will I have to get it replaced ?? pics dont show alot but you will get the idea

Image



Image

Posted: Wed Jun 16, 2004 2:04 pm
by Bartso
cant see why not as long as you do it properly you know grind it back and weld it up again

Posted: Wed Jun 16, 2004 2:07 pm
by grumpy221
thats what i thought ......just get a few opions first

Posted: Wed Jun 16, 2004 3:00 pm
by bru21
the previous owner welded mine GQ rear housing near centre. still good.
i say break out the mig! :D

Posted: Wed Jun 16, 2004 3:26 pm
by Reddo
yeah, i agree, just clean it up and welded the farker :D


James

MIG?

Posted: Wed Jun 16, 2004 3:36 pm
by Damo
Race tape :finger:

Posted: Wed Jun 16, 2004 4:01 pm
by J Top
Drain the oil first!!!!!!!!!!!!!!
Then leave the bungs out.I was welding a nissan truck diff in the 80s and the oil blew out the molten metal with a large flame and minor bang.
The bungs out will leave somewhere for the pressure to escape.
J Top

Posted: Wed Jun 16, 2004 4:23 pm
by auto_eng
As other said, grind it back properly first but before you start I would drill a small hole (all the way through) in each end of the crack. This helps to create a stress distribution point in the parent metal. Grind, weld and all should be good again. If you wanted to get fancy you could check your weld with a penetrant dye.

No legally binding advice, blah blah blah. Show to a registered professional blah blah blah

Posted: Wed Jun 16, 2004 4:36 pm
by 4sum4
Grind it back flush a Vee prep it

Posted: Wed Jun 16, 2004 4:39 pm
by bj on roids
J Top wrote:Drain the oil first!!!!!!!!!!!!!!
Then leave the bungs out.I was welding a nissan truck diff in the 80s and the oil blew out the molten metal with a large flame and minor bang.
The bungs out will leave somewhere for the pressure to escape.
J Top


Id pull just the filler bung and jam a rag in there, that wont let pressure build up!

A good idea on grinding it out and drilling a hole on either end, thats all I would do, hell id probably sort of wipe it and weld!! :cool:

But thats me and I'm a bit of a Russel Coight!

Posted: Wed Jun 16, 2004 5:59 pm
by Bitsamissin
Jabbers have been known to do this...................
Swartzy has had his welded up 3 or so times in different spots.
Like said above grind back the old weld and run a new bead over it.
Some guys (especially Ralliart) weld gussets from the diff housing to the axle to stop any axle housing flex which could crack the welded seams.
The cause is thought to be overloading or jumping the vehicle (heavy landings).
You been a naughty boy with your Jabber :lol:

Posted: Wed Jun 16, 2004 8:25 pm
by J Top
At a guess I would say you have disconnected your rear sway bar.
J Top

Posted: Wed Jun 16, 2004 8:31 pm
by Troll
Mig Welded a locker Actuator plate on a mates rangie.
We were unable to get a good weld due to the steel being impregnated with oil. When it was heated up the vapourising oil stopped the weld sticking properly. looked a fantastic weld and was strong. pity it leaked oil.
Diff guy in Warrigul said to prep the steel first to get rid of the impregnated oil residue.
He ended up brazing over our weld .
But If its only a crack should not be much of a prob.

Posted: Wed Jun 16, 2004 10:50 pm
by grumpy221
Bitsamissin wrote:Jabbers have been known to do this...................
The cause is thought to be overloading or jumping the vehicle (heavy landings).
You been a naughty boy with your Jabber :lol:


oops busted yer i gave it a good run ....had too... had a mate with a lifted 80 series I was showing the tracks to had to do some thing to leave him behind....he was impressed
and no sway bar is still attached ....absolutely stock.......

Posted: Thu Jun 17, 2004 6:50 am
by Noisey
Must be one of them Jabber things.

Mine is showing the same symptons after I snapped the axle - flaked off paint around the weld like it has been bent.

Overloading or jumping the vehicle look like the winners.

Posted: Thu Jun 17, 2004 9:35 am
by bundyrum4x4
Cracked my rear welds on the Mav twice now. Last time I braced the diff as well, no problems yet. Pull the housing out and drain oil, grind back old weld and put a V along the crack. Weld in short sections allowing to cool inbetween to avoid distortion. Do not use water to cool as this will make the weld brittle and more prone to re-cracking.

Posted: Thu Jun 17, 2004 9:42 am
by bundyrum4x4
:oops:

Posted: Thu Jun 17, 2004 9:43 am
by bundyrum4x4
:oops:

Posted: Thu Jun 17, 2004 7:54 pm
by grumpy221
mmmm dont want to take the thing out should be able to weld "in car" but bracing seems like the go

Posted: Thu Jun 17, 2004 10:38 pm
by Reddo
remember to disconect the battery or you'll cook something



James

Posted: Fri Jun 18, 2004 8:43 am
by bundyrum4x4
grumpy221 wrote:mmmm dont want to take the thing out should be able to weld "in car" but bracing seems like the go


Why not take out of car? only ads about 1 hour extra work as you will have to jack the car up to get access anyway, and being on a bench is alot more comfortable for weilding thus usually giving you a better weld. Also then you arn't welding or grinding near the fuel tank.

My first crack happend in SA on holidays. Re-welded in Hawker at the local servo, all looked fine. 12 months later, happened again. This time at home I did is how it should have been done the first time.

You need to do a better job than the weld you are replacing. It didn't crack for no reason.

Do it once and do it rite.

Hope this helps.

Posted: Fri Jun 18, 2004 3:03 pm
by Reddo
bundyrum4x4 wrote:
grumpy221 wrote:mmmm dont want to take the thing out should be able to weld "in car" but bracing seems like the go


Why not take out of car? only ads about 1 hour extra work as you will have to jack the car up to get access anyway, and being on a bench is alot more comfortable for weilding thus usually giving you a better weld. Also then you arn't welding or grinding near the fuel tank.



Yeah i agree with this, it will make the weld so much easier to do and it's not that hard to rip the back end out a 4bie. Also as you weld the diff under the 4wd, the weld will have a tendance to run down hill.

James

Posted: Fri Jun 18, 2004 4:46 pm
by hypo
yea just make sure u get all the oil off it with some degreeser or something or the weld wont take

Posted: Fri Jun 18, 2004 9:06 pm
by grumpy221
mmm......... thanks for your input will have to think about it some more

Posted: Fri Jun 18, 2004 9:26 pm
by GUJohnno
J Top wrote:At a guess I would say you have disconnected your rear sway bar.
J Top


Now I've heard something about this before. Whats the deal with getting cracks because the swaybars are off. Curious because mine are off at the mo.......

Posted: Fri Jun 18, 2004 9:33 pm
by grumpy221
Johnno wrote:
J Top wrote:At a guess I would say you have disconnected your rear sway bar.
J Top


Now I've heard something about this before. Whats the deal with getting cracks because the swaybars are off. Curious because mine are off at the mo.......


dunno mine r still on......