Broke my welded diff

[Grimbrother]

[youtube]http://www.youtube.com/watch?v=MbgWjHRp_6Q[/youtube]

Recently bought a 1989 240sx with a welded differential. Was fine for the first week of me driving it with the inevitable wheel skip and whatnot. But one day I drove it pretty hard in the country and a terrible noise came from the back (see video) This noise would randomly happen and so i took it to my friends house and we lifted it and the wheels spun independently of each other, so it was clear that the welds had been broken. I drove it home immediately afterwards and realized that my back bumper and hatch were covered in oil splats on the outside and there was differential fluid dripping out of the housing.

i guess my real question is on top of replacing the differential, what else should i consider replacing inside the car so that it drives like new?


what criteria should i be looking for for a new differential?


1989 240sx hatch
86.7k miles on KA24E

thanks.

[Alisaihin]

Well, if you're driving it regularly I wouldn't get a welded differential for one. Low speed turns are hard as hell on those and the tires too. If I were you I'd check the driveline components that come off the diff. Common sense tells me there might be other stress if the weld snapped.

[Meoff Jack]

shoot id just take it out, open it and then Reweld that bish! Just do a better Job than they did. Look up PBM WELDED DIFF. Thats how its done. I welded mine like that and it hasnt broken from heavy daily abuse

[Alisaihin]

shoot id just take it out, open it and then Reweld that bish! Just do a better Job than they did. Look up PBM WELDED DIFF. Thats how its done. I welded mine like that and it hasnt broken from heavy daily abuse

Also...might as well mention, if you're going to reweld it...make sure you clean the surfaces REALLY WELL. Oil, maybe residue from previous welder might foul the weld and weaken it. Also...I'd suggest preheating the parts, too (A small propane torch, maybe). And run a fairly hot setting (Especially since you'll be putting in a lot of spot welds). The last two bits combined will help with weld fusion and penetration, and reduce likelihood of cracking. I like what PBM does by putting an insert in the middle. I'd weld up the differential gears before putting in the insert though, welds stand up best to tensile forces, not torsion. A variety of weld locations will help the welds hold each other up. And...watch actual weld size. After about 1/3 inch the weld is less effective as it becomes larger-multiple overlayed spots will be much better than a single fat one.

One final bit-if you are going to add layers of welds...try and see if you can't clean them up with a wire brush. It'll remove spatter and residue that might interfere with it.

[Meoff Jack]

yes, excellent advice ^^......I prolly shouldv mentioned that lol sorry

also make sure that it doesnt have any brake cleaner or any chemicals on it when your welding because iv heard that it can create fumes that are very damaging to your health.

[Alisaihin]

yes, excellent advice ^^......I prolly shouldv mentioned that lol sorry

also make sure that it doesnt have any brake cleaner or any chemicals on it when your welding because iv heard that it can create fumes that are very damaging to your health.

No problem. I weld for a living so I kinda have to know this stuff...and while I think driving daily on a welded is a silly thing, I can't really bash the guy for wanting to. I'd rather he be happy with a sturdy welded diff than to chastize him, heh.

But you are right, welding with stuff like brake cleaner on it can cause some nasty fumes...not that the fumes a clean weldment creates are exactly healthful either.

[sean9497]

I would go VLSD. Look into them. I daily drive a welded diff too and my tires arent happy. You have to adapt to it, take corners slower and wider, easy turns, etc. also, wheels just slide in the rain.