welding diff

[jonn]

i thinking about welding the diff in my f13 gearbox for autocross/grass racing, would this cause any problems? would i beable to weld it if i take the plate off the bottom of the gearbox(the engine and box are still in the car)

[Jonlem]

No problem at all, and yes you can do it with the sump pan removed.

Clean the diff so its immaculate first though or you won't get good penetration.

Make sure you do big welds, don't leave any small bits in there as they will come off at speed and punch a whole through the gearbox casing or sump pan ;)

[jonn]

ok thanks, i have no grip at all with the standard diff

[grasser26]

Hi-As above it should'nt be a problem-I've done it before.On mine I had the gearbox on the bench so it was easier,I cut a small piece of metal-about 40x25x6mm that would fit on the gears in the diff and welded the side gears to it-try googling welded diffs for a pic-some people reckon welding the gears to the carrier ok-I haven't on mine.Again,as above make sure it's as clean as possible before and after welding.Maybe use some anti-spatter spray before you weld.

[jonn]

i took the plate off the bottom of the gearbox and let the oil out and i cleaned off the oil around the diff, im going to weld it 2moro, when its welded does it handle ok on grass/ off road?

[L14MNP]

FWD welded diffs are a source of interest to me. I can't imagine it being fun on anything other than a grasser!

I blitzed my Volvo's with the MiG and it's been trouble free. As Jonlem says, nice big welds. No pigeon sh!t tacks and you'll be right.

[grasser26]

Hi-On my car it's a r/engined autograss car,so it's rwd.I don't know what effect it has on a fwd but I find if I drive the car on tarmac or a grippy surface at slow speeds you can feel and hear the tyres snatch and it's difficult to manouvre in out of sheds etc.It makes a huge difference for starts on the loose though!