Hi All,
Just a quick one for you all. I will be checking the diff & gearbox oil level tommrow. All running gear is stock and been around the world a bit.

Will it hurt if I top up both diff & G/Box with 85/140 gear oil if needed ?? Ive got this oil here and Im not sure weather I should use it or not.

I think that if both are worn it shouldent hurt and may be even better if there is normal wear , what do you guys think ??

Regards & Thanks
Andrew (amshaw )

I think that once a year, you should drain the gear lube and replace it with as thick of lube as you can find possible. A lot of the newer cars recommend using automatic trans fluid in the gearboxes. I think they want to sell you another gearbox. In the very cold months, the thick lube will be stiff at first but it will warm up soon enough after driving a couple of miles.

Mareo

Yes, I'd top up with this. If someone know why this shouldn't be done, speak up.

Oil manufacturers warn about mixing different types of oils/greases together, but slightly different weights is not a big deal. It's like mixing engine oil 30-weight with 10w/40 oil. Only less critical since the gears aren't being subjected to the same temperature and combustion by-products like engine oil.

I've seen a lot of gears go 150,000+ miles without the gear oil (90 weight) ever haven been changed. I can't think of one that failed due to lack of change. They usually fail due to leaking, running out of oil (or breaking due to doughnuts!).

The newer cars use light oil for fuel-economy reasons. These probably should be changed regularly.

Mareo you need to get your facts straight, thicker isn't necessarily better.
For the record, for those who will question the validity of what your about to read, I got my first 1200 in 1973, I have been working on cars and trucks professionally since 1975, and I spent more than my fair share of time working for a Datsun/Nissan dealer, and teaching others mechanics.
Heavy gear lubes work great in differentals, and ONLY differentals, PERIOD. When thick oil is cold, it will not flow and will starve the bearings for oil, manual transmissions have needle bearings in them that require lighter oils to propperly lubricate them, thick oils, until they get hot will not flow. more to the point, and think please before you get mad, how often on a cold morning do you have trouble shifting your trans? this is because cold thick oils are by nature sticky and hard to stir. EXAMPLE take a small amount of 90W gear oil, put it into a cup and then put it into you freezer for an hour, after it's cold, try to pour it out.
With this in mind, think about how well this same cold gear oil is lubricating the inside of you transmission. it doesn't take much to see that it don't work too well, does it?
more to the point, almost all new car manufacturers now recomend using a lighter oil in thier manual transmissions,this includes for replacement in older models, some have gone to the point of making it a pollicy of voiding warrantys if anything other than motor oil or ATF are found inside thier transmissions. WHY? simple, lighter oils flow better when cold and they can handle the heat when hot. transmissions almost never see the heat that is generated inside of a running engine.
Before anyone slams me for this, think about it, I can back it up with facts, not myth.

I stand corrected, rgrinder, thank you, but read on.

One more thing that will make an engine, transmission, and differential last much, much longer is to add a magnetic drain plug. What happens in most transmissions and differentials is they never get the lube changed and the metal wear in the lube oil looks like the metal flake in paint. This metal flake is being run through your bearings and gear mesh surfaces and causes a lot of unneeded wear. The magnet traps a lot of these metal flakes.

I highly recommend changing the lube oil every year in transmissions and differentials and cleaning off the magnets. But, I will still keep on using heavy lube oil in MY transmissions and differentials. I got over 300,000 miles from my trans and rear end in my first 1200 and never had any problems with either unit. I did go in once and put shims into the pinion and ring gears to take out some minor backlash.

At my uncles scrap yard, I have seen too many differentials go out in Subaru's and I always thought that they were from using too thin of lube. I may be wrong and Subaru's just have weak diff units.


Mareo

Mareo, please don't misunderstand that what I put applies ONLY to transmissions. I have an 85 300ZX with 240,000 miles and the only thing that has been in the trans is ATF, that's the way it came from the factory.
Always use gear lube in a rear end, they need it, and any thing else will trash one in very short order. Again thicker isn't always better, 85w/90 is fine for the cliimite you live in, but if it regularly sees temp. above 100 then use 85w/140.
Most important of all what ever you use make sure that it meets the API GL4 spec. or better, as in GL4, GL5, or GL6. that way you can be assured that your diff. will have addiquite lubrication.

Hi All,
Well I checked the oil in both Gearbox and Diff. The diff was full but the G/Box needed a bit. I found some 80/90 oil in my box of tricks in the shed that I forgot I had.

Bloody hell it's a pain trying to get the oil into the box !! I have only ramps and axle stands etc so I was flat on my back trying to get the container up near the engine pipe then hold a finger over the end of the tube then let go and try and get it into the fill hole without wearing some oil !!

Got there in the end but there must be a better way of doing this. Next time I might make up a longer tube to fit the container and a plug in the end , so I can fit it up there some where and then just place the tube where I need it , then in the hole etc. Any idea's anyone ??

Maybe I will ask around and see if I can put the ute up on someones hoist, but I hate asking people for that kind of thing as I like to "Do it Myself"

Regards
Andrew (amshaw)
Aus

Some companies sell a little plastic pump that screws on to the gear oil container. It obviously doesnt fit all containers so I sometimes pour the oil into a jar, put the pump end in it, the other in the trans, and pump away.
I still have to crawl under the car (ramps, jack stands) but it seems to work, with less mess.
I've tried the I.V. method. The oil is so thick, it took to damn long.
angelo

Thanks Angelo,
Good idea, pump that is. The oil I used was flowing down the tube fairly quickly (that was 1/2 the prob) so thats why I thought of making a longer tube up , so I had a bit more control over it .

At least I could sit the container in the engine bay somewhere then just feed the tube down towards the G/Box, with a stoper in the end of course.

Andrew (amshaw)

Before trying to put the thick lube oil into a trans or diff, put it in hot water for 15 minutes. That will thin the lube oil and make for much easier flowing. I just bought a hose that threads onto the lube oil container and has a push/pull plug on the end. I take the shifter boot off and put the fill hose down through the the boot opening. I can see the fill plug through the opening so as not to overfill. I still have to go under the car to remove the fill plug from the trans but filling is much easier than laying on the ground.



Mareo