Nitro rear axles

[FJ73]

I am running the full float nitro rear Toyota 60 series axles and there 3 months old and I broke the long side axle last night. Has anyone else done the same thing? I had a set of poly performance in a 75 series diff that lasted over 3 years before one let go. On the poly axle the spline is really twisted and snap beside the side gear really ruff surface with 10 mm from the highest to the the lowest at the break. The nitro snapped about 250 mm from the flange but the break is smooth and straight just like a stock axle when they snap at the flange. What's the thoughts on the different axle break surfaces? Yes I'm pushing the boundaries with 40's on but I'm running the stock 3f and I'm not that hard on it.

First photo is the nitro axle
The bottom two are the poly performance axle

 

['74 UA FJ]

Would need to know the conditions in which they broke, but from your story and the pics, I'd go with the PPs.

 

[bustanutley]

You are pushing the design limits of 30 spline axles regardless of material. You could get a 12 bolt spool and put 35 spline shafts in it, or, get a bigger axle all together.

 

[mookie]

upgrade time bro

and by that i mean 14bolt, FOrd9, D70 etc. time

 

[camcruiser13]

agreed, time for more beef

 

[FJ73]

I would love to upgrade to a better diff but funds do not allow that at the moment. So I need to get a set of chromo axles and am after others experience on both of these axles to see if anyone has had a similar experience.

 

[Tapage]

I'm moving my heavy ass Tencha on 40" with SF rear PP .. so far .. ( knock wood ) no problems .. but I know ( as you may know too ) I'm just pushing the limits .. no so long was guy here from Fl. IIRC offering 4340 rears SF and FF for Toy axles ..

Other option could be 80 series rear .?

 

[Tigerstripe40]

Other option could be 80 series rear .?

Doesn't the 80 series rear use the same diameter 30 spline axle shafts as the FJ40 and FJ60? I know that the rear diff is the same.

 

[mookie]

i musta misread this, i thought you was already breaking chromo rear shafts. still i say that the money you will spend on chromo's would have you well on your way to a much better axle. are your treps sticky's?

 

[bustanutley]

Doesn't the 80 series rear use the same diameter 30 spline axle shafts as the FJ40 and FJ60? I know that the rear diff is the same.

Yes, but most are full float so they are a little stronger since the shafts themselves are only exposed to torsion, while SF axleshafts have to also deal with bending from supporting the weight of the vehicle.

I think you should just use stock shafts and drive a little more gingerly until you can swing a bigger axle.

 

[Hulsty]

Yes, but most are full float so they are a little stronger since the shafts themselves are only exposed to torsion, while SF axleshafts have to also deal with bending from supporting the weight of the vehicle.

I think you should just use stock shafts and drive a little more gingerly until you can swing a bigger axle.

The shafts in questions appear to be FF not SF.

 

[FJ73]

As I said I would love to upgrade the diff too bigger and better but that's not an option at the moment. These diffs you suggest will cost me well over $4000 to buy and ship here to Australia with locker, gears and I need 6 bolt hubs. Or $605 for new chromos for the axle I have now witch is what I can afford now. Yes im running sticky treps as I said I no im pushing the axles to far and it inevitable they will break but I can deal with that if I get 12 months out of them till I can afford to swap out the hole diff to something that will handle it. I was hoping that I could get feed back on other peoples experience with either of these axles and witch I should go with next.

 

[bustanutley]

The shafts in questions appear to be FF not SF.

Its pretty clear that I was replying to tigerstripe's query about the differences in the 80 axle, as quoted in my text.

 

[bustanutley]

OP, what I gathered from the treads of past, it seemed that chromo shafts for the SF cruiser rear ends were not worth the money. I would run stock shafts and save your pennies to get a bigger axle.

https://forum.ih8mud.com/hardcore-corner/255557-2nd-long-rear-broken.html

 

[Hulsty]

Its pretty clear that I was replying to tigerstripe's query about the differences in the 80 axle, as quoted in my text.

Yes but you are being confusing with all the SF talk which has limited relevance to this application. I will clear it up for you.

Comparable 40 series and 60 series FF shafts are pretty much exactly the same as 80 FF shafts save for a length difference, there is virtually no strength difference. Due to the longer length of 80 FF shafts a little more deflection over the entire length would occur before failure.

To the OP,

Maybe look at a 105 series rear end, could be had as a cheap upgrade, bonus being wider too, they are 32 spline so you would need to change the side gears on your existing locker or use the 105 gear set which is apparently stronger too. They also run 10mm studs. Would need 5 stud wheels though which may or may not be a problem for you.

Or

Run drive flanges on the rear, 80 series front flanges, and get bobby long to make a set of custom axles, straight axle with no need to neck down, no flange, I "think" the seal area is very close to the same as the axle size too, per his 30 spline front super set, would end up being pretty much a custom length front inner axle.

Or

How easily do you break stock axles? I have broken and seen a few stock axles break, they have all broken at the outer flange, makes replacement very easy and they are cheap, I bought 5 pairs for $50 a little while back, problem is the shock load from breaking the axle can damage other drive line parts further up stream, my ARB shattered.

 

[FJ73]

Yes but you are being confusing with all the SF talk which has limited relevance to this application. I will clear it up for you.

Comparable 40 series and 60 series FF shafts are pretty much exactly the same as 80 FF shafts save for a length difference, there is virtually no strength difference. Due to the longer length of 80 FF shafts a little more deflection over the entire length would occur before failure.

To the OP,

Maybe look at a 105 series rear end, could be had as a cheap upgrade, bonus being wider too, they are 32 spline so you would need to change the side gears on your existing locker or use the 105 gear set which is apparently stronger too. They also run 10mm studs. Would need 5 stud wheels though which may or may not be a problem for you.

Or

Run drive flanges on the rear, 80 series front flanges, and get bobby long to make a set of custom axles, straight axle with no need to neck down, no flange, I "think" the seal area is very close to the same as the axle size too, per his 30 spline front super set, would end up being pretty much a custom length front inner axle.

Or

How easily do you break stock axles? I have broken and seen a few stock axles break, they have all broken at the outer flange, makes replacement very easy and they are cheap, I bought 5 pairs for $50 a little while back, problem is the shock load from breaking the axle can damage other drive line parts further up stream, my ARB shattered.

So are the 80 FF axles are the same diameter?
The change in stud pattern will be a real pain as I only just got custom 17" rims fitted and new treps on them now its really brought out the weakness of the axles. The 105 would need 4.88 gear set and the side gears for a marginal upgrade not worth the hassle.
I was considering this after seeing a buggy running the set-up great idea but they need to be 27 spline on the flange end and boggy only custom makes the 30 spline axles so the diff width would need to be changed to work may be centred diff with two long side axles.
I have broken heaps of sock axles and am sick of it as it happens as the worse time and its unsafe. As you stated on breaking to rear axles at once I smashed the arb locker costing me the price of a new one to fix it. The rig only weighs in at 2100 kg so its not heavy I would have thought the axles would cope better.
:whoops:

 

[Hulsty]

Either way you go IMO the gear set probably doesnt have much strength left to give with 40's.

 

[FJ73]

Either way you go IMO the gear set probably doesnt have much strength left to give with 40's.

The only problem if had with the gears is snapping the pinion off up at the spline from shock loading with uni bind or hitting the tail shaft to hard. I have the gears mesh real tit with lots of per load.

 

[mookie]

so they've never sold anything with 1 ton rear axles in Australia?

 

[Hulsty]

so they've never sold anything with 1 ton rear axles in Australia?

Landcruisers/Patrols are all 1 tonners so are many smaller vehicles, do you mean vehicles with dana 60/70s etc or the big GM diffs from Silverados etc? If so yes they have sold them here, but not in any great number and they are very expensive to buy, get parts for etc.

Landcruiser/Patrol parts are very cheap and plentiful in comparison.