Tips on replacing my Posi
 

I tore up my posi pulling my truck and Im replacing it with a powr lok that just came in today. Its a dana 70 and I got new bearings and races and the posi unit. I'd like any tips or advise from anyone whos changed these before. Now This is my first shot at internal rear end work other than hubs and seal, but I have a decent amount of knowledge about them and I build engines for a living I am confident at this.

When I swap the ring gear to this new posi unit and put it back in will I have to worry about my backlash if I dont touch the pinion gear? What things do I need to pay attention too? I can't afford another $700 posi unit so I need to do it right the first time. Any help is greatfully appreciated, thanks.

I have done many gear changes in the past but haven't pulled a Dana 70 apart. Does the 70 use shims or threaded cones to adjust the carrier bearings?
Most Dana equipment have very tight tolerances so in many installs that call for shims, you can get away with using the same amount of shims that came off the original unit in the new unit.
Take the old bearings and remove a small amount of the inner edge of the bearing so that they will slide onto the carrier and use them as setup bearings. That will make things much easier.
If the Dana 70 uses cones to adjust the carrier, it is just a matter of taking your time on the adjustments. You want approximately 1/8 inch travel on the pinion when everything is set up correctly.
There is alot I left out because of time limitation but send me a note if you have any questions.
Good luck.
Ken

Dana 70 is a Power-Lok on our trucks.... if that helps you help him. I have replaced the steels & clutches, but not had the ring/pinion apart.

RJ

I actually have mine apart right now. Waiting on a new ring and pinion, master bearing kit and power lock clutch kit. If you tore out your locker you may be able to get by with a clutch kit for the locker. Thats if you didn't burn out the spider gears. The clutch replacement is gravy. I called Jeff @ Jaws gear and axel. www.jawsgear.com paid $78 for the clutch kit. If you resuse your ring and pinion you won't even have to remove the carrier bearings. But I would advise you to replace the bearing while you are in there. If you pull the bearing caps and the carrier falls out, replace the bearings and races. I would always check proper pinion depth and backlash when changing bearings and gears. Almost everwhere you order from will send you detailed instructions on the whole process. It really is pretty easy if you take your time. Keep in mind that Dana recommends a refresh every 150,000 so if you are close do it while you are there.

well Im using the existing ring and pinion, I just have to take the ring gear off to put it on the new posi. Every single spider gear in the old posi was shattered so that is why I have a new posi unit. I plan on not touching the pinion gear if I can get away with it, but no matter what I am replacing the bearings. I have about 196K on the truck. Thanks for all of the help, If someone has a page with detailed instructions that would be great too.

Try this http://www.drivetrain.com/ringpinioninstal.html This is pretty good information and diagrams. It should be enough. If you have any questions just ask. Are you going to replace the pinion and carrier bearings, or just the carrier? And do you have your new locker, or do you need one? If you have a used on I would suggest a new clutch kit be installed in it. Good luck.

Cool site.
I saved it for when needed

Im just replacing the carrier bearings. I really don't want to mess with the pinion, and this is all just going to last me untill a dana 80 swap. I have the unit already. I bought a complete new unit from ringpinion.com. Thanks for the link.

I don't think my stock posi has ever worked right.

If you mean does not grab well, it's because Dodge does not stack ALL the steels & clutch disks.... to avoid customer complaints about too much chatter.
Pull it and alternate all the plates for full Dana 80 LSD effect. :)

RJ

are there instructions anywhere for restacking the LSD clutches in a Dana 80? I bought mine with 74,000miles on it and it hasn't worked worth a lick since I got it. And I changed the oil in the diffs when I first got it, so I know it has the LSD in it. Xchris1632x, I would do like suggested earlier, and grind a little bit out of the inner part of the bearings so you can slide them on and off of your knew LSD. I'd start off with the stock shims and check your back lash and see where it winds up. If you need to change shims, you can just slide the bearings off, put the different ones on, and recheck. Once you get the backlash set, you can press your new bearings on. You shouldn't have to worry about the pinion depth if your not messing with that, but you can always put some marking compound on the ring gear and turn it just to double check your how the pinion is contacting the ring gear. Also, you might wanna have a case spreader on hand in case your diff doesn't come out easily. And make sure you have the spec for how far you can spread the case, you don't wanna go to far. I needed to use one when I pulled my front diff out to change my axle seals.

Servie Manual has excellent instructions/pictures for removing the Rear end. Recommend anyone doing their own work had one of these!

Once in there...the restacking is pretty obvious.

RJ

Ok so I want to say thanks to all those who have helped out. I've been rather busy with things over the course of the past few weeks and havent been able to really work on the truck but I do have the old posi out and it came out fine. I was trying to remove the bearings the other day really bent one up with the puller I was using. Im not sure Ill be able to use the old bearing to mock it up. Im taking it tomorow to have them removed so I can atleast try to salvage it and the other side. What do I do if the bearing is messed up too bad. Im ready to ring gear is going on the new posi tomorow and as soon as I can make sure my backlash will be ok Im going to have the new bearing pressed and stuff it back in.

Also anyone have any tips on removing a little surface rust on a ring gear? My barn is very moist and a bit of surface rust started to form on one section of the ring gear. Some was already there when I took it out, like it formed in the case after the truck was sitting for awhile. Would polish do the job?

You will need decent 2 finger puller, 1 1/2 inch button or something to cover the end of the carrier. You may need a 4 1/2 inch bearing separator to pull the bearings if the carrier isn't notched for a puller.
I have used 2 finger pullers and a clamp on the puller holding the fingers into the notches before to get a good bite on the bearing.
The bearing will pull easy once it is started.
You can always reshape the cage after if it gets damaged while you are pulling the bearing off.
Do not reuse the existing shims because they will get damaged removing the bearing.
Keep track of what size and how many shims came off each side and duplicate that with the new ones to start with.
The gears are pretty hardened so you should be able to use a wire wheel or brush to remove the rust if it isn't too bad.
Is the rust on the face (teeth) of the gears?
Soak the area with oil or WD-40 after you are done and it should be fine.
Where are you located?
There may be someone on the board with the needed tools.
I have everything you would need but you are probably not near me.

can you document that?