Weld Spider Gears On Open Differential?
 

What do you all think about welding the spider gears on an open diff? I'm really tired of having a one wheel drive car. If I bought a clutch type lsd, I was going to rebuild the clutchpack so that it was more biased anyway, so I'm thinking why not just weld the gears I have. If it sucks, I'll get another open diff for cheap, or just get a clutch type lsd whenever I find one. I figured I would find one by now, but so far, none have turned up in local junk yards.

Anyway, I can weld, so this would be a free mod for now, I even have some Royal Purple gear oil sitting in the shop, so it would only take some time to get this done. Has anyone here ever done this before? I've been planning on welding the spider gears in my 4x4 truck, but never got around to it. Would I have to remove the chunk, or could this be done with it installed in the rear? I'm thinking I'm going to have to remove it to get some good welds, but I've heard of people welding them while they were in the rear, you just have to get your ground on the chunk itself. Thanks.

I haven't done this on a Miata but I did do it on a 70 Buick GS 455 Stage 1.

Sucks balls going around a turn but straight line it was nice until the 700 Ft/Lbs of torque blew it in to about 30-40 little piece and about 4 big chunks.

I really don't think you would like it unless you are only going to drag it.

yeah dude dont do it cause it will suck

To access the gears you have to pull the carrier, it's a front loader as you know. You can't just pull the cover to weld it up there is no cover. You could do it and it might be ok. I would rather deal with a one wheeler so when i got a different rearend the open diff was still worth something to someone.

Yea, I would have to pull the carrier. I DD the car and drag race it. I drive it pretty hard in the city, and I hate not being able to launch it since all it wants to do is spin 1 tire. Lauching at the dragstrip is soooo unpredictable with an open diff. I'm not sure how bad it would suck in the turns though, but I don't really push the car in the turns anyway, I'm more in to straight-line performance. I'm not sure what an open diff is worth, but I figured it's not enought to try to resell, so I figured why not give it a try.

MX5-5me- does it suck just driving down the interstate, or only when making turns in an intersection? I've drove a truck with a true track locker, and it's nice, but they're really expensive.

When making turns i'd hear a big clunk and wheel chirping because everything trys to spin at the same speed but when you are turning one wheel needs to spin faster than the other.

it will also cause your car to push, you have to be VERY careful in the rain or you will spin out.

That right there pretty much kills the idea in my mind.

For drag and maybe drift, welded is probably fine. For DD, I'd want something better. Personally, I think a welded diff would ruin the miata's best attributes. Keep your eyes open for a $100 RX7 clutch pack.

why, have you driven one? feels exactly like my over-torqued clutch diff.

if thats what you want to do go for it, i personnaly would never

agreed- it'll suck on the street (tight turns) and work great for launching and turns where it wants to spin the inside. Even then the car is less predictable in the turns because it won't have the variable power application of an lsd. And driving on the street is going to be very hard on the driveline when making turns- the tire hopping is brutal.

MX5-4me- yea, I would definately have to be carefull in the rain. So far everyone thinks it's a bad idea, so I think I'm gonna go for it. :bigtu: Well, I don't know, but I'm thinking I'm gonna try it and see what happens. I guess if I had a clutch type lsd that was rebuilt to be a lot more aggressive, it would do what I want, but probably wouldn't churp the tires turning. However, that would cost a few hundred probably, by the time I find the lsd, and get a rebuild kit for it, and shim it tight and all. That would be almost the same as welded spider gears in my mind.

A torsen would be ideal, but they're hella expensive. I'm probably gonna give this a try, and see how it does. If it sucks balls too bad for DD, I'll have ruined a perfectly good open diff, and have to find a lsd. I'd be out my time and a open diff, which Cjernigan tells me is worth about 100 bucks. If nobody here has ever done this to a miata, I'm thinking I'll try it and let everyone know how it does.

Welded spider gears would be great for launching, but would hinder the cars turning ability, but that's a compromise I'm willing to make. I've seen people do this to trucks, but those aren't sports cars.

Go for it man.. let us know how it turns out.. Don't forget to buy and extra Axle or two.. ;-)

Not sure what this is going to do your your CVs. I've only done this on solid axles.

Ugh, did it once (non-Miata) and I'll never do it again unless it's a dedicated off-roader.

Really? So, you like your overtorqued lsd? Does it feel just like a welded diff to you? Please elaborate, I'm all ears.

Kyle- what kind of car did you do it too? Was it a inependent suspenions diff or solid axle?

it's pretty much locked all the time, I measured about 180ft/lbs to make it slip (stock is 40-50 lbs). Slight wheel hops in parking lots. I love it. My buddy has a welded dif, it was a bit harsher in that respect, but other than slow turns, i couldn't tell a difference.

That's what I wanted to hear.... An overtorqued clutch type is gonna be similar to a welded diff. I'm gonna weld them in a week or two and I'll report back when it's done. I haven't done any research, but is there anything I'll need to remove and install the diff.? I can reuse the old shims and bearings, as the same diff. is going back in. I guess I may need the gasket where I seperate the carrier, I don't know. Maybe some RTV will work there.

There is no gasket. OEM calls for RTV.

I've raced and street driven a 90/1.6 Miata that had it. It totally sucked on the street with anything but sweeping turns. On the track it was better than an open, but you still had to compensate for the push induced from the 50/50 lock on the rear.

Well, my car already understeers in the corners, so this probably isn't gonna help that any. I did a Lanny's allignment a while back and it helped, but it still has understeer.