what oil on Distributor box, gearbox and axels ? ural 375D

[Mydland]

i was wondering what the correct type of oil is for the distributor box, gearbox and axels ? on ural 375d

and also. someone told me that, i should not use pure gasoline on the engine, but mix with 20 % kerosene, is this true ?

[Mark Preston]

I have a 4320 and have used Hypoid 90 for all the running gear. You could probably use almost anything though - they are Russian after all.

[Mydland]

I have a 4320 and have used Hypoid 90 for all the running gear. You could probably use almost anything though - they are Russian after all.

yes i know but since i need to buy the oil, i will go for the correct type of oil

but do you know anything about the mixture of the kerosene ?

[Mark Preston]

Indeed - if you have to buy new oil then I'd go for Hypoid 90 gear oil. If you can - after draining the old oil - I'd pour a good quantity of paraffin in the filler to wash out any crud in the bottom.

I don't know about kero in the petrol. The only reason that I can think of doing that is to reduce the octane rating to stop pre-ignition. Knowing the Russian reputation for poor quality fuel, maybe the 375D is setup for lower octane? It would probably be easier to retard the ignition a little than have to keep track of how much petrol vs. how much kero has been added.

That, however, is a pure guess - so please heed the opinion of other over mine,

Cheers

Mark

[Abrs]

Indeed - if you have to buy new oil then I'd go for Hypoid 90 gear oil. If you can - after draining the old oil - I'd pour a good quantity of paraffin in the filler to wash out any crud in the bottom.

I don't know about kero in the petrol. The only reason that I can think of doing that is to reduce the octane rating to stop pre-ignition. Knowing the Russian reputation for poor quality fuel, maybe the 375D is setup for lower octane? It would probably be easier to retard the ignition a little than have to keep track of how much petrol vs. how much kero has been added.

That, however, is a pure guess - so please heed the opinion of other over mine,

Cheers

Mark

Agreed, & just to add, avoid GL-5 spec oils, these are known to attack some yellow metal bearings & older style seals, although to be honest I don't know if that is an issue on the Ural but I would say better safe than sorry.

Also, most of these older Russian engines were designed to run on low octane fuel, you have to advance the ignition timing a 'lot' for our fuel, anything up to 20-22 degrees BTDC on the Zil/Ural engine.

[Mark Preston]

Yes, ADVANCE the ignition not retard. My bad.

[duncan]

Since you seem to ask about all your gearboxes and axles, take one thing into account: Do NOT put Hypoid oil in manual shift gearboxes. Hypoid oils have special additives for hypoid gears (hence the name), making them slide into eachother with less friction. However, you need this "slide friction" bit in your gearbox for the synchronizing wheels to work properly, otherwise you will have a hard time shifting gears. It will work (I ran a gearbox on hypoid a while, had nothing else available), but the difference is very noticable.

[Abrs]

Since you seem to ask about all your gearboxes and axles, take one thing into account: Do NOT put Hypoid oil in manual shift gearboxes. Hypoid oils have special additives for hypoid gears (hence the name), making them slide into eachother with less friction. However, you need this "slide friction" bit in your gearbox for the synchronizing wheels to work properly, otherwise you will have a hard time shifting gears. It will work (I ran a gearbox on hypoid a while, had nothing else available), but the difference is very noticable.

Indeed, i.e. GL-5 is actually designed as a heavy duty hypoid gear oil even if it doesn't say so on the container, it's the additional EP(extreme pressure) additives that are harmful to yellow metals, these are mainly phosphorous/sulphurous compounds which are corrosive. Seen a tractor gearbox once that had been filled by mistake with it & it had turned all the bushing etc green, & they were pitted to buggery.

That said GL-4 is also a hypoid gear oil but is considered the standard spec for most manual gearboxes, although it is safe for yellow metals, it contains less of the EP ingredients of GL-5, especially the harmful ones and also offers a higher coefficient making it better suited to older manual shift boxes for both syncro and non syncro types, however both oils are actually suitable for use with synchronises, it depends on the design of box and of course the intended oil grade rather than just the API classification.

For an old style gearbox box like in the Ural I would say a GL-4 90 or 80/90 is fine, or even a GL-3 which is non hypoid, I wouldn't risk a GL-5 though because of the corrosive aspect.