Rear axle case swap

[Mossberg]

During the process of applying Lanoguard to the truck, I was brushing and poking all the rust and crud away the best I could so I could identify areas needing attention.  I was looking at my rear axle and brushing with a wire brush/poking with a screwdriver.  Noticed a long hole in the shock mount - poo! but never mind as you can buy weld on replacements.  Looked at the other side and the same story (I didn't know they had a slot in as standard). Ho hum, never mind, they can be replaced!

Anyway,  I  then moved onto the bump stop plate.  What a s**t place to collect mud! In goes the screwdriver poking all the crud out and the top flips off without too much effort.  With further poking I can see the actual casing is also seriously crusty,  and whilst I can fit a bump stop plate, I was not happy with the state of the casing. With this potential hole/weak point I decided I would look at the cost of a replacement axle case - I didn't want a full axle as the other parts seemed OK anyway appart from the parts I would probably replace on an axle anyway (calipers/discs/etc).

Anyway I got a price for a replacement at £80  Well I can live with that as it also means I don't have to mess around with the other bits.

I collected the case which also had the hubs, calipers and parts of the A frame & trailing arms attached (I picked it up from a local off road enthusiast who obviously needed it for the drive gear - which was removed). I was happy that the attached bits would u/s but at least it would give me the opportunity to strip it down and thus gain a bit of much needed experience. I managed to get everything appart without too much drama.  The A frame to joint was a  bit challenging as one bolt didn't want to come out - but the 600mm breaker bar managed to sort it with lots swinging and backward/forward small "crack" type movements with lots of plusgas. Whilst it was a pain I am gaining experience of what is likely going to be required when doing the job removing the axle, so all good. 

Next onto the A frame ball joint to the axle. Out comes the 30mm socket and 600mm bar - feck! socket won't fit on. I don't have a 30mm spanner so I tried the large adjustable  - that won't fit either,  though I am not a fan of them anyway. So off to my friend who is a mechanic and he kindly lends me a 30mm spanner. 

Well the split pin is not coming out so its just brute force and ignorance applied and the nut comes off  - no real drama once I had reassembled my vice (which was in the middle of a clean and paint job). Now onto removing the joint from the axle.  I put the nut back on and gave it a few good whacks using a piece of 25mm dia bar as a drift. I try to undo the nut but my application of force has made the nut grip the joint. I grab the spanner,  give it a turn and the ball turns with it (ffs). I tried holding the joint at various angles but no joy. I reached for a good set of mole grips but knew that I nay have issues on the hard and very shiny joint but thankfully it came off.

So with everything off I cleaned the axle ready for a bit of derusting in the electrolysis tub. I only gave a 40 ltr tub do I can only get the ends in. Thankfully it is just deep enough to cover the bump stop plates and I will do the centre part of the casing with a wire wheel in the grinder. I do both ends and they come up good. I then attack the central section with the wire wheel but I am not happy as it removes the surface rust but just polishes the crusty stuff underneath.  So the hunt for a 200 ltr barrel starts - £17 on ebay but all miles away. A couple of posts on local Facebook groups and I have one for free within a mile of me - all good, I  fill the barrel and setup the kit, axle in the barrel,  switch on and let electricery do its magic. After 24 hours,  get it out and remove the major rust, then back in for another 24 hours. 

Out it comes and it gets a good wire brushing. Their are still some black deposits in the area where the rust was (generally around the welds) so I decided I will give it a coat of phosphoric acid.  I  applied the acid in the afternoon with the intention of hosing it down and putting it in the garage overnight.  However,  things don't go as expected and its dark when I get back. I  don't want to mess about with it in the dark due to the acid so decide leaving it out overnight won't be an issue as its not due to rain anyway. 

Well things don't turn out quite as expected.  I check the axle in the morning and itc covered in condensation  - never thought of that! I have to go out for about an hour and a half  and when I get back the axle is covered in a flakes scale.  Aargh,  ffs, poo! I triedjust jet washing but that ain'tenough - i have to wire brush it again to remove the scale. Do about 45 mins of brushingandjet washing and it comes up clean - but then starts toflash rust!

I was going to paint it in a couple of days time,  but I didn't want lots of rusting so decided to wipe it down, scotchbright it,  brake cleaner de-grease and paint.

So, two coats if Bonda Rust Primer and left for a few hours before putting back in the garage.  I will leave it a few days to fully dry and harden before I apply a black top coat.

For those managing to get to the end of this post,  we'll done, I hope I have not bored you too much 😀 

A few photos 

The replacement casing 

 

First lot of electrolysis 

 

 

Centre part of casing after wire brushing  - just polishes the rust!

 

After electrolysis, wire brushing and pressure washing 

 

You can see the difference here between the section that gas not yet had electrolysis. 

 

The flakey scale after phosphoric acid/condensation.

 

After wire brushing the residue and pressure washing. Leaves a dull grey finish.

 

And after two coats of Bonda Rust Primer. 

 

I will add more as I progress, but I am still using the truck so will probably be over a few weeks. 

Well done if you managed to get to the end. 

Mick

Edited March 24, 2022 by Mossberg

[cackshifter]

Looking good; one point(and don't know if this applies to Bonda primer) many primers are slightly porous and will absorb water, which isn't good as it gets trapped under the top coat. Best if you don't let it get damp again before a top coat is applied

[Mossberg]

11 hours ago, cackshifter said:

Looking good; one point(and don't know if this applies to Bonda primer) many primers are slightly porous and will absorb water, which isn't good as it gets trapped under the top coat. Best if you don't let it get damp again before a top coat is applied

Many thanks for that. I never thought of that with Bonda.  I have put the axle in the garage until I top coat and will make sure I keep it dry until the top coat is on.

[Troll Hunter]

What does your electrolysis bath do to non-rusted, machined surfaces?

Mike

[Mossberg]

4 hours ago, Troll Hunter said:

What does your electrolysis bath do to non-rusted, machined surfaces?

Mike

The electrolysis only attacks the rust - that is one of the great things about this process. I will list some of the good and bad points;

Good 

It leaves the Good material alone. This process only works on the rust of the steel. 

It gets into areas you can't see.

It loosens thick rust so that you can pick it off with a screwdriver etc.

Any rust that is treated but still remains in pitting etc is not rust anymore - but have a look on youtube for a video of the chemistry as I can't explain it.

It's relatively easy.  You hang your part in the bath, connect up and switch on, then take it out and clean up.

You don't create lots of grinding dust!

 

Bad

You can only treat what you can fit in your bath. Your part does not need to be fully submerged,  but it only works on the submerged part. Originally my bath (large bucket) was about 450mm deep.  I did one end of my axle, cleaned it up,  turned it over and did the other end. However the middle section was not done and I was going to do this with a wire wheel in the grinder  - unfortunately this was just polishing the thick rust. I the changed to a 200 ltr drum, but this still would not fit the full axle so needed one end then the other.

You still need to clean the part. A lot of rust just comes off but you still need to remove the black residue.  I used a combination of flat bladed screwdriver to pick off the crusty stuff, various sized wire brushes and a pressure washer.  I would brush/wash/brush/wash until I was happy with how clean the part was. This obviously needed a suitable area to do it, though small parts could be cleaned in another bucket or sink, so no need for the pressure washing. 

Some parts benefit from a two stage clean - treat in the bath, take out and clean (at this stage you can pick lots of the scale/scabs of rust off. After the first cycle just assess if it needs to go back in, if it does, just repeat.

Areas you can't see will still be treated. The bump stop plates on my axle were only accessible for cleaning with a screwdriver  - I could not get the brush in there.  The pressure washer cleans a lot out,  but this is an area that will rust so you want a good treatment here. I did my best with cleaning and then painting, but in here will get a good amount of Lanoguard (or whatever treatment you prefer).

Time! This process takes time  so if you are addressing a rusty item in one afternoon this will not be an option. 

This process only works on rust on steel - it does not work on corrosion on other materials so you can't use it on aluminium etc.

As this process is wet you can get flash rusting. You need to dry the part quickly to avoid this and even thennit is not easy to avoid.  If needs be, spray the part with WD40 to get rid of the water,  which is OK for parts you are not going to paint. 

Also, remember that this process removes the rust. Once the rust is gone you are left with the remaining steel.  Thus may mean you are left with holes, but you may just be surprised at what does remain. Some things look far worse when they have all the rust on them and you wonder if they can be salvaged, but some come out OK (but obviously not pristine!).

 

If you want to try this it is relatively simple and you can use various power supplies. I  have used a modern battery charger (Aldi £12.50 type) but with an old battery in line to fool the smart electronic bit or I believe this type may not work if connected directly.  I now have an old style battery charger that I connect directly. BE AWARE OF THE SAFETY REQUIREMENTS  - THIS PROCESS PRODUCES HYDROGEN WHICH IS EXPLOSIVE,  AND ALSO YOU ARE USING ELECTRICITY WITH WATER!

Some parts from yesterday's batch. Please note that these parts gave also been treated with phosphoric acid after the electrolysis though I am not sure if this is needed.

Note the stub axle as this was treated fully submerged in the bath - the bright steel is unaffected. The flange that had rust would have been a blacker colour but the phosphoric acid turns them grey.  I  wire brush and wash after the acid treatment and I don't really know if there is any advantage in doing the acid process (I bought the phosphoric acid before I discovered electrolysis so thought I may as well use it!!)

 

 

Edited March 25, 2022 by Mossberg

[Mossberg]

Just one note - I was going to get new brake shields but decided against it as they were all painted black and I presumed it was going to be the carp paint that so many parts have. To be honest I would prefer bare steel as at least I could use a more resilient paint process. I decided the existing ones painted properly would probably last as long a a brand new set!

[Filbee]

Looking good! Those bits have come up really clean 👌

[Mossberg]

45 minutes ago, Filbee said:

Looking good! Those bits have come up really clean 👌

I just hope the painting is good enough to stop the rust 🙏 

[smallfry]

Excellent job. Can you do mine ?

[Filbee]

1 hour ago, Mossberg said:

I just hope the painting is good enough to stop the rust 🙏 

I've had some good results with 2-part epoxy mastic paint brushes or rolled direct to clean (previously rusty) metal, with a rattle can top coat to stop it chalking up

[sean f]

What do you use as the electrolyte?. Seen various suggestions but what every you are doing seems to work very well.

[Bowie69]

Washing soda is great, as it softens the paint as well!

[Mossberg]

3 hours ago, sean f said:

What do you use as the electrolyte?. Seen various suggestions but what every you are doing seems to work very well.

Just soda crystals.  79p for a bag from Home Bargains. Wire brushes and paint brushes are also a good price from there.

[Troll Hunter]

Hi, Mossberg, many thanks for such a comprehensive reply.  I was expecting a couple of sentences at the most.  You've got some very good results there.  I should have tried electrolysis on my chassis instead of grit blasting it before galvanising.  Too late now.

Mike

[Mossberg]

2 hours ago, Troll Hunter said:

Hi, Mossberg, many thanks for such a comprehensive reply.  I was expecting a couple of sentences at the most.  You've got some very good results there.  I should have tried electrolysis on my chassis instead of grit blasting it before galvanising.  Too late now.

Mike

I think grit blasting would be a good choice.  I think a big advantage of blasting is how it removes all the paint etc.

Inside the chassis is a different story as I am not sure how good the blasting would be inside as your line of sight and the openings to blast being very limited.  Someone I met once said aquablasting was the best method of cleaning as you ended up with no shot inside the chassis,  but I have never experienced this so can't comment. 

So would I use electrolysis to clean a chassis- yes I would consider it. I think you could make a suitable bath by using a damp proof type membrane.  I did wonder if you could plug the holes on the chassis and do the inside that way, but I don't think that would be viable and I still think you would need to clean off the residue - though a drain type pressure washer attachment may be suitable for this task.

If you are cleaning your chassis in preparation for galvanising then this may be an option as the Pre-galvanising acid bath may remove that residue- note I say MAY as I really don't know.

[Snagger]

Great results.  Every time I see a member post their electrolysis results, I’m impressed at what they achieve.  Seems a much easier and more effective method than blasting or brushing.

I think YRM make galvanised brake shields, but if you already have intact units, then cleaning and decent repainting is sensible.

[Troll Hunter]

Yes, it isn't difficult to build a bath big enough for a chassis from plywood and to line it with a polyurethane sheet from your local builder's agent.  Next time I need to renew my chassis I'll remember this.  

PS:  I'm 79 now, so I don't think I''ll be doing the next rebuild!

Mike

[Mossberg]

Well I eventually took the old axle casing off today. I think I made the right decision to replace it! The hole in the diff pan was just a stain with a pin prick hole in it - I didn't even know it was there!

 

[Mo Murphy]

Yup, thats due for a change 👍

Mo

[Mossberg]

Well,  I got the diff out of the old axle and would appreciate your wisdom regarding the state of it, and suggestions as to if I should fit the diff to the axle case before installing, or fit the axle case bare then fit the diff after? My thoughts are fit the diff first, but I welcome your advice. 

Some photos of the diff - it's a 10 spline!

 

 

[Bowie69]

Looks alright to me... as long as there is no play in bearings then slap it in the new case.

[Mossberg]

Thanks Bowie, I will do the best I can to check. I thought it looked quite clean but then I wouldn't know what to look for!!

[muddy]

I don't think you can fit 10 spline stuff into a 24 spring axle, I could well be wrong but I don't think the half shafts go through the stub axles.

Might be worth trying before you button everything up.

[Mossberg]

Thanks for the heads up, but the axle case is now fitted.  I will check it tomorrow but the stub axles look very similar. I can always fit the old stub axles as they look OK, it's just that I have cleaned up the others. 

I have also measured up the hubs.  Although they are different the measurements of the bearing seat are within 0.4mm, which may be machine tolerances. I checked the stub and hub as I wanted to use the ones from the replacement as it gave me time to refurb them.

Unfortunately I haven't been able to finish as I forgot to order the stub axle seals!!

 

 

[Mossberg]

Feck!

Can anyone explain the difference between the stub axle oil seals. I have purchased some as I am doing an axle refurb and I have found the ones on my existing and donor axles are both different to the ones I have just purchased.

The ones I have just purchased are FTC5268.
The ones from my existing axle were FTC0951. This is a 10 spline axle.
The ones from my donor axle were IN53275. - I am assuming this was a 24 spline axle.

The problem is you never know if the ones you are taking out are the correct ones anyway!!

The axle I have just taken off did seem to have a bit of oil in the hubs - but is this because of the incorrect seal or was it just warn?

Some photos showing the differences. One side, then the other.