NAA Major Service/Maintenance

[jim warehime]

In the process of getting my grandparents
old NAA up and going again, tractor was
used very hard over the years and got very
little tlc. Plan on completely rewiring and
updating electrical system to 12 volt neg
ground and electronic ignition (everything
has been already purchased from Brillman).
Oil filter conversion and oil change, new
valve cover and crankcase breather filters,
pre cleaner cleaned and new oil in cup.
Fuel system cleaned. As for new fluids what
is everyone's recommendations for engine
oil, hydraulic fluid for hydraulic system,
transmission fluid and rear diff fluid?
Also is there any maintenance needed on
Sherman transmission? Thanks Jim, btw my
background is IH H/M series and Gas Start
Diesels...

 

[pomester]

Lubricant questions always bring a diversity of strong opinions.

A modern 10W-30 is appropriate for the engine. Originally the manual called for 10/20/30W depending on the outside temperature. A lot of people recommend the readily available 15W-40 and I don't see any problem with that.

Many will recommend that same 15W-40 for the transmission/hydraulic/differential. Originally specced as hypoid gear lubricant (90W) in the transmission and differential and hydraulic oil (nominally 10W) in the the hydraulic reservoir, I don't see any reason to use different oils now that we have modern lubricants. The 15W-40 or Spec 134d hydraulic oil (5 gallon buckets at the farm store) in all reservoirs keeps life simpler.

The Sherman is an interesting question. It has an oil slinger on its output shaft to keep it filled with transmission oil. It has a drain plug. Ideally I guess you would drain and refill with transmission oil. Practically, I don't know how that's done short of a split. If it's working well, I don't think I'd mess with anything.

 

[ErnieD]

I would add,
the NAA has a fuel reserve accessed by fully opening the sediment bowl shut off valve, fully open and completely drain fuel tank if not already done so.
The NAA uses a vane hydraulic pump, fime if it still works, otherwise upgrade to piston pump and new style manifold.
Change and flush cooling system, blow out radiator fins.
Check steering sector lube level.
Inspect rear axle/hub for play. Renew as necessary.

 

[jim warehime]

Thanks for the input, my intention is to overhaul engine next winter once I'm done using it for the summer. I know the rear hubs are a little loose which I plan on addressing along with new brakes and seals/bearings. The right side axle trumpet also needs to be replaced as the 3pt arm stud is loose and was used that way for many years wearing the housing. My intentions are not to restore tractor but to use it heavily on my property for mowing along creeks, woods trails and for seeding and establishing new yard/food plot areas where my larger loader tractor or zturn mower isn't practical.

 

[pomester]

RE: the trumpet

I have a 900 where this was an issue - a worn housing/3 point anchor - as a temporary fix I cleaned things up, buttered the worn hole with JB Weld and replaced and tightened the anchor/pin. 20+ years later the fix is holding with no problems. The tractor has been used for plowing and anything else required.

So, if you don't have a fresh trumpet handy, this is something you could consider.

 

[showcrop]

What is best for hydraulic, transmission and rear axle oil depends, believe it or not, on how you will be using it. Everybody wants to be able to say that they are performing the best possible maintenance, so they want to include the best possible oil. Well, modern tractors, due to wet brakes and clutch packs need the best modern oil. Your NAA has neither wet brakes nor clutch packs so it will be just fine with the old spec cheap oil. Now, about the usage. Every week there is another post here about someone's hydraulic oil that is milky or coffee milkshake color and thickness, or it is mid-winter and suddenly it won't move. This is virtually always because the tractor has the modern UTF in it and has absorbed moisture from condensation. Water is not a good lubricant. If you will be using the tractor hard enough to get the oil good and hot for long enough, frequently enough, to drive the moisture off regularly go ahead and use the expensive oil. Otherwise you must change it every six months. The sensible alternative is to use the cheap stuff, which does not absorb the water, and just crack the drain every-other month and check for water and let it drain out, which it will do because it stays separate from the oil.