Super major diff locked on.

This forum is for the Fordson New Major, including the Super Major and the Power Major.
Billy26F5
True Blue
Posts: 697
Joined: Fri Jun 26, 2020 12:01 am
Location: On Billy

Re: Super major diff locked on.

Post by Billy26F5 »

The final reduction gear is the largest gear in a Major and is attached to the axle shaft with a LH thread nut (works the other way round). Unstake the seal housing just next to the hub, remove the nut and hold the gear with something (a wooden wedge will do fine) and pull out the axle shaft about 6". Lift out the gear and then you can access the bull pinion carrier, remove making sure that you count all the shims between the main casting and the carrier flange and don't loose any, as they control the pre-load and backlash in the diff and crown wheel. Everything is very heavy! If you can't get it out the stuck diff lock could have something to do with that, you'll then need to do the other side and check the crown wheel thrust pad comes out too (shims and or gaskets there too). It should then come out.
Sandy
ImageImageImage

Emiel
True Blue
Posts: 549
Joined: Wed Apr 16, 2008 3:22 pm
Location: Netherlands

Re: Super major diff locked on.

Post by Emiel »

Hi,

Don’t forget to mark the position of the nut against the gear and count the number of turns to undo the nut. If you reassemble the same then the bearing preload here should be fine.

Setting pre load isn’t difficult but involves a lot of work when you do it by the book.

Regards
Best regards

Emiel

N 1937, E27N 1948, 8N 1948, E27N 1950, E1A Diesel 1953, E1ADKN PP 1956, Dexta 1959, NH Clayson M103 1964

shepp
True Blue
Posts: 241
Joined: Thu Oct 06, 2011 8:24 pm
Location: Lancashire

Re: Super major diff locked on.

Post by shepp »

I am a bit concerned at the amount of dismantling that you are being encouraged to do here. Some say to take off the top cover so you "can see what is going on". You will not be able to see and cannot see what is going on - the diff lock coupling is enclosed within the diff and even if you look down the hole in the diff casing that is nearest to the crown wheel I doubt that you will be able to see the coupling, all you will be able to see is a few teeth of the left hand differential side gear. From the picture you have posted all you can see is that there does not appear to be any corrosion and all seems well lubricated. If you go down the route of un-stakeing the axle shaft oil seals, removing the reduction gears and withdrawing the axle shafts, then in my opinion you will have to fit new oil seals and set the bearing pre- load up again - or run the risk of leaks from the oil seals once they have been disturbed!

The diff lock coupling is essentially an extension of the right hand bull pinion shaft and it slides in the female splines of the right hand differential side gear on the end of the bull pinion shaft. When the diff lock pedal is depressed the push rod moves against a spring connected to the coupling to slide the coupling towards the left hand differential side gear to engage with the female splines in the left hand gear. This locks the left hand and right hand diff side gears together and consequently the left and right hand bull pinion shafts together which results in a solid drive to the rear axle. When the diff lock pedal is released a spring in the end of the right hand bull pinion shaft moves the push rod back and it brings the coupling with it disengaging from the left hand diff side gear and releasing the solid drive to the axle.

There are two possibilities. The first is that the coupling is stuck in the left hand diff side gear or the right hand diff side gear or both. The second is that the " feathering spring" or the washer that abuts the coupling has collapsed and a bit has got between the coupling and the end of the right hand bull pinion shaft so that the coupling cannot fully withdraw and disengage from the left hand diff side gear. If the first case applies you will not be able to remove the right hand bull pinion shaft and it's housing even after going to the trouble of removing the axle shafts and reduction gears, because the bull pinion shaft assembly will still be stuck in the diff. You will then have to go through my suggestions outlined below and use a drift inserted from the left hand side to drive out the coupling from the left hand diff side gear and/or the right hand diff side gear, taking the right hand bull pinion shaft with it. If the second case applies you will be able to withdraw the right hand bull pinion shaft and housing, the trouble is you will not know which case applies until you get there!

In my view it is essential to get the left hand bull pinion shaft out before you dismantle any further. Make up a tool by obtaining two exhaust clamps about the size of the bull pinion shaft. Obtain two lengths of about 2 inch flat bar which are long enough to span the width of the bull pinion housing. Drill the flat bars around the middle of the length with two holes to fit the width of the clamps. Drill to one side so that when both clamps are installed it will be possible to have both flat bars in the same vertical plane. Assemble one U section and top section of a clamp onto the pinion shaft, but before fitting the nuts place one of the bars onto the clamp then fit the nuts and tighten down securely! You will not damage the pinion shaft, the material is much harder than the clamp. Then assemble the other clamp and flat bar at 180 degrees to the first, diametrically opposite on the pinion shaft with both bars parallel, tightening down firmly.
Obtain 2 lengths of screwed rod the same diameter and thread as the bull pinion shaft bearing housing retaining bolts, together with nuts. Obtain two plates wide enough to span the distance between the two flat bars, which will be more than the diameter of the bull pinion shaft, and drill the plates centrally. Pass one rod through the gap between the flat bars, place a plate on the rod behind the flat bars then a nut, then screw the rod into one of the bearing housing retaining bolt holes. Do the same with the other rod and plate on the opposite side of the bull pinion shaft so that the two rods are at 180 degrees to each other. Run the nuts up to the plates, then using a spanner half a turn at a time you can put pressure on the plates and hence the flat bars and clamps and slowly withdraw the bull pinion shaft and bearing. Having withdrawn the left hand bull pinion shaft and bearing, try the same method on the right hand bull pinion shaft. If it fails to withdraw due to the coupling being stuck in the left hand diff side gear or right hand diff side gear then you will need to insert a drift through the left side bull pinion shaft bearing housing and the left side diff side gear and gently tap the coupling out of the left hand and right hand diff side gears also bringing the right hand bull pinion shaft and bearing out. Use a tubular hollow drift of a diameter that will just go through the left hand diff side gear so that it contacts directly onto the outer rim of the coupling and not onto the nut on the end of the pushrod, to avoid damaging the pushrod and nut.

Once you have got the right hand bull pinion and bearing and diff lock coupling out, you can examine for damage and dismantle the assembly to check it out.
1946 E27N, 1952 Major Diesel, 1959 Power Major, 1962 Dexta, 1962 Super Dexta, 1963 Super Dexta NP, 1964 Super Major NP, 1965 Super Dexta 3000, 1966 Major 4000, 1967 3000 PF, 1994 5640,plus Basildon built NH.

Nickm
Not Quite Blue Yet
Posts: 18
Joined: Fri Apr 16, 2021 3:53 pm

Re: Super major diff locked on.

Post by Nickm »

Sorry if this is a repeat post...
Anyway, it's quite unbelievable how many things can go wrong with getting stuff delivered. Been waiting weeks for a couple of tools.
I'll update this thread when there's more I can add.

Nickm
Not Quite Blue Yet
Posts: 18
Joined: Fri Apr 16, 2021 3:53 pm

Re: Super major diff locked on.

Post by Nickm »

Well after weeks of waiting I finally received some tools.

I have managed to spend several hours over the past few days having a further go at this problem.

I have got nowhere.

Shepp, I understand what you are saying about all the dismantling, but I had already removed the top cover when I read your post. Besides, there is a good chance something could have come loose and needs retrieving from the oil somewhere.
But I have tried a method similar to what you describe to remove the left hand pinion (and right hand pinion).

I put quite some pressure on both to pull them out and neither will budge. I could have put more pressure on, but really don't want to break anything.

I also did pull out the left axle shaft to try to remove the reduction gear. But there isn't enough room around it to manoeuvre it and lift it out. Mainly because it fits quite deeply into the pinion shaft housing, and also because of the bits that protrude on the back of the reduction gear
(Hmmmm....Can't remove the reduction gear without removing the pinion housing and can't remove the pinion housing without removing the reduction gear).

So, I am stuck.

It's a bit of a nuisance to say the least.

Billy26F5
True Blue
Posts: 697
Joined: Fri Jun 26, 2020 12:01 am
Location: On Billy

Re: Super major diff locked on.

Post by Billy26F5 »

The final reduction gear is very heavy, with the axle shaft out it should lift out fine if you first move it towards the hydraulic pump. As the bearing comes out move the gear backwards to clear the bull pinion carrier.
Sandy
ImageImageImage

Nickm
Not Quite Blue Yet
Posts: 18
Joined: Fri Apr 16, 2021 3:53 pm

Re: Super major diff locked on.

Post by Nickm »

Ok thanks sandy.
I'll certainly try that again today.
Would really love to get this problem sorted.

shepp
True Blue
Posts: 241
Joined: Thu Oct 06, 2011 8:24 pm
Location: Lancashire

Re: Super major diff locked on.

Post by shepp »

If you are using a set up like I suggested to try and remove the bull pinion shafts with their bearings then you will not cause any damage to the axle components no matter how hard you tighten down on the extractor nuts. Make sure you have used high tensile studs/threaded rod and high tensile nuts. Apply even heat to the rear axle casting that the shaft and bearing sits in using an electric heat gun if available. Once the casting feels warm to the touch keep heating and tighten the nuts a quarter turn at a time, give the casting a few taps with a hammer and keep heating and tightening. You will strip the threads on the screwed rod or the clamps will give way long long before there is the slightest chance of damaging any of the axle components. It will probably need pressure equal to a 5 ton press or more to remove the bearings/pinion shaft from the housing after being installed for so many years, so don't be shy about putting pressure on the nuts. Even if you get the reduction gear out it probably won't take you any further forward.
1946 E27N, 1952 Major Diesel, 1959 Power Major, 1962 Dexta, 1962 Super Dexta, 1963 Super Dexta NP, 1964 Super Major NP, 1965 Super Dexta 3000, 1966 Major 4000, 1967 3000 PF, 1994 5640,plus Basildon built NH.

Billy26F5
True Blue
Posts: 697
Joined: Fri Jun 26, 2020 12:01 am
Location: On Billy

Re: Super major diff locked on.

Post by Billy26F5 »

It will probably be less fuss to remove the bull pinions complete with the carriers, as access to the diff lock will be equally good if only a bit heavier, as the carrier is quite heavy too. You're probably just as well to check the differential too, as the pinion thrust washers get very worn and will probably benefit from replacement. Remember to count the shims between the carrier and the rear axle casting.
Sandy
ImageImageImage

Nickm
Not Quite Blue Yet
Posts: 18
Joined: Fri Apr 16, 2021 3:53 pm

Re: Super major diff locked on.

Post by Nickm »

I've had another go at lifting the gear out.
There's just not enough room.

The front of the gear is right up against the pinion holder.
The back/bottom of the gear is right up against the hydraulic pump. The bearings at the right of the gear hub are not really close to clearing the casing.

Hope these pics are ok.

Image

Image

Image

Billy26F5
True Blue
Posts: 697
Joined: Fri Jun 26, 2020 12:01 am
Location: On Billy

Re: Super major diff locked on.

Post by Billy26F5 »

Try bringing the gear backwards, it should come. If it doesn't you could try loosening the RH axle casting and moving it out a wee bit.
Sandy
ImageImageImage

Nickm
Not Quite Blue Yet
Posts: 18
Joined: Fri Apr 16, 2021 3:53 pm

Re: Super major diff locked on.

Post by Nickm »

Well, I unscrewed the axle casing as much as I could without it coming off completely, which was about 2cm-ish.

This created more room.

But still not enough to remove the reduction gear.

It's caught mainly between the pinion housing, the hydraulic pump, ridges and bumps at the back of the casing and the side of the casing still, even though the axle casing wasn't in the way this time.

Think I'll have a cup of tea and a think!

Image

Image

Billy26F5
True Blue
Posts: 697
Joined: Fri Jun 26, 2020 12:01 am
Location: On Billy

Re: Super major diff locked on.

Post by Billy26F5 »

That looks pretty clear, remember it's very heavy and carefully lift it out.
Sandy
ImageImageImage

Nickm
Not Quite Blue Yet
Posts: 18
Joined: Fri Apr 16, 2021 3:53 pm

Re: Super major diff locked on.

Post by Nickm »

It's fixed.

Had to unbolt and move the hydraulic pump to remove the reduction gear.
It just didn't have enough room otherwise.

Then getting the pinion out still inside the carrier was easy

It was then obvious what had happened.
The nut and split pin were gone from the end of the push rod.

The split pin was in three pieces still inside the top of the coupler (is that what it's called).

The nut had vanished.

Fished around in the oil underneath the differential, and promptly found several pieces of broken up castellated nut.

So, put a new nut and split pin on. All works.
Just need to spend a couple of days reassembling everything.

Here's a pic of the coupler with various broken bits.

Image

Thanks to everyone on here for your help.
Wouldn't have had a clue otherwise.

Billy26F5
True Blue
Posts: 697
Joined: Fri Jun 26, 2020 12:01 am
Location: On Billy

Re: Super major diff locked on.

Post by Billy26F5 »

Good stuff. Hope everything works properly now.
Sandy
ImageImageImage

mathias1
Site Governance Team
Site Governance Team
Posts: 647
Joined: Fri Jul 08, 2016 7:11 pm
Location: Antwerp - Belgium

Re: Super major diff locked on.

Post by mathias1 »

while you are there, better replace the o-ring on the shaft
Fordson Super Major New Performance
County Super 4 built on the Fordson Super Major

shepp
True Blue
Posts: 241
Joined: Thu Oct 06, 2011 8:24 pm
Location: Lancashire

Re: Super major diff locked on.

Post by shepp »

Good job, just re-assemble methodically now, it is a bit of a puzzle why the nut disintegrated, all it had to do was to withdraw the coupling. Have a good look see if you can see any reason for it.
1946 E27N, 1952 Major Diesel, 1959 Power Major, 1962 Dexta, 1962 Super Dexta, 1963 Super Dexta NP, 1964 Super Major NP, 1965 Super Dexta 3000, 1966 Major 4000, 1967 3000 PF, 1994 5640,plus Basildon built NH.

Billy26F5
True Blue
Posts: 697
Joined: Fri Jun 26, 2020 12:01 am
Location: On Billy

Re: Super major diff locked on.

Post by Billy26F5 »

The reason for this nut coming off is as mysterious as Billy's oil pipe support coming off and a diff pinion breaking up, causing the same effect as a diff lock. Ensure everything is strictly clean before reassembly.
Sandy
ImageImageImage

Nickm
Not Quite Blue Yet
Posts: 18
Joined: Fri Apr 16, 2021 3:53 pm

Re: Super major diff locked on.

Post by Nickm »

Must admit to being a bit concerned as to why the split pin or nut failed in the first place.

Don't know when it failed either.
6 months ago or 50 years ago.

I will just be checking everything is clean before reassembling.

The very few times I have driven it there was no nasty noises or anything, so fingers crossed, all the bits are no longer causing a problem.

None of the bits I can see looked damaged.

Billy26F5
True Blue
Posts: 697
Joined: Fri Jun 26, 2020 12:01 am
Location: On Billy

Re: Super major diff locked on.

Post by Billy26F5 »

Do make sure everything is clean, other than that just be careful with the weight of the various parts.
Sandy
ImageImageImage

Post Reply