Dana 41 rebuild questions

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Hey guys and gals. I'm looking for some help with rebuilding my Dana 41. Actually I'm looking for help getting it torn down so I can then ask for help rebuilding it. I opened it up today and the oil that came out was really rusty. 


Im assuming that's common on these old junk yard scores. Any way, the ring and pinion seem to be in decent shape. There wasn't any metal in the pan. I'm wondering if anyone know what is causing the marks all the way around the ring gear just inside of the teeth. I can't see anything that come in contact with that part of the gear. Maybe it's of no concern. You can see them in the picture below. Also is that a retaining pin through the pinion shaft or has the head of the retaining bolt been broke off? Everything I read says it's a pin but I don't want to beat on it if it's threaded.


Also, both hubs are different. One sits flush as if it's attached to the brake drum and the lug bolts are pressed into it and the othe has about a half inch gap between the hub and the drum and the lug bolts are loose. I can wiggle them around.


I tried to use a cheep puller on the one with the gap but it wouldn't budge. Guess I better find a better puller. Question is should the hub and drum come off as one assembly? 

Also, the pinion seams to has a bit of slop in it and nothing feels very smooth when I turn the axle. I'm guessing the advice would be to put in new seals and bearings? 

Thanks!

[Deleted]

First off your 2 jaw puller, well it's not gonna do it!, the hub is really on there, and without the proper puller you'll just wreck something and or hurt yourself. There is a tool thread on this forum, Sir Binthere recently fabricated a puller to do this job, you should check that out. You can also rent a puller from an Auto supply, they are common and used on front wheel drive cars as well.

You will also need a slide hammer and a an adapter to pull the Axel from the housing. Once you have them out you can remove the caps from the differential assembly Mark them by center punching or whatever means you prefer so you get them back in the same order you removed them... Beyond that it gets pretty technical, I highly recommend a manual befor diving into th pinion and diff side bearings, this is secret squirrel stuff, if you misplace a shim or two, your screwed.... Not saying it cannot be done in your shop, it can and there are knowledgable bastages here that can help..

Lee

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Thanks Lee. I just ordered a manual and I'll check with a couple auto parts stores to rent a puller. I appreciate the help.

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Puller is a must. A air impact wrench is also a huge help. Re-building a differential is not for the feint of heart. Keep track of all shims and where they went. The hubs are a taper fit to the axles and have a key. Study how that key goes with the tapered end. If you put it back wrong and tighten the nut, you will ruin the hub. If the brake drums are not all ridged, leave them alone. If you have the drums turned too much, your brakes will not adjust up. The drums are swedged to the hub around the lug nut studs. If you push on them with a press without cutting the swages, you will warp the drums. Pay attention to how the axle tube end shims and thick washer go. The bearings on the carrier have shims under them. Keep these ID'd and which side they were on. To set the running pattern on the teeth, these shims move it left to right, and the shims on the pinion move it front to back. Preload, pattern, Oh Boy. If the water that was in the oil has not rusted and pitted the bearings, and they look good, just clean things up and put it back with new seals. There are inner and outer seals on the axle depending on if you are working on the front or rear diff. A Dana 41 is the rear, so the seals are out board with gaskets and metal retainer. I can't remember if the "pin" you mention is a bolt, or a pin that is peened in the hole. Read the manual. No clue on the marks, but check all the ring bolts and heads. Looseness of the bolts, etc. The bearing caps are marked usually with a vertical or horizontal "O" or something and have a corresponding one near it on the housing. These are machined caps and need to go back as original. You are entering a job that is very finicky and if not done right, will make alot of noise and problems. Sometimes it is easy, other times it's a bitch. I've done about 5 of them. Be careful with the new bearings when you press things. One false move and you get to buy them again. Easy to put 300.00 in them, in a hurry. It sometimes makes financial sense to just buy a good used one. Oilly

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Biggs
On the home page here, just scroll down to Accessories and click on tool time. I just posted some pictures of the hub puller that I made in about one hour. Simple and easy, and unbreakable! Check it out!
Guess one should read all the posts before spouting off! LOL

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OilLeaker, thanks for your detailed response. I'll make note of your suggestions and pay close attention as I get deeper into this. Much appreciated! 

Binthere, thank you! I'll check out the tool you made. Maybe I can make one too.

Any suggestion on how to remove the hub on the front (Dana 25) after I twisted off EVERY SINGLE LUG because I'm an idiot and didn't know they were reverse thread? Go ahead boys, I can take my licks.

[Deleted]

Next time look at the ends of the studs. "L" means left hand thread. "R" means right hand thread. I've had a Jeep that the DPO (Dumb Previous Owner) installed the hubs opposite. I darn near did what you did. To remove the hub, first read your manual and look at the pictures. Show and tell sort of. Then get yourself a hub nut wrench. ( big Socket affair) Be careful with the lock tab washer. They are pretty tough. My money is on you having nuts tightened with a chisel. Don't do this. Use the big socket. Your Jeep manual will pay for itself in a hurry. Oilly

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So, I received my service manual today and it says I need to "spread the carrier as the differential bearing has initial preload". Is this really necessary? I've never seen this mentioned before. Where would I get a "housing spreader tool"?

[Deleted]

Sorry, read further and it looks like I can use a couple pry bars inplace of the spreader tool. 

[Deleted]

The spreader makes it easier as all tools do, but not necessary, never had one not come out with a little pry action, per patient it will come out.

[Deleted]

If you have a slide hammer, you can rotate the carrier and with the two jaws grab the shell part and it pops right out. Going back in, you can put the cups on the two side bearings and angle them a bit to get it started. Then a piece of hardwood and hammer and tap it back in. Be careful with the pinion and ring meshing together. Oilly

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Thanks guys! Still waiting for the hub puller I ordered. What do you think about this? Is this too much slop for the pinion gear. 

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I would say yes, and it sure looks like the pinion is moving up/down in it's bearings. That movement is called backlash and you measure it with a dial indicator. check the manual specs, but i think it's .004-.006. Oilly

[Haines Garage]

There is way too much play there.

[Haines Garage]

Don't give up! The axles are tough.

[Deleted]

Success!! Got both hubs off today. I know, it's a minor achievement, but it sure was satisfying when it finally broke lose. 

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Perfect!