Is there a "recommended" birf type for larger tires or air lockers?

[CodyRx7]

From searching around the vendor websites and the 80's forum, I have a few questions regarding birfs.

I have 5.29 gears and the tires are 38.7" tall.

Some sites mention "not recommended for tires larger than 39""....

Some threads say Longfields wear out faster and aren't good for a daily driver?

Is there a special or recommended birf and/or axle type for my rig with ARB lockers front and rear?

I've ran the stock birfs with 31s, 35s, and now these 38.7s with slight clicking since the 35s that I can remember.


What splines do the 80s use? 27? 30?

Is there a difference between the 30 and 27 spline "Chromoly Super Set" and the "FJ-80 Chromoly Birfields" listed on the Longfield site? Definately a difference in price between each type... Does a "Super Set" include the inner axles too?


Recommendations?

 

[619TOY]

If I were in your shoes, I'd run the Longfields. Yes, it's true that they don't last as long; I've read that they last about 60k miles. Let's assume they do; would it be all that terrible to have to buy another set in 60K miles?

I think about it like this: how much is it worth not to have to deal with the inconvenience of a broken birf on the trail? I've replaced mine so I have a little experience and could probably replace one relatively quickly on the trail. Would I want to.......hell no! It's a messy, messy procedure. Add to that the possibility of bad weather, etc. No thanks.

There is only one set that fits your axles so you needn't worry about spline count etc. And yes, the super set for the 80 includes inner axles as well.

While you're at it, you may want to look into chromoly rears as well. I have PolyPerformance on my rig. On the upside, the rears are cheaper and don't wear out. I tried to post a link but it looks their site is down.

My .02

 

[Romer]

I was told that Bobby Long said they last 15K miles of regular street use. I would only run a longfield or newfield if it was a trail rig only. If you put a lot of miles on the street, than Toyota birfs.

I would call and talk to Slee as he sells several different kinds of Birfs. He will give you a straight answer for your setup

 

[CodyRx7]

Any reason why the birfs would fail in like 15k miles of STREET use?

From what I have read, the chomoly birfs are a softer metal, accept more twisting torque without shattering, etc...

Street use wouldn't seem as brutal as bumping and bouncing over rocks...

60k miles seems fine.....but 15k?

What is supposed to happen at 15k? Birf clicking? Birf explosion?

Can anyone confirm how long these will last from real use?

Are there other options besides Longfields...or is it just different vendors selling the Longfield products?

 

[Romer]

From when I had a similar question and wanted to switch to a different birf

https://forum.ih8mud.com/80-series-tech/167973-damnit-christo-another-product-looks-good.html

the 15K may have been too low a figure after reading it. May be closer to 30K where as a stock birf will last >150K miles

But then the stock birf is more likely to break, on the other hand I have seen longfields break as well.

There is a post about them clicking on an 80 after 20K miles in that thread

 

[FredTJ]

Regarding many street miles that you can expect from a Longfield, simply give them a call. Takes all of what, 5 minutes, and no one will give you a better answer than them.





Fred

 

[Fly Rod]

Any reason why the birfs would fail in like 15k miles of STREET use?

From what I have read, the chomoly birfs are a softer metal, accept more twisting torque without shattering, etc...

Street use wouldn't seem as brutal as bumping and bouncing over rocks...

60k miles seems fine.....but 15k?

What is supposed to happen at 15k? Birf clicking? Birf explosion?

Can anyone confirm how long these will last from real use?

Are there other options besides Longfields...or is it just different vendors selling the Longfield products?

Cody,

There is a direct relationship between hardness and how brittle steel is. Hard steel has better wear characteristics than soft metal. Hard metal lasts longer under normal loads. Soft metal wears faster but also flexes rather than breaks under shock loads. So given the same metal type the soft one will work better for wheeling, or shock loading. That same metal will wear very quickly under a constant dd load. So for dd you want a harder birf, OEM's. For wheeling you want a softer birf, Longfields.

With all that stated, you are running tires and gears way out of the "normal" range. You run a higher risk of shock loading your birfs than the rest of us "normal" mudders. Consider the risk if you are going to wheel. Your choice is to carry spares on the trail and be ready to do a trail repair or do more regular pm on your softer birfs.

Hope that helps.

 

[alkaline747trio]

Longs, Aisin Hubs, drop the front shaft for long drives.....bout the best option for you other than swapping out your axles. Stock birfs wont last you with those tires and a front locker, if you get more than 5 good wheeling trips on the stockers locked I would be blown away. Longs are the only way to go, Aisin Hubs are the only option to keep the wear down...don't go aftermarket with the hubs either, or you'll be breaking those instead of birfs.

 

[Cruiserdrew]

I would run the stock stuff and always be prepared with a spare inner and birfield. Those are big tires and you are going to break stuff. No big, just take the parts to fix it on every wheeling trip.

 

[ArmyFJ]

Do the part time kit and then run longs. When I break my birfs I am going to go to longs.

 

[sleeoffroad]

Cody, you are not going to get many miles out of either a Longfield or a Newfield HD. You could do the part time thing, but then you will end up breaking hubs. In the ends I used Newfields and drive flanges and just deal with the accelerated wear.

 

[ArmyFJ]

Will you give me a discount if I break my hub?

 

[CodyRx7]

I talked to Bobby Longfield today, mentioned the truck specs and he suggested the 80 series Super-Set.

While I understand he is a vendor selling me a product - he said these axles are good for about 100k miles, but in a daily driver too I might get half that at 50k miles.

I figured out a good compromise.

I bought the Super-Set, they said I should have it by Thursday....and I'll daily drive the LX450 less.

I won't get that much better gas mileage, but I will have a nicer ride and less wear and tear on the LX450 since we've decided to start shopping for a new car and settled on the IS-F.

Now just have to find a purdy red one.

 

[concretejungle]

I won't get that much better gas mileage, but I will have a nicer ride and less wear and tear on the LX450 since we've decided to start shopping for a new car and settled on the IS-F.

Now just have to find a purdy red one.

Sweet car, but the Audi ate it's lunch.

 

[reffug]

yaa the Audi is impressive.

course that lex is no slouch.

all that aside you should be quite happy with longs. its a nice feeling on the trail to use the front locker with a little less trepidation.

 

[FredTJ]

Yup, the Audi is impressive, the Lex is no slouch, however the real deal is the BMW M3






Fred

 

[619TOY]

I bought the Super-Set, they said I should have it by Thursday.

I'd wait until it's time to change out your "break-in" oil before making the axle swap. Kill two birds...

 

[ArmyFJ]

Its still throwing two stones though....

 

[Romer]

So are the super set harder than the regular longfields?

 

[ArmyFJ]

Just comes with the inners and outers.