Blew my dana 35

[Warren99]

Happened a few weeks ago but I blew my rear diff doing dumb things lmao. I went and got a whole axle from a 94 xj and will swap the guts sometime soon. I've never worked on a diff before but I should have some help. Regardless if theres anything useful to know about these specfically please let me know. Thanks!

[Pete M]

but... why would you swap guts instead of swapping out the entire axle for something that will survive your... life choices. 

[89 MJ]

I personally don’t love the idea of swapping used differential parts. I was told that if the parts aren’t wearing the same as they were in their original differential, they’ll howl and wear quicker. 
 

I'd look at an 8.8 out of an Explorer Sport Trac, an XJ 8.25, or an MJ or XJ Dana 44. They are all more work, but at least it’ll live. 

[ghetdjc320]

23 minutes ago, 89 MJ said:

I personally don’t love the idea of swapping used differential parts. I was told that if the parts aren’t wearing the same as they were in their original differential, they’ll howl and wear quicker. 
 

I'd look at an 8.8 out of an Explorer Sport Trac, an XJ 8.25, or an MJ or XJ Dana 44. They are all more work, but at least it’ll live. 

 

another option is a KJ 8.25. But why not swap the whole axle from the YJ you got? It should be close to bolt in for an MJ

[Pete M]

is it just the spiders that blew?  or is the ring/pinion affected too?

[TurboedMJ]

Put something stronger in, or it will just break again. 

[Big_Mark]

DANA 60 time!!

 

LOL jk

 

I agree with the others, definitely swap in a whole new axle, or waste time and money trying to patch together what you have.

[gogmorgo]

As someone who has sunk money into rebuilding a Dana 35, I recommend doing not that. I had something else going on the second time it failed in my ZJ and needed a full rebuild and it was less time and effort for me to rebuild a second time. Ditto on the third rebuild. So far it’s holding on but I’m not rebuilding it again. If a swap isn’t on the table I would still try finding a decent used axle, and put new bearings and seals in that before rebuilding the same housing again with all new gears. 
 

If you’re just swapping the carrier and reusing the MJ’s gear set, it shouldn’t be too big a deal. Get a dial indicator and measure your gear lash before pulling the MJ’s carrier, keep track of any shims when you disassemble it, (you might find them under the bearing cup on the housing or between carrier and bearing cone) and make sure they go back in the exact same place. Measure the lash again and make sure it’s the same.

 

If you’re trying to reuse the XJ’s gear set, this is complicated. You don’t really want to wear a second pattern into the used gears. To do it “correctly” you would need to measure lash and then pinion depth in the XJ (this requires $$$ specialized tools), get the pinion depth exactly the same in the MJ, and then get the lash set exactly the same as the XJ.

You can get reasonably close just using gear marking compound and replicating the XJ’s contact pattern in the MJ, but you likely won’t get it perfect. And the result of a new wear pattern is that any high spots in the old pattern will wear off quickly in the new pattern, massively increasing gear lash and flooding your diff with bearing-eating chunks of metal. No guarantees it’ll blow up, but I wouldn’t do it for a diff I want to get more than 10k miles out of. Its a game of thousandths of an inch, and it doesn’t take a lot of error to end up with a poorly performing contact pattern. 

 

But the small stuff, while you’ve got it apart clean everything as best as you can to get any random chunks of metal out of there. Change every bearing and seal you can while you’re in there, make sure there’s no damage to the bearing surfaces on the axle shafts, give every bearing a healthy bath of oil before it goes in and wipe some on the seals, RTV on the pinion yoke splines to seal them, and use a new lock nut on the pinion and loctite it or it will back off on you. You also probably want a new crush sleeve on your pinion if it’s not going back into the same housing it came out of. 

[Drahcir495]

Gogmorgo is always a great source of knowledge for all things mechanical. Just follow what he explains above 

[Warren99]

Thank you all but I should have clarified, I do plan to upgrade both axles in the future at the same time when I swap my mercedes' om606 TD. I'm aiming for around 300hp and not planning on doing any super crazy rock crawling or anything so I figured dana44 front and rear should work good, just not yet sure the best kinds to get.

 

I daily my 98 e300 td, but I'm still basically just trying to get my truck back and moving as cheap and easy as possible, thats why I went and got the first dana35 I saw from a junkyard. I know the proper way to do things would be to just start with a fresh diff but, as I said, I just wanna throw this together as cheap as possible, and it only has to last for a little while until I have the money to build and swap my engine and get better axles.

 

With that being said, I had my diffs apart today and discovered that my trucks diff(keep in mind my trucks axles aren't original, they came from some XJ some years ago) is a non-c-clip type, but the donor axle was a c-clip axle. Also, my spyder gears where what blew up, but the ring and pinion are unphased so we tried just taking the gears from the donor axle and putting those in the original carrier but they are ever so slightly different and won't fit. What I think I may do is see if I can find just the spider gears for sale somewhere, or just go back to the junkyard and search for some from there.

[Warren99]

[89 MJ]

46 minutes ago, Warren99 said:

Thank you all but I should have clarified, I do plan to upgrade both axles in the future at the same time when I swap my mercedes' om606 TD. I'm aiming for around 300hp and not planning on doing any super crazy rock crawling or anything so I figured dana44 front and rear should work good, just not yet sure the best kinds to get.

You don't need a D44 for the front with that diesel. My dad's old YJ (LS, stick, 35s, 4.10 gears) was romped on pretty hard in 4 wheel drive and the stock D30 lived with no problems. That's not helpful for the time being, but I figured I'd let you know.

[Warren99]

17 minutes ago, 89 MJ said:

You don't need a D44 for the front with that diesel. My dad's old YJ (LS, stick, 35s, 4.10 gears) was romped on pretty hard in 4 wheel drive and the stock D30 lived with no problems. That's not helpful for the time being, but I figured I'd let you know.

Ah ok, I mean if I find one I may swap it just for the peace of mind, and also I wouldn't wanna put much money into a dana 30 for a locker and CAD delete kit.

[Pete M]

late model d30 with the bigger ujoints is nearly as strong as a 44.  pair that with a liberty 8.25 and go nuts.    the 98 ZJs with the 5.9 had a dana 30 front.  low pinion at that. 

[Warren99]

9 hours ago, Pete M said:

late model d30 with the bigger ujoints is nearly as strong as a 44.  pair that with a liberty 8.25 and go nuts.    the 98 ZJs with the 5.9 had a dana 30 front.  low pinion at that. 

I thought low pinions were less desirable? Not sure if it has to do with strength or ground clearance but I had the impression that high pinion was always better

[Pete M]

1 hour ago, Warren99 said:

I thought low pinions were less desirable? Not sure if it has to do with strength or ground clearance but I had the impression that high pinion was always better

 

 

it is.   I mention it because the low pinion 30 was strong enough that the factory put it behind a 5.9 v8   

[gogmorgo]

I mean that’s not saying a ton, the ZJ only came with a D35 for the first couple years even with the 5.2.

[derf]

6 hours ago, Warren99 said:

I thought low pinions were less desirable? Not sure if it has to do with strength or ground clearance but I had the impression that high pinion was always better

All of the above.

 

High pinion is less likely to drag on things.

 

Low pinion is driving the coast side of the ring gear, which is not desirable. 

 

High pinion gives you a better front driveshaft angle.

 

Sure, Jeep put it in front of a 5.9.  But that doesn't mean it was a good idea.

[Warren99]

Ah ok thank you

[ExpatMJGuy]

Since we're on axle topics I'm hunting an a front Axle for a 4wd conversion.  I'm finding some conflicting information when it comes to axles used.  I don't remember where I found this but I've held onto this screen shot for a long time.  But I just read from somewhere else a blanket statement that the MJ shipped with 3.55 gearing.  What is the truth here?  My MJ is an 88 Manual with the 4.0L so I was thinking I was looking for a 3.07 axle.  3.55 would be nice... There's a lot more of them out there.

 

[gogmorgo]

The chart you’re looking at is reasonably accurate for both XJ and MJ. There are a few exceptions, of course, but they’re not common, and usually the result of a swap.

The one thing that’s missing from the list, the 2.5 was available both with a four-speed and five-speed manual transmission, the AX4 and AX5 respectively. The AX4 would come with 3.55 gears and the AX5 with 4.10. I suspect that’s what that blanket statement is referencing but sometimes information available online is simply not accurate. 
 

[89 MJ]

25 minutes ago, gogmorgo said:

The chart you’re looking at is reasonably accurate for both XJ and MJ. There are a few exceptions, of course, but they’re not common, and usually the result of a swap.

The one thing that’s missing from the list, the 2.5 was available both with a four-speed and five-speed manual transmission, the AX4 and AX5 respectively. The AX4 would come with 3.55 gears and the AX5 with 4.10. I suspect that’s what that blanket statement is referencing but sometimes information available online is simply not accurate. 
 

This, plus some 84-86 2.5s with 5 speeds came with 3.73s. 

[Warren99]

My 2wd 89 MJ with a 4.0 and the ba/10 5 speed came with 3.07s

[jpnjake]

@ExpatMJGuy
Here’s a chart my dad made back in the day using factory books and lots of research, only factory 3.73 gears came in 84-86 Trucks 

 

[Warren99]

Returned the c clip axle to the junkyard, and found a bunch of other c clips, seems like a non c clip dana 35 is like 87-89 or something. Regardless, took the destroyed side and spider gears plus some 1/4 inch steel plates and welded the diff, so far it's held up.