help to identify a front differential

[Ironlung1948]

good stuff. I'll check it out and keep you posted . I understand the limitations to the d30 but i dont plan on going off road really. Also I have 2 extra D30 axels from a old bronco laying out back as well. So silly question, if I need a full rebuild does that include the locker ? ( do i have a locker ?)

 

[DirtDonk]

good stuff. I'll check it out and keep you posted. I understand the limitations to the d30 but i dont plan on going off road really. Also I have 2 extra D30 axels from a old bronco laying out back as well.

Then you're probably good for now, unless you find out the housing is buggered as well. But that's a whole nutha thing...

So silly question, if I need a full rebuild does that include the locker?

Not usually, but there might be kits around that have everything. Just too many options for each, so what you normally get are:

1. The ring and pinion gear sets. In whatever ratio you choose.
2. The rebuild "kit" that usually just includes the things you need for a standard rebuild, like bearings, races, seals, shims, new ring-gear bolts, and maybe some setup liquids and sealants and thread locking compounds.
3. The carrier. Whether open, limited-slip, or locking. Up to you and there are literally dozens of companies that make them. Most of which offer at least something for the Dana 30.

You don't always need a new carrier, and most that already have a locker or limited-slip are just changing their gear ratios or replacing buggered parts. Not replacing the carrier.
Even you might not need a new one.

( do i have a locker ?)

No. You have what is called a Limited-Slip.
Unfortunately most of the manufacturers used some variation of the word "lock" in their company's product's names. From "loc" to "lock" to "lok" and whatever else they could think of to be cute.
But other than the GM Gov-Lok which does lock up after a certain amount of spin, they're all just simple limited-slip diffs.

This particular model you have uses clutches and springs and things to try to transfer torque to both wheels even if one wheel is spinning in slippery conditions. Some use a crazy arrangement of bevel gears (or whatever they might be called) and another uses clutches in the shape of cones rather than flat materials. But they're still called "limited-slip" differentials because they don't literally lock the two side's axle shafts together as one.

A locker does just that. It uses some manner of dog tooth parts, levers acting on centrifugal force, or whatever.
Some are what we call "set and forget" types, such as the old Detroit Locker, and some are "selectable" where you push a button, pull a knob, or move a lever to lock things together.

The final type is a spool, which with it's splines and solid body, keep both axle shafts always locked. This is mostly for racing, because it's simple and functional. It's less expensive too.

Most of the selectable lockers that I'm aware of are either fully open, or full spools and not normal lockers. The ARB air locker is like this.
So with all those choices, there are probably not going to be any "kits" out there that have it all. But hey, someone may put them together upon request and you just get it all in one stop.
But most of us sell the individual pieces based on what you want in each category.

Paul

 

[Ironlung1948]

If you look close in the pics you could see where there was a broken bolt or lease where it looks like it. In the 6 o’clock position. Since there’s no hole in the cover in that location, I assume it’s a broken bolt or where someone welded the broken Bolt and there was some imperfection left. 30s for some reason we’re notorious for breaking cover bolts. That’s my guess – broke a cover of old, welded in the bolt and ground smooth and welded said hole in cover.

You were correct sir. After cleaning it off more , a broken bolt was noted in the thread and filed down to make it flush . Ill have to take it to a machine shop to burrow it out

 

[Ironlung1948]

Then you're probably good for now, unless you find out the housing is buggered as well. But that's a whole nutha thing...



Not usually, but there might be kits around that have everything. Just too many options for each, so what you normally get are:

1. The ring and pinion gear sets. In whatever ratio you choose.
2. The rebuild "kit" that usually just includes the things you need for a standard rebuild, like bearings, races, seals, shims, new ring-gear bolts, and maybe some setup liquids and sealants and thread locking compounds.
3. The carrier. Whether open, limited-slip, or locking. Up to you and there are literally dozens of companies that make them. Most of which offer at least something for the Dana 30.

You don't always need a new carrier, and most that already have a locker or limited-slip are just changing their gear ratios or replacing buggered parts. Not replacing the carrier.
Even you might not need a new one.



No. You have what is called a Limited-Slip.
Unfortunately most of the manufacturers used some variation of the word "lock" in their company's product's names. From "loc" to "lock" to "lok" and whatever else they could think of to be cute.
But other than the GM Gov-Lok which does lock up after a certain amount of spin, they're all just simple limited-slip diffs.

This particular model you have uses clutches and springs and things to try to transfer torque to both wheels even if one wheel is spinning in slippery conditions. Some use a crazy arrangement of bevel gears (or whatever they might be called) and another uses clutches in the shape of cones rather than flat materials. But they're still called "limited-slip" differentials because they don't literally lock the two side's axle shafts together as one.

A locker does just that. It uses some manner of dog tooth parts, levers acting on centrifugal force, or whatever.
Some are what we call "set and forget" types, such as the old Detroit Locker, and some are "selectable" where you push a button, pull a knob, or move a lever to lock things together.

The final type is a spool, which with it's splines and solid body, keep both axle shafts always locked. This is mostly for racing, because it's simple and functional. It's less expensive too.

Most of the selectable lockers that I'm aware of are either fully open, or full spools and not normal lockers. The ARB air locker is like this.
So with all those choices, there are probably not going to be any "kits" out there that have it all. But hey, someone may put them together upon request and you just get it all in one stop.
But most of us sell the individual pieces based on what you want in each category.

Paul

Great information thank you. I pulled out my carrier and took it to 4wp to have it serviced. The service department agreed that it would be foolish to not replace the case or limited slip. option 1 was to replace with a Eaton Trutrac limit slip for $450 or a detroit locker for alittle over $600. Or I can provide the part myself if I chose. are these good brands ?

 

[DirtDonk]

Both are made by Eaton (nowadays anyway, after several corporate purchases over the decades), and both are considered to be among the best at what they do.
But I have to ask, because I don't think we've discussed it yet, just what are you planning to do with this Bronco?
Reason I ask is that it can determine which way you go.

Personally I would almost always go with the Truetrac, especially in the front. A full locker like the Detroit is pretty severe in it's action, and leads to very funky steering action when you're in 4wd.

If you're not going to be doing any serious four-wheeling (and I mean "serious") why would you put a full locker in the front diff? You normally would not.
So if you need anything at all, which most of us don't, go with the Trutrac. And that's not really a horrible price for it either.

My personal opinion is that you're not increasing the value of the vehicle by putting any kind of a traction-aiding device in the differentials. Not for most buyers these days.
And if it's just for you, and you're not planning any off-road adventures (and even if you are) you can easily get away with a standard open differential you could probably get for under $100 bucks. If not for free when someone swaps in a locker!

Being in Cleveland, you may want the four-wheel drive for inclement weather. That's a good reason, but you have to decide if the ups outweigh the downs in driving an old 4wd rig with a limited-slip in the front.
It's nice to have all four wheels trying to do their job when the going gets tough and icy and snowy and muddy and all, but ask those that own them if they always appreciate it when all four tires are sliding!

I'm not an expert on that subject, which is why I bring it up. My four-wheeling is mostly in perfect weather on rocks and dirt roads. So a locker is not in the cards, and I much prefer a limited-slip.
But I've always wheeled with an open front diff, because that's what mine had. And I'm cheap!

Good luck.
But wait for more opinions on this important subject.

Paul

 

[Broncobowsher]

Way back at the start of this thread you said the 30 was fine because you were not really going to use 4WD. With that in mind I wouldn't spend that kind of money. Just run an open diff.

The Detroit being a bit severe is true. It will turn tires or turn expensive parts into scrap metal. The teeth already popped off the existing 30, more traction will be even more stress. And if that lives, the U-joints in the axles won't.

The true trac is the best modern limited slip there is. But if you are going to sink this kind of money into an axle, start with a 44.

I keep looking at you are determined to sink as much money into a low value axle as possible. You don't have to keep that axle.

 

[Ironlung1948]

Both are made by Eaton (nowadays anyway, after several corporate purchases over the decades), and both are considered to be among the best at what they do.
But I have to ask, because I don't think we've discussed it yet, just what are you planning to do with this Bronco?
Reason I ask is that it can determine which way you go.

Personally I would almost always go with the Truetrac, especially in the front. A full locker like the Detroit is pretty severe in it's action, and leads to very funky steering action when you're in 4wd.

If you're not going to be doing any serious four-wheeling (and I mean "serious") why would you put a full locker in the front diff? You normally would not.
So if you need anything at all, which most of us don't, go with the Trutrac. And that's not really a horrible price for it either.

My personal opinion is that you're not increasing the value of the vehicle by putting any kind of a traction-aiding device in the differentials. Not for most buyers these days.
And if it's just for you, and you're not planning any off-road adventures (and even if you are) you can easily get away with a standard open differential you could probably get for under $100 bucks. If not for free when someone swaps in a locker!

Being in Cleveland, you may want the four-wheel drive for inclement weather. That's a good reason, but you have to decide if the ups outweigh the downs in driving an old 4wd rig with a limited-slip in the front.
It's nice to have all four wheels trying to do their job when the going gets tough and icy and snowy and muddy and all, but ask those that own them if they always appreciate it when all four tires are sliding!

I'm not an expert on that subject, which is why I bring it up. My four-wheeling is mostly in perfect weather on rocks and dirt roads. So a locker is not in the cards, and I much prefer a limited-slip.
But I've always wheeled with an open front diff, because that's what mine had. And I'm cheap!

Good luck.
But wait for more opinions on this important subject.

Paul

What I plan on doing with it is to use it as a second daily driver to and fro work . Not doing any 'Serious' off roading at all. however We rent a beach house in N.C for a week every summer and we typically rent a 4x4 when we go so the bronco would serve that purpose. The second trip is once a week for hunting season in Northern Michigan mostly driving through woods but depending on the weather it would be heavy snow or no snow at all . Besides those two trips i'm driving like a granny ( with the top off . I want to keep the truck as original / stock looking as possible. I do not plan on selling it.

Another question that arose the other night is my rear differential. From my limited knowledge it looks like I have a 9" ford rear. I have no idea if the rear needs rebuilding or if putting a open diff in the front would pose problems if the rear is a limited diff ?

( btw my dana 30 gear ratio is 42/12 so 3.5)

Im not at all opposed to an open differential especially at that price point. Infact I dont think the service department even gave me the option for an open diff. my only hesitation is getting stuck in a rut on the beach or in mud when I do want to 'off road' it otherwise the only real obstacle i'd face on a day to day are north east ohio right turns and random weather changes. ( first world problems )

 

[Ironlung1948]

Way back at the start of this thread you said the 30 was fine because you were not really going to use 4WD. With that in mind I wouldn't spend that kind of money. Just run an open diff.


I did not realize the detroit locker was that aggressive.

Are you saying that If I run an open diff , I am unable to utilize the 4wd on the truck ?

 

[Broncobowsher]

No.

An open diff is completely acceptable in your application. That is a normal differential without any limited slip or locker function. It is how the majority of the vehicles are built. Including heavy equipment and tractors. My 4WD tractor has an open front differential and it works perfect. The 4WD is needed and gets used.

The downfall for an open differential is in hard off-roading. Where you get crossed up, one tire in the air or in a no-traction situation. Doesn't sound like you are planning any of that. The open differential is the most drivable on the street as well, no fighting side to side. Just driving on a snowy road or getting up a grassy hill in a field an open diff will work fine.

 

[DirtDonk]

You have an interesting situation Ironlung. And a dilemma in the making.
For street driving, the open differentials are best. And why most manufacturers even to this day use that as their standard. Basically it's seamless driving and no funny business.
Modern vehicles that do use some sort of limited-slip or locking differentials usually control them with the computer with the help of sensors, so not really comparable to what we're dealing with here.

But you need yours to do literally double duty. Which means that, in terms of older vehicles, you're going to have to compromise one way or the other.
On the sand you can easily run into situations where all four wheels MUST be working for you. On the trails and dirt roads, they might come in handy every once in a blue moon, but when they are needed it's very nice to have.
On an unimproved hunting trail that might get ugly due to inclement weather and natural wear and tear, and variations in terrain, having all four wheels capable of transmitting engine torque to the ground might be the difference between getting out, and getting stuck.

For the street, a full locker in a short wheelbase vehicle like a Bronco is not all that friendly. Yes, you can get used to it, and no it's not automatically dangerous. But will it be just you driving it, or will other people with less driving-savvy be sharing in the vehicle fun?
Many members here will tell you that you'll never notice a full locker like the Detroit in the back. Well, all I can say is "your results may vary" and leave it at that for now.
The exception are selectable lockers like ARB Air Lockers, E-Lockers and the like.

So yes, a Detroit is that aggressive.
And yes, with an open diff you will often have only truly 2-wheels at any given time doing the work. We call them "one-leggers" when one side can be allowed to slip.
Sometimes both tires on an open-diff axle will deliver torque, but give enough slip to one tire (put one side in the mud or ice, and one side on the road and you know what I'm talking about. Or watch the final half-hour of "My Cousin Vinny" for that classic courtroom scene!;D ) and you will be left with one side spinning freely and one side doing nothing.

The best compromise in my opinion is the Truetrac at both ends. In most situations (other than very slippery roads) you will likely never know a limited-slip is doing it's thing in the diff. And when off road and in loose traction situations, they may be just enough to get you through.

Selectables are the best of both worlds, but are more expensive (not necessarily a reason to avoid them) add complexity in the form of more wiring, more plumbing for air and a compressor (with ARB's) and control levers and buttons that don't look stock.
So the last bit is simply by way of not looking all that stock anymore, if that's enough to sway you.

But I would definitely not recommend a full locker at either end from what I'm reading of your expectations.
Other's opinions may vary...%)

Paul

 

[Broncobowsher]

Remember, how much money is wise to invest in a Bronco Dana 30?
A good limited slip can cost more then the complete rebuilt axle is worth on a good day.

 

[Ironlung1948]

Remember, how much money is wise to invest in a Bronco Dana 30?
A good limited slip can cost more then the complete rebuilt axle is worth on a good day.

I understand a dana 30 is weaker but given my application will it matter really ?

Also I can't find anywhere a EB dana 44 front axel rebuilt let alone one reasonably priced. TBP has fully rebuilt dana 44 with disc brakes for a crazy $3500 . Im not opposed to swapping my front axel but I cant seem to find any locally so im growing content with the d30.

 

[Broncobowsher]

good stuff. I'll check it out and keep you posted . I understand the limitations to the d30 but i dont plan on going off road really. Also I have 2 extra D30 axels from a old bronco laying out back as well. So silly question, if I need a full rebuild does that include the locker ? ( do i have a locker ?)

Why not just use one of those?

 

[gnpenning]

Another option you have for your hunting trips is to carry tire chains. Far cheaper and only used when you need them. It's amazing how much difference you will notice on ice and deep snow.

Sounds like for your use the money would be better spent on something other than a locker.