Technical A Moron's guide to figuring out the rear gear ratio

I got home late today and decided to pull the axles after I had already put them back in the housing, J removed the nuts from the pumpkin and got one axle out, I beat the **** outta the other one and I don't have the correct puller, so it was tired and read to eat so I gave up for today, I'll get the other axle out tomorrow and pull the pumpkin.

Thank you sir and you are right, I won't try and deceive anyone. HRP

 

It is apparent I tend to do everything the hard way, But like Mel Fisher so eloquently put it when I get up in the morning, "Today's the day" HRP

 

or you can go to settings on your device and turn the auto correct off......
General- Keyboard- auto capitalisation- auto correct.

 

Whatza “chunk”?

 

What’s the origin of the rear end before the Model A Danny?

I ask because if it’s a 56.5” wide 8” from a Maverick or Comet (5 lug 8” axles are usually from V8 equipped cars) it’s most likely a 2.79 ratio which the majority of them were with the SBF and C4 transmission.

 

In this context, I think we are talking about the second picture.

 

I think you're correct on both counts...

 

Larry, I'm guessing it's one of those or possibly a early Mustang. HRP

 

Thank You!

Ray

 

HRP just got out of the hospital and I started reading this before I went in. How did you go from the axles being out and Alchemy recommending pulling the pumpkin to having to knock out the axles? I thought only I did things the hard way. Did you find out anything yet.

Pat

 

I don't have a patent on doing things the hard way.

The axles were out, some one said stick them back in and count rotation, that didn't seem to work so I tried to remove them, one side slide right out, the other side wants to put up a fight, I don't have the proper tool to removed the axle.

So l started beating the axle with a hammer yesterday, today is the day I look for my 3 lb sledge hammer, that axle IS coming out today. the nuts on the center chunk are off and awaiting the removal of the axle. HRP

 

A log chain hooked to the axle and used like a whip works pretty good as an axle puller. There might not be room in the garage to do that though.

 

Good Luck my friend, just hearing about your escapade convinces me to go make myself a drink and sit on my porch and watch the cars go by.

Pat

 

When I decided to post the rear end in the cl***ifieds I obviously did not give a thought to someone needing to know the ratio, my thought process was that the housing was ready for a set of coil springs, the shock mounts are there and the hair pin/ ladder bar brackets are there.

Realizing now that anyone interested needs to know what the ratio is I realize I need to do some detective work, with the new world order,the pandemic Brenda has lost a employee & another p***ed away I have become gainfully employed and spend a lot of time at the shop and very little time in my garage, thus I have put it off, out of sight out of mind type thing.

As I said earlier I intend to get that stubborn axle out this afternoon. HRP

 

Ok, I went to battle with the stuck axle and after trying vast and sorted, some laughable but that center chunk/ pumpkin is now laying in the floor.

Now for the original question, how do I go about determining what the ratio is? HRP

 

You either have to physically count the teeth on both gear's or look for the number's that are stamped on the ring gear, and divide the bigger number by the smaller number, and that will be your ratio. (10 tooth pinion/37 tooth ring gear = 3.70 gear ratio, just for an example)

 

The ring gear is 39 tooth and the pinion is 13 from what you guys have told me it looks like a 3.00 HRP

 

HRP of the many 8 and 9" Ford rears I've dealt with, the majority have been that. Now don't put it back together let the buyer inspect it. Good job now go and relax.

Pat

 

I am cooling my heels now and out of the heat.

I had my su****ion it would be in that range but guessing would not be telling a potential buyer the truth, pulling the pumpkin out was the right thing to do, I appreciate all you guys taking the time to post and explain how to figure the ratio. HRP

 

Never too old to learn a new trick.

 

Funny how it turned out to be a 3.00 after all. HRP

 

Danny,is this the rear axle you want to sell?

 

Turn one wheel 10 times by watching your favorite lug nut.

Count the number of times the driveshaft rotates by watching your favorite u-joint cap.

Divide the number of driveshaft rotations by 10.

 

No drive shaft. HRP

 

Well there's your problem. That car's not going anywhere without a driveshaft.

 

I guess you didn't read the thread - the axle in question is not in a car and the identification tag is missing. HRP

 

Yes John, it's in the cl***ifieds. HRP

 

Before I bought an axle puller, I would put the drum on backwards, then put the lug nuts on a couple of turns. Push the drum in then jerk it back hard. Pops em out most times.

 

Could have saved you some work.

 

Hello,

From the time that I was given the job of replacing the 4:11 gears with a new 4:56 third member in my brother’s 58 Impala, it was get under the car for the two hour+ job on Thursday nights. Why Thursday nights? He wanted to be ready for the Friday night cruising scene and then the all day Saturday at Lion's Dragstrip. So, under the car I worked every Thursday after school. At first, it was a very long procedure with the drums, axles, drain the oil and numerous nut removals, etc.

Gradually the more I did the weekly/bi weekly exchange, I got faster and better at the removal and installation. Since my brother really wanted 4:56 Positraction gears to be compe***ive at Lions, he actually bought a complete 3rd member with Positraction. The parts department had one in stock and he jumped at the opportunity. Now, instead of changing the ring and pinion gears, I could just take out the old third member and install the new third member. A family friend gave us a Walker Hydraulic Jack and that saved my teenage arms and cold back.

But, after many hours in the dark with only a shop light under the Impala, things tended to get confusing. Maybe I was getting tired, but with the two third members sitting on the blanket, which was which? I had to count the gears on the pinion gear and the teeth on the ring gear. Dividing the ring by the pinion was the rule of thumb for the exact gear ratio. I had that straight, but late at night, laying on the cold concrete upside down, was not the best place to remember which third member was which. No way was I going to take out the 4:11 gears and put in the same 4:11 gears as a mistake due to being tired or upside down on the concrete.

So, with a small paint brush, I wrote 11 on one and 56 on the other. No one could see it when installed, but only I knew where it was. Now, even if I was overworked and tired, I could tell which one was which and I would not make a mistake like installing the same one I just took out.

Jnaki

Yes, I know it seemed like a lot of work for changing the gears. But, when all else is the same in the A/Stock car cl*** racing, (1958 Chevy, 348 motor, 3 carbs, 280 hp 3 speed stick shift transmission) every little bit has its advantages. The consistent winners had the 4:56 gears, so now we were again all even and it came down to the quick reaction of the drivers as to who got out in front and stayed there to the end.

Why did I change the 4:56 gears back to 4:11 on Sunday night? Well for the next 6 days, it was daily driving to high school, a job and errands. The 4:56 gears were good for the drags and the sometimes street encounters, but it did wind the motor tight. It was not a 65 mph scene on the freeways and straight coastal highways. But, the 4:11 gears had just enough for daily street driving and those 100 miles drives down south or up north, into Los Angeles/Hollywood. We could go 60 and not worry about over burdening the motor/trans system.

Was it worth it? The trophies that we won were well worth it, if not for the experiences. It is nice to get out in front and stay there to the finish line. If anyone or other 58 Chevy sedans somehow p***ed us up at the finish line, it was a call for a tear down and protest. We were all the same from the factory, with the exceptions of the 3:78, 4:11 or 4:56 gears. No cams, no port/polished heads, no engine work except for being stock from the factory. It all ended up being the quick reactions of the driver that consistently won.