Hub gears and wheel bearings

[heinkeljb]

Gary,

Aren't we lucky you were the guinea pig! As you say, other than different part numbers, there is no mention of the fact that gears are a different THIICKNESS between front and rear hubs.

What's the betting that there are a lot of Haflingers out there which are running the narrower ones in all 4 hubs.... Sort of makes sense to have slightly thicker ones in the rear as the vehicle is mainly rear wheel drive with part time 4 wheel drive.

John

[AustHaflinger]

Gary,

Aren't we lucky you were the guinea pig!
John

I am beginning to feel like that - I have the old gears spread out on my coffee table in front of me and at a quick glance the difference is not obvious but on closer scrutiny there is about 3 mm in it. I agree with your logic about why there is thicker ones at the rear but really at the design stage they could have all been made the same size - as a military vehicle it would be one less item that would have to be carried in the inventory.

Cheers

Garry

[heinkeljb]

So far, the only thing on these vehicle that makes any sense as it being a "military" vehicle is fitting a governor! Oh. and possibly the sealed ignition system, but that should be available on any off road vehicle.

It was obviously never thought that this would ever be a front line vehicle or else they thought it would never break down!

I hope you guess correctly when you take one of the rear hubs apart and get the other narrow gear first time - Can I take a bet on which hub you have put it in?
(other side front)

John

[AustHaflinger]

I hope you guess correctly when you take one of the rear hubs apart and get the other narrow gear first time - Can I take a bet on which hub you have put it in?
(other side front)

John

Do I wish but it is not going to work like that - the smaller gears are also thinner in the front and thicker in the rear so I need to check these also.

The lot needs to come back out - but having learned all the tricks it will not take long - the brakes stay on and the wheel bearings are already shimmed up so this does not need to be done.

Cheers

Garry

[heinkeljb]

Shimming will change when you remove the big cog wheel and replace with one of a different thickness surely? I don't remember shims under the small cog, but if you have fitted a different thickness one there then it might need shimming too.

Just had a thought, it might explain why you had to change the shims when you first started doing the swap. Maybe with the correct thickness cogs in place the shims will be nearer what you took out.

John

[AustHaflinger]

No shims on the small cogs - re the shimming for the wheel bearings the thickness of the cogs only apply to the outer rims where the teeth are - the inner faces where the splines are and where the spacers are all the same. When replacing the original 70kph cogs with the new 75kph hubs redoing the wheel bearing shims was necessary as the inner faces of the new cogs slightly different to the old ones but I have taken this difference into account by redoing wheel bearing clearances.

On reflection I misunderstood this comment from Jim

A few quick tips, do them 1 at a time and measure gear height, replace with closest match from new set.

Clearly Jim (and once again thanks for your input) was referring to a measure that would have prevented the position I now find myself in - I took the comment to mean check the diameters of the cogs rather than the thickness of the cogs - doh - I need to take more notice of the valued comments provided. The light had not come on about this comment until I was out at dinner last night and my host mentioned he had read the posts on here and said Jim had raised this issue and what a dummy I was

A lesson learnt.

Hopefully as a result of my folly others in the future will not make the same error - but anyway thanks to Jim and Constantin mistake picked up and all will be well.

Garry

[kerry460]

if I remember correctly there were 4 different ratios .
I did have a retired machinist make a number of different spacers when I was doing the bearings .
kerry

[AustHaflinger]

All cogs now in their right spots - both left hand hubs were right and both right hand hubs were wrong - all fixed.

Moved on to the drivers CV - not as good as the passenger side as it had virtually no grease in it and is a little loose but marginally OK. Maybe I should replace it but given their cost I will refill this with new grease and risk it and if it turns out to be not so good I will then buy a new one.

With my knew found expertise in hub removal and disassembly it would not take me long to replace it and I might save a few hundred pounds if it is OK.

I am going to drill a hole in the side and braze in a plate like the other side so that I can fill the CV with grease without having the remove it.

Garry

[AustHaflinger]

Just a final post on this (I hope).

Everything back together and covered about 500km. Engine revs are much lower and I happily cruise at 70kph at 4000rpm with a top speed somewhere around 85-90 (I haven't tried it) with engine revs staying below max redline. There is no noticeable loss of acceleration or climbing ability and it still hangs on in 5th gear up normal sized hills when on the highway so I have achieved what I wanted to.

The hubs were not OEM but reproduction - cast then the teeth machined to take off the rough castings (dags). This was done but the teeth were still a bit rough so I was expecting for them to take a while to bed in and to through up a bit of excess material in the hub oil. A magnetic drain plug would have been nice to have in the hubs.

Because of this I decided to change hub oil very early which I did about 50km and as expected the oil was very silver like metallic grey paint with very tiny flecks of metal. In with the new oil and now at 500km I have changed the oil again - still very silvered but the hubs all work fine. I will flush and change the oil again in about another couple of hundred kms as it is clear the hub gears are still bedding in.

Learning Point.
When I did the hubs I replaced the wheel bearings but if I had to do this again I would have probably left the old bearings in and ran them until the hubs were fully bedded in, and silvering of the oil stopped. Then dismantle the hubs and put new bearings in. While I don't think that the microscopic metal particles from the hubs bedding in will be an issue for the new bearings I put in, who knows. On refection replacing them after the hubs have bedded in would have been the better option. Likewise adhering a small magnet to the drain plug would be a good idea.

Cheers

Garry

[heinkeljb]

Point well made about leaving the old wheel bearings in until the gears have stopped shedding metal

You can drill a small hole in the end of the hub oil drain plug and then use some thing like "chemical metal" to bond a magnet in to the hole. Would be a useful addition, particularly now whilst you know the oil is going to have metal bits in it.

Well done that man!

John

[kerry460]

i would ad a small rare earth magnet .
also flush with kerosene , or diesel .
but preferably on jack stands and idle over to mix it up .
but after you install the magnet .
kerry