DIY Pinion Seal Replacement Dana 80

[smokeythedodge]

Alright, kinda wish I would have taken more pictures, but I was hot and ready to get it back on the road... So here is what I got, perhaps this will help someone looking to replace their own.

First things first. Go out and take a look at your Dana 80. Now, I don't have a photo of the other type for comparison, but there are actually two different Dana 80's in the 2001 and 2002 model year. This is important to get the proper seal. For my axle, in a 2001.5 Ram 3500 quad cab 2wd diesel 6 speed, it has the non flanged yoke and the double stepped down pinion shaft seal.

Part number is 5015618AB from Dodge...

Now the other seal (for the flanged yoke) is 5073944AA... Here is a picture of what a NON FLANGED YOKE looks like.

So.. If yours looks like this, you must go with the top seal ending in AB...

Now for the required tools.....

-Some kind of torque multiplier (Pinion nut is TIGHT)

-Various hand tools (sockets and driver to remove the driveshaft)

-Craftsman, 2 jaw puller, small one and the large one

-24" Pipe wrench or miller tool 6719 yoke holder. I am poor, so I used a pipe wrench.....

-1 7/8" craftsman 3/4" drive socket. Details later....

-torque wrench

Now, about the 1 7/8" socket... You can go try and find a thin wall socket of that size, or you can spend $25 bucks at sears for this socket and take some meat off it (yoke is thick inside around the nut for strength)

Now how to do this.... First, the service manual says you need to check pinion bearing preload with an in-lb dial type torque wrench with the wheels and brake completely removed. I did not do this. Why? Because I used to work at a Dodge dealer and we NEVER had any problems doing it the way I did mine and am about to explain to you.

This axle does not use crush sleeves for bearing pre-load... It uses shims, like most H.D. rear ends. Now, the way I do this is the same way that the FORD service manual spells out the procedure for their trucks equipped with the dana 80.

Ok, so here is the problem...

1. First thing you want to do is clean and dry up everything around the yoke as best you can.

2. Mark everything with a sharpie or paint pen to realign it later.

3. Block the front tires and support the rear of the truck with jack stands.- or do this on your lift. Also put tranny in neutral.

4. Remove the u-joint retaining hardware. The u-joint caps on mine were rusted into the yoke... Don't use a hammer to try and free it if yours is this way, you can damage the pinion bearings. Take a big pry bar and pry it apart. It will come.

--Now you can see that beast of a nut. I sprayed some penetrating oil on the treads of the pinion shaft to make it easier to unscrew.

5. Take your pipe wrench or yoke holder and pin it against the frame or put a cheater pipe over the end and brace it against the ground. You are trying to secure the pinion and yoke from rotating as you try to remove the nut.

6. Hope you ate your wheaties, if you don't have a tq. multiplier you are going to have to get a 3/4 drive breakover bar and cheater to get this thing loose or a beast of an impact... I used a 1:6 torque multiplier that is 1/2" input and 3/4 out. It was tight.

and once its loose, you can just start unscrewing it.

7. Get your 2 jaw puller and go to town on that yoke.... MARK IT FIRST!!! It needs to go back on in the same position it came off!!! It is tight all the way off!!!!

Inspect it... Probably will have a nice little groove... Mine did... If the groove is bad enough, it WILL ruin your seal quickly. You can get a SKF Speedi Sleeve for the yoke or buy a new yoke from dodge ($140)

8. Now you can pull the seal out. Mine was a bit** and I ended up just destroying it to get it out... :banghead:

Now you are almost to the finish line!!!!

9. Use a seal driver to install the seal. Make sure it is seated fully.

10. Put the yoke back on. It is tight!! You will have to use a rubber mallet probably to get it seated far enough to thread the nut and washer to get it cinched down the rest of the way....

11. Tighten it up until the yoke is back in it's home completely.

12. Get your pipe wrench again and pin the yoke where it wont try and rotate. Torque the nut to around 450-500 lbs. Most will disagree on this step, there is some debate about on the correct torque for used bearings... I have seen them do it at most shops, they just impact it off and then back on... I don't trust that method... I set my torque wrench to 80lbs through a 1:6 multiplier and came out with something close to the factory tq. spec. NOTE: most say to use a new nut, but I did NOT. WE shall see if this bites me later on. I don't THINK it will loosen up from 500 ft lbs. That is pretty tight. But who knows....

[Mopar1973Man]

Could you list places to get some of these tools like the torque multiplier and pullers and such?

[smokeythedodge]

Could you list places to get some of these tools like the torque multiplier and pullers and such?

You got it.

Snap on makes a great torque multiplier... BUT they are pricey!!!! The one I used came from Northerntool.com BUT it is an older one that has been discontinued... They do have another one that looks to be pretty good. About $179. Little expensive I know, but I have found it to be very useful on the farm on stuff like tractor lug nuts and dozer track bolts and such. LOVE it and you can disassemble it and grease all the planetary gears up real nice, should last forever if not overloaded!

The pullers, you can get them from sears.com. They sell a 2 pack of craftsman branded ones that are guaranteed forever which is always good! Or you can get them from Snap-on, mac, and similar... Make sure that it is has long teeth though! The seal on my dana 80 was HARD to pull because it was mostly rubber, have to really get a puller with long teeth to get in far enough to get to the metal part of the seal to pull it.

Torque wrench, just anywhere. I had a snap on but, it was stolen...... SO, because money is tight, I looked around a lot and found northerntool.com has some good prices as well as a lifetime warranty on theirs!! SO that is what I went with. Anybody have any other questions, feel free.

--- Update to the previous post...

Also, you need to check the pinion bearings for play. With the driveshaft removed and before you pull the nut or yoke, see if you can move the yoke and pinion up and down. If you can, then you are going to have to look into replacing the pinion bearings. They can get bad over time when the fluid level in the rear axle is low...... But if you keep up with fluid changes and stay on top of leaks you should be good to go! My seal failed because it simply wore out after 10 years... ALSO, check your axle vent tube for obstruction as well as the vent orfice on top of the axle, stick a pick in it and wiggle it around. One reason a pinion seal can fail is a plugged diff vent...

[dobienut]

Good right up, i'm sure it'll help someone out that's going to do this job. One thing I want to compliment you on is I see you have the jack stands under the housing...good to see that, to many people rely on the jack to hold the truck up. Hydraulics can fail , good to have a back up

[smokeythedodge]

Good right up, i'm sure it'll help someone out that's going to do this job. One thing I want to compliment you on is I see you have the jack stands under the housing...good to see that, to many people rely on the jack to hold the truck up. Hydraulics can fail , good to have a back up

Thanks, I hope it will help someone. Absolutely right about the jacks failing! Better safe than dead!

[KOYOTE]

:lmao:better safe than dead:lmao: do you oil or grease the seal before reinstalling the yoke or run it in dry?

[smokeythedodge]

Lil dab of gear lube on the lips. I have put them on dry before though and haven't had a problem.

[dually]

Did you pack the spring with grease?I do just in case, i dont want it to pop off when i install it.

[smokeythedodge]

Did you pack the spring with grease?I do just in case, i dont want it to pop off when i install it.

Good tip!

[hawkeye213]

Which spring are you refering to? I didn't see it mentioned anywhere in the write up.Thanks Rob

[Wild and Free]

Which spring are you refering to? I didn't see it mentioned anywhere in the write up. Thanks Rob

He was referring to the spring that is inside the lip of the seal. I have always just used a good 1/2 inch impact or a 3/4 impact to remove and install the yoke nut. About half the time I have to hold it with a Channel lock model 460 "My preference". Been doing it that way for many many years with no issues at all. But if you want to spend the time and money to get all those tools for a seal replacement have at it.

[smokeythedodge]

He was referring to the spring that is inside the lip of the seal. I have always just used a good 1/2 inch impact or a 3/4 impact to remove and install the yoke nut. About half the time I have to hold it with a Channel lock model 460 "My preference". Been doing it that way for many many years with no issues at all. But if you want to spend the time and money to get all those tools for a seal replacement have at it.

Sounds easy!!!! I don't know man, I've got a pretty sweet 1/2 inch impact gun, supposedly does 650 ft lbs and it wouldn't budge that nut. NO problem on a 10 bolt chevy rear end or a dana 70, all day long easy! But this thing is torqued to like 500 lbs on a dana 80 and its a nylock nut with green thread locker paste they put on at the factory. Sure, it's real nice if you have a 3/4 impact, that makes life a lot easier. Dana 70 torque is like 250 or thereabouts, Dana 80 torque is like 500 ish. What 1/2 impact do you use?? I want one

[Wild and Free]

I run only IR impact tools. 1/2 inch I have 2 231 IR guns rated at 600 ft lbs plus most places I have worked along with my personal compressor are always set over 125+psi. I have an IR 271 3/4un rated at I believe 1100 ft lbs. At work all we run are the IR Titanium guns and they are awesome also.. I will try it with the 1/2 and sometimes it will some times not then I grab the 3/4 and off it comes. If I didn't have access to my 3/4 then a little heat applied to the nut to melt out the nyloc and then the 1/2 takes them easily.

[smokeythedodge]

I run only IR impact tools. 1/2 inch I have 2 231 IR guns rated at 600 ft lbs plus most places I have worked along with my personal compressor are always set over 125+psi. I have an IR 271 3/4un rated at I believe 1100 ft lbs. At work all we run are the IR Titanium guns and they are awesome also.. I will try it with the 1/2 and sometimes it will some times not then I grab the 3/4 and off it comes. If I didn't have access to my 3/4 then a little heat applied to the nut to melt out the nyloc and then the 1/2 takes them easily.

Ah ok that is cool. I have the yellow IR one called the "thunder gun." What do you do about torquing it back down? Just guess?

[Wild and Free]

When the 1/2 inch gun won't move it anymore, Its torqued. There is no preload on the Dana setup, Its shimmed between the pinion bearing "unlike the crush sleave on Other brands of axles which sets the bearing preload" and with the nyloc nut once its tight to where its solid its plenty ok. After having done this for over 20 years and getting to know the torque capabilities of my guns and the hardware I am working with, 90% of it is just by feel. I have seen many old time techs assemble everything including engines without ever touching a torque wrench without any issues....................Mind you I have never done this except to get to the stretch point on a torque turn bolt on main and rod bearings where space/accessability were factors on some heavy equipment, but I still got the primary torque done with the tq wrench then gunned it to the propper turn angle for the stretch. The thunder gun is an awesome gun "If you like listening to the extremely excessive noise it makes." I worked with a couple guys who used them and both got rid of them for the titaniums as nobody could put up with the noise from them.

[hawkeye213]

I finally caught on to the spring in another thread. We tried and failed to get that nut off last night. Snapped the end right off a 3' 3/4 break over bar. LOL Guess I will go rent and impact gun. I called around about a renting a torgue multiplier but know one even knew what it was . Hell I had never heard of one till I read this thread. Oh well will git er done hopefully tonight.Thanks Rob

[smokeythedodge]

I finally caught on to the spring in another thread. We tried and failed to get that nut off last night. Snapped the end right off a 3' 3/4 break over bar. LOL Guess I will go rent and impact gun. I called around about a renting a torgue multiplier but know one even knew what it was . Hell I had never heard of one till I read this thread. Oh well will git er done hopefully tonight.

Thanks Rob

First time I did one, we had the truck up on the lift I broke or bent a drawer full of various 1/2 inch drive snap on breaker bars and ratchets, then put a 4 foot cheater pipe over a snap on 3/4" breaker bar, didn't budge... Had to call another guy over to help pull down on it before we snapped it. That thing is tight! I am going to have to get one of these beast impact gun's Wild and Free uses ^^^^

--- Update to the previous post...

When the 1/2 inch gun won't move it anymore, Its torqued. There is no preload on the Dana setup, Its shimmed between the pinion bearing "unlike the crush sleave on Other brands of axles which sets the bearing preload" and with the nyloc nut once its tight to where its solid its plenty ok. After having done this for over 20 years and getting to know the torque capabilities of my guns and the hardware I am working with, 90% of it is just by feel.

I have seen many old time techs assemble everything including engines without ever touching a torque wrench without any issues....................Mind you I have never done this except to get to the stretch point on a torque turn bolt on main and rod bearings where space/accessability were factors on some heavy equipment, but I still got the primary torque done with the tq wrench then gunned it to the propper turn angle for the stretch.

The thunder gun is an awesome gun "If you like listening to the extremely excessive noise it makes." I worked with a couple guys who used them and both got rid of them for the titaniums as nobody could put up with the noise from them.

Man it is awesome to have you on this site! Tons of real world experience! I'm just a kid though with tons to learn.... Got any suggestions for a good 3/4" impact gun?? I guess IR would be a good one? I have had awesome success with other IR tools. You are sooo right that thing is LOUD!!! *** *** *** *** it does good on about everything I have ever tried to use it on, except the dana 80 pinion nut....

[thebullet83]

i picked up a used torque multiplier a while back after i broke my 24" snap on 1/2" breaker bar. had to make a handle for it, but that thing makes short work of nuts! with my 150 ft/lb. torque wrench, i can pull 700ft/lbs on the fastener! and you have to lean into it a bit to get to 150 ft/lbs.