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Gear oil in a 203.

Where is all this straight 30 weight nonsense coming from?


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Please explain:dunno:
 
Thats a page out of the manual for my 77. Showing that a 203 takes 10w30 or 40 motor oil.
 
Dangit! I put 80-90 in my 203! Going to drain it and replace with 10-30 when i change the oil next...
 
i bet that happens alot. everyone just assumes. i probably would have, but i didnt even check the fluid in my 203 before i yanked it apart. it does have gear oil now. but its just the range box.
 
I have an old repair manual from GM stating the NP203 takes "10W-30,10W0-40,or 20W-50 engine oil"..says SAE 30 or 40W can be used in hot climates too--says nothing about NOT using 80W-90 gear oil though!..

I have 3 old Sears garden tractors that have a hi-lo 6 speed trans that holds 5 qts--many people assume they use gear oil ,so the put it in them--they are supposed to have 30W non-detergent in them...but all the ones I've had apart that had gear oil looked MUCH better inside than the ones with motor oil (especially the ones that never been changed once in 40 years!)...I think its not so critical what you use,its keeping it FULL and changing it every so often that matters most...personally I feel motor oil belongs in motors and gear oil for gears!..but I do stick with manufacturers reccomendations most of the time--on the case of gearboxes already run many miles wit the wrong" lube,its probably not going to make much difference,since any potential damage has been done already..
I read some gearboxes use bronze bushings & synchros that gear oil can corrode or dissolve...I suspect most NP-203's have had gear oil put in them by clueless lube techs at least once in their lifetimes,how often they were "ruined" is debateable--I doubt it hurt them much if any ,myself..
 
I have an old repair manual from GM stating the NP203 takes "10W-30,10W0-40,or 20W-50 engine oil"..says SAE 30 or 40W can be used in hot climates too--says nothing about NOT using 80W-90 gear oil though!..

It also doesn't say anything about NOT using water either :deal:
 
Diesel4me, My dad has a 79 K30 with 320,000 rough miles as a plow truck/service truck for the crusher he bought it new, it's ALWAYS had the correct lube in the NP203 and the chain is just as tight as when he bought it.

throw some 90w in a 208 and see how long they last, it wont be pretty I can tell you that.

Its the chain that needs the lighter oil
 
I suppose the chain "might" suffer if the gear oil is too thick to get to it fast enough,but on the other hand,I'd say gear oil,having "EP or Extreme Pressure" charecteristics might just be better at preventing wear,it was made for ring and pinion spiral cut gears that have a lot more forces acting upon them than straight cut gears do...

I think the chains stretch out more than anything,especially if you stuff a big block or hi-po small block in a 4x4 truck with big tires,tall gearing,etc...
 
The chains dont really "stretch" the pins and bushings wear out and they get sloppy 90W is to thick to get into the small areas and provide proper lube
 
The issue with the 203 is the chain is the oil slinger for the rear output bearing. Gear oil will not make it back there. This is the same problem that part time kits cause.
 
The owners manual for my 95 Ford Contour has warnings about siphoning gas--says if someone on an anti-alcohol drug to stop their drinking and they accidentally ingest any gas with ethanol in it,they will suffer "extreme adverse reactions"...

Oh yeah--the gas might cause suffocation,pneumonis and death!...:rolleyes:
 
I wonder how many of the older owner's manuals say not to drink beer while driving.........

But tequila's okay.

I get a kick out of the 70's ads that say "Power steering -- now the little woman can drive", stuff like that :haha:

-- A
 

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