Fiat 50 c crawler info

[Ian.Stewart-Koster]

Thanks, D.P. are the trunnions just the 'knobs' that the push arms pivot on, or are they the whole long bit of angle iron/channell that the links & hydraulics all attach to?

I hadn't thought of that idea.

(edited to fix a typo & then another one)

[Ian.Stewart-Koster]

Thank you again, DP.
I had not ever thought of the idea of extended trunnions. Are they an expensive commodity? Would they need much bracing back toward the back driving gear?
The caps that go around them will also benefit from being renewed too-the 55 had been used in pretty sandy abraisive country for much of its life.

You're right, too-Hydreco has also faded by the wayside...

We appreciate the advice.

[Deas Plant]

Hi, Ian.
The trunnions are the fittings that the blade push arms attach to at the side of the track frames, the 'knobs' as you called them - NOT the whole lift ram mounting-lift triangle mounting arrangement. If you extended them outward, it would be advisable to make those exrtensions fairly 'robust' as they will be required to transfer all the 'grunt' that the tractor can put on the ground to the push arms of the blade and thence to the cutting edge. Some steam tube about 100 mm diameter or some HEAVY wall RHS about 100 mm square by about 10-12 mm wall thickness properly welded and braced, oughta do it. If I were using the RHS for this, I think I would be setting it on the diagonal, that is corners up and down and fore and aft, 'cos the corners would be the strongest parts to weld your fore-and-aft bracing to.

I have attached a photo of a 55L with a hydraulic dozer fitted and I have outlined the outer end of the TRUNNION in blue. In this case, the trunnion is mounted outboard of the sprocket and outer track frame pivot bearing. Most were mounted further forward on a mounting plate that bolted to the side of the track frame. In some cases, this mounting plate was an integral part of the blade lift mounting as well.

I chose this particular photo 'cos it illustrates another point about dozer construction as opposed to crawler tractor construction. If you look carefully, you may notice the track plates under the front idler appear to be on a plane slightly above the tracks plates under the rest of the track, i.e. under the track rollers. This is an agricultural configuration, intended for drawbar work, NOT for carrying a dozer blade. It makes the tractor VERY nose heavy when you hang a blade on the front of such a tractor.

Most larger oval-track crawlers intended to be used as dozers have a 2-position front idler mounting, the high position for drawbar work and a low position for dozer work. Some of the smaller crawler manufacturers, notably Caterpillar, made small front idlers for drawbar work and larger diameter idlers for dozer work. The early Cat D2 and D4 modesl were examples of this. It didn't make a whole lot difference if you used the larger front idlers for drawbar work, maybe SLIGHTLY harder to turn, but it sure made a difference if you were using small front idlers for dozer work - VERY tip-toe-y.

It is possible to have small front idlers rebuilt to suit dozer work and I would imagine that Trackex in Toowoomab would be quite capable of doing it for you if you needed/wanted it done. The best way to check is to put the tractor on a hard, flat surface, preferably a concrete floor, and see if the front of the track under the idler is resting firmly ON the floor or if there is a small gap there, either between the track and the floor, between track chain and the idler, or a bit of both. If there is some gap, it's a pretty safe bet that you have small diameter front idlers intended for drawbar work.

I have also attached a photo of a Cat D5 Low Ground Pressure - LGP - dozer that gives you a view of the extended trunnions, outlined in red, to give you some idea of that about which I write. From your earlier post in which you gave the dimensions of both tractor and the blade, it seems that you a pretty fair idea of what you need to achieve. Hopefully, you will now have an idea of how to achieve it.

One thought does occur to me about this procedure to fit the dozer to the smaller, narrower tractor but it's not a 'biggie', You would also need to move the lift link attachment points on the blade C-frame inward about the same distance as the length of the extension that you make for the trunnions 'cos the blade lift rams and triangles will be that much closer to the centre of the tractor and blade.

Just my 0.02. Hope I haven't over-taxed the grey matter.

[Ian.Stewart-Koster]

Thanks again DP. I had to read it a couple of times, but it all makes perfect sense now.
I've snapped a couple more photos of parts of both the 50 & the 55.
The 50 shows the radiator & the hole through to the harmonic balancer, for the hydraulics.
It does seem to have a slight upward tilt toward a smaller front/idler as you mention.

The 55 has the trunnion joined all-in-one to the braces that hold the rams & the triangle lifter.
Extending the trunnions would involve starting with a sleeve over what's left of these I guess...I'll have to think about it.
Also of course the triangle supports act as sliders for the blade pushbar-to stop excessive sideways slop. If we extended the trunnions, then we'd have to pack the uprights outards the same amount.
I'm starting to wonder about just cutting the pushbar narrower instead...

I do appreciate your input & advice-thanks!

The rtadiator front bottom on the 50L

URL of the original image: http://www.aussieheavyhorses.com/ASSETS/Fiat-50L-55L-crawler/Fiat50L-radiator.jpg

The right hand side trunnion & blade push arm end:

URL of the original image: http://www.aussieheavyhorses.com/ASSETS/Fiat-50L-55L-crawler/Fiat55L-tracks-etc3350.jpg

URL of the original image: http://www.aussieheavyhorses.com/ASSETS/Fiat-50L-55L-crawler/Fiat55L-tracks-etc3351.jpg

URL of the original image: http://www.aussieheavyhorses.com/ASSETS/Fiat-50L-55L-crawler/Fiat55L-tracks-etc3352.jpg

URL of the original image: http://www.aussieheavyhorses.com/ASSETS/Fiat-50L-55L-crawler/Fiat55L-tracks-etc3354.jpg

The push arm back end is a bit bodgied here on the left side:

URL of the original image: http://www.aussieheavyhorses.com/ASSETS/Fiat-50L-55L-crawler/Fiat55L-tracks-etc3359.jpg

[Deas Plant]

Hi, Ian.
I can understand your concerns about the work involved in extending the trunnions out from the track frame. How-wevver, if your trunnions, caps, etc., are in good shape and all your track frame pivots and brace are likewise in good shape, those 'sliders' on the lift mounting frames are not necessary. Some crawler manufacturers used them, i.e. Allis Chalmers, but most did not. Some after-market blade manufacturers used them but most did not.

The main frame of an angling dozer blade such as yours, what you call the 'pushbar' is usually called the 'C' frame. This frame is pretty rigid in itself and can only move out of line to whatever extent the trunnions and cups/caps are worn. (Yours are not exactly flash, I think you will agree.) If the track frame pivots, i.e. the diagonal brace pivots under the rear of the tractor above the drawbar and the track frame outer bearings outboard of the sprockets, are in good order, they should hold the track frames in line, both horizontally - fore-and-aft - and vertically, without any help from the blade frame. After that, how tight or worn the front idlers and their mountings might be will largely determine how true the track chains run.

On the other hand, if you did decide to narrow the C frame. you would either have to make equal cuts either side of centre and take out HALF of the amount you need to narrow it by or make ONE cut right in the centre and re-install the centre blade pivot as part of the re-welding process. You would then need to narrow the actual blade by around the same amount, again by half on each side of centre to retain the centre pivot point, and ALSO shorten the angle braces to match and probably re-locate the sockets for the angle braces as well. In the doing of all of this, you would need to make sure that you didn't bring the middle of the C frame in so close to the front of the tractor that it interfered with that front-mounted hydraulic pump, because narrowing it will bring the centre of the C frame closer to the tractor.

Now which appears to be the easy option? And I am not trying to rain on your parade. I am only trying to help you undertand what is involved.

That trunnion mounting arrangement being part of the lift ram mounting that you mention on the 55 was VERY common back in the days when blade lifts were mounted on the track frames, before the main frames became strong enough to carry the weight of the blade plus whatever leverage was applied to it via the blade lift. I think Caterpillar was amongst the first to make their main frames strong enough for them to be able carry the blade and loadings and even they did it on the larger models for quite a while before the D2's and D4's got that treatment.

Hope this helps. Please feel free to ask any further questions or express any concerns.

[JimInOz]

I think the Hydreco pumps were used in IH/Hough gear too.
Maybe it's an American Co,& I think they had a lot of different pump models.
I have one here,which I bought with a bunch of IH crawler parts.

GW tractors might have info on these crawlers...they had one in their Melbourne yard several years ago.I'm sure they'd have manuals,etc.

Jim

[Ian.Stewart-Koster]

Thanks again, Deas, and Jim.
I can see now that extending the trunnions would be the least work-I hadn't thought of having to narrow the blade, as well as the C frame if we went that way.
There is still 'plenty' of clearance between the c frame & the hydraulic pump, in my opinion though, and the Fiat 50L is 10cm shorter in the firewall to radiator length than the 55L is. I do appreciate your frankness and clarity!

We haven't tried to take the hydraulics off yet-though the oil reservoir is still full of clean oil, and with no leaks obvious. The former owner said the hydraulic system had been 'done up' (or serviced, at least) about 90 hours before they had problems with the head bolt rusting through, which spelled the end of it's operable days. A neighbour of his took the head off-and that is how it has spent the last 12(?) years-out in the weather.

A couple more photos.
The bracket on the C frame that the lifters go onto has been rebuilt once at least:


The hydraulic pump and the radiator grille guard plate, from above:


The hydraulic pump:


The lifting triangle & ram etc:


Jim, we have managed to borrow a 55 manual to copy, and a Fiat 70 (?) parts manual as well-the neighbour who had that said there was little difference between the 55 & the 70 from a general parts diagram point-of-view. I was surprised to see what GW tractors has though...thanks!
There's also the mob north of Kingaroy who are good for parts-but the orange Fiat 50L we want to put the blade & hydraulics onto doesn't seem to need any parts-it runs nicely & is not worn to death like this yellow 55L!

[Deas Plant]

Hi, Ian.
Armed with the additional information of your latest post and after having another look at all your photos, if you decide to go ahead with mounting the blade and hydraulics on the 50C, I would suggest mounting the lift frames as far back on the track frames as you can get them without interfering with the track frame outer bearings or compromising the clearance in front of the hydraulic pump. The reason I suggest this is that it will help to keep the blade closer to the front of the tractor, thus minimising its effect on the fore-and-aft balance of the whole rig.

The closer a dozer blade is to the front of the tracks, the easier it is to control. There is a bit of a trade-off between handling and blade visibility but I always prefer to go for the handling. Even if you can't SEE your cutting edge over the top of the front of the tracks, you can still get pretty darned good at 'guessing' where it is in relation to the bottom of the tracks and the ground. On the plus side of having the blade closer to the tractor, it makes controlling the blade easier because it doesn't move up or down as much or as quickly when the tractor goes over a bump as it would further out from the tractor.

I also - vaguely - remember you mentioning that you thought the 50C had a slope up to the front idler and that you thought it was the smaller agricultural version. If you go ahead with the swap and you can see your way clear to having the idlers enlarged, I would advise doing it. The difference it makes to controlling to dozer is WELL and TRULY worth it. As I mentioned earlier, I am fairly sure that Trackex in Toowoomba could do this for you with little or no hassles. It does involve removing the idlers, which involves breaking the track chains but the end result is like chalk and cheese compared with trying to work with the smaller idlers.

Or, if you can get hold of a parts book for the 50C, it may just be that Fiat actually made a larger diameter idler for them for dozer work. Then all you would need to do would be to find a pair. Aren't I the comedian?

There used to be a place down just South of Wauchope that specialised in used spares from agricultural tractors. They had a big yard full of old tractors of all makes and models that they were slowly cannabalising for spares. For love nor money. I can't remember their name but it was NOT Expressway Spares. They were about 4 or 5 K's South of Wauchope, down towards Kew.

Again, just my 0.02. Hope it helps.

[JimInOz]

Deas & Ian,
Maybe it was Griffiths Traders near Wauchope.
Another good place is Rockhampton Tractor Wreckers & Rural Wrecking...they tend to do a few crawlers too.

Jim

[Deas Plant]

Hi, JimInOz.
That may well be the name of that outfit down at Wauchope. It does seem to ring a bell but it was about 6 years ago that I was last past that way and I have never been in there. Some friends of my down South of Bulahdelah on the Bucket's Way got several lots of parts from there for an IH B250 and for a smaller, newer Fiat dozer and reckoned they had been well served by that company.