Diagnosing front axle problems!

So there i was tootling up a hill towing 20 sheep when bang.... front axle lost all drive, fortunately Bang, into diff lock and into the first field i see.

About two mins before this I got wiffs of a burning rubbery / burnt oil smell, this has been occaisonal for about 2 weeks appearing usually on uphills, I put it down to just Pulling hard uphill with a new Exhaust pipe, and the paint burning off (I Paint everything in redoxide).


SO far ive jacked the front end up and can turn both y freely without them turning the prop shaft output, they make a rattling clunkish noise but not a heavy one. - Ive taken the prop shaft off - the transfer and gearbox work fine.

Is their a guide to diagnosing what this means? Is it a cv joint of the diff? Obvs i understand that the diff would send any input drive to the path of least resistance - ie the broken bit!

Why do you paint everything in red oxide? That’s a primer?

if it works in diff lock it won’t be a tranny or gear box problem.

Most likely culprits are snapped halfshaft - easy fix. Or shredded hub splines - also an easy fix but check splines on CV joint as they are likely worn as well.

payydg said:

Why do you paint everything in red oxide? That’s a primer?

if it works in diff lock it won’t be a tranny or gear box problem.

Most likely culprits are snapped halfshaft - easy fix. Or shredded hub splines - also an easy fix but check splines on CV joint as they are likely worn as well.

Click to expand...

Because im a farmer, my soil is naturally acidic at 5.5 and manure eats metal - red shows up good on a power wash showing any bits not clean, but also any missing chipped paint, or rust patches showing up. Its also protection so always welcome. On wet acid clay soil 2mm steel plate on a feed trough can be rusted through in 2... to 3 years....

Dcoximus said:

Because im a farmer, my soil is naturally acidic at 5.5 and manure eats metal - red shows up good on a power wash showing any bits not clean, but also any missing chipped paint, or rust patches showing up. Its also protection so always welcome. On wet acid clay soil 2mm steel plate on a feed trough can be rusted through in 2... to 3 years....

Click to expand...

Im assuming you wax the inside of your chassis in that case? They rust from the inside out as I’m sure you know. I’d be surprised if a bit of primer makes a huge difference and I’d suspect it’s more the regular cleaning that’s of benefit but all welcome as you say.

Pull the half shafts out and see. If they’re fine take the front off the diff.

Dcoximus said:

Because im a farmer, my soil is naturally acidic at 5.5 and manure eats metal - red shows up good on a power wash showing any bits not clean, but also any missing chipped paint, or rust patches showing up. Its also protection so always welcome. On wet acid clay soil 2mm steel plate on a feed trough can be rusted through in 2... to 3 years....

Click to expand...

Also, I know this isn’t the point of your post, but doesn’t red oxide make it difficult to see where it’s rusted through? Being that both are red and all?

I seem to remember that one of the reasons red oxide was used so prolifically on bare metal was because It essentially made it harder to see the surface rust.

As others have said possible broken half shaft. What lead you to believe it is the front axle that has the problem ? If a shaft or drive flange goes in either front or rear axle all drive will be lost and only be available with centre diff lock engaged.

Get the vehicle on level ground, start, put in gear with hand brake off and look underneath to see which prop is turning. This will tell you front or back. Then take to plastic caps off to see if the shaft is turning in the drive flange. If neither is pull the half shafts out.

payydg said:

Also, I know this isn’t the point of your post, but doesn’t red oxide make it difficult to see where it’s rusted through? Being that both are red and all?

I seem to remember that one of the reasons red oxide was used so prolifically on bare metal was because It essentially made it harder to see the surface rust.

Click to expand...

Rust is brown and modern red zinc oxide is quite a vibrant blood red, the brown streaks are very visible, I can assure you!