Fixing a broken original 57 differential with a 10 bolt.

I should have known better. I go to a friend’s house for Sunday afternoon cocktails. While some old tall stories are being told to pass the time we were blesses with some new blood. A new guest arrives and I get introduced to my kind of guy. He is a car loving, motorcycle loving, and gun loving flatlander from Illinois. Well we are old friend from the minute we meet.

A 1957 Chevy 150

Time passes much too quickly and it is time to go home. I very juiced, no not from drinking but from talking about old cars and Hot Roding. I even told most of my hot Roding tails. To make matters worse I have driven my 57 Chevy that day.

Picture the day, a spring day, the sun shining, birds chirping and everyone is happy with the world. I back my old school hot rod 57 out of the driveway with the exhaust pipes purring like kitten. I now have an audience admiring my 57 pumped with the knowledge of how powerful the 383 mill is under the hood, how fast off the line I am with the 3:55 gears driven by a Borg Warner 4 speed. How 57s in general are made to lay rubber because of the lightweight body with hardly any weight over the rear tires. My wife is now hearing my little voice ringing in my head that is starting to scream, “Get on it”. She says, “Don’t do it”, but do I listen, no. Do I rely on my 20 of experience of tearing thing up, no. I rev the mill to 4 grand, pop the clutch and damm; the car is in third gear. I smoke the clutch. Embarrassed, I slam it into first and lay caution to the wind. Then the worst thing other that wrecking the car happens when you are laying rubber, nothing happened except a loud band.

I get out of the car with a stupid grin on my face while my wife says, “What are you 18 or 40?” I recite, “I always did say make it or break it.”

Well, After getting a tow home I find the spider gears were in more pieces that they were supposed to be and parts of it got into the ring gear and destroying it as an added bonus.

I have said this before and it needs repeating, “If you like old cars you have to like working on them.”

Now begins my odyssey of fixing the rear in differential.

A picture of my old differential before I took it out.

My first thought is to buy a new Ford nine inch or a 12 bolt brand new. Bamm! I’m hit by sticker shock. We are talking 2 to 3 grand for one of those puppies. Plan B. I look for parts to fix my broken differential. Problem B. Again sticker shock, I didn’t' want to wait for parts to be sent to me in the mail, and besides the old differential was two wide and my tires rubbed on the fender. Plan C. I was told by a buddy that a 10 bolt from a 80s blazer is a direct fit. Well, it depends on how you define a direct fit.

Off to the wrecking yard I go. I find a differential. I check and the measurement looks good. I make the deal and go home.

I’ll make this short. The differential works great. With 50 series tires it is a great fit. What you have to do to make the differential work is to: Weld on new brackets for the springs to attach to. I cut off the old one and used them. The drive shaft is a problem.

I had to go and buy a new universal joint for rear of the drive shaft. They actually make a special U-joint that adapts the two.

My drive shaft is about an inch too short and will have to have it redone.

Easy job really. My only problems were welding the brackets on at the correct angle. You don’t want too much angle on the drive shaft. The welder I used is not with the car so I goofed up and had to reweld the brackets a couple times. Hooking up the emergency brakes look a little ghetto but it’s under the car.

I enjoyed my self so much I took the dustpan off the front to sand blast it and repainted it. Nothing is ever easy,I had to take off the whole bumper and grill to get the dust pan off the car. But, hey working on an old car is half the fun.