12 Valve Cummins Dana 70 Axle Seal Replacement

Here is a detailed video on how to change an axle seal on a Dand 70/71 axle typically found on a 1st gen cummins. Listed below are two tools that will make this job much easier!
Seal Puller ($17): amzn.to/35ZITGF
2 9/16" socket ($17): amzn.to/2HZmX68
Check out my website for merch and informational articles: www.decentgarage.com
Check out my other videos: / decent1stgen
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Contact Info
Email: [e-mail]
Address: PO Box 154, Payson UT, 84651
Instagram: decent_1st_gen
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#1stgencummins #cummins #DecentGarage

[@decentgarage]

What are some other tasks on these trucks you guys would like to see me do?

[@franklogan494]

Rear Drum to Disc Brake Conversion.

[@MikeSmith-nu9wt]

Let the truck decide , if it dont break everytime you use it , then come get mine , lots of content for ya ..lol

[@MikeSmith-nu9wt]

I got 7 to chose from , i wont miss it much ..

[@jorgemendoza5188]

No air in cab due to vacuum leak

[@wrightm707]

Thanks for the post. Doing an axle seal and new bearings on my ‘92 W250’s Dana 70 because I watched this video and learned for you. Thanks again!

[@decentgarage]

Glad it was helpful!

[@tomjohn4687]

Thanks bud, gave me a really good idea of what needs to be done on my 89 cummins

[@decentgarage]

Glad it was helpful 👍

[@matthewturan9343]

Great video. Getting ready to put new seals in my 92 w250

[@decentgarage]

Thanks! 👍

[@onthepin299]

Very informative 👏 made this job a breeze after watching!

[@andrewmccarthy4144]

Amazing how similar this is to my 1958 Dana 70, from a Dodge W300. Thank you!

[@decentgarage]

Very cool!

[@thepeeve]

Just a small tip, pour gear oil on the spindle and just wipe it over all of it and the seal mating surface. Helps it go together without risk of damaging the deal

[@brucerazor5202]

Thanks very professional

[@decentgarage]

Thanks Bruce!

[@HoosierDynamics]

Just did my rear pinion seal. I need to my axles seals next. Needless to say I don’t think my exhaust will rust for awhile. Highly recommend a pinion repair sleeve if you do yours.

[@decentgarage]

Noted.

[@OvensGarage]

Just watched your front & rear brake vids, as well as this. This will be a good guide for me when I go to do my brakes on Ol' Blue in a week or two. Just a tip for all, if you can get your hands on a race and seal driver kit from harbour freight/princess auto/amazon, they have the perfect size aluminum pieces to drive in seals..and if you are doing your wheel bearing races they work great for driving in the new races. Also used one of those seal pullers for the first time last time I did my seals on the red truck. They are a game changer...can't believe I used to struggle pulling those suckers out with vise grips..lol

[@decentgarage]

I'm looking forward to seeing your video

[@OvensGarage]

@@decentgarage If we make one! I like the idea of doing one side first to get the hang of it then record the other side ;) Got a heavy duty tie rod sleeve kit from NorthWestFab to replace the bent one on Ol' Blue too. Hoping that gets here within the next week.

[@decentgarage]

Yeah that was my first time doing that so i had to learn how first 😂

[@MarkShinnick]

Actually, a 2 1/2" 6 point will work just fine. I'm more a fanatic about bearing cleanliness, but you laid it all out there very nicely and EZ for the 70, thanks :)

[@decentgarage]

Thanks Mark 🙌

[@iandalton188]

Do you know where I can get that gasket that goes between that end cap on the axle and the hub?

[@TheRustyGarageandHomestead]

Hey Mr Tim im currently doing this same job.. At 8:25 you talk about torqueing the axle nut down to 80 ft lbs then backing it off 1/4 turn. I'm just curious where you found that spec. Or if it's differences in the years of the trucks. My 1993 dodge service manual says under the wheel bearing service pg 3-33 to torque the axle nut to 120-140 ft lbs then back off the adjusting nut 1/3 turn to provide 0.001-inch to 0.008-inch wheel bearing end play.

[@decentgarage]

Great question. I scoured the forums to find a concensus on that number. It seems that no one could agree so i went with this. You can't go wrong following the fsm though

[@RobertKohut]

Nice!!

[@decentgarage]

Thanks!

[@kveltman4672]

Thanks for the videos. After watching this one and your "Top 5 things to look for when buying a first gen" video, I can tell I will be watching more of videos. Question about the rear axle seal... How do you know when it's time to replace the bearings? Also, do you not need to put any gear lube in the hub when you replace the seals and/or bearings? Thanks for any tips you can offer.

[@decentgarage]

For the bearings I go by two things. If I clean the grease off and there is coloration from over heating I'll replace. I also check the races for scoring. The rear axle is lubricated by axle gear oil so no need to grease. 👍

[@kveltman4672]

@@decentgarage thank you very much for the rapid response! One more question, and I'll see if I can figure out how to post a picture to help with this. For the inside seal on the hub, drum brakes, does the large seal coming in from the back of the hub sit flush with the hub, or go past flush until it contacts the bearing?

[@decentgarage]

@@kveltman4672 flush with the hub 👍

[@NG1871]

In both this video and your brake job video, the hub assembly slides on and off easily. I fought to get my hub/bearings off and now and struggling to get it on. It appears the inner bearing takes a press fit to go back on- but. It’s not far enough to leave any spindle threads exposed to press it on. Did you have this problem or is there any truck to it? I assumed the bearings are correct. Although oddly the outer bearings slide on and off easily.

[@blakedelay149]

Hey I was wondering, my truck has the getrag 360, what is the highest I could go with upgrading the engine before I need to worry about the transmission getting problems

[@decentgarage]

I don't have much experience with the getrags. This crew cab that I just bought is my first getrag. Some people swear by them and some people say they are junk. Just depends on who you talk to.

[@grw707]

Hey Tim, do you think it necessary to check diff fluid to see if it’s run low?

[@decentgarage]

Absolutely necessary! Running it low on fluid or tow too much with it low and you'll end up with a solid welded diff that won't move.

[@paulweber6963]

Wish I'd stumbled on this video before learning through trial and error how to take my drums off! One question since you seem to know these machines. Mine doesn't have bolts holding the axel shaft in, they're shafts threaded on both ends (one end is fine, the other coarse) with a nut and conical spacer. Is that a different rear end, or just because mine's an '89?

[@decentgarage]

That is interesting. I'd have to hop on Google and do a lite searching.

[@lanajacknichols8397]

you have a semifloat axle mainly used on 1/2 ton trucks the free float axel in the video is used mainly on 3/4 ton and up trucks as well as nascar it can handle a lot more weight it's stronger ,and safer as well

[@taymDodge]

I'd like to see a video on changing the manual transmission fluid. I've read where guys add additional fluid from the top side of the shifter due to factory fill volume being inadequate. Have you tried this method or know a trick for over filling? Also, my inner and outer shifter boots are ripped, need to a replacement since OEM are unobtainable.

[@decentgarage]

I haven't done a manual tranny fluid change but, yes, I have also heard over and over that you need to over fill by 1-2 extra quarts through the shifter. For shift boots go check out stronghold shift boots. Best on the market and tons of options for color and stitching color.

[@taymDodge]

@@decentgarage ok, when I say inner and outer shifter boots, I'm talking about the rubber boots underneath the part you suggested. These boots are like the one on a CV joint. There is one on top of the trans(inner) and one that is on a square plate(outer). Then there is the one you recommended, so a total of 3 boots just on the trans shifter. I do actually need a new transfer case shifter boot, so thanks for the tip! Hopefully I can get some red stitching 😝

[@Valve-sb7ne]

You can fill it from under the truck, but it is a huge pain! I did it in mine, and it almost takes two people to do it, one to fill it, and the other to plug the hole once the fluid starts running out. It helps when you over fill it to park on the end of a slant, if lucky enough, at the end of your drive way(if it goes down at a slant). Make sure that the filler on the side is facing up of course. This is what I did when I changed mine.

[@iluvducttape1]

I put a brass 90 on my fill hole pointing up. This allowed me to put in an extra quart without having to pull the top cover off

[@taymDodge]

@@iluvducttape1 that is good to know, I was actually thinking last night if something like that would work! Thanks!

[@2eyedjack433]

I replaced the berring, seals, brake shoes and drums. After 2 months the passenger side is leaking. So I need to do it again... is there a different nut that you and retrofit it with instead of using the same nut with the little barbed holder? The plastic on the axle nut on mine has been changed a few time. Lol..

[@jasontruman1215]

Absolutely, any spindle nut for a dana 60/70/80 front or rear will work. I highly recommend stage 8 locking nuts (kinda spendy but bulletproof)

[@brycecook4000]

Dana 50/60 spindle lock nut. Part #10008

[@nynoperales6521]

I went to Napa to get the seals but they are smaller than the old ones

[@decentgarage]

That's weird. Sometimes the parts guys don't really think about what they are asking for and they just do what the computer tells them It's frustrating.

[@ronsre-creations5289]

Thumbs Up !

[@decentgarage]

To you as well!

[@lcpd696]

Where did you get the rear seals from I have a 91 Cummins needs new rear seals???

[@decentgarage]

I got mine from Napa. I dont recall the part number but they were Able to pull it up right off the computer

[@brucerazor5202]

I’ve gotta do that to my 99 dodge Cummins

[@decentgarage]

It's not a bad job

[@elibrown9442]

Yes you should replace the axle nut on the dually first gens since it’s a nylock style nut. Dana 70U

[@decentgarage]

Only on dually's?

[@elibrown9442]

Yes they are a 35 spline instead of a 32 and the axles are shorter but from research and with taking mine apart since I rebuilt my gears there is a nyloc style axle nut and they are becoming harder to find:/

[@sirridok]

@@elibrown9442 baught an e450 with chewed pinion..got it in pieces..are there no inner axle seals in the diff? Just at the wheels? So the axle tubes literally get filled via filling diff with oil? First rear end rebuild, dana 70 dually, thanks for any tips!

[@elibrown9442]

@@sirridok yea just the wheel seals,diff cover and pinion. When you fill the diff the axle tubes fill with oil as well. As a precaution I usually pack the bearings with bearing grease even if they get lubed with gear oil

[@sirridok]

@@elibrown9442 thanks brother!

[@sirridok]

So there's no inner axle seal inside the diff? On a dana 70 rear..?

[@decentgarage]

No, it's all open

[@sirridok]

@@decentgarage thanks

[@samueldesroches5210]

Is a d250 a dana 70 rear?

[@decentgarage]

Yes

[@topfuelr473]

Did you replace the brake shoes and clean the drum?

[@decentgarage]

I did that about 2 months ago.

[@topfuelr473]

@@decentgarage yes but now they are soaked with differential oil/grease. I had a GMC that had a seal that kept leaking on the right rear and every time I replaced the seal I put new shoes and use brake cleaner on the drum to get all that oil off. Finally got it to stop on the third seal.

[@decentgarage]

@@topfuelr473 oh gotcha, I cleaned them all up well with brake cleaner before I put the drum back on. Why'd your seal keep going out?

[@decentgarage]

I meant to mention cleaning them really well with brake clean! I'll add that note to the description.

[@topfuelr473]

@@decentgarage Probably not careful enough putting it back on the first time. The second time I cleaned everything real well and was careful putting the hub back on and that worked, no more leaks. Keep up the great videos, I like the info. One of my next challenges is the governor spring and fuel pin.

[@SkyR620]

I lost my entire drivers side axle a few months ago driving at about 55. Dang thing came loose and literally flew across the road and lets just say I wish I would have had those Depends on when it happened. I had just had the back brakes inspected and the "mechanic" used the old key when he put it back together. No bueno. Total failure. Maybe a vid that shows a replacement with a double nut locking axle nut and never worrying about that key again would be worthwhile?

[@decentgarage]

Dang! That would be horrible.

[@jimkillen1065]

OK been down this road . Yes absolutely do Not reuse the nylon nut . I recommend getting the I think Spicer don't know for sure part numbers double locking nuts and washer . My father use to be a Forman of a machine shop and I have his lathe and Bridgeport mill that was his personal equipment. When the nut come off it destroyed the end of the spindle . We went to a salvage yard and cut off the end of a axle housing . My father made a jig to hold the part straight while I welded it on . I welded at a power plant then . Basically you cut off the ends of housing and bevel the two parts . I used 6010 root . 7018 fill and cap . I weldeded the spindle on through the windows of the jig . . There are companies that do this to larger trucks . They all really have spindles made up . The repair worked well never had a problem with that . But I learned a lesson and how to repair the damaged rear diff . This was on a first Gen dodge diesel but my 95 has those single Nylock nut

[@claytonpollard220]

that inner bearing sounded bad, or is hat just me?

[@decentgarage]

It was good.

[@franklogan494]

Great Video's, But Please Use Safety Stands, Your Family and Viewer's want you around for a long time. Safety First!!

[@decentgarage]

Thank you, I will

[@franklogan494]

@@decentgarage Your welcome.

[@b4aftermatch257]

great job on the Dana 70 I just try not to watch the DIY guys without jack stands or something between you and the ground when the Hydro Jack fail just ask OSHA on how many got hurt and are not around atleast push the tire removed under the Diff.. its just a thought

[@decentgarage]

Good point. I'll keep an eye out for that