Welded differentials.....who is willing to admit that they have done it?

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Kern Dog

Build your car to handle.
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Some call them "Lincoln Locker" based on the Lincoln brand of welding units.
The Roadkill guys have done it several times. One was a 73-76 Dart with a 7 1/4" axle. They welded the side gears to the differential case for some drag racing action. They had a fairly stock 318 or 360 in the car, I don't recall. I do remember that they sprayed a LOT of nitrous through it and got the car into the 11s.
I have several 8 3/4" dropouts, maybe 3 of them are 3.23 open diff. I am thinking of giving it a try. The car is a beater. I haven't even registered it since 2017. I drive it around the backyard here sliding in the dirt like a redneck. It sure is a lot of fun.
There is a 4.10 Sure Grip in it now.
I know that these welded differentials are spooky on wet pavement and tight turns.
I'd like to hear from guys that have done this to their cars.

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Yup. With full disclosure and disclaimer. Did it on a Dana 60 in a 4x4 Chevy truck with 44s. I never "heard" that it broke. But we told the guy not to bring it back if it did. lol It was what he wanted and was willing to pay for. So he got it. That sumbitch was one mass of weld in the carrier when I was done, too. It was purdy.
 
I've seen them welded between the side gears and bevel gears but the Roadkill guys welded the side gears to the case. That looks like if the welds broke, the differential would just return to normal operation unless slag got between the gears.
I will not be drag racing the car. This is just for dirt road drifting and off road fun.
 
Weld-a-loc, posi-weld, yup, about the winter of 67 my beater 57 Chev, hammered the spiders. So we yanked er out and welded 'er up. Drove all winter with that thing you learn a few things about driving. Dirt track? Pleauzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz................... Snow, ice, "track" I admit, I got "out of the track" a couple times LOL

I had a 56 Chev that came with welded 456's for a short time. That is a another sad story. Long and sad. Got that car from a Coeur d Alene guy named Ernie Flegel. Died of cancer a few years back.

With matched rear tires, a welded rear is not any worse most of the time that a very tight limited slip. My old 440-6 Dana RR when it was "newish" was almost impossible to drive around a gravel road corner without simply sliding the thing. This was in San Diego (Navy) we didn't get much rain through those years.
 
Back in high school my friend built a 1980 mustang and threw a 351 in it. I welded up the spiders in it for him and he drove it on the street like that. It was rough going around turns. Not something I would do now.
 
No...I want to pull the 4.10 and sell it!
You know what I can get for a 4.10 SG 3rd member?
$ $ $ $ !!!
 
No...I want to pull the 4.10 and sell it!
You know what I can get for a 4.10 SG 3rd member?
$ $ $ $ !!!

But how much will a complete rear end cost after breaking from a welded carrier? Just something to think over.
 
Did it a few times. In the 80’s I was into sand dragging and mud drags. Had a 76 Dodge 340 on alcohol. Dana 60 with a SG. And a Dana 44 front. I got the bright idea to weld the front. I figured hell I only drive it off road. Bad idea. Even in dirt or mud I couldn’t drive it to the starting line. When you turn, you had a point of return. It wold rip the steering wheel out of my and **** the wheel which ever direction I was turning. Did it on a 71/4 and 8 1/4.
Here is a couple pictures. Second one shows what happens when the front 44 breaks and locks up. And I can’t tell you how many front axles I broke. I use these broke axle studs now days when I build 8 3/4 SG’s to keep splines lined up.

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True story.....
I installed a mini spool into a factory cone style sure grip unit over 20 years ago....
I believe I machined 1/8” off of the cones(the side where the spring plate is) and the mini spool fit. I might have machined the cones for the mini spools axle splines to be “located” too... IIRC
Perhaps beer induced but it worked!
Mini spools were designed for “open” rears and were only $29.... lol
 
A lot of procedures years & years back were alcohol induced. Where do you think the phrase "Hold my beer & watch this" comes from?
 
Yes the mini spools usually state for off road only.
Uncle Tony's Garage welded up his 8 1/4'' in Project Bottle Rocket it went a few rounds and broke a axle.It's behind a 4 speed. He is now going to a 8 3/4 SG.
If you do weld it up and drive in dirt only I would bet you won't break it.
 
They used to sell what they called a mini spool, which was a couple splined blocks to replace the spider gears. Cost like 20 bucks years ago. Can't find them anymore. But put a set in my kids drag car years ago. still in there. Never had an issue. Even on the street.
 
I welded one for an enduro car. I also bought a Duster with a 488 welded. He said it was a spool and had a receipt from the garage for the install.
 
I used to weld the spiders in the dirt track cars we raced in street stock, they'd last the entire season with no issue. It was crude....but effective!!!

Some advice if you're going to do this....

Spray the spiders down with brake-clean or something similar first to get as much of the oil out of there as you possibly can. Make the first welds with a 6010 or 6011 rod....just enough to get a good base weld in that ties the gears together. Then switch to a 7018 low-hydrogen rod and go to town building up and fusing together all that you can. If you start getting porosity in the weld, stop and switch back to the 6010/6011 rod and burn the porosity out, then back to the 7018 to finish.
 
Had a friend in high school with a 71 Cougar, 351C, some performance parts, cam, headers, carb, etc. Had 3.70s in a 9 inch welded up, street drove it 12 months of the year, went through a LOT of rear tires. I drove it occasionally, was a ***** making tight low speed turns.
 
I have a friend who did it to his current daily driver '81 Datsun 510. He said he loves it and is a blast on the dirt, his only complaint is that tight turns while parking are noisy and difficult and that he goes through tires a lot quicker but tires are also dirt cheap on his car so it doesn't bother him too much.
 
a lot of dirt track cars are welded in the street stock classes and last forever with 10 inch tires and manual trans
 
I welded one for an enduro car. I also bought a Duster with a 488 welded. He said it was a spool and had a receipt from the garage for the install.

Well technically, it "was" a spool. LOL
 
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