So upgraded birfs..... (1 Viewer)

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I'm currently at almost 5 years and 65k miles on my OG Longs with AWD and still going strong. Axle was rebuilt when they were first installed and then again in 2015 after the front left axle seal sprung a leak on the Rubicon.

:beer:
 
You're assuming I haven't diagnosed the problem.

Well, according to you...

I have sprung a leak that I would guess is due to the seal wearing into the softer metal of the shaft.

I could interpret that as that you actually disassembled it, found a groove, and are guessing that the groove might be your problem, but it sounds more like you haven't and are guessing what might have happened. So which is it?
 
No offense but you should do some triaging and disassembly before just assuming your seals are bad because they wore out your axle shaft... its possible of course but seals wear out too and afaik the axle shaft is just a run of the mill 4340
^x2; only the wear surfaces are hardened. (The ends)
 
^x3 :rolleyes:

No not according to RCV or Bobby Long, when I talked to Bobby about the original Longfield superset made by RCV, he was very careful to explain exactly how Longfields got their strength. Go watch any of his axle break videos or look at the data and you can see how much deflection the upgraded axles take, they are softer to twist not shatter.

PRODUCT / ................................................. FT.LB. TORQUE/.... % 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........................................5,00 0.....................35
Yukon 4340 Birfield Eliminator kit (ear failure)............5,500......................50
Longfield 4340 30 spline (shaft failure)......................8,500............... ......175
Longfield 4340 27 spline........................................6,50 0.....................75
Stock Toyota Birfield.......................................... ..4,200 .....................45
Stock Toyota Inner Axle.......................................5,000 .....................45

175* twist compared to 45*

Not only is my set not 4340 "We have gone a step further by upgrading the inner shafts to 300M" They entire shaft is not case/thru hardened to the same rockwell as OEM.
 
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^x3 :rolleyes:

No not according to RCV or Bobby Long, when I talked to Bobby about the original Longfield superset made by RCV, he was very careful to explain exactly how Longfields got their strength. Go watch any of his axle break videos or look at the data and you can see how much deflection the upgraded axles take, they are softer to twist not shatter.

PRODUCT / ................................................. FT.LB. TORQUE/.... % 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........................................5,00 0.....................35
Yukon 4340 Birfield Eliminator kit (ear failure)............5,500......................50
Longfield 4340 30 spline (shaft failure)......................8,500............... ......175
Longfield 4340 27 spline........................................6,50 0.....................75
Stock Toyota Birfield.......................................... ..4,200 .....................45
Stock Toyota Inner Axle.......................................5,000 .....................45

175* twist compared to 45*

Not only is my set not 4340 "We have gone a step further by upgrading the inner shafts to 300M" They entire shaft is not case/thru hardened to the same rockwell as OEM.

High strength steels permit a much greater degree of elastic deformation before yielding. Pretty much all steels have the same modulus of elasticity though. A torsion bar is as hard as a coffin nail but will twist a lot better than a stick of cold rolled. Anyway, thats beside the point. What I meant is that it seems like you havent disassembled it yet. If you have, can you share pics of the worn out seal surface?
 
So the problem with trail gear is birf click or ???? I have several things from them and never had an issue, but never bought a machined part from them. I can get dealer cost on trail gear, but thats only 150-200 less than other companies, so id rather have a better part instead of something that will need constant attention or annoying quirks.

Any other issues with them?

Iv wheeling the long fields for 6+ months on 40s without a single problem, don’t know why people bash them so much.
 
I think they are probably fine. The original Trail Gear birfs seemed to have some issues but were corrected. I think the biggest issue most people (and I can lump myself in this group) have with trail gear is that they are known to take designs and “copy” them overseas at a low cost. Their birfs are no exception. When Bobby passed they took over the Longfield name but just took RCV’s product sent it to China to have it copied. So if you want the original Longfields you have to buy from RCV if you want the Chinese copies you buy “Longfields” from Trail Gear. Everyone can make their own choice based on their globalism beliefs. But RCV’s are made in the US.

Iv wheeling the long fields for 6+ months on 40s without a single problem, don’t know why people bash them so much.
 
Ive previously have had my diff apart to replace seals, clean out all the axle grease in the housing, replace diff fluid and replace my rotors.

The groove on the long side is close to 1/8” deep. PO version of maintenance was add more fluids if the old ones leak out, great rust preventative. The truck would lurch to the right because so much grease was on the pads and rotor.

I talked to Beno today, wow he is knowledgeable!!! Very valuable asset to the lc community. He suggested the rcv because i may upgrade tires or horsepower in the future even though i dont need it right now, better off safe than sorry
 
I have found the perfect solution for my RCV's. I just get so frickin busy they just sit there new in the box!

Seriously, I am planning to go part time kit too since no winter driving anymore (ih8salt), so it should make a good combo.
 
FWIW, last year I order rcv’s from who, I can’t remember but they screwed up my order because my RCV’s came directly from RCV but the vender also sent me a set of trail gear shafts.

I could not tell a difference between the rcv stub shafts and the rcv stub shafts excepting they didn’t have RCV written on them. The difference that was obvious was the thinner inner shaft had standard splines whereas, the rcv’s I ordered were the 30/30/30 spline version.

My rig is part time so wear will never be something I can comment on.
 
That was true for a few months. That is no longer true. RCV does not make Trail Gear shafts or birfs any longer. They only did while Trail Gear was setting up production overseas.

FWIW, last year I order rcv’s from who, I can’t remember but they screwed up my order because my RCV’s came directly from RCV but the vender also sent me a set of trail gear shafts.

I could not tell a difference between the rcv stub shafts and the rcv stub shafts excepting they didn’t have RCV written on them. The difference that was obvious was the thinner inner shaft had standard splines whereas, the rcv’s I ordered were the 30/30/30 spline version.

My rig is part time so wear will never be something I can comment on.
 
That was true for a few months. That is no longer true. RCV does not make Trail Gear shafts or birfs any longer. They only did while Trail Gear was setting up production overseas.
Ok so everyone should stay away from TG!
 
That's up to the buyer. If they want the original "Longfields" made in the US than get the RCV's. If they want a copy that is cheap that is made in China than get the Trail Gear. I am just putting the actual information out there what anyone does with it is up to them.

Ok so everyone should stay away from TG!
 
Well I know many people have questioned longevity with upgraded birfs with the softer heat treating in a Fulltime 4wd truck. I had heard Bobby Long say they are good for 60,000 miles. I didn't think anything of it since at the time I was maybe driving my truck 5-8000 miles a year. Fast Forward to 4 years later, 2 trips across the country north to south and two trips across the country east to west a lot of daily driving and somewhere around 50,000ish miles. I have sprung a leak that I would guess is due to the seal wearing into the softer metal of the shaft.

Just an FYI for those of us using our trucks to sight see malls more than wheel you could save a little money on the RCV 300m superset. lol.

Did you inspect your axle shafts and find grooves?
 
So....reading through this and having not yet torn into the axles of my '94 with 275K mi on it, got me to thinking (that's usually dangerous and/or expensive...lol). I'm thinking, going with 5.29s for my own reasons, and the oem 30 - 24 spline neckdown on the front axles is a weak point. I'm trying to upgrade for strength running larger tires and pulling an off road trailer for overlanding. The stock 9.5" & rear axles should be fine. Noticed on the rcv website a warning: "Some trimming may be required depending on the application". What are they talking about? Any other tips when replacing oem with these? I'm keeping the full time setup for now. Being that they're "using only high-strength chromoly materials" is this a bad idea for longevity? I've heard that chromoly is best used on a part time setup, where they're not spining constantly.
 
So....reading through this and having not yet torn into the axles of my '94 with 275K mi on it, got me to thinking (that's usually dangerous and/or expensive...lol). I'm thinking, going with 5.29s for my own reasons, and the oem 30 - 24 spline neckdown on the front axles is a weak point. I'm trying to upgrade for strength running larger tires and pulling an off road trailer for overlanding. The stock 9.5" & rear axles should be fine. Noticed on the rcv website a warning: "Some trimming may be required depending on the application". What are they talking about? Any other tips when replacing oem with these? I'm keeping the full time setup for now. Being that they're "using only high-strength chromoly materials" is this a bad idea for longevity? I've heard that chromoly is best used on a part time setup, where they're not spining constantly.
24 spline is a different diametrical pitch btw
 

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