Semi Float Chromoly Axles?? (1 Viewer)

[Ronthebiker]

Did a lot of searching and I’m wondering why it seems that next to no one makes chromoly rear axle shafts for a semi float? I’m thinking about putting a lunchbox locker in and and I’m currently sitting on 31’s but want to go to 33’s down the road and thought this would be a good idea so I don’t ever have to worry about the rear end but I can’t find any?

 

[FJ60Seth]

I’ve heard/read that chromolly axles are not recommended for full time use.

 

[Ronthebiker]

I’ve heard/read that chromolly axles are not recommended for full time use.

I’ve never heard of this. Can you explain?

 

[65swb45]

I think that’s a helpful hint from a well-respected member that a thread search will answer your question.

 

[Ronthebiker]

I think that’s a helpful hint from a well-respected member that a thread search will answer your question.

I’m probably missing something but I just searched agian and couldn’t really find a answer as to why no one makes them or why they are not needed.

 

[offrd63]

I think mine came from poly performance. It been 15 years or so but I got them with my original longfields.

 

[Ronthebiker]

I think mine came from poly performance. It been 15 years or so but I got them with my original longfields.

I saw some from Polly Performance which seems to be the only place but it says that it’s only for 79 and up Land Cruisers. I’m assuming maybe something to do with the bearing race since I believe they were all 30 spline after 67 or 68.

 

[FJ60Seth]

Again, I’ve only heard/read this, it could be urban legend. The chromoly axles are softer than stock which allows more twisting before they break. They will also wear out faster.

 

[FJ60Seth]

Here’s one thread.
Question about chromoly birfields and longfields

 

[MOTOV8R]

You can find 4340 rear axles for other applications. There were some made by poly performance and nitro for 40s, maybe others. My guess is they didn't sell enough of them to keep making them.

DISCONTINUED Toyota 9.5'', FJ40 Land Cruiser, LC, 30 Spl, Semi Float, Long Side, Nitro Rear 4340 Axle Shaft

Toyota 9.5'', FJ40 & FJ60 Land Cruiser, LC, 30 Spl, Semi Float, Short Side, Nitro Rear 4340 Axle Shaft

 

[Ronthebiker]

Very interesting thanks for posting that link. I never thought about chromoly being softer. I imagine the rear axles are probably strong enough from the factory which is why most people just say to upgrade the birfields and call it good. So I guess I’ll just run the factory axles and I should be good since I’m pretty easy on the gas when I’m on the trail.

 

[65swb45]

I have wheeled my 40 on 33s for 29 of the 32years I’ve owned it, including at least a dozen times over the Rubicon and a half dozen on the Dusy. Never broken a rear axleshaft.

 

[Ronthebiker]

I have wheeled my 40 on 33s for 29 of the 32years I’ve owned it, including at least a dozen times over the Rubicon and a half dozen on the Dusy. Never broken a rear axleshaft.

That’s good to know. Sometimes I go overkill and want to make things stronger then they need to be but there’s probably a reason why no one makes these things and I’m pretty gentle on my 40 when I’m in the rocks cuz I know what can happen and it’s my only vehicle so I should be ok.

 

[FF LC FREAK]

I have wheeled my 40 on 33s for 29 of the 32years I’ve owned it, including at least a dozen times over the Rubicon and a half dozen on the Dusy. Never broken a rear axleshaft.

Rubicon + turbo 3B + 33s + bouncing =

If you wheel sanely and don't bounce and spin tires at the same time, you'll probably be okay.

By the way, this wasn't me. But it was my old BJ42.

 

[Ronthebiker]

Rubicon + turbo 3B + 33s + bouncing =

If you wheel sanely and don't bounce and spin tires at the same time, you'll probably be okay.

By the way, this wasn't me. But it was my old BJ42.

Damn that’s crazy! Side question to you’re BJ42; I see you had stock steelies on there, is there any issue with the width difference between the rim and tires?

 

[FF LC FREAK]

Damn that’s crazy! Side question to you’re BJ42; I see you had stock steelies on there, is there any issue with the width difference between the rim and tires?

Nope. They did fine. They were 33x10.50x15s KM2s. The guy driving it on the Rubicon had them aired down a little too low and popped the bead a couple of times, but they did just fine in normal driving and wheeling.