I think it’s time for a new transmission

[Asshat]

So, here it is running on jack stands. Finally got the exhaust on, so it’s not quite as loud.
It was running in fourth gear, I believe, for most of the video.


https://youtu.be/b6HZs9YsHK0

[Steeveedee]

Originally Posted by Asshat

So, here it is running on jack stands. Finally got the exhaust on, so it’s not quite as loud.
It was running in fourth gear, I believe, for most of the video.


https://youtu.be/b6HZs9YsHK0

Have you had the cover off your diff, yet? I noticed late in the video that the noise was reduced when the driveshaft stopped turning.

[Asshat]

Originally Posted by Steeveedee

Have you had the cover off your diff, yet? I noticed late in the video that the noise was reduced when the driveshaft stopped turning.

No, I have not. It’s had oil in it the whole time, looks pretty clean too.

What would I look for if pulling off the cover? I wouldn’t mind removing the posi, if that’s possible. Not sure if it would help.

[Steeveedee]

If the diff is bad, it will be obvious when you take the cover off. If you mean the outside is clean, that's one thing. I blew up a ring and pinion in my '66 Le Mans but managed to limp it home to replace it. It was clean on the outside, too! Someone before I bought it must have been in there, because one of the ring gear bolts came out (not sheared off) and got in the gears.

[Asshat]

Looks good from the pics.

https://youtu.be/6aaJkhZn1Kk

https://youtu.be/qhMpWUPo2nU

[Asshat]

Another video.
http://www.youtube.com/shorts/MJIOZ4DqmO0

[Asshat]

Well, I think I am going to remove this center section and get a 4:10. I found a guy that has one and, hopefully this will work. And, it’s better than a 4:56.

Any advice on removing the differential? Pretty straightforward, right?

[Steeveedee]

I don't think that that punkin looked bad, but changing to a lower numerical ratio would be good to do, in the end. You have to pull the axles out, and then take the punkin out. Since the axle bearings are a tight fit, you MAY have to put in new axle bearings and seals. Be warned, those bolts holding the punkin in are tight, and I've known people who stripped the heads removing the bolts, even back in the '60s.

[Asshat]

I’m rethinking this, it’s probably not worth putting money into this noisy rear end. Seems like all these low geared farm truck run loud.
I think I will just look for a rear end. And, I can sell the posi differential out of mine, right? Or, is it easier selling the complete rear end?

What is the best year to get a taller geared rear end, 1973 - 1979?

[The Rocknrod]

I used the original truck 12 bolt housing. Went to Quick Performance and bought everything else. Gears, carrier, bearings, seals and 31 spline axles.

[cwcarpenter98]

If you're trying to keep it 8 lug, go with a 14 bolt rear out of a squarebody. You would also need to weld on new mounting perches to work with the trailing arm suspension. I'm not sure how much the year matters. What's more important is figuring out what gears you want. 3.73s would be good with an overdrive and you could still do some towing with it if that's your plan

[Asshat]

Would this work on my truck?

Looks like a 14 bolt, 8 lug with disc brakes.

[cwcarpenter98]

Anything can work with some fabrication. For that axle, you'll have to remove the old spring perches and weld on new perches that work with the trailing arms. You'll also have to do something to the driveshaft to make it all work together

[Asshat]

Originally Posted by cwcarpenter98

Anything can work with some fabrication. For that axle, you'll have to remove the old spring perches and weld on new perches that work with the trailing arms. You'll also have to do something to the driveshaft to make it all work together

I understand the driveshaft modification - that’s a given with any rear end change.

If it’s a 14-bolt, that means it’s a Dana, and I can change the gear ratio - correct?

[Asshat]

Originally Posted by cwcarpenter98

Anything can work with some fabrication. For that axle, you'll have to remove the old spring perches and weld on new perches that work with the trailing arms. You'll also have to do something to the driveshaft to make it all work together

I understand the driveshaft modification - that’s a given with any rear end change.

If it’s a 14-bolt, that means it’s a Dana, and I can change the gear ratio - correct?

[Asshat]

So there seems to be a multitude of possible configurations for the rear ends that would fit my truck. Is there some sort of cheat sheet or spreadsheet that shows which ones would work?
How do you tell the difference between all these different rear axles?
Eaton, 10-bolt and Dana 14-bolt?
Dana 70 rear end?
Are all 8-lug rear ends geared low? The lowest I have seen in ads is 4:10.
Are all 8-lug Dana rear ends capable of changing out the differential for a taller gear, like 3:73 or 3:08?

How the heck can you figure out what to buy without getting a degree in this stuff? I started reading through the posts, but it's difficult sifting thorugh all the information and what everyone is talkking about. Geez - frustrating.

There's a guy on Facebook that has a disk brake Dana 70 with 3.73 for $550. What exactly is a Dana 70? And, what is full-float?

['63GENIII]

Originally Posted by Asshat

Would this work on my truck?

Looks like a 14 bolt, 8 lug with disc brakes.

*That looks to be a AAM 14. Later model 2005 ish out of a 2500hd maybe. Pretty much same axle I have in the '63 that replaced a Dana 60 that came out of a '73 Dodge van.

Both the D60 and the 14B were full float - the axles only turn the hub which rides on the ends of the axle tubes instead of the axle supporting the load of the vehicle as well as turning the wheels. Just a heavier duty axle.

I think that the 14B will be easier to source than a D60 and parts may be more available as well.

Disc brakes "might" be better than the drums depending on who you talk to. My drum brake 60 stopped as good or better than the 14B that's in it now. The 14B was a good deal though and I thought having rear discs would be "cool"

Originally Posted by Asshat

So there seems to be a multitude of possible configurations for the rear ends that would fit my truck. Is there some sort of cheat sheet or spreadsheet that shows which ones would work?
How do you tell the difference between all these different rear axles?
Eaton, 10-bolt and Dana 14-bolt?

*Eaton - HO52 and HO72 are round in the center or "banjo" and have a drop out 3rd member - poor man's quick change

*GM or AAM 14B full float are very angular, and have a removable pinion carrier.
Note; there is also a semi float 14B used in vans I think and a later 14B HD version without a pinion carrier. The 14B FF with the removable pinion is the one that I generally think about when someone says 14B. I have seen them in a 3.73 from time to time.

Dana 70 rear end?

The only GMs that Ive seen with a D70 have been duallies. Had one in a 77 CC dually that I converted to 4wd years ago. If you have to move it around out of the truck, be prepared to lose a few years off of your back. They're heavy.
Pretty sure Dodge used them in their single rear wheel trucks a lot.

Are all 8-lug rear ends geared low? The lowest I have seen in ads is 4:10.

*A lot of the time yes.

Are all 8-lug Dana rear ends capable of changing out the differential for a taller gear, like 3:73 or 3:08?

*Im not sure if there is a carrier break for the 14B as Ive never swapped gears in one but pretty sure that gears can be swapped to 3.73 and pretty sure Ive seen 3.73s before. Taller than that, someone else here may be better able to answer.

How the heck can you figure out what to buy without getting a degree in this stuff? I started reading through the posts, but it's difficult sifting thorugh all the information and what everyone is talkking about. Geez - frustrating.

Take your time and keep on asking questions. I would start by getting the drum face to drum face measurement from your existing axle. Nothing worse than having your front and rear wheel track be way different. I personally would stick with the 14B as they came almost exclusively in GM trucks from '73 up to '05+ and although the mounting might be different, the width didn't change much over time. Theres a lot of aftermarket support, tons of parts, they are generally cheap and virtually bulletproof.

There's a guy on Facebook that has a disk brake Dana 70 with 3.73 for $550. What exactly is a Dana 70? And, what is full-float?

*I wonder what that 70 came out of? IMO, It'd be overkill and even more difficult to get down into the 3.08 range that you're thinking of.

['63GENIII]

Originally Posted by Asshat

Looks good from the pics.

https://youtu.be/6aaJkhZn1Kk

https://youtu.be/qhMpWUPo2nU

Just went back and looked at your clips again. Just sounds like a little slop in the rear and although annoying Id be inclined to take a look at the 4.10 center if you can get it for a decent price? I think that although parts might be a little harder to find (carriers and maybe posi units), I think those old Eatons might share some parts with the 14B. If you could find someone that knows their way around them (id be thinking big truck shop), you might be able to run your 4.56s til the new center section is ready and just pop in the new center section? Wouldn't have to hassle with a bunch of research and fab work for hanging a new axle (that you may want to throw a new set of gears into anyway)..

If Im not mistaken, your axle is an Eaton HO72. I had one in a '57 Napco truck as a kid. Yeah, it was noisy and it leaked but it was a robust axle from what I recall.

['63GENIII]

Did a little digging here and found this..good to help identify what you have.

https://www.google.com/url?sa=t&rct=...8Hh8F7xRAvY9Hd

On another forum, I found that the only ratios offered for the Eaton axles were 4.10, 4.57 and 5.13..

Might start looking at 14B axles