Welding a Diff

I've never done this before. I'm going to do it.

Before fools rush in: Just clean everything up really well and weld everything to everything else with big beefy high-penetration welds?

Going to be using a decent MIG with .023 wire, unless someone tells me that thicker wire will be better. I can stick sheetmetal and thin plate together okay, thick stuff like diffs is new territory to me. And it's in a place where if it comes apart, it will really suck.

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Pete Remner
Cleveland, Ohio

1984 RX-7 (rallycross thing)
1978
Silence is golden, but duct tape is silver.

Somebody is telling you to run 035 wire.
You gotta deposit some material and not dwell for hours poolin in piddly 023 wire and mainly overheating the hell outta everything.

Your tips will thank you, your welds will thank you.
You can thank somebody.

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John Vanlandingham
Sleezattle, WA, USA

Vive le Prole-le-ralliat

www.rallyrace.net/jvab
CALL +1 206 431-9696
Remember! Pacific Standard Time
is 3 hours behind Eastern Standard Time.

Just dont weld it like this guy...







Edited 1 time(s). Last edit at 06/18/2012 06:16PM by Racinkid13.

.035 it is then! Fairly sure we have tips for that, too.

Any specific wire grade to look for?

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Pete Remner
Cleveland, Ohio

1984 RX-7 (rallycross thing)
1978
Silence is golden, but duct tape is silver.

Quote
Pete
.035 it is then! Fairly sure we have tips for that, too.

Any specific wire grade to look for?

Make sure the liner in the gun cable will accept it.

Any old grade will do.

unless i was doing a lot of very thin sheetmetal, i would think about thin stuff, 030 is my lightest wire.

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John Vanlandingham
Sleezattle, WA, USA

Vive le Prole-le-ralliat

www.rallyrace.net/jvab
CALL +1 206 431-9696
Remember! Pacific Standard Time
is 3 hours behind Eastern Standard Time.

i use .o23 ez grind wire for body work, everything else .030 and up. the ez grind is awesome stuff, especially when you're at the bubble gum stage of your welding carreer. spent a whole summer practicing on a model t body...

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what could go wrong?

Best way I have seen to weld the diff is to make some plates that lock the spiders together, then weld those in. Remember to have the akles poked through to set everything in position, and you will still need to be abe to get the axle clips in and out if it is that style. Best to do it on the bench, that limits the slag deposited in the housing. Clean ALL the weld spatter and slag out before re-assembly.



Edited 1 time(s). Last edit at 06/19/2012 12:57AM by phlat65.

and of course, brake cleaner is great for getting it oil-free for welding, but be sure its the Non-chlorinated stuff. Chlorinated solvent + welding = nerve gas and a seriously fucked up you.

I pulled mine out and cleaned the shit out of it with safer brake clean then just welded everything together everywhere I could. It's held up pretty well and even after running it with no fluid for a buncha stages still seems to be working fine.

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Grant Hughes

I worry about getting the side gears centered, but it feels like if you push the side gear as far "outboard" as you can then it self-centers, so should be good to go there.

Good idea on the blocks. I'll have to do that.

I just got another Kia 4.78 gearset, which came with a complete front "axle" wrapped around it, so after swapping my clutch diff into the pumpkin I have this open diff lying around. I figure I can weld it up and if I don't like it then I can take it back out. Have pumpkin swaps down to an hour working my myself.

I don't *think* it will drive any differently, since the clutch diff is so tight it doesn't ever break free. Driving in town is a riot.

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Pete Remner
Cleveland, Ohio

1984 RX-7 (rallycross thing)
1978
Silence is golden, but duct tape is silver.

Tim welded the one for me with it all fully assembled. Give the axles a few turns as you tack.