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

Kern Dog

Kern Dog

Life is full of turns. 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.

IMG_5047.JPG
 
This is what the voice in my head is saying....

DO it 3.jpg
 
Used to do it to all the Demo derby & figure 8 cars.
 
My A100 had a mini spool when I bought it...that was scary enough on a dry road. Probably not too far off a welded diff.
 
No thanks, never did it. A sure grip is annoying enough in the wet....
 
Only on racecars, mostly dirt track stuff. Never did it to anything I needed to get home with.
 
Never on a mopar. Several Chevy trucks and several 9inch fords. Buddy had a square body Cherokee with the 4.0, it was a beater in every sense of the word. Not a straight panel on it, the doors ended up being removed, including the rear. It ended up being just a mud toy. We called it the “war wagon”. I was 16/17 he was probably 20, shoestring budget and we welded his rear, that thing was unstoppable. Then he welded the front, you couldn’t get it stuck but you also couldn’t turn it. I say weld the rear, especially if you have other dropouts in case you don’t like it. But I don’t think that’ll be the case.
 
The car is cool.
You should see what people call a "beater" around here!
 
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.
 
It's got a sure grip.
Wouldn't another option be to drain the gear oil and put in some plain hypoid fluid?
Make it grab more.
Might take some highway driving to heat it up good and get it to be really grippy though.
 
Thanks.....I don't know if I'll actually do this. I only have a MIG welder though.
 
I doubt you can get the nozzle of a MIG welder in good enough position to get a good fused weld on the spiders. And the oil and grease do not play well with a MIG. I always had better luck with the old school stick welders as the rod is much easier to get into the proper position to make a strong weld, and the stick welding isn't as much affected by the oil/grease...
 
Have done it on circle track cars and demo cars. I would never do it to a car that is driven on the street.
 
It was just an idea....I'm off work and ideas come through my head all the time.
 
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