Rear passenger (UK nearside) Drum

[heinkeljb]

Went to Dersingham for club meeting, drove there with a couple of issues along the way. The lid for my home made battery box fell off, but luckily I was able to retrieve it and put it back on. Then later one of the exhaust pipes that goes between the exhaust manifold and the heat exchanger decided to fall off! Couldn't find that to try putting back on, so drove the rest of the way with one cylinder venting into open air!
Saturday morning managed to find some flexible exhaust tubing and cobbled together a repair. Went on the run with only a slightly blowing exhaust system. Next day went to put in petrol and just before I got to the petrol station, loud screeching noise from the back end. At the petrol station felt the drums - sure enough the near side rear was HOT! Took the wheel off and was met with :-

Got trailered back to the camp site and looked deeper. The circlip holding the handbrake Return spring had obviously fallen off allowing the centre cone shaped bit to move on the stud. This along with the spring had then eaten through the drum! Also damaged the back plate - so lots of replacement bits going to be needed.
Ended up getting the RAC to recover Lurch back home.

John

[AustHaflinger]

You have upset someone in a previous life - not a good run but is all fixable with the bits.
With that damage to the drum, I am surprised that it was not audible before hand.

Back on the road soon

Garry

[Julian B]

Yikes - that drum looks horrible!

Is the cast back plate damaged as well? It looks like there is a crack at the top? That would be much harder to fix...

[heinkeljb]

We were off-road all the day before and didn’t hear anything. There was also the issue of the cobbled together exhaust system which might have helped mask any sound coming from the hub.
I went round a roundabout and then heard a screeching noise - as I was less than half a mile from the petrol station , I continued at slow speed to it to be able to park up and get out and look to see if I could work out what the screeching noise wa.
The back plate has also suffered damage - cracked from the crack you cans see all the way down following the weakest line found the oil carrying part of the hub as far as the brake adjuster hole.
So the back plate, and brake drum will have to be replaced.

Won’t happen for at least a couple of weeks as I am flying out to South Africa today to sort out my Dad’s funeral.

John

[Julian B]

John,

So sorry to hear about your father's passing. And with him being so far away must have made things even harder for you all.

Best Wishes,

Julian

[AustHaflinger]

The same here John - very sorry to hear of your loss.

Garry

[heinkeljb]

Thank you.

Will attempt to get internet access whilst I am there, but it is likely to be sporadic depending on where I am.

John

[heinkeljb]

I have now had a chance to strip the rear passenger side hub. Things came apart easily.

Brake drum

Brake shoe

Backplate

It appears that the little circlip that goes on the pin that goes through the brake shoe to hold it in place came off, allowing the pin to move. It then rubbed on the drum and started the squeak. I stopped and checked the wheels and felt all the hubs, but none where hot. So I thought it was just a stone that had got trapped in a brake drum and I would take the drums off back at the camp site. So I carried on to the petrol station, it being only a mile or so from where I was. THe squeak got louder and I drove slower.....
At the Petrol station, felt all the drums again and the rear passenger side one was hot - Ah! Brakes binding / stone embedded in a brake shoe, I thought. Took the wheel off to be met with the wrecked brake drum!
Phoned Paul Nibblet back at the camp site and he organised a trailer to get Lurch back to the camp site. After considering various options, like removing the hand brake bits completely, borrowing a Brake drum so I could drive home, I opted for using the RAC recovery system.
Luckily the agent I spoke to understood that they were not going to fix it at the side of the road so they didn't send a man-in-a-van first. Still had to wait 4 hours for the flatbed, but he then took me all the way home.

Been on to Dale at Haflinger Technik and order replacement parts. I have a replacement backplate and drum, so I only have to buy the bits inside which are mangled!

Then comes the rebuild!

John

[AustHaflinger]

Hi John - I cannot believe that backing plate cracked like that - they are incredibly strong. I lost a wheel while doing 60kph a few years back and the vehicle travelled on the bitumen for well over 200m on the backing plate and while it got ground down a bit, it did not crack up like yours.

If you have the parts it should go back together ok - just a bit of a pain.

Good luck with it.

Garry

[heinkeljb]

Having ordered all the parts I thought I needed and whilst waiting for them, cleaned the replacement backplate. New bearings to go in the back plate, only to discover I haven't order the bearing for the top little cog. Still I can use the one out of the broken backplate as it is still good. It goes in nicely.
Now to put the outer ring in for the the hub flange shaft. It goes in a little too easily! I thought this was because I had heated the back plate and put the bearing in the freezer for half an hour. I left the backplate to cool down overnight and looked at it this morning - I can turn the outer bearing race ring in the backplate with my fingers and very little effort!
I shall have to take it down to a bearing shop and see if they have a solution. If not then I shall have to look for another backplate.

So another week without the Haf, and I have a trials meet tomorrow which I was going to go to with it. Oh well, I shall just have to go and marshall instead!

John

[AustHaflinger]

If the bearing is hand tight but could spin - putting Loctite bearing fit will hold it. https://au.element14.com/loctite/641-50 ... dp/1370136

[heinkeljb]

I have spent the last couple of weekends sorting out my spare backplate , cleaning it up. Getting bearings etc. Was looking at it trying to decide what else I need to do when I looked at the handbrake system... B**locks ! The backplate is for the other side!!

Thought I might be able to make it fit as the casting is suitable for either side. Only trouble is it looks like there is bush fitted in the hole that is machined to take the handbrake lever shaft. So I would have to drill through the blanked off hole, and then try and get a suitable bush to put in. Not something I have the equipment to do.

So I am going to have to look for the correct side back plate. Oh wait, I think I might have another backplate in my spares.... Rummage through.. Ah, another backplate! Wrong side. Yes!! Another backplate... wrong side!!! So I have three spare backplate sand they are all for the right hand side rear wheel.

Don’t you just love your Haflinger!!!

John

[AustHaflinger]

You have the same luck as I do

[heinkeljb]

Have now got another backplate, correct side this time! It will need a good clean before I use it, but that should not take too long.
I will have to undo the little cog in order to set the wheel bearing preload or it might make the pressure wrong. I will be very lucky if when I have put the new bearings in, the old pre load shim turns out to be the correct size!
Any bets as to needing a bigger or smaller shim?

John

[heinkeljb]

That word which begins with B has a couple of G’s in it and ends in er!!!

The replacement backplate I received yesterday and because it was filthy started cleaning this morning has shown it too has a couple of cracks which I would rather not use it either! So now I think I am going to have to find a machining shop to mill out the blanked hole in my first replacement backplate and put a thread in the open hole so it can be capped. Then I have a useable backplate.. so another couple of weeks as I get no time during the week to do these things - Lurch will have been off the road for at least 2 months over this backplate issue...

Well, on with the welding then!

John

[AustHaflinger]

That word which begins with B has a couple of G’s in it and ends in er!!!

John

You mean this - not a bad word over here - indeed is in our Toyota Ads

https://www.youtube.com/watch?v=6RfAYnCxkK0

Just weld up the cracks

Garry

[heinkeljb]

Yes, I could just get the crack welded up but it will work out about the same as getting getting the hole machined out and there is a possibility the welding the cracks will cause the backplate to warp. So I will go with machining the good backplate.

Actually, even if I welded up the cracks, there would still have to be some machining to clean up the welds as they are right alongside the machines face you put the gasket on. So simpler machining operation to line up and drill a hole and put a bush in it if required.

Gary, did you take the little cog off when you set your bearing preload?

John

[AustHaflinger]

Gary, did you take the little cog off when you set your bearing preload?

John

To be honest I cannot remember - but I thought the bearing that holds the driveshaft and the small cog is not a cone bearing so does not need preload (unlike the wheel bearing on the big cog). I thought by torquing up the drive shaft nut on the driveshaft to the correct torque it covers everything but I cannot remember.

Sorry

Garry

[heinkeljb]

The little cog bearing is just a straight roller bearing with a center that is not fixed in the bearing. The wheel flange shaft is the big bearing which is a cone bearing and therefore needs the pre tension on it. I am pretty sure you should take the little cog off the shaft and put the hub together with out it so you only have the friction from the cone bearing to deal with rather than the added friction of having to turn the little cog / drive shaft / differential bearings as well.
I suppose I should read the work shop manual and see if it says anything other than how you set the preload tension.

John

[AustHaflinger]

Oh Ok - when I have had mine apart I cannot recall setting that bearing up as the outer case was not changed and I used all the bits and shims etc that were already in there.

Yes if in doubt - read the instructions even if they are a bit hard to read.

Garry