Polly Rebuild

[StanK]

Polly Restoration
Hello all, as I briefly introduced my three Haflingers in the Show and Tell section I decided a post in the restoration section might be appropriate. I have encountered a problem that maybe someone can advise on. Hopefully it isn’t an “of course what was I (not) thinking” moment.
I have stripped the Poly cabin Haflinger back and am doing a complete refurbish with drivetrain strip an inspect, engine rebuild (later), rust removal and repainting and interior repairs as well. All guaranteed to keep me poor and off the street for a long time. Luckily, I have an understanding wife!
So refurbishments status so far is:
• Cabin off
• Lots of minor refurbishment and painting done on minor parts
• Body off and whip blasted to inspect rust status
• Chassis partly dissembled (stopped work – see below)
A couple of photos of some items for interest.

Body and off and whip blasted to check rust status.

Typical Rust damage in double floor

Rust damage in rear footwells

Partly disassembled

Now, where I’ve been stopped is that I can’t get the LHS front tube axle (swing arm) off. The book seems to suggest it just comes off and, and indeed the RHS one did. As you can see the LHS one is free of the diff housing but just stops solid when pulled (it is loose). What am I missing? Do I need to pull apart the drive elements on the RHS (Item 19 Group 2 25)? Any thoughts?

The other thing that is troubling me, is the removal of the front (and by extension the back) diff housing from the torque tube, as there seems to be nowhere to gain purchase to pull it off and the dissimilar metals seem to be acting as a glue. I suppose gentle heat and persistence is the go?
Any thoughts/advice?
Stan

[AustHaflinger]

Hi Stan - looking at that pic of the front diff you seem to be trying to take the entire side of the diff off with the swing arm. It is best to take the swing arm off first. I assume you have removed the hub etc off the outboard end of the swing arm.

On the inboard end you need to remove the swing arm fulcrum pins out first - these screw out and the swing arm should just pull out (the boots need to be undone) with the axle inside. You can then do what it looks like you have been trying to do and remove the side of the differential.

On removing the entire front diff housing - hmm I rebuilt the entire front diff a while back and even with the bolts loose I was not able to remove the diff housing from the tube. It was loose but I could not get the housing off. There is something that keeps it on - a large circlip or something similar but I could not work it out. I was able to rebuild the diff with new bearings but had to leave the bearing in the tube that carries the drive shaft from the rear - was all OK.

Unfortunately that Haflinger workshop manual is not the best and is very hard to follow with steps often missing.

[heinkeljb]

Have you taken the oil drain plug out? the little magnet on it sticks up enough to stop you taking the diff out.

John

p.s. The diff only comes out one side.

[AustHaflinger]

Stan I am not sure if this will be of any assistance but this is a link to my thread when I did my front diff.

http://thehaflinger.com/viewtopic.php?f=5&t=2927

Garry

[StanK]

Thanks all, I will gird my loins and have another look when my son has removed all his furniture form the shed!
Garry your thread may have answered my other question regarding the removal of the diff housing from the centre tube with the reference to the small threaded holes at 11 o'clock and o'clock. Thanks John, I have removed the oil drain plug, (but only because the manual says so). It's good to know why.
As for removing the fulcrum pins initially, I didn't get the impression I had to as
(a)the (obscure) manual didn't say to and
(b)I had seen a post from Jeff under Fulcrum pins with a photo of a swing arm on the bench and still attached to the diff side housings.
but I'll revisit the process as soon as I can, and report progress
Once again thanks
Stan

[heinkeljb]

You don't have to take the pins out, it just makes the things you are carrying lighter...
Once you have undone all the retaining bolts holding the flange to the housing. The swing arm will part company with the housing just by pulling the whole arm and flange away from the housing.
If it does not want to come away and gets stopped after moving a few mm / cm. Then I would hazard a guess that the two square "stones" are getting caught on a "wear ridge" in the diff unit. I think you will just have to try pushing and pulling - like using a slide hammer, to get the drive shaft to come out.
Then you can clean up the relevant surfaces afterwards.

John

[StanK]

Thanks John and Garry, I have had success with the rear swing arms in taking them off (although the RHS rear swing arm with entire diff was little heavy), but I have not had any success yet with getting the RHS front swing arm off. The two square "stones" on the drive shaft you mentioned John seem to be loose and rotate freely around their shaft. The actual drive shaft in the swing arm goes back and forth freely, but I seem to be having the same problem Garry alludes to ... it just wont come out. See photos.

So my current plan is to get the swing arm off in situ as Garry suggested and see if that improves things. I am also thinking of getting a borescope and see what is happening now I have opened it a little
My next challenge will be separating the front diff housing form the torque tube. I have taken the nuts off but I reckon the studs have rusted and swelled in the aluminium housing so I might be faced with a grind and cut, and restud the area later. We'll see.
Incidentally I love a vehicle I can put on my bench ... no bending over for me!

[heinkeljb]

Other than the drain plug, only things holding the flange on now are the studs. Plus gas and work the flange back and forth down the studs.

John

[StanK]

Well, it seems that I am at an impasse!
The RHS plate front diff side won't 'come off at all. It's strange, because the other three cover plates (front LHS, and both rear diff ones) came off easily, it's as if the bearing has encountered a ridge on the main shaft and just has won't move any further than about 3 cm. I don't have good heating facilities (and am wary of all the grease and oil in the area in any case), so I am trying to get the diff off the torque tube so I can get it to a workshop with better facilities.
Of course the diff housing doesn't want to come off either, so my next plan is fairly destructive (unless someone has another idea) I plan to cut the studs off flush with the tube and then drill out the studs for the depth of the tube flange. This means that I will need to re stud the whole housing but I can then restore hole dimensions on the tube.

Two other things to ask if I may
1) Is there any special process in taking the gearbox off the torque tube? The nuts have all been removed but I don't see any movement and as usual the manual appears to be silent on this procedure (although there is some info on remounting it)
2) Lastly is this the place on the forum to discuss and ask questions about all this? I'm not sure of the correct protocol/courtesy. It seems that "Polly rebuild" as title covers a multitude of things and could just become a mish mash of questions and answers that help me but may not be of any use to the other members. What do people think?
All the best
Stan

[AustHaflinger]

Two other things to ask if I may
1) Is there any special process in taking the gearbox off the torque tube? The nuts have all been removed but I don't see any movement and as usual the manual appears to be silent on this procedure (although there is some info on remounting it)

I had the same issue as you when I tried this a few years back and I gave up as the bearing noises I had were from within the diff. I could not work out how to remove the front diff from the tube so took a bunt that the bearing in the end of the tube seemed OK which it has been. Yes I found the workshop manual to be no use at all.

I do have a spare tube with front diff attached down in my backyard and was going to look closer to this at some stage but have not got around to it.

I wanted to check my bearings in the tube as there is a filler but no drain so no idea what the quality and quantity of oil is like in the tube - supposed I could park on a slope and suck the oil out but one day I am going to put a drain plug in - in the mean time I just put in a little oil from time to time - the capacity of the tube is huge compared to the oil in it so excess oil is not going to cause an issue.

2) Lastly is this the place on the forum to discuss and ask questions about all this? I'm not sure of the correct protocol/courtesy. It seems that "Polly rebuild" as title covers a multitude of things and could just become a mish mash of questions and answers that help me but may not be of any use to the other members. What do people think?
All the best
Stan

My view is that this is a flow on from you original thread so no problems with it being here. However, equally you could start a thread on each individual sub project but in my view really no need - is up to you - in my view.

Garry

[robw]

Hi,

I separated the centre tube out a few years ago (the central bearing was noisy which took a lot of tracking down) the details are blurry but I don't think that it was much of a problem, also had all the swinging arms out at some point but that was even longer ago.

My experience is that the parts manual (or at least the diagrams in there) are much more useful than the repair manual which is a total waste of trees - never look at it except for settings and torques etc. From the diagrams, the central tube has a male boss on either end and a gasket so it should come apart although obviously clearance is needed. Photo is of the end of a spare gearbox so that you can see what you're dealing with

Rob

[heinkeljb]

Do you have access to a welder? If yes, then weld a nut on the end of the studs and whilst everything is still hot, Unwind the studs. Will mean buying new ones, but that shouldn't break the bank.

Using an angle grinder to cut the studs off and then trying to drill down the middle of the stud is probably going to be difficult as you are unlikely to be able to get a drill to go nicely down the middle of the studs due to things being in the way where you want the drill to be!

You can use the weld on nut trick on ALL the studs, i.e. those holding the swingarm flange as well as the centre torque tube. The heat put into the diff should help with releasing the swing arm and the torque tube.

John

p.s.
Just had a thought. You could make your self a tool using some lengths of thick threaded rod and the nuts used to join threaded rod together. One piece of threaded rod against the diff casing, a long nut, another piece of threaded rod up against the protrusion on the torque tube. Wind the nut to push the two part apart. Might need another set of rods on the other side to keep the pressure even. Similar sort of tool to remove the swing arm flange.

[gren_t]

Hi Stan,
Just a quickie to say thanks for taking the time to post, good luck with the rebuild I suspect I'll be in a similar position soon and will be referencing your progress.

[StanK]

It's been a while since I last posted (and yes I have donated as I really enjoy this site).

Anyway, Polly is now in pieces and is in the throes of having new bearings and some minor gearbox (transaxle) repairs, body repairs, painting etc. … you get the picture.
To my current (minor) issue.
Can anyone suggest a supplier for the double ended studs that connect the front diff to the torque tube (yes I did damage them in disassembly). These are Item 5 in Group 3 05 and are M8 x 100 long DIN 835 grade 8G, with 15mm of thread on one end and 13 mm on the other end.

Yes I know I could use all thread or cut down Grade 8.8 (bolts but I have three objections
1. I would like to do the restoration "properly" if I can and basically all thread is functional but ugly
2. I believe there are some suppliers that can assure me the grade (640 Mpa yield) is OK but I am not convinced, so I am reluctant to go down that road. Can you imagine buying extras to get them tested and then start an argument with a supplier for 8 bolts! Loser!
3. I could butcher some Grade 8.8 bolts but I lack the machinery to cut good threads and hand cutting the threads is a bit of hard work. I will if I have to though.

I am happy to order from overseas if necessary as I live in Australia but surely Oz has someone!
Anyway thoughts/suggestions gratefully received

Some photos of the restoration for everyone to laugh at.

Gearbox

Front Diff

Torque Tube

All the best
Stan

[heinkeljb]

Hi Stan,

Overseas suppliers:-

James at www.haflingerparts.com - UK
Dale at www.Haflingertechnik.com - UK
https://www.autoquariat.at/englisch/teilesuche_eng.php
and probaly several others.
There is Benard Callahan in OZ who has some parts, but probably not those bolts as they arn't a high turn over part.

John

[gren_t]

Hi Stan, Is that a drain plug on the Torque Tube?

cheers..

[heinkeljb]

Hi Gren_t,
Unfortunately not! It is a fill only plug. Another of the strange design quirks of a Haflinger designers mind! Once installed, yo have to use a suction pump to try and remove part of the old oil you ave put in if you have a LWB Haflinger as there is bearing half way down the tube which effectively cuts the oil in two.

No resaon you could not put two drain plugs in if you were rebuilding the main torque tube and clean up the swarf / weld etc, afterwards.

John

[StanK]

Thanks John, regarding the torque tube, I didn't think too much about the plug initially but when I really looked at it, I realised the way it sits won't allow it to be a drain plug. Good to know.
I haven't found how much, or what grade oil to put in the torque tube but I hadn't looked to much yet. When I bought Polly it came with a bunch of spares, including a brand new assembled torque tube still in its paper. I'm not sure what series it is but I might have a look later.
As for the studs thanks for the feedback. I was hoping to just buy them as a conventional item from a bolt company, but I guess I may have to go down the more formal route.
Thanks again
Stan

[heinkeljb]

Oil in the torque tube is the same as the wheel hubs and gearbox / Differentials. About .5 litre. Just remember that there are 4 different torque tubes so measure yours to decide if you have the right one for your particular Haf. (Short wheel base, 4 speed box. Long wheel base, 4 speed box. Short wheel base 5 speed box, long wheel base 5 speed box).

You might be lucky finding the studs via a local nut and bolt store, but they will probaby have to get them for you as a special order so I don't think you will gain much going that route.

John