Question on differentials?

[BigPapa]

I was referring to the spreader.

You will need a set of setup bearings. I bought two sets of bearings and used a carbide burr to remove just enough of the inside race where it was a slip fit on the carrier.

 

[Ozymandias]

Don't underestimate that job, it needs some knowledge and especially you need to be able to lift that 60lbs differential Carrier out of the pumpkin - lying on your back. Don't hurt yourself. Be realistic.

 

[rotohead]

I know its a issue of preference, but new bearings require preload, thus the case spreader. I have a set of setup bearings (can be removed easily) i use then press on the permanent ones once I have the final shimming figured out.

I got it. Saves the in/out of the carrier to get the settings right. Good idea but I don't mind the repetitiveness for this one time. I've watched a number of utobe videos where I understand what you're doing to save time.

 

[BigPapa]

new bearings require preload, thus the case spreader.

Preload is created with the proper shims.

Y’all want to buy or rent a spreader, go for it.

 

[Ozymandias]

I was referring to the spreader.

You will need a set of setup bearings. I bought two sets of bearings and used a carbide burr to remove just enough of the inside race where it was a slip fit on the carrier.

I did it opposite - put the (bigger in diameter) shims outside of the bearings between case and race.
So the shim-load was easy to change till it matched.

 

[rotohead]

Don't underestimate that job, it needs some knowledge and especially you need to be able to lift that 60lbs differential Carrier out of the pumpkin - lying on your back. Don't hurt yourself. Be realistic.

I got it esp since I'm in a wheelchair. Ha!! I've figured out how to do things most people would think I'm crazy.

 

[jfmaz]

Preload is created with the proper shims.

Y’all want to buy or rent a spreader, go for it.

No disrespect intended, but the pre LOAD is accomplished when the case spreader is removed and the case returns to its original size. Otherwise you have to beat the crap out of the carrier to get it in. Yes it is determined by the correct shims. Used bearings are a different story
Also Dana 70 shims go between the bearing and the carrier, not the bearing and the case

 

[rotohead]

No disrespect intended, but the pre LOAD is accomplished when the case spreader is removed and the case returns to its original size. Otherwise you have to beat the crap out of the carrier to get it in. Yes it is determined by the correct shims. Used bearings are a different story
Also Dana 70 shims go between the bearing and the carrier, not the bearing and the case

so if I understand it if using the old bearings will allow a easier install but may not be the long term answer.

 

[Timd32]

This stuff is heavy! That's for sure. Agree on the don't underestimate this project, there is a lot too it. My little Dana 44, is nothing compared to a real LS Dana 70 or 80, not even close in weight and application.

The bigger the more precise it has to be.

The issue I see if the carrier changes you need to start from zero on your carrier measurements, I highly doubt you can start with your stock shim stack, but never hurts to start there.

There is a work sheet on where to start with the shims based on a few measurements, but it requires taking the pinion out, which adds alot more work, it all snowballs really....

A shop that does these knows all the tricks and has all the tools and knowledge to use them.

It's not a we can't do it, it was more of man I just want to drive my rig and enjoy it, I get tired of working on stuff endlessly.

This easily becomes an endless task, it can spiral failry quickly.

 

[rotohead]

This stuff is heavy! That's for sure. Agree on the don't underestimate this project, there is a lot too it. My little Dana 44, is nothing compared to a real LS Dana 70 or 80, not even close in weight and application.

The bigger the more precise it has to be.

The issue I see if the carrier changes you need to start from zero on your carrier measurements, I highly doubt you can start with your stock shim stack, but never hurts to start there.

There is a work sheet on where to start with the shims based on a few measurements, but it requires taking the pinion out, which adds alot more work, it all snowballs really....

A shop that does these knows all the tricks and has all the tools and knowledge to use them.

It's not a we can't do it, it was more of man I just want to drive my rig and enjoy it, I get tired of working on stuff endlessly.

This easily becomes an endless task, it can spiral failry quickly.

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As I get more into this and I read all your post here I'm deciding this is a hire out project. I have two or three shops in the area that have reasonable prices, I don't have to bother my friend for help, I can get it done in a week, I can go fishing when it's getting worked on, etc.
I appreciate all the input and advice. I've had this truck since new and been a member of TDR shortly after and never had a bigger value to any membership. Thank you all for these posts.

 

[Ozymandias]

FYI - I took a transmission apart and back together (46RE) before I moved on to set up a differential.
This is from my point of view the most difficult part on the drive train.

Just a little bit of by a thousand and you do it again, and again, and again, until it is totally messed up.
And every time you get 500 nice Miles in between that you think GREAT i did it because the new oil can mask a howling gear set nicely for some time... OMG, that Jeeps rear End drove me insane.....

 

[BigPapa]

No disrespect intended, but the pre LOAD is accomplished when the case spreader is removed and the case returns to its original size. Otherwise you have to beat the crap out of the carrier to get it in. Yes it is determined by the correct shims. Used bearings are a different story
Also Dana 70 shims go between the bearing and the carrier, not the bearing and the case

Wrong on the preload, spreader, and "beat beat the crap out of the carrier to get it in."

I know where the shims go. That's why you need the setup bearings.

Too much YouTube.....

 

[Timd32]

On the spreader, I have 3 rears to rebuild so I thought it would help, the Dana 44 the shim go under the bearings not behind the cups.

With this new style bearing puller it's 15 seconds to pop the carrier bearing after about 30 seconds of set up, maybe 2 minutes max if the tool is on the shelf, it's crazy once you use it.

They no longer make the Dana 44 set up bearings, you can buy a second set of bearing and enlarge them, but I also have a Dana 25 to do.

For just a second set of bearings to enlarge would be $73.96, the case spreader was $118.39, so a difference of $44.43, if I added the Dana 25 bearings they would exceed the cost of the spreader.

The spreader works nice on the bench and again it's pretty crazy how precise that thing is you can dial in the spread to the .001", it's almost zero work, the spreader is 40-45lb so it heavy.

For me it was not a huge cost item, but it's a gimmick for sure that you would not need for a one off, they show a 5lb dead blow to tap in the carrier which is easy peasy.

My Dana 44 is broken out on the PDF. Including tools, but missing the locker.

These should all work for the full series of Dana Rears, but read the descriptions.

Here is a photo of that bearing puller deal.

 

[Ozymandias]

I perfectly know that the shims are put between bearing and carrier at the factory - I just said that it is much more DIY friendly to put them between case and race.
The set-up is so much easier. Not everyone in the field has access to set-up bearings or a proper bearing puller, so the shortcut there is to change the position of the shims.
The factory has a whole different way of setting it up. They only measure the case in all three direction, then put all the needed shims on pinion and carrier and then simply drop in the whole unit - done. No second try needed there.
Something we can't accomplish in the field.

 

[Matt42]

After reading all of this thread, I am thrilled that my 1996 came from the factory with a LSD.

 

[LorenStrodtman]

I have a dana 70. Would I need a case spreader?

I have a 70U and I certainly didn't need a spreader - the carrier fell out once the caps were removed. Thankfully the rear sway bar was there to catch it.

The rear end in my truck is worn out, to say the least, but it does have new spider gears and the like.

For those saying the spreader is a gimmick, you'll have to explain why the FSM and even the DANA service manuals say to use one.

 

[Ozymandias]

Worn bearings = no preload.
No spreader? No preload.

Mexican Version? Beat the carrier in - preload accomplished. No spreader needed.

Just replace bearings? Same shims go back in as manufacturing tolerances of the bearings are a fraction of even the thinnest shim.

Change carrier? Start from scratch.

 

[Timd32]

I have a 70U and I certainly didn't need a spreader - the carrier fell out once the caps were removed. Thankfully the rear sway bar was there to catch it.

The rear end in my truck is worn out, to say the least, but it does have new spider gears and the like.

For those saying the spreader is a gimmick, you'll have to explain why the FSM and even the DANA service manuals say to use one.

Maybe gimmick was taken the wrong way, its stupid simple how these spreaders work you can basially almost spread it by hand once hooked up on my little Dana 44. There are often tools that to me are so simple and that's the gimmick part, if you did an infomercial on a spreader I'm not sure I would believe it.

But they also show using a 5lb soft dead blow when one is not available in the Torque King manual.

The Torque King book is a good read, it's cheap and provides a wealth of real world knowledge to the smaller shop / DIY person. They have pictures and descriptions of both methods. The person behind their manual is pretty amazing with the shared knowledge he provides on these differentials.

The spreaders work amazingly precise, you can dial in the spread to the .001", but for a single rear it's still a high cost for overall project budget for something you will use one time. If one was able to.borrow one local or do the free rental, I say grab it. I have a healthy tool budget so was easy purchase for me.