D44 going in! Few axle strengh questions...

[Cody]

You're right that weight and power are a huge part of the equation, but I still think that if you are breaking toy axle parts, you're going to be breaking 44 parts too. I just don't see that much difference in strength between a toy 8 and a 44.

I can understand your situation greg, but I think you would agree that for your runner, a toy axle with superbirfs would have been plenty strong as well, and it would have cost less and been less of a pain to put in the super birfs than it would have been to swap in a 44.

the width could be a consideration for some though. I'm not sure how wide you can get on a toy axle with some wheels with very low offset.

 

[rholbrook]

I have an Aussie in my TJ and have broken axles with no affect to the locker. Its like any other auto-locker where you need to have baby hands and fingers to take it appart and put it back together if you bust an axle. Maybe its because I have to take it apart to remove the #*&^& c-clips. On the trail I can replace a broken axle in 45 minutes and most of that time is because I have sausage fingers. Anyway, the locker is not as quiet as Aussie claims and it is sloppier than I would like. Aussie claims that my backlash, etc is not correct but it is and it still has a lot of play in it. I guess you get what you pay for, I will be replacing my D35 with a D44 and then I will put a selectable locker in so it won't matter then.

 

[ID Bronco]

With Chromo's a 44 can hold up very well. I never changed a bunch of shafts with 38-39" tires on the Bronco, but after the first failure I just spent the money on Yukons. I am not very crazy, but I have wheeled some good trails with good results. A 60 is always in the back of my mind and probably would have been the best way to go.....as I think about it, anyone want to buy a great 44/9" set up for an early bronco? lol

 

[Cody]

Chromo's are great, but I think you can buy a 60 for the same cost as buying a 44 and then buying chromo shafts.

 

[ChestonScout]

I recently broke a front chromo on my 60. It was a cool break and I thought the Detroit would have went to.

The splines twisted a ton! We couldnt get the broken piece out of the Detroit so I had to pull it out. I got the broke piece out and to my surprise the splines were not twisted at all inside. The chromo broke right where it sits in the detroit. So....decided to tear the detroit down to check it. Gears stil look new! So a broken shaft does not mean a broken detroit. I wont say it cant happen but its not going to be every time.

Having said that....I did blow a side gear out of the same detroit when i first got it. It was its first trip out! I think I had a defective piece from the looks of the break. No broken shaft....just detroit. I just rebuilt it myself and it has been perfect since. I think that was 2 years ago.

 

[Greg]

You're right that weight and power are a huge part of the equation, but I still think that if you are breaking toy axle parts, you're going to be breaking 44 parts too. I just don't see that much difference in strength between a toy 8 and a 44.

I can understand your situation greg, but I think you would agree that for your runner, a toy axle with superbirfs would have been plenty strong as well, and it would have cost less and been less of a pain to put in the super birfs than it would have been to swap in a 44.

the width could be a consideration for some though. I'm not sure how wide you can get on a toy axle with some wheels with very low offset.

Stock to stock a Dana 44 is stronger than a Toyota mini truck axle, I'd guess as much as 40% or so. Stock Birfields are notoriously weak around the ouside of the Bell. Toss a locker in and you're breaking Birfs with small tires.

From what Andrew said in the first post, and since this thread is about his Toyota, he doesn't have money for chromo shafts (or Longfields apparently). A Dana 44 under his Toyota with stock shafts & joints on 35's will get him by until he's ready to upgrade. If he wants to run 37's, then upgrade the shafts.

For my 4Runner, the Dana 44 is what I wanted. My original plan for the 4Runner was a dual purpose rig with 35" tires max. Stability was the priority, not strength. I didn't want 3" spacers, huge offset wheels, etc. I'd been down that road before and wanted something different and I was very happy with my Dana 44. Once I ditched my original plan and bolted on the 38's, everything changed.

Longfields are awesome, hands down the best upgrade for strength in a Toy axle. I'm not debating that they're not.

 

[leorn]

Longfield results for refernce...

I know most of you have seen this, but for reference if you trust the Longfield machine for information on axle/component strength it shows:
PRODUCT ...................................... FT.LB. TORQUE / DEGREE TWIST

Yukon 4340 Dana 60 35 spline short side axle ...12,000 / 130
Stock Dana 60 35 spline short side axle ............6,500 / 35

Yukon 4340 Dana 44 30 spline short side axle ....5,800 / 35
Stock dana 44 30 spline ................................5,000 / 35

Longfield 4340 30 spline (shaft failure) .............8,500 / 175
Longfield 4340 27 spline ................................6,500 / 75

Stock Toyota Birfield ....................................4,200 / 45
Stock Toyota Inner Axle ...............................5,000 / 45

Stock Toyota Hub .......................................5,800/
Longfield Treated Toy Hub ............................6,800/

found here http://www.pirate4x4.com/forum/showthread.php?t=467075

 

[Cody]

are the longfields more expensive than buying a 44 and setting it up for the toyota? it seems like gears/locker/wheels to match or adapters, consumables etc etc would add up to more than what longfields are. I guess I really haven't priced them.

 

[Greg]

I know most of you have seen this, but for reference if you trust the Longfield machine for information on axle/component strength it shows:
PRODUCT ...................................... FT.LB. TORQUE / DEGREE TWIST

Yukon 4340 Dana 60 35 spline short side axle ...12,000 / 130
Stock Dana 60 35 spline short side axle ............6,500 / 35

Yukon 4340 Dana 44 30 spline short side axle ....5,800 / 35
Stock dana 44 30 spline ................................5,000 / 35

Longfield 4340 30 spline (shaft failure) .............8,500 / 175
Longfield 4340 27 spline ................................6,500 / 75

Stock Toyota Birfield ....................................4,200 / 45
Stock Toyota Inner Axle ...............................5,000 / 45

Stock Toyota Hub .......................................5,800/
Longfield Treated Toy Hub ............................6,800/

found here http://www.pirate4x4.com/forum/showthread.php?t=467075

I'm curious if that includes the angle of the u-joint, as if the front wheels were turning. Everything is stronger straight, but when turned u-joints and Birfs both get weaker. IMO the Birfs are weaker stock to stock, that's why Bobby Longs idea of welding a ring to stock birfs took off & they became Super Birfs. I'd like to see breakage numbers on both Dana & Toyota shaft & joint assembly's breakage while turning.

are the longfields more expensive than buying a 44 and setting it up for the toyota? it seems like gears/locker/wheels to match or adapters, consumables etc etc would add up to more than what longfields are. I guess I really haven't priced them.

Bolt pattern is the same on Toyota as GM or Waggy axles, 6x5.5... no adapters or different wheels needed. Lockers cost about the same, so do gears. I also liked how my Dana 44 turned tighter than my old Toyota axle.

 

[Cody]

ya, but you didn't have a toy axle already in place to start with so you don't count.

I guess my opinion is based on the abuse that Kell Smith and Olli and others have put on alloy superbirfs, abuse that I know would have kasploded my 44.

 

[Greg]

ya, but you didn't have a toy axle already in place to start with so you don't count.

I guess my opinion is based on the abuse that Kell Smith and Olli and others have put on alloy superbirfs, abuse that I know would have kasploded my 44.

Your 44 with alloy shafts? What u-joints were you running?

 

[Rot Box]

I spent a long time debating this swap and here are a few key factors in my desicion making. Keep in mind my Toyota axle was all stock aside from a bigger tie rod and the Z-bar.

I hate the stock width of the Toyota axle. I have 2" spacers and although the width was ok they really took their toll on my steering.

I needed hi-steer bad, but after having seen almost everyone I know bust off the typical 4 stud style at least twice I knew I would have to spend the $650 on 6 shooters (or spend time making the still iffy 5 stud upgrade) if I planned on a front locker and 37's. Also the FJ80 rod ends have nothing on the 1 ton GM's that I'll be using for size and strength imo. The Reid kuckles I have will also make for a stonger Hi-steer arm mount.

Birfields... Enough said. Longs are one of the most amazing products in 4 wheeling history, but again another $650.

Housing itself. Toyota housing bend surprizingly easy, and even with the aftermarket gussets I feel the D44 housing is still stonger than the Toyota.

Brakes. I melted my rotors (now a sweet blue color ) on the ride home from Moab and I was not abusing them at all. Even if I upgraded to the FJ60 rotors (also requires different hubs because mine is a rare 79 version) they still aren't nearly as big as my D44's.

Pinion. If I were to run the Longs the next weakest link would be my pinion. I think it would go long before the hubs would. The D44 isn't a lot bigger, but enough to say it is probably stronger.

Price wise I'm probably close to the same either way... I think steering and brakes are probably the most important thing you can have on any vehicle, and with big tires I feel more comfortable with the D44 for a few of the above reasons. I plan on Yukons, and will probably just go ahead and order them for peace of mind, and carry my flanges as a backup.

I don't believe a D60 would be the same amount or even a little more money. There are too many things I would have to do to put one under a Toyota and have it be street legal that the cost wouldn't make one practical for this application... But I sure wish I could

 

[cannoncrawler]

all good reasons.....


I really do love the look of my wide runner......good luck to ya!!!

 

[waynehartwig]

I was going to say that you could always do a D44/TOY hybrid. Take the Toy axle and just put GM outers on it and run D44 inners. But it sounds like you don't really care for the housing, gears or dropout. Which I don't really understand, because I have 8" 4CYL centers behind V8's and on 40"+ tires living in the rocks and I know of others that are doing it.

If you were to go D44, then you would have the same bracketry and customization as you would if you went D60 - so call that a wash.

D60's are more expensive than D44's. From the complete junk yard housing to gears to lockers to shafts...everything, right down to hubs being twice as much. But if you have the tools, you can narrow a D60 yourself using off the shelf shafts. It's fairly easy. There are guys on here that have clocked their knuckles themselves with no previous knowledge. At that point they are just one step away from narrowing a housing, IMO...

As for clearance, a D60 hangs down about .5" lower than a D44. I believe the numbers are 5.5" and 6" - I'd have to go measure again to be sure I'm remembering it right....

So IMO the only real reason not to go to a D60 is the cost involved and not because it's too big, too wide, etc. But like others have said, the sheer strength increase over a D44 is well worth biting the bullet now instead of later.

 

[Rot Box]

Which I don't really understand, because I have 8" 4CYL centers behind V8's and on 40"+ tires living in the rocks and I know of others that are doing it.

So IMO the only real reason not to go to a D60 is the cost involved and not because it's too big, too wide, etc. But like others have said, the sheer strength increase over a D44 is well worth biting the bullet now instead of later.

The Toyota thirds are very strong there is no doubt about that, but I figured that If I was going to put the time and effort into a custom axle I'd just go D60 and be done with it. The 44 I have is a perfect width, and I got my gearset (Dana brand gears) and axle for really cheap.

I have the tooling to cut down the D60 and narrow it. And it is the cost more than anything. I really hope I don't regret the D44, but with 60 horse power, a relatively light frontend, and 35-37's I think I have pretty good odds :-\

 

[leorn]

Longfields setup

I'm curious if that includes the angle of the u-joint, as if the front wheels were turning. Everything is stronger straight, but when turned u-joints and Birfs both get weaker. IMO the Birfs are weaker stock to stock, that's why Bobby Longs idea of welding a ring to stock birfs took off & they became Super Birfs. I'd like to see breakage numbers on both Dana & Toyota shaft & joint assembly's breakage while turning.

You'll have to read the thread on pirate, but I interpret it to be the Birfs turned and the Dana stubs separate w/o U-joint. I wish Bobby (Longfield) would post more stuff. I know he has broken things that are not posted. I agree it would be interesting to see it straight vs turned.

Bolt pattern is the same on Toyota as GM or Waggy axles, 6x5.5... no adapters or different wheels needed. Lockers cost about the same, so do gears. I also liked how my Dana 44 turned tighter than my old Toyota axle.

Width w/o spacers and turning radius are huge advantages to a 44. Don't forget the 44 knuckles and housing are also stronger.

I can't comment on whether Bobby's numbers are proportionate, but I they seem to be correct in showing stock 44 shafts > stock toy shafts. Is there only a 16% gain in strength over stock for 44 cromos? I can't say as I don't have any buddies running them.

Also note the degrees of twist which I'm guessing would help shockloading? It is also important to note that cromos from different companies may perform better. Theoretically somebody should be able to make the 44 cromos just as strong as 30 spline birfs since they are the same diameter.

Just for fun this is the theoretic strengths of axle shafts of different diameters.

How strong are the different axle shafts?
(note these figures are subject to much debate)

Standard Dana axles (1040 steel, induction hardened)
-30 sp 1.31" 6,044.1 ft/lbs
-35 sp 1.50" 8,966.2 ft/lbs.

Moser Engineering (1541m, induction hardened)
-30 Spline - 6,200 ft/ lbs.
-35 spline - 9,600 ft/lbs.

Aftermarket 4340 steel, thru hardened
-30sp 1.31" 9,923.5 ft/lbs
-35 sp 1.5" 14,721 ft/lbs

The Formula is:
Yield Torque (in/lb)= Tensile Strength ( psi) x polar moment of inertia/ radius of material

The theoretical axle size by spline to percent strength increase, assuming same material, diameter, and heat treat is: 30 spline � 35 spline: ~40%