Stronger pinion

[Jonathan Hanson]

The metallurgy of the SF shaft differs than that of the FF due to its need to axle as a bearing surface, a seal surface, a drive surface and a shear beam. Its generally accepted that they are a more brittle structure than the FF shafts.

Ah - now we're getting somewhere.This is what in knifemaking terminology is called the difference between strength and toughness. A steel high on the Rockwell scale of hardness, that will hold an edge well, is considered strong. A steel that can resist bending without breakage or chipping of the edge is considered tough. The two characteristics are rarely complementary. It makes sense that FF axles could be made of tougher steel than SF axles, since they don't experience the surface wear of the bearing load. A tougher axle would be more resistant to abrupt twisting stresses.

I'd be willing to bet this is the salient feature that would make FF axles less prone to breakage.

However, I'll also still maintain that for use other than severe rock crawling, the stock LC SF rear axle is plenty strong. The one in my FJ40 has 309,000 miles on it, and it has towed sailboats and kayak trailers for its living, in addition to a fair amount of technical trail use.

 

[cumminscruiser]

I'm ok with something breaking I wish it was the U joint, behind the cummins is a Nv4500 no problems there then a FJ62 transfercase a little stronger than the FJ60. Then FJ60 axles.

What would be nice is a shear pin in the drive line. My mower attachment for my tractor has one.

The 6BT has lots of torque and its not forgiving (wont stall under load). Very dependable and gets great milage. As soon as I can find a FF axle I'll get it. I like the FF mostly becouse I can drive out on my own.

 

[Jonathan Hanson]

The advantage of being able to remain mobile with a broken FF axle shaft is not to be underestimated. Millions of Series II and III Land Rover owners will attest to that.

 

[Mike S]

There used to be a guy who made a FF conversion kit for LCs and there was a link on MUD at one time. I think he is quit now.

As for Warn hubs in the rear, I have a Warn FF conversion on my '47 Willys (41 rear) with Warn Premium hubs and it seems plenty strong. The Willys tows like a wagon, but then, it is very light - just 2200 lbs.

 

[cruiseroutfit]

There used to be a guy who made a FF conversion kit for LCs and there was a link on MUD at one time. I think he is quit now.

There have been a few renditions of them. Warn was making them for the LC's 10+ years ago, I've got a 'demo' cut-away model showing their spindle, bearing, hub assembly. It was pretty strong but never really took off like Warn hoped and they canned the project. There are still a handful of them running around here in SLC, 2 or 3 in the Wasatch Cruisers. Its a fun hoax to constantly unlock their hubs when they are parked or stopped for an obstacle

FROR was also doing them for LC's or at least said they 'could', I'm not sure if they ever did it or not.

I think both fell victim to the influx of non-US part making their way to the US. Why buy a $750 Warn kit when you can buy a $400 OEM axle that accepts all your existing components and offers the ease of replacement parts (such as wheel bearings which are interchangeable with the front, etc). 10 years ago FF's were much harder to get, we were buying them from an Aussie based source and they usually were shipped 100% complete, shafts, brakes, 3rds and thus we often sourced them with the cable lockers. But they were $1500-2500 which at the time was big money (still is to some degree). When SOR and MAF started heavily importing these, the prices dropped, you could by a 'core' FF for $400-500 and swap all your components over (diff, drums, brake hardware, etc).

 

[CaliCruiser]

Doesn't seem like the pinion is the problem here. Spring pearch just doesn't break easily..

I agree that it doesn't sound like the pinion is the problem here. If you put any pinion into a bind ( Ford 9", Dana 60, Dana 70 or custom) it will snap.

It has led to good advice to go FF but we are still discussing the same pinion gear.

Dylan

 

[nickw]

I'm ok with something breaking I wish it was the U joint, behind the cummins is a Nv4500 no problems there then a FJ62 transfercase a little stronger than the FJ60. Then FJ60 axles.

What would be nice is a shear pin in the drive line. My mower attachment for my tractor has one.

The 6BT has lots of torque and its not forgiving (wont stall under load). Very dependable and gets great milage. As soon as I can find a FF axle I'll get it. I like the FF mostly becouse I can drive out on my own.

http://www.powertrainsavers.com/info.php?ccuser=

 

[cumminscruiser]

Pinion

That's the ticket, their smallest one is 2000 ftlbs of torque, I fixing my spring pearches today and starting the anti axle wrap as well, I saw some goo ideas at the sawp meet.