Welding gears, to housing. (welded-diff)

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Hello yall, i been asked several times by freinds to welding there rear ends. This will make both of the tires spin.What is the material of most rear end spider gears? And the hosuing? Will there be bi metalic welding?  Im leading towards the smaw process, any rod suggestions?Any info our advice on this subuject would be greaty apprciated.happy new year
Reply:There was quite a discussion about this recently. See "welding diff done best" in mechanics park forum. I don't recommend it myself as it puts quite a strain on the axles and carrier and if on a slick road there's no guarantee you'll make it around corners. Also wears tires faster because inside tire on a turn is trying to travel same speed as outside one.  If they still want this done,almost any rod will work(6011,7018).Just weld spider gears to each other where they mesh together. Make multiple passes,if welds crack and gears try to climb up on welds the carrier will break.               Best of luck,                               MikeOl' Stonebreaker  "Experience is the name everyone gives to their mistakes"Hobart G-213 portableMiller 175 migMiller thunderbolt ac/dc stick Victor O/A setupMakita chop saw
Reply:Don't do it.  Tell your buddies to buy a spool.  People have died as a result of this type of welding.
Reply:Unless your building a all out drag car...dont bother with a spool..get a detroit locker instead..welding spider gears is so 60'S... the welds will come apart and make a mess like you've never seen..you WILL end up replacing the whole housing eventually..and besides its illegal anyway as far as passing tech goes..spare yourself and your friends the aggrivation..because when it does go boom your friends will point at you..you were the last one to touch it so "your it"dont be "it"...zap!I am not completely insane..Some parts are missing Professional Driver on a closed course....Do not attempt.Just because I'm a  dumbass don't mean that you can be too.So DON'T try any of this **** l do at home.
Reply:zap is right the last one to work on it is the one that broke itChuckASME Pressure Vessel welder
Reply:There are all kinds of mini spools that will convert a differental to a locked rear end, some are the $50 price range. But as others have said just don't do it. Street driving with a locked rear end is quite dangerous. Just a bit of water or sand on the street in a corner can cause the car to spin around with very little throttle. On dry pavement turning corners with a lock rear end is harder on the axles than launching a car at the drag strip with slicks. When I was 17 I did the welded rear end thing It ended up causing body damage to the car. On a C-clip type axle if the axle breaks the axle slides right out of the rear end. This sucks if you're driving at that time.
Reply:Rock crawlers and off-roaders still weld their spider gears together. We used to weld them in our Stock Mini Toyota race truck.I have never heard of anyone getting killed or hurt because of welded spider gears off-road.On road is another story. I would NEVER weld the diff in a road car.A spool or locker are the best options but if you are using the vehicle off highway for trails or desert, you can weld the diff... but expect failure down the road. I have never seen a "Lincoln Locker" that lasted very long. If you weld it, make sure you don't get any spatter on the pinion or ring gear. This will cause almost immediate failure.- Paulhttp://all-a-cart.comWelding Cart Kits and accessories
Reply:Crawlers don't get turned into a wall when an axle breaks under load.
Reply:This is how I did mine.By the way this is for a demolition derby car.Not for road use.
Reply:Good pic, no question how to do it now. Just if to do it...If you don't have the time to do it right, then you definitely don't have the time to do it over.
Reply:Well guys, I'm semi-new to welding, but know enough that is NOT how to do it. I've done about 8 welded diffs for friends (mostly low-budget cars, although I have done a few turbo rwd's before including my 300whp 240sx). Anyhow, the way I do it is spin the sidegears until I can fit 4 2" long bolts at least 1/4" diameter between all the gears, then wiggle the sidegears until they rest. Then I weld the gear teeth to the bolt on both sides, and work my way diagonally to avoid heating the cast iron too much. Then I weld each side gear / spider to the carrier. Then the head of the bolt is used as a bridge to close up the area between the gears. Then I flip it all around, and everything is all lined up ready for 4 more bolts in the corner, rinse, repeat. I've broken 4 cv-shafts launching with 15psi of boost on 26x10 slicks on my turbo car, and the diff makes absolutely no noise. A little tack weld on the corners of hardened steel gears is NOT the way to make a spool.
Reply:Originally Posted by JohnRWell guys, I'm semi-new to welding, but know enough that is NOT how to do it.
Reply:Perhaps because they do not make spools for J30 diffs. The closest they have is a viscous LSD that usually goes for 600 for OEM + axles, or an aftermarket clutch-type for 1000. Sorry, I have a grand total of 2,800 including the price of the car, which runs low 12's.. stops on a dime, and will out-handle 90% of the cars on the road today. The reason I believe 8 bolts manually jamming the sidegears to the spider gears, having everything welded up tight, then having each side gear / spidergear welded to the case. The fact is I can guarantee that 1/2" to 3/4" of weld on the edges of sidegear/spidergears is NOT strong enough. I have seen everything from low-budget mud running trucks, to 9s turbo mustangs run on welded diffs. The ones that go into the shop for a new carrier + gears after a small weld breaks and the associated shrapnel gets stuck in the ring/pinion gear are the ones with poorly designed welded differentials. The reason he welded his that way, I assume, is to be able to pull the carrier and ring gear, and pull the gears out incase he didn't like the outcome of the spool. I trapped at 110mph in those pictures, with obvious lack of traction.
Reply:I don't like the Licoln Locker, as they don't last. As for dangerous??? Nah. That's BS. Lousy driving with a locked rear is dangerous. We in the past had good luck with first spot welding them to hold it in place, then brazing it. Seemed the softer filler did the job without making the gear nearly as brittle. But you really have to clean it up  in there to get the braze to stick well. I drove a brazed rear end on my cutlass with a 'vette engine for  a year, and I was pretty mean to it. We swapped rear ends after that, when my buddy bought the car. It never failed when I drove it. But, I have broken a welded diff in one day of hard wheelin'.
Reply:Welded diffs are fairly common with low budget Datsun rally cars here in Australia.  If you have a half shaft failure on a stage, a locked diff will allow you to limp to service*, where a LSD will just burn out.I've never seen an R180 spool either...* - Changing a broken half shaft is a pain of a job, but you can do it in about 15 minutes...
Reply:Welded diffs can be dangerous in "C-clip" style rear-ends where there is no outer axle retainer, like the pic that crashbro posted.When the diff fails the shrapnel can take out the c-clip or the end of the axle shaft and let the axle go flying out of the diff. housing.Wow JohnR, low 12's @110 and you wearing your NHRA approved safety baseball hat. Smart....and from the pics it looks like you don't have a roll bar either. Even smarter.I know plenty of people run lincoln lockers, especially off-roaders. It's just something that I prefer not to do. In 10 years of building race cars I have found that the best thing to do when building a competitive, winning race car is to take out variables, like lincoln lockers, that have high failure rates. Why put something in a vehicle that is almost guaranteed to cost you the race?- Paulhttp://all-a-cart.comWelding Cart Kits and accessories
Reply:. Why put something in a vehicle that is almost guaranteed to cost you the race?
Reply:Originally Posted by ZTFabWow JohnR, low 12's @110 and you wearing your NHRA approved safety baseball hat. Smart....and from the pics it looks like you don't have a roll bar either. Even smarter.- Paul
Reply:BTW their rulebook states nothing about "welded" differentials.
Reply:a number of the folks I wheel with use welded or poured"lockers", granted we're talking about rigs with well under 100hp and under 300lbs, but can be put thru a decent amount of stress with large tires and some pretty intense gearing and loads..At least from what I have seen, far more are working fine than I have heard of failing...and a number of these guys arent gentle on the skinny pedal!
Reply:Ohh Man what a topic.... good points on all.  I'm no expert but I'll to you my experience with this.  I installed a lockright locker on my toyota 4x4. It stripped out on the trail. We welded some spacers in the locker via underthehood jeep welder (portable) It got me out of the woods. Then I had lockright send another and same result....they and myself were concerned with correct spacers used so I had that one installed by a pro.  Maybe thats just a poor locker choice on my part for my set-up, probably so.  But I went to toyota and ordered new spiders and welded them with 7018 rod. Very slowly, stopped clean and kept repeating the process untill the welds took up all tooth walls so tight and flush.  Its been 4 years with 38 inch tires and no troubles.  Hey thats 4 wheelin  I know it can be done very succesfully, however ;if I had a race car with speed and other varibles, I would spend the money on the spool or the detroit locker.  So my thoughts are for the trails maybe but the track probably not even if your type of racing accepts it. weld it like you own it