rear axle question

[dropped65c20]

I have a 65 c20 and i am having a hard time trying to find out which rearend i have. I haven't had any luck with tags, i know it's a 10 bolt though.

[jason65]

I don't know when they started it but 10 lug is a 1-ton pattern.

[justcuz]

It does not have 10 lug nuts, but 10 bolts holding the rear cover on right?
Take a look at the front where the driveshaft goes into it. Does it look like the center section comes out of it like a ford 9 inch? If it does the you have an HO52 rear end. It is a corporate design made by Eaton. The housing should be a welded steel housing not a cast center section with the metal tubes plug welded into the center casting. It is a strong rear end for normal usage almost as strong as a 14 bolt full floater. They usually have a 4.10 or 4.56 axle ratio and some came with a No-Spin (Detroit Locker).

[jason65]

Guess i need to learn to read to. Oh well.

[dropped65c20]

It does have 10 bolts holding on the rear pan and it is welded together as stated. I have heard that it was an eaton rearend (old one). I would of included a pic but was experiencing camera problems. More or less though the pic would of showed at the 3 and 9 o'clock positions 2 bolts close together and the other six spaced out evenly between the top and botom.

[Captainfab]

If your truck has coil springs, it would be the Eaton HO52. If you have leafs then it should be a Dana 60. The rear cover on the Eaton HO52 is perfectly round whereas the Dana is irregular shaped. Both have 10 bolts on the cover.

[dropped65c20]

Ya, it appears to be a perfectly round rear cover. I currently am running a 283, with an aluminum 2 speed powerglide. I have 16 inch rims with if i remember right 225/70. All i know is the truck runs fine doing 55, 60 sounds like it's screaming and anything higher sounds like it's going to blow. From what i am hearing this rearend is quite possibly 4.56. Sound about right?

[chevytrucknut]

4:11 or 4:56 were the options.

[Texasdeere]

Originally Posted by dropped65c20

Ya, it appears to be a perfectly round rear cover. I currently am running a 283, with an aluminum 2 speed powerglide. I have 16 inch rims with if i remember right 225/70. All i know is the truck runs fine doing 55, 60 sounds like it's screaming and anything higher sounds like it's going to blow. From what i am hearing this rearend is quite possibly 4.56. Sound about right?

I am running almost the same set up. I have 235/85/16's tires. There are numbers on the gears or you can just count the teeth and divide. I have a 4.56 in mine. I plan on a TH700R4 conversion in the future. The noise from the fixed radiator fan doesn't help much in the noise department.

[justcuz]

Sounds like you need a 700R4 overdrive automatic.
If you have 4.10's overdrive will put you at 2.90 highway gear in OD
If you have 4.56's overdrive will put you at 3.20 highway gear in OD
This should put you at about 2200 at 65 to 70 with 4.10's and 2400 with 4.56 gears.
These are rough mathematical estimates I am doing in my head but you can do the math on a calculator. OD in a 700R4 is .70 in final drive. So reduce your gear ratio by 30% to calculate final drive ratio.

BTW a disc brake conversion is easy on the Eation/HO52. you can use the same bracket and parts as you would a 14 bolt. Brake parts for the HO52 can be hard to find. Front discs are pretty much a bolt on as well, from a a later model 2wd 3/4 ton. Tie rod ends may be different but 90% is a bolt on.

[justcuz]

Looks like Texas and I were thinking the same thing at about the same time!
Nice upgrades to these trucks are the discs, preferably all 4, an OD automatic and an HEI distributor. Thats all you need to bring these trucks up to dealing with todays traffic and improving reliability.

[64c20crewcab]

Originally Posted by justcuz

Sounds like you need a 700R4 overdrive automatic.
BTW a disc brake conversion is easy on the Eation/HO52. you can use the same bracket and parts as you would a 14 bolt. Brake parts for the HO52 can be hard to find. Front discs are pretty much a bolt on as well, from a a later model 2wd 3/4 ton. Tie rod ends may be different but 90% is a bolt on.

I have the disc brake conversion on my EO52. Great upgrade. Just need ta get the front end swapped out - soon i hope. btw, I bought the brake kit on ebay bout 450 for the kit - i think. not gonna swap out for the late model 14bolt as planned. 700r4 comin soon....

[justcuz]

Hey Norm, I saw you today on Main Street! Were your wipers working?

[64c20crewcab]

Originally Posted by justcuz

Hey Norm, I saw you today on Main Street! Were your wipers working?

yup they were! finishin up a carb swap right now..

[dropped65c20]

Originally Posted by Texasdeere

I am running almost the same set up. I have 235/85/16's tires. There are numbers on the gears or you can just count the teeth and divide. I have a 4.56 in mine. I plan on a TH700R4 conversion in the future. The noise from the fixed radiator fan doesn't help much in the noise department.

Does your powerglide make a whine? Well, at least i think it's the transmission. While driving, i hear a high pitched whine. So, i take it out of drive and put it into neutral and most of the time it goes away.

[Captainfab]

Powerglides are kind of a whiney tranny IMO. Could also be the rear end. The HO52 on my '66 C20 had some gear noise.