Only a Little-Oil-Seal !

[awemawson]

On my 1979 (new to me) Ford 4600 tractor, there is an annoying oil leak on the off side rear wheel - oil fairly pours out of the half-shaft oil seal.

Just a little thing - not much to it really - a £12 item

[awemawson]

So the obvious thing to do is change it. Well it's a bit more complicated than that 

The seal sits on the end of the axle 'trumpet', just behind the inner half shaft flange onto which the wheel mounts. The only way to remove the half shaft is to remove the axle trumpet from the central axle differential casting.

It's all a bit inaccessible 

[awemawson]

So the first thing to do it get the tractor up on my loading dock, far enough forwards and to one side so that when I eventually uncouple the trumpet, I can get the fork lift in close enough to take its not inconsiderable weight.

So here it is with the wheels chocked

[awemawson]

Then we need to loosen the wheel nuts that have probably been on since Adam was a lad. Torque amplifier needed here ! And also remove all the Three Point Linkage arms and rods as they get in the way

[awemawson]

So with the wheel nuts loosened but not removed, jack up the back end and pack it with strong packing, then remove the wheel

[awemawson]

At this stage I decided there was too much 'mud' around - well not actually mud - more cow poop ! It had obviously been on a dairy farm.

Time to break out the steam cleaner - just normal pressure washing wouldn't touch it!

[awemawson]

Came out far cleaner - not perfect but much better to work on

[awemawson]

Here is my Steam Cleaner. It's a Karcher 'MPDS' - it was made for the Military as a nuclear decontamination unit to decontaminate vehicles that had been subjected to battlefield radiation. Totally independent it has a diesel engine and diesel burner - will even suck it's water from a stream if needed. Awsome animal - it can generate super heated steam at up to 214 deg C but my lance and hoses aren't good for that - I limit it to 100 deg C

[awemawson]

So now to drain the oil and get on with the job!

It was at this stage that I realised that the drain plug was where my 'blocking up' was. Incidentally, blocking up like this in the centre is not very stable - it relies on the weight of the wheel that is still attached not to fall over - but it cannot be blocked up anywhere else without putting weight on the trumpet that is being removed 

OK a quick temporary re-jacking block moving and pick up hitch removal to get at the sump plug. B*****r to remove - ended up using an impact wrench - drained the vast amount of oil out - it's supposed to be something like 45 litres, I suppose I got of the order of 30 out - it had stopped leaking as the level had fallen to below the seal 

That's all I got done today - tomorrow I need to remove the various linkages for brakes and the differential lock, and chock up the cab so I can unbolt the trumpet housing.

These trumpets not only have the oil seal, and half shaft bearings, they also have 'wet' ie oil immersed brake disks, a sun and planet reduction gear set, and a dif lock mechanism - but that's all fun for tomorrow!

[tom osselton]

Years ago I had a leaking points seal on my Norton I tryed 2  times tearing it both time but you don't see that till it is back together then I read in a old Nicolson's book to use some paper oiled both sides wrap it on the shaft then slip the seal over it and it works like a hot dam!

[awemawson]

Nice tip Tom. I've always greased them to slip on more easily.

[mattinker]

Were did you get you "Karcher"? It looks like a great machine!

Regards, Matthew

[awemawson]

eBay Matthew. Need you ask

They turn up occasionally

[Meldonmech]

Andrew

              It must be nice to continually have all these varied and interesting challenges in your life, you lucky man.

                                                             Never be bored
                                                                                          Cheers David

[awemawson]

No time to be bored David 

So the weather smiled on me this morning despite the forecast. I started removing the differential lock, hand brake and foot brake linkages. Not too bad, a few seized pins needed the blow lamp to convince  them to come out, but out they came.

I thought it wise to check all the oil was out - it had ceased dripping last night so I'd put the plug back in - but this lot came out - just as well I checked 

[awemawson]

Then while I was still able to have a jack under the end of the trumpet loosened all the bolts holding the cab support on, and the trumpet to the differential housing. Just as well really as some needed quite a bit of swinging on before they loosened.

Then I jacked up the cab so that its weight came off the trumpet / cab support tower and removed the cab support

[awemawson]

Now the serious stuff starts

I removed all but the top two trumpet bolts and brought in the fork lift for a bit of moral support !

[awemawson]

It wasn't possible to get a strop on the trumpet at a likely balance point - it was going to drop on the inner end, so I put a baulk of timber under it and crossed my fingers, took the strain on the forklift and removed the remaining two bolts.

Using the side shift on the fork lift I was able to withdraw the unit from the axle - the drive shaft protruded far more than I had expected but it came out ok in the end.

[awemawson]

I had to take a break then as business phone calls got in the way.

I'll have to devise a better way to get it back in, as the fork lift wasn't sufficiently controlled. I've placed it on my pump up trolley, and I think this is what I'll use to re-install it. I'll need to make a wooden cradle to hold it level, and it'll take a bit of maneuvering as it has to come in from the rear to avoid the cab then go towards the centre to mate the bolts up. Lucky that I modified the trolley when I got it so that all its wheels swivel!

[vtsteam]

Yikes, what a production! Learned something already today, about the oiled paper ring when installing seals. Replaced front bearings and seals on my '51 Deere M, but that was a piece of cake by comparison.

[awemawson]

Well if it was easy it wouldn't be a challenge Steve 

This afternoon I started dismantling the trumpet starting with the dif lock actuator then the brake assembly and actuator

[awemawson]

Then I took out the brake outer housing which allowed the intermediate shaft and planet gears to come out

[awemawson]

So now I could unscrew the bolt that retains the half shaft - well I could if I could stop the half shaft turning 

I resorted to desperate measures and tangled the wheel studs in the handle of the trolley - it worked eventually

[awemawson]

So all that now retained the half shaft in the housing was the oil seal that this effort was all about, but it wasn't giving in easily. I eventually had to carefully cut through the seal housing with a cold chisel and saw and bully it into submission.

This allowed the shaft to come out. Fortunately the bearings are in good condition as is the seal face on the shaft.

[awemawson]

So all that remains to be removed is the outer bearing inner race - need to make an extended puller but that's a job for tomorrow

[awemawson]

So all keen and enthusiastic I made a few mods to my bearing separator - essentially just longer spacers and a longer bridge piece and went at it.

End result - no movement  Tried all the tricks - warmed the race up, gentle taps when under pressure - nowt, zilch, nothing

So I need to find a bigger separator - this one is supposed to do up to a 75 mm bearing inner race but doesn't really have either the beefyness or the spread.

[awemawson]

Received wisdom seems to be to cut the bearing off with a disk cutter and replace - apparently they are notorious for their reluctance to move according to my local agricultural engineer. New bearing on order

[vtsteam]

Irritating.

Leave the pressure on with penetrating oil applied for a few days, tapping lightly, and guaranteed, it will pop loose ten minutes after you have the new bearing in hand!

[awemawson]

You are probably right Steve - that's life !

Spent a little time today making up a timber cradle to make putting it back on the tractor a little easier - seems to work - I did a trial 'offering up'

[vtsteam]

Good thinking! 

[awemawson]

Cradle will also make doing the other side easier - I REALLY should do the other side, but I'm tempted to leave well alone. I suppose if it does start leaking I can drain and reuse the hugely expensive oil I've just ordered (50 litres at £130 inc vat - ouch)

My current concern is the journal that the oil seal runs on - there is scoring on it from a bit of grit - an initial inspection had left me with the impression that it was ok, but now the seal is cut away there is an 1/8" wide score deep enough to catch you nail on. I need to do some measurements to see precisely how deep it is. There a three possiblities:

A/ Use is as is and keep fingers crossed

B/ Mount it up in the cylindrical grinder and loose the scoring

C/ Fit a 'repair sleeve.


A/ Depends on my measurements tomorrow - it may look worse than it is.
B/ Is only applicable if having lost the scoring the journal is still within the interference  range of the seal - I think shaft tolerance on this size shaft is +/- 0.003" but I cannot find figures on how much interference  is engineered into the original fit.
C/ Would be the easiest, but I've not yet found one this size (3.250")

Good news is that the new bearing 'should' be delivered tomorrow

[awemawson]

Just scurried off to the workshop to make some measurements. The seal journal is bang on 3.250" using a Starrett micrometre to measure it. Now measuring the groove is a bit flaky - I had to use a Chinese 12" digital vernier as my Mitutoyo one's jaws aren't long enough to reach round 3.250" - I make the bottom of the groove 3.233 so 50-33 = 17 thou or 8.5 thou deep.

I may turn up a dummy at 3.230 and see how the seal fits on it - no way you can actually measure a seal !

[vtsteam]

Yeah you can, just put some sleeping pills in a mackerel and feed it to him.

 

[awemawson]

Yeah you can, just put some sleeping pills in a mackerel and feed it to him.

 

I thought that Vermont was land locked - what do you know about fishes and seals even if you did live on a boat 

Well the good news is I've tracked down an SKF 'Speedi Sleeve of the correct size

http://www.skf.com/group/products/seals/industrial-seals/power-transmission-seals/wear-sleeves/wear-seals-skf-speedi-sleeve/index.html?prodid=791701160

Found a supplier and placed an on line order. I'll need to turn up a collar to install it as the installation tool they supply won't accommodate a shaft of this length

[vtsteam]

And another thing learned....never knew about wear sleeves.....

Oh the mackerel trick? There's a Roald Dahl story about poaching a flock of game on an estate, involving sleeping pills and raisins. 

[RussellT]

There's a Roald Dahl story about poaching a flock of game on an estate, involving sleeping pills and raisins. 

Danny, the Champion of the World.

[awemawson]

New bearings arrived this morning, so I was happy (wrong - prepared!) to cut off the old one. Went ok -

First I gripped the cage with Molegrips to stop it rotating and cut it with a 1 mm abrasive disk
Then I prised off the cage and rollers - sure those rollers will find a use somewhere 
Then I carefully cut a channel in the inner raceway. As I did this there was a satifying 'crack' as the raceway cracked and coud be removed by hand.

[awemawson]

It was obvious that there had been a bit of fretting between the shaft and inner raceway as can be seen on the picture - this was probably why it wouldn't pull off

[awemawson]

I cleaned it up gently with some 220 grit wet and dry paper but won't do much more before I see how the Speedi Repair Sleeve and the bearing fit. I'll probably put a bit of low strength Loctite bearing retainer on it at assembly time.

I just nicked the shaft with the grinder - but I'm not worried by that as it's very light and the bearing will seat perfectly ok over it.

Sleeve delivery promised for tomorrow

[John Stevenson]

Taper roller inners.

Run round them with a welder turned up high, big wide bead, smack with BFH and they come loose.

Anyway Mawson stop pissing about you could have got away with two wellie tops split diagonal, loaded up with silicone and two big jubilee clips

[awemawson]

Back from your travels then John?

[awemawson]

So the Speedi-Sleeves have proved a bit of a red herring. The one I originally ordered proved too long, the sleeve would have overhung the shaft shoulder by 2 mm where it reduces from seal diameter to bearing diameter. This potentially would not only have interfered with the bearing, but acted as a sharp edge when installing the sleeve. I realised this before it was dispatched and had it replaced by a shorter one that they had in stock.

Now I hadn't realised but the seal actually has TWO lips - an outer smaller one as a dust shield where the wear groove is, and an inner one 10 mm further in where the actual oil seal is. This seating is not noticeably worn, but the Speedi-sleeve wasn't long enough to reach it and having a 'one on one off' situation wasn't ideal  There is a Speedi-sleeve listed that is the ideal length, but it's on 8 weeks back order 

So rightly or wrongly I've decided to re-assemble it with the new seal and bearing and see what happens. If it leaks again I'll order the right sleeve and live with the leak until it arrives.

So I put the trumpet back to together today and managed to get it back on the tractor. To aid this I turned up a 'guide stud to help alignment.

Just got the brake and dif lock linkages to refit and it should (may) be good to go.

[micktoon]

Its some job you have there Andrew , just for an oil seal , I hope to god it fixes the leak after all the effort of fitting the new seal, I will be keeping my fingers crossed for you 

  Cheers Mick.

[awemawson]

Glad to say Mick that that phase seems pretty much over now (fingers crossed)

This morning I got the brake and diff lock linkages back on without too many issues - a few fork holes needed cleaning up, new split pins and she's back.

Replaced the screw on hydraulic filter - the back axle oil in most tractors is used as the reservoir for hydraulic implements)

Then I pumped oil back into the axle - all 47.5 litres. The filler plug is under the back of the cab, so even if you could get a decent sized funnel in it, actually pouring from a 25 litre drum would be pretty hard. So in a flash of inspiration I used my diesel transfer pump. This is a small submersible that fits through the drum opening and works off 12v DC (ie the tractor battery).

All went well pumping the first drum, then part way through the second drum oil started pouring out of the brake operating rod aperture. This is sealed with a little rubber boot - I think it's a daft design to have it below the normal oil level, but that's how it is. Turns out that the spring that closes the boot tight on the shaft was stretched. It now rejoices in a small ty-wrap holding it close to the shaft and seems ok. I would have replaced it in the normal course of things but they seemed unobtainable. However google found me one this afternoon, and I'll keep it 'just in case'.  Continued pumping until dip stick showed full (oil previously never reached the dip stick!) and there were no immediate signs of leaks.

Then I fitted the Hedge Flail right hand bracket (this is what all this palavour has been about!) and put the wheel back. Drove it round the yard a bit, proved that the brakes still worked, and put it back on the loading dock to put the other flail bracket on.

No oil leaks from the wheel bearing seal yet, though it's very early days - there was a single drip from the brake rod seal, though that is likely residue from the previous leak.

So now at long last I can measure up the spacing between the flail brackets so I can start welding up the new flail mount - that will provoke another thread I'm afraid 

[vtsteam]

Good!!



i hope...

[awemawson]

Update:

The axle oil seal is holding up, but that brake operating shaft oil seal started dripping more oil than I was prepared to put up with this morning. So today I drained 25 litres of oil out of the back axle to get the level below the seal and replaced it. Shame I didn't have it to hand when I stripped the axle, but it wasn't too bad (Apart from the fact it was pouring down this afternoon and I got soaked in rain as well as disgustingly oily 

[vtsteam]

Glad the first one worked, Andrew! 
Pain in the neck about the second, but it sounds like you fixed it easily.
Rained here today, too.