Freggels 4DM maintenance and fixing blog

[Freggel]

Last week I joined the Nuffield club by buying a Nuffield 4DM (Universal Four) and because everyone likes pictures:


I'm the 4th owner of the tractor. The previous owner only had the tractor for a year and I had the opportunity to have a chat with the 2nd owner as well. The tractor looks good on the outside, although the engine has been patched up because it has been frozen once a long time ago.

The previous owner didn't do any maintenance on it, so I knew from the start that I would firstly have to change change oil, filters and give everything a few squeezes with the grease gun.
While loading the tractor on the trailer, they somehow forced the steering, breaking the bearing and seperating the steering shaft with worm from the rest of the tractor...

The previous owner returned me a decent amount of money because he broke the steering, more than enough to buy a new bearing, filters, oil and grease,... And have some left for other supplies.

Fitting the new bearing was an easy job, putting the worm back in the trunnion nut (is that the right English name?) without removing the fuel tank and steering column was a bit harder. But I succeeded I took out the top oil plug from the steering box so I could wiggle the nut around and fit the worm in. By the way, the bearing has the same dimension as a regular 6305 bearing (25x62x17 mm) but that type can't handle the forces while steering, you need a self aligning bearing type 1305 (not the K -konisch - tapered type!)
The bearing balls of the old bearing are in the bottom of the steering box now, so when the new oil arrives, I will drain the steering box so I can get the bearing balls out.

This is beginning to be a bit of a long post, I'll stop here and write the rest in a next post

[Freggel]

When I did the test drive a few weeks ago I already noticed a rattling sound coming from the injection pump. Thanks to the people on the forum I learned that it was probably the pump drive coupling disc that has some play and causes the rattle.

So after repairing the steering I checked the fuel pump coupling and found that the disc indeed has a lot of play



I started searching for a new one, and learned there exists a newer type that is rattle free. I found a forum member who is disassembling a 460 with the newer type "silent drive" and was willing to sell it (and I was willing to pay the right price for it) so that's on it's way to Belgium now.

I took the pump off the engine and found that there was no oil in it, put some in and it slowly leaked out through the shaft seal. Not the best sign, the pump has probably run dry for quite a while... So I decided to take the pump apart and found that the bearing races are pitted... Disassembled a bit further, the crankshaft is still in good condition. A few spots, but not to be worried about if it's lubricated like it should be. Same for the cam follower rollers. Unfortunately I was in a "zen zone" (I find working on this equipment very relaxing) while working on it and I forgot to take pictures of the camshaft and rollers...
The bearing is a not a standard size. It is an angular contact bearing size 20x47x12 mm. A normal size would be 20x47x15. Luckily I found a UK website that sells injection pump parts so the correct bearings are on their way. The shaft seal looks like a regular 20x35x7 mm.

Fuel pump on the bench:


Bearing outer race:



With the pump removed I got a chance to check the side of the engine, clean it a bit and see how they patched the engine crack. It is patched with a stainless steel plate, probably with a sealing compound behind it.


Unfortunately three days after cleaning and degreasing I found that it leaked a few drops...


Maybe try tightening the bolts a bit, otherwise I will have to take off the plate and check behind it, clean everything up and try to seal it again...

One last thing I noticed was that the v belt was running very deep in the pulleys, found out it is a 10mm wide belt while it should be 13mm.

[diggerdeano]

thats some repair job looks to be a well executed job . thats the problem with block repairs stopping them from leaking .

[Bill Edwards]

Somebody spent some time on that repair.

If you end up taking it off and putting sealant on it you should consider using a thread sealant or at least thread locker on the bolts, as it might be that coolant is leaking through the threads. Oil can certainly do this, I don't know if water would manage it but I'd consider it a possibility.

[Rick Cobley]

Hi, Loctite 510 might be a good sealant, its a hydraulic sealant for gaps upto 0.5mm and also an adhesive. Dont see why it shouldn't work for water!

Regards Rick Cobley

[Freggel]

It looks like a well executed job. Also I didn't notice any leaks when I did the test drive and the the coolant level is still OK, even though the previous owner never checked anything. So it must be a very small leak. But now that the fuel pump is off it would be the best moment to clean everything and reseal it.

Hi, Loctite 510 might be a good sealant, its a hydraulic sealant for gaps upto 0.5mm and also an adhesive. Dont see why it shouldn't work for water!

Regards Rick Cobley

Thank you for the advice, I will look up the exact specs. I have a lot of experience with Loctite 574 (flange sealant) but according to the specs that only seals up to 0,25mm. In the past I also worked with Loctite blue silicone(don't know the number) which seals up to 6mm.

Will keep you posted on the project, but I also have a family and job that come before the hobby

[Bill Edwards]

Hi, Loctite 510 might be a good sealant, its a hydraulic sealant for gaps upto 0.5mm and also an adhesive. Dont see why it shouldn't work for water!

Regards Rick Cobley

It wouldn't be my choice for sealing a plate like that. Good stuff for many jobs, but not my choice for this.
It should work if everything fits together tightly enough, but if the plate bows a bit between bolts or anything isn't spot on I'd expect a leak. Anaerobic sealants are designed for machined surfaces that bolt onto machined surfaces.

I'd use something that's capable of filling large gaps, high temperature RTV would be a good choice. Very important to use it correctly though - many people just shove the entire tube on, throw it together, tighten it up and end up with bits of it everywhere and as a result it gets a bad name.

What you have to do is apply a continuous bead to one surface (thickness depending on the job), then surround all bolt holes. Assemble and finger tighten until it starts to squeeze out of the joint then leave it for 1 hour to partly cure (more in certain condition), then tighten. This way you don't end up with it going places it shouldn't, but leaving it to cure is a nuisance. I use Permatex one minute gasket maker these days for jobs that flange sealant isn't perfect for, but it's expensive stuff.

[Freggel]

I looked it up and Loctite 510 has almost the same specs as the 574 I use regularly in my job (working on tractors and motors is totally new to me but I have experience in industrial maintenance) it also seals only up to 0,25mm, but is resistant to higher temperatures (204°C vs 150°C)
An anaerobic sealant works very well on relatively smooth flanges that fit well together, but for this job I also think a silicone based sealant would be better: seals larger gaps, stays flexible, is very resistant to high temperatures and resists thermal cycling.

The more things I disassemble, the longer the to do (and to order) list becomes.
Because the rpm gauge doesn't work and the cable shielding is almost completely worn away, I thought the cable was broken because the gauge itself looks good. After removing the cable it appears the cable is in working condition, but the gauge is stuck and the part where the cable fits in is broken. To do: fit new cable and order new tractometer.

I also took off the v belt so I can mount the new one, now I noticed the dynamo shaft has a lot of radial play. It's probably still the original dynamo so the bearing might be worn. To do: open the dynamo and check for damage. Replace bearing, replace dynamo if there's more damage.
I was thinking about maybe mounting an alternator because the 11 Amp dynamo is barely sufficient for the tractor lighting. 2 36W front lights, 4 10W sidemarkers and rear lights (I know they should be 5W, but with all those modern LED taillights on cars you barely get noticed in the dark) makes a total of 114W, that's almost 9,5 amps! And in Belgium we are obligated to have at least one orange beacon when driving in dusk/dark, so that will take some more power. I found a dynamo alternative: a 45 Amp alternator, built in a dynamo housing. It looks exactly like the original Lucas 39C dynamo, fits the original pully and mountings, but it delivers far more power and you don't need the external regulator anymore. Maybe something to keep in mind... I could also change all the lights to LED, but I don't know if I will like all that bright white light on a classic tractor.

One last thing that luckily didn't disappoint me was taking off the valve cover. Doesn't look too dirty, so I think I'll just leave that the way it is and maybe just check the valve clearance.

[Rick Cobley]

Hi, This might help if fitting an alternator

viewtopic.php?f=14&t=17

Regards Rick Cobley

[Freggel]

Last week the new bearings for the fuel pump arrived, so I reassembled the fuel pump after soaking a few last things in degreaser.

If anyone would be interested: the bearings seem to be "E20". Never heard of that before, I bought them from a webshop that specializes in fuel pumps. Knowing now what they are I could probably buy them at a local store.


A few last items soaking in degreaser. The pump is put upside down so the cam followers won't fall out without the camshaft supporting them.


The pump is reassembled now. I took it apart to clean, but I didn't take the control rod out. Also I kept everything in place, all parts from cilinder 1 are back to 1, 2 to 2 etc. If you switch parts between cilinders it might need to be phased and calibrated again.

Before I can put the pump back on I decided to take the stainless steel plate of the side. So I drained the coolant and removed all the bolts. It came off quite easily. It appears a sort of silicone was used to seal it and the same stuff was used on the bolt threads.


After cleaning everything off it looks like someone has tried to weld the block. Apparently that didn't work, so in came the silicone sealant and the stainless steel plate...


Now I'm waiting till the sealant I ordered arrives, together with a new fuel filter (a Mann P824x seems to be the right equivalent for the Simms fuel filter) so I can seal it up again with the plate and put the fuel pump back. This time with a 2nd hand "rattle free" coupling off a newer model Nuffield.