Dana 44 Ring Gear Swap Question
 

Good morning everyone!

I am in the process of restoring my 1967 K20. My plan is to keep the Eaton HO52 in the rear, and swap the Dana 44 closed knuckle front axle with a Dana 44 open knuckle front axle that has the "Big Hub" Spicer Hub Loc setup. The original axle on the truck has a 4.55 gear ratio (the data tag was intact) and the new axle that I acquired has a 4.10 gear ratio. Can I just swap the ring gear and pinion from the closed knuckle axle to the open knuckle axle? I think that the open knuckle axle came out of a 1973 K20.



Thanks, Clay

Re: Dana 44 Ring Gear Swap Question
 

Yes you can. BUT do a pattern check and back lash check before so you can get it close when it goes back together in the different housing.

Re: Dana 44 Ring Gear Swap Question
 

Thanks much!

Next question, would I be best to transfer the shims out of the closed knuckle axle, or use the shims that are in the new axle? I will definitely check the wear patterns and such, but would it be better to keep the shims and oil slinger with the donor pinion?


Thanks, Clay

Re: Dana 44 Ring Gear Swap Question
 

You will be playing Russian Roulette by using either of the set-ups.
If it was easy GM differentials would all have the same shims or even better, none at all.

That said, you could get lucky? If I was lucky using the shim set from the original gears may be your best option.

I recommend purchasing a new set of bearings and starting over like you were installing a new gear set, which in essence is what you are doing.

Re: Dana 44 Ring Gear Swap Question
 

You may want to swap the ho52 to a 4.10 and keep your 4.10 in the front. I would use the rpm calculator

Re: Dana 44 Ring Gear Swap Question
 

I would suggest look at getting rid of the HO52. Unless times have changed, there is little support for that axle. 14 bolt it and call it a day. I have a HO72 here and cant even give it away. Call a place like Randy's and say HO52 and see what they say. Again, times may have changed...

As far as rebuilding the Dana 44 goes, it is not as easy as a 12 bolt. You will fight the carrier if you don't have a case spreader (I put the gloves on). Maybe you won't have to. Moving old parts from one axle to another is a gamble.

Smitty

Re: Dana 44 Ring Gear Swap Question
 

I do have the matching 14 bolt rear end that came out of the same truck. Both the front and the rear were geared the same way (4.10). I had actually contemplated ditching the Eaton so that I could have a better driver. The truck will never be offroaded.....I am doing a restoration, but will be getting rid of the drum brakes, adding power brakes, and power steering.

How difficult would it be to swap the perches and the shock mounts? I may go that route instead.



Thanks, Clay

Re: Dana 44 Ring Gear Swap Question
 

Yes, Yes, 14 bolt very good idea. You can buy perches and shock mounts from Ruff Stuff and google will find others. Maybe off road design as well.

Re: Dana 44 Ring Gear Swap Question
 

Measure the perches, they may be the same width. I picked up some shock mounts from my local metal place that cuts that stuff and sells it.

Smitty

Re: Dana 44 Ring Gear Swap Question
 

I agree that you would probably be happier leaving the front 4:10 and changing the rear to match. I went from 4:56 to 4:10 several years ago on mine and am very happy with the change, works great both on and off road.

I would disagree though for the need to swap the entire rear to do it though. I was able to find a doaner pumpkin with the right ratio for a good price. Is a very easy swap. Despite what others may say if you keep it full of clean oil (just like any diff) it will outlive you. I’ve been using HO’s HARD for 40 years and never had a problem, or seen anybody else have any either.

Just my opinion. Whatever you do have fun with that cool and rare old truck.

Tom

Re: Dana 44 Ring Gear Swap Question
 

I’m in the camp of see if you can find a HO52 4:11 3rd member as well. Theres still some parts around for them and every bit as strong as a 14 bolt. My K20 has a 14 bolt in it and I am happy with it. It was already (half ass) in the truck when I bought it.

Re: Dana 44 Ring Gear Swap Question
 

Well, I have decided to just go with the 14 bolt for the rear. I am doing a complete frame off restoration on the truck, so I can get to everything now very easy and quick. Also, since I already have the axles and they match with 4.10 gears, I think I will be happier in the end.

Welding on new spring perches and shock tabs will be no problem. My question now regards the pinion angle. As this is a stock truck, with no lift, when I move the spring perches on the 14 bolt, I plan to locate them (clock them) the same way that they are now. Will that work? Does anyone know if the pinion angle on the HO52 is the same as on the 14 bolt? I didn't think to check the angle of the HO52 pinion before I removed it from the truck frame.


Thanks, Clay

Re: Dana 44 Ring Gear Swap Question
 

Clay;
You will need to match the transmission angle is all.
If the transmission is pointing down 3 deg, the diff will point up 3 deg.
The vehicle should be on the ground and weighted like you will be running it.

Re: Dana 44 Ring Gear Swap Question
 

Cool beans, thanks much!

I have another question though, what about the jounce bumpers on the front of the axle (HO52)? There are none on the 14 bolt. Should I cut them off of the Eaton and reweld them on the 14 bolt, or is there a source for new ones? They are rubber triangle looking things that mount to metal tabs on the front of the Eaton axle.


Clay

Re: Dana 44 Ring Gear Swap Question
 

Here is what I am talking about.

Re: Dana 44 Ring Gear Swap Question
 

Here is a better picture.

Re: Dana 44 Ring Gear Swap Question
 

Nothing wrong with the 14 bolt at all, parts are definitely easier to come by, and equally as strong at the 52.

You’ll most likely have to cut them off or build a new set of bump stop mounts. A fab shop with a CNC plasma cutter could easily and quickly build the brackets parts, then you can weld them to the 14 bolt. If you haven’t found your 14 bolt yet look for one out of a 1 ton square body. (a full floater out of a 3/4 ton is not the same as the 1 ton, the perch spacing is different) They should be bolt in with out having to move the perches at all. You’ll need to re-locate the rear shock mount to the front and that should be it. The 1 ton square body trucks still use the 40.5” perch spacing as opposed to the 3/4 and half ton trucks that use the 42.5” spacing.

Re: Dana 44 Ring Gear Swap Question
 

Yeah, I think that your right.....I will just try to fab something up. It looks to be 3/16" steel and it doesn't look overly complicated. I made a mini press brake for my cheapy HF shop press, so maybe I can fabri-cobble something similar.

Clay

Re: Dana 44 Ring Gear Swap Question
 

Glad you now have a plan of attack for the axels.

While unfortunately there is not a big market for 4.56 HO 52 parts, PLEASE don’t make a boat anchor from that Dana front end. The 3/4 ton versions have some unobtanium parts, especially the drums and brake hardware if still in good condition. Also if the knuckles are still smooth and un pitted or gouged they would be useful for either a 1/2 or 3/4 ton restoration. While closed knuckle front ends and HO axels are definitely an acquired taste, one man’s trash is truly another’s treasure in this hobby.

Good luck with the project. Looks like you are preparing to do everything to a high standard. Please share pics of your progress.

Tom

Re: Dana 44 Ring Gear Swap Question
 

Hi Tom!

I will most likely list the left over parts here on the board for sale when I am done with my chassis. I definitely won't be trashing anything. I just don't want to get rid of anything yet until I know that it will all work out. I had contemplated just redoing the existing axles, but I really wanted disc's in the front, and this is a more economical solution for now.

I have been keeping a journal / build thread detailing my progress here with lots of pictures. https://67-72chevytrucks.com/vboard/...d.php?t=841272

Clay

Re: Dana 44 Ring Gear Swap Question
 

Hey Clay,
Saw your build thread after I posted. Like seeing the K20’s getting some attention, I’ll be checking it out. I think you’ll be happy with the 4:10’s, a great all around ratio for these trucks.

Others selling unneeded parts really helped me with my project and I’ve tried to do the same. Glad you’re going to be onboard, the sharing of both parts and knowledge is what makes this hobby possible. I agree though that you never want to unload stuff too soon, been burned by that myself more than once. When the time comes you might want to list the parts on both the 60-66 as well as 67-72 sites; as a lot of them will work on both series’s.

Have fun with the project!
Tom

Re: Dana 44 Ring Gear Swap Question
 

I think it would be close. But why not wait till you get the transfer case mounted and the front end sitting on tires and rear springs in. Then you will be able to dial it in. But my guess is the original location will be close but you will have to shim in either direction.

j

Re: Dana 44 Ring Gear Swap Question
 

I actually decided to just stay with the HO52. It was working, and the only real reason I was thinking of going to the 14 bolt was to have 4.11's front and rear, but the 4.56's will be fine for me. This is just going to be a cruiser to go and get ice cream from time to time and not a daily driver. Also, it will set me in a good place if I do ever decide to lift it and go with bigger tires.

I actually found a couple of 1971/72 Eaton HO52/72 hubs that accept 9/16" studs, so I think that I am going to do the 14 bolt brake mod to the HO52 so that I have larger and more modern brakes. That really gets me the both of best worlds. I am going to just sell the 14 bolt axle.


Clay

Re: Dana 44 Ring Gear Swap Question
 

I purchased my axles as take offs from a military ambulance. They come with 4.56 gears. I got the 14bolt(which was a SRW one ton, so it bolted right in no perch issues) along with the front Dana60. If I had found a good post 1970 44 or 60 on their own I would still be running the eaton. I liked the eaton... but I don't miss it.

I am running 33"s on my truck with 4.56s. It's fine for around town. I occasionally take it on the freeways for short distances out of convenience, the harmonics get pretty loud. I'm running some Hankook tires that are really loud too, I hate them. Plus my truck is a bit of a rattler anyway.

If you do the cheapest way for a straight line now... you can always swap stuff out later; no harm no foul, just a bit of elbow grease.

j