After learning the hard way, you cannot weld a LSD..... I'm in need of a new diff! hahahahahaha, first you might ask, what the heck is this kid doing welding a LSD? welllll it wasn't locking up anymore, tried changing the fluid, that didn't do anything. So naturally I thought to myself
"im gonna need a new diff, so might as well try to weld this one!" The welds held up for about a month or two, but i clutch kicked it with 3 passengers, ended up with a broken axle, (ill come back to that later) fixed the axle, and put a stiff diff-> subframe bushing in. About a month later I hit the Tail of the Dragon and the diff unwelded itself about halfway through haha. Didn't take it easy the hour drive back home, got it to a local shop they pulled chunks out of my diff! it was pretty funny to see their reactions, haha! My mech told me he wouldnt let any one he loved drive my car with the diff the way it is, he told me it would lock up on the highway and sling my car sideways, 150mph later, sadly, no lockup! ANYWAY I'm debating buying a properly welded diff for 250$ from Z1, and getting 2 built axles, thats 1 option. second option being a proper diff, my budget being about 1500$, I daily the car, but i slide it literally every turn I think I can, ( haven't wrecked yet somehow) so i really need something that locks up quick, but doesnt wear out, i'm leaning towards the welded diff and built axles, I plan to keep this car for forever and eventually make it a proper driftcar, thanks for any suggestions!

P.s. I know i'm a stupid 19 year old you don't have to tell me it won't change me hahahahaha

 

I'd only recommend a welded diff for a straight-line vehicle. It's just too much of a pain in the *** if this is anything other than a track car.

Your two main options are a clutch LSD and a helical LSD. Quaife makes a great helical and ATS makes (imo) the best clutch LSD for the G35/350Z for street use. Lots of options for clutch LSD though, you SHOULD just save up the money and do it right, this is definitely something you can do yourself but you'll want to make sure to look up video's on setting preload and backlack, it's not rocket surgery but you will need a dial indicator and a dial in/lb torque wrench.

Or you can get an open diff and weld it PROPERLY with a plate in the gears, that will be good for more power and traction than the vehicle could ever make.

I'm guessing your welded VLSD failed because it wasn't thoroughly cleaned and welded in enough points though.

 

When my diff was welded, it chirped and skipped at low speeds, but thats really it. Do you think having the diff welded would cause any wear on the suspension / drive train? I'd have the built axles, and i've already got a built driveshaft, Mostly concerned about wear on suspension and bushings etc.

 

It is going to cause extra stress on everything. Which is why welded diffs are primarily found on track cars. Most weld them for drifting where they use crappy tires to begin with. So obviously a larger/softer tire will amplify the effects. I never owned a welded diff since I went with the Quaife LSD. But in very rare instances my LSD remained engaged for a second or two while in a turn and I'm definitely not a fan of my rear tires chopping in that scenario. Same thing with my truck that has a crappy G80 in the rear axle and it's obvious when that thing is still engaged when it shouldn't be.

 

I appreciate the input, I think I will go with the Quaife, how do you like it? does it lock aggresively enough for drifting? i'm not going to a track or anything, I just like to slide around on some nearby backroads and stuff.

 

I never noticed a delay. Had over 500 torque through it for the past 6 years and used countless times with drag radials at the tracks. I'm happy with it. I went with a Quaife because a VLSD would not have lasted very long and my car is setup for better grip, not to break traction easier while in a turn.

Since you don't plan on tracking your car an aftermarket LSD may be overkill. They still go for $1K+ before installation. You can pick up a 3.7 geared VLSD from a G37 for under $350 and hope it lasts a while. You've already experienced your car with a welded diff so it's up to you if you want to find a cheap open diff and weld it. Just do the research and know the pro/cons of each.

 

Firstly... I can't believe you're trash talking one of the greatest mechanical diffs ever made, the Eaton unit used by GMC... I won't even own a Chevy truck if it doesn't have the G80 RPO code in the glove box, you can always manually pull the locking pawl by downshifting, as soon as the vehicle transbrakes the pressure is off the pawl, or just come to a stop. If it's not disengaging properly it probably just needs new 75w-90 synthetic with NO FRICTION MODIFIERS EDIT: Or if it's engaging over 25mph you DEFINITELY need new fluid.

Now, back on topic. Welded diff would typically be used only for drag racing and drifting, the chirping/hopping around corners is mostly just going to wear out tires quicker since one of them has to slip on the road, axles should be fine on the G35 since there really isn't much of a contact patch anyways, it's mostly big trucks with giant tires that have fully locked axle issues.

As for helical vs. clutch LSD it mostly depends on what you want from the vehicle. Clutch LSD won't engage in the snow because it requires traction to engage, a helical is far superior in winter conditions, however clutch LSD is a 50/50 torque bias which is great for drag / drift. Helical however is not an even torque bias, usually it's around a 25/75 split between the two wheels, definitely not ideal for high power drag applications but it's GREAT for street use.

Another factor is longevity, a helical diff will pretty much last forever until the gears wear out, a clutch LSD longevity depends on how badly you're pounding on it, every engagement has some slip on the clutch packs and they do wear out over time.

And then there's the NOISE issue, clutch LSD's are noisy, even the ATS super silent is a little noisy.

For a track car that's drift/drag you definitely want a welded diff, nothing to wear out.

For a performance street / minor track use car you want a clutch LSD if the majority of your use is going to be straight-line stuff and you don't mind the extra chatter from the axle, otherwise get a helical LSD.

For a street car that's not being abused (adult driven, no burnouts, no track use) stick with the stock VLSD, it's smooth and quiet, has good bias, and under normal use will last the life of the vehicle.

 

The G80 has earned the nickname of "grenade", and not for a good reason.