Author Topic: Only a Little-Oil-Seal ! (Read 27887 times)

awemawson · « **Reply #25 on:** July 16, 2014, 05:50:05 AM »

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 · « **Reply #26 on:** July 16, 2014, 06:32:20 AM »

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 · « **Reply #27 on:** July 16, 2014, 08:37:18 AM »

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 · « **Reply #28 on:** July 16, 2014, 10:26:30 AM »

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 · « **Reply #29 on:** July 16, 2014, 10:38:27 AM »

Good thinking!

awemawson · « **Reply #30 on:** July 16, 2014, 02:41:21 PM »

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 · « **Reply #31 on:** July 16, 2014, 03:09:53 PM »

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 · « **Reply #32 on:** July 16, 2014, 03:13:59 PM »

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

awemawson · « **Reply #33 on:** July 16, 2014, 04:49:42 PM »

Quote from: vtsteam on July 16, 2014, 03:13:59 PM

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 · « **Reply #34 on:** July 16, 2014, 09:47:33 PM »

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 · « **Reply #35 on:** July 17, 2014, 06:13:26 AM »

Quote from: vtsteam on July 16, 2014, 09:47:33 PM

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 · « **Reply #36 on:** July 17, 2014, 06:26:08 AM »

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 · « **Reply #37 on:** July 17, 2014, 06:29:45 AM »

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 · « **Reply #38 on:** July 17, 2014, 06:33:25 AM »

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 · « **Reply #39 on:** July 17, 2014, 06:43:12 AM »

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 · « **Reply #40 on:** July 17, 2014, 06:46:24 AM »

Back from your travels then John?

awemawson · « **Reply #41 on:** July 19, 2014, 11:34:20 AM »

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 · « **Reply #42 on:** July 19, 2014, 05:43:22 PM »

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 · « **Reply #43 on:** July 20, 2014, 11:47:38 AM »

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 · « **Reply #44 on:** July 20, 2014, 12:42:51 PM »

Good!!

i hope...

awemawson · « **Reply #45 on:** July 27, 2014, 05:23:40 PM »

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 · « **Reply #46 on:** July 27, 2014, 07:55:10 PM »

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.

News:

Author Topic: Only a Little-Oil-Seal ! (Read 27887 times)