Replacement gearbox oil

[major m]

Hi all
May i be one of the first to wish all a very merry Christmas
I have a question regarding gear oil in my super major. It seems to have an EP type oil in it that has that typically gear oil smell. Would it be advisable to change it for the correct oil as in engine and rear end or would be harmful to the gear box

Many thanks
Mark

[fnoller]

I think fordson newer used gearbox oil, they used sae 30hd http://www.fordsontractorpages.nl/phpbb ... ?f=2&t=827

And merry christmas to u too

[major m]

Thank you for the reply fnoller. At least now I won't need to replace the oil, only top it up as its quite low.
Didn't realise how low until I fitted a belt pulley and the oil was at least 2 inches down from the opening for the pulley

[AdrianNPMajor]

If your gearbox is that low, I'd consider draining the existing oil and replacing with new. Brian recommends Morris oil products and I must say I like them too. If you choose their classic vehicle range, you'll have no more misgivings.

The very low oil level is something that needs to be addressed asap. The bearings at the top of the box will be starved of adequate lubrication and will be in danger of overheating and breaking up. The one at the top rear is particularly prone to this- on my NP Super it had fallen apart under these very circumstances. When I acquired the tractor, she was parked in a hedge and when I heard the clatter in 3rd gear high ratio, I knew why! [gearbox rebuilt now and pulls like a train ].

Lastly, you need to find out why the oil level in the gearbox is so low. It may be that the lower of the two seals that stop the oil from flowing into the rear axle has failed. If it has, you'll need to drain the gearbox, remove the pto shaft, and drop the pto idler gear housing from the bottom of the gearbox. This is where the seal in question is located. Bit of a s*d to get out (but easy to get the new one back in).

Hope these thoughts are helpful.

Happy crimble to you too!

Adrian

[major m]

I've had the tractor about a year and have driven it only about 600 yards as its been sat in the garage doing not a lot..
I'm not sure of the history but when I got the tractor there was 12 litres of oil in the engine due to the wrong dip stick being used, the rear core plug had been repaired with filler and water spued from radiator breather, so not well looked after me thinks.

Thanks for the heads up Adrian ill check the seals out. It seems a possibility your right as the back end is over filled by a good margin according to the dip stick. I'm new to all this tractor lark so still learning I hope

Many thanks
Mark

[AdrianNPMajor]

Hi Mark

When I say drain gearbox before removing the pto idler gear assemble, I should have said drain gearbox and rear axle. You'd have to do this anyway to remove the pto shaft, but does no harm to be absolutely clear.

There is also an upper gearbox seal that really ought to be replaced for peace of mind. This fits around the final drive going into the rear axle. You have to split the tractor between rear axle and gearbox, but once you've got her apart, the seal is easy to get at and to replace.

More detailed info as you require it, if you need it.

Best wishes

Adrian

[major m]

Advice most appreciated and yes this could become a regular request for advice

Many thanks again

Mark

[AdrianNPMajor]

Got photos as well, Mark. They explain a lot.

Best wishes

Adrian

[major m]

The two seals you refer to, can you tell me where to get these and what the technical name is for them.
I get a bit confused with all the different names/types of seals

[AdrianNPMajor]

Hi Mark

These photos show where the seals are located. More explanation to follow.

Best

Adrian

[AdrianNPMajor]

Hi Mike

The first photo is of the pto idler gear assembly removed from below the gearbox, cleaned and partially disassembled. If you look into the opening you will see two shoulders. The first is where the seal sits, the second where the bearing sits. I tapped the shaft and bearings off their shoulders in the casting so that I could get behind the old seal to draw it out. Bit of a struggle but it will come. The new one pushes in easily. The seal prevents oil from traveling from gear box to rear axle, and from rear axle to gear box, so it needs to be a double lip seal. I got mine from Silver Fox Tractor spares. Speak to Jeff. He's very knowledgeable and helpful.

The upper seal is easy to get at and replace - once you have split the tractor between gearbox and rear axle. The third photo shows the final drive coming out of the back of the gear box. Remove the collar secured by the locking bolt, then the seal housing held in place by the four bolts. The seal is then a doddle to remove and replace.

The plug above the final drive gives access to the uppermost bearing at the rear of the gearbox. It was this one that had broken up on my tractor.

The fourth photo is just for reference to show you what you're going to see when you open her up.

These two seals won't have seen the light of day for nearly fifty years. That's why I would recommend replacing them if possible. You then have peace of mind and you'll never have to touch them again.

Hope this is helpful.

Best

Adrian

[Pavel]

Adrian, have another go at those pics please.
Pavel

[AdrianNPMajor]

Hi Pavel

Photos are visible when I view the page. Are you unable to see them?

Best

Adrian

[fnoller]

Hi Pavel

Photos are visible when I view the page. Are you unable to see them?

Best

Adrian

Their also visible when im looking

[major m]

Thanks Adrian
Received photos and you make it sound so simple I just hope it's as easy as it seems. I'll let you know when it's done but please don't hold our breath you may turn a bit blue

Thanks again
Mark

[AdrianNPMajor]

Hi Mark

So sorry for getting your name wrong.

If you decide to split the tractor and do the upper seal, it would be wise to do a few more seals while you've got her drained of oil and apart. In photo 4 you will see the two seals on either end of the brake/clutch pedals shaft. These are a ten minute job to replace.

Also, with the pto shaft out, you may as well replace the seal that sits just inside the backing plate casting. A spring clip holds the drive gear in place. Remove the clip and tap the gear of its shaft fit. Then remove the next clip that holds the casting in place on the bearing and then tap the casting off the bearing, which will remain in place on the shaft. Look inside the casting recess and there you will find the seal. Extract, replace and reverse the above steps.

The only other seals in the rear axle section are the brake bull pinion seals. These can wait for when they fail, because you can do them without draining the rear axle - just drive the tractor up onto a block on the side you want to change to keep the oil away.

Have fun!

Best

Adrian

[AdrianNPMajor]

This photo might help with removing the pto seal. I should have said that there are two circlips securing the pto drive gear - one either side.

[Dandy Dave]

Thanks Adrian
Received photos and you make it sound so simple I just hope it's as easy as it seems. I'll let you know when it's done but please don't hold our breath you may turn a bit blue

Thanks again
Mark

As long as it is Fordson Blue, you will be alright. Dandy Dave!

[Pavel]

Thanks, Adrian -- excellent pics visible. No idea why not before.
Whilst not splitting SM yet [not for a long while, I hope] but like downloading things for future reference.
Pavel

[AdrianNPMajor]

Pleasure, Pavel.

Until I did them, I was always a bit mystified as to where these two seal were, and what it took to replace them to stop the oil from leaking from the gearbox into the rear axle.

On the lower one, when you come to replacing the pto idler gear assembly, there is a large O ring seal that mates up against the gearbox proper, sealing the pto shaft tunnel. I found it tricky to keep this in position whilst offering up the casting to get the bolts in (it's quite a heavy lump). The first time I did it, it leaked. The second time I superglued it into position on its shoulder and for good measure applied some black silicon liquid gasket. It worked perfectly.

Best

Adrian