axles sizes

[Hen is a total nutcase]

Weld the teeth of the spider gears together and weld the spider gears to the casing of the diff centre. You can put a square metal plate over the spider gears and weld all the gears to this too if you like, but that's overkill in my opinion.

The bolts may have been put into the "corners" between the spider gears and welded onto them. Not really needed I think.

Breaking an axle can be pretty subtle, I didn't realise for 15 minutes or so when I did one. You can mistake the bang for axle tramp too.

Breaking a crown/pinion makes horrible grinding clunking noises until you stop.

Hen

[Joel-AE86]

As Hen said, if you have a decent welder (MIG not arc), securely weld the spider gears together, and then gears to the casing.

Anything more is overkill, and you can create issues when using unknown steel type bolts or plates or whatever, compromising the quality and strength of the welds. I have seen diffs where bolts are used, and over time the welds to the bolts have factured and the bolts freely floating in the centre (which ended up jamming between the crownwheel and pinion causing the rear to lock randomly at 80km/h!).

Most steel bolts are zinc coated and are usually a high carbon steel, which is very shit for welding, and hence the welds easily fail.

The welds between the spider gears will be the strongest as the gears would most likely be the same composition steel and would be a low carbon. The welds to the housing will not be as strong as the spider gear welds as the housing is cast steel and has a very high carbon content.

[Cerby]

I've had a guy swear blind to me that i shouldn't weld plates onto the sides of the spider gears. in his words 'You have to understand the forces involved! The centrifical force is way stronger than a weld is and the plates will come free and make you crash!'
cough cough!
Apparently this happened to a wrx that was worth over 100 thousand dollars and made it crash!
now i'm only a 1st year engi student but i'm pretty sure that ain't right LOL

[HYPNTK]

ok thats a great help actually guys...will post up pics of whats been done now and what exactly you mean by welding the spider gears to the diff housing coz it seems weird/hard to do...pics tomorrow hopefullly

[Hen is a total nutcase]

Cerby, I don't think I need to point this out, but the guy spinning you that story was full of shit and had absolutely no idea. No question at all.

Hen

[Cerby]

yeah i know i just love it when people who obviously have no idea start a sentence with 'You have to understand the forces involved!'

Oh yeah and have any of you guys locked the centre by pouring hot lead between the spider cogs? I've heard of this system but i've never seen it down.
Cheers
Cerby

[HYPNTK]

heres the picture of the inside of my t-18 diff...its a bit welded (the bolts that were in there fell off) and i wanna weld it properly but not understanding when you guys are saying to weld the spider gears to the diff housing unless you mean that thing thats surrounding the spider gears

[attachment=8822:attachment]

[Hen is a total nutcase]

Weld the spider gears together where shown with red circles.

Weld spiderr gears to casing along the green lines.

Then flip the centre over and do the same on the other side. Use a MIG on fairly high current so you get really good penetration into the spider gears. You should be melting into the gears, not just laying a line of weld down on top of them. And don't get any spatter on the crown wheel.



Hen

PS, given my awesome paint skills, anyone wanting to hire me for graphic design jobs please speak to my booking agent.

[Blown86]

You do any other graphic porn other than car porn??

One point is to make sure that the bits your welding are VERY clean to ensure proper penetration, that gives the strength to the weld. Oil and crap will reduce the effectiveness of the weld.

It can be done with sticks, MIG is easier to setup well. Should be choosing a rod suitable for medium carbon steel if you use sticks.

Lead would be great for increasing the weight of your diff, really no reason to use it if you can weld half decently and keep things clean.

[Cerby]

Yeah the only reason i mentioned it was because i had heard that it is a bit easier on the drive train ie shafts. Apparently the soft lead allows a small amount of movement thus stopping shock loading which is the thing that breaks shafts.