Is Transmission oil really 30w

[Eleven]

Motor oil? That's what the book says, anyone know any different before I low crawl under the car again?

 

[Green67Alpine]

That's what they say...And I'm planning on using unless I hear different. Isn't OD non detergent 30W ?

Tom j

 

[jumpinjan]

Whatever you use, don't used rear axle gear oil (hypoid gear oil). Ian & I use Castrol HD30 in the trans & engine all the time. Don't get side tracked/confused that you must have a non-detergent oil too.

 

[lemansvk]

Yes it's definitely engine oil and 30 grade non-detergent is what's recommended - if you can find that. A more modern multigrade like 20 -50 will do. The important thing is not to use heavy grade transmission oils like 80 or 90. I Have known a couple of people who bought cars that it was hard to shift gears in - problem solved by getting the 90 oil out and an engine oil in.

Cheers, Vic

 

[Eleven]

Wow

Glad I checked. I half filled it with the 75w gear I always used in the TR and then needed more. Half wit that I am, I decided to check then and saw the motor oil. Thanks guys, will drain and try again.

 

[ozzie alpine]

I'm going to be using Shell Lawn 4 in my gearbox. Easily available in Aus (marketed for 4-stroke lawnmowers), 30 grade , non-detergent. Recommended to me by well respected Rootes man in Brisbane, John H, and confirmed by Shell technicians as being suitable. Not all "monograde 30 oil-for-small-4stroke-engines" is suitable though, as some have detergents.

 

[Wombat]

When I bought my SIV, the gear changes were hard when the 'box was cold. They got better when it warmed up, but still not good. I drained the oil that was in it and refilled with engine oil (Castrol GTX 20W50) and it worked perfectly. So yes, engine oil is the go.

 

[Alpine 1789]

When I "built" my SV in 1977 by combining all the best parts from two different cars, I originally put gear oil in the car. However, I checked with a mechanic I knew who told me that I needed to use motor oil. I drained the gear oil and put in 10w40. No, he told me, it had to be 30 wt. So, I changed it again. "Non Detergent" he asked me later? Finally, after four oil changes I got it right and stayed with the ND 30 until I replaced the tranny with an OD unit about 6 years ago.

 

[SIVAllan]

Here's a link to an article on OD oil...seems to agree with the sentiments of this board...

http://www.quantumechanics.com/categories.php?op=newindex&catid=11

Good luck!

Allan

 

[husky drvr]

WARNING! WARNING!

Nick O'Dell,

do not follow link!

 

[SIVAllan]

What's the problem?

Allan

 

[husky drvr]

What's the problem?

Allan

Allan,

No real problem, Nick has a pet peeve about certain terminology used when discussing oil and its viscosity. Otherwise, I thought the article interesting.

 

[SIVAllan]

Don,

I think I slipped a gear. Somehow went directly to wondering about the tech side.

Probably a good thing to agree on terms, though.

Allan

 

[Nickodell]

Allan,

No real problem, Nick has a pet peeve about certain terminology used when discussing oil and its viscosity. .

What, me? Nah, I'm just your typical loveable cuddly teddy bear.

Really.

I don't care if people call SAE 30 oil 30W, or "thirty weight."

Really, I don't. Just a cuddly teddy bear.

..

..

..

..

 

[panjang]

So many think that gear oils are many times more viscous than engine oils (and write a lot of nonsense based on that assumption).

In fact the ratings overlap, and an SAE90 gear oil has a viscosity in the same range as an SAE40 or 50 engine oil, as can be seen here

The SAE grades assigned to the different types of oil were deliberately not directly tied to the viscosity in order to avoid people accidentally using the wrong type of oil just because it had the same SAE number.

 

[65beam]

transmission oils

just remember one thing; DON'T PUT CONVENTIONAL GEAR OIL IN YOUR TRANSMISSION! the extreme pressure additive in gear oil[ that item that makes it stink so bad] attacks yellow metal on contact and the corrosion process can not be reversed.so guess what happens? your syncros go bad long before they should.use conventional motor oil.and keep in mind that except for some cheapo oils ,non detergent oils of the type used in our cars has not existed for many years. use a straight 30 oil and no problems will pop up.

 

[Bill Blue]

Non detergent oils were not used in the engine or transmission. The workshop manual calls for Shell X100 to be used in the engine, transmission and overdrive. Single viscosity (30w) being recommended for summer use, 20w for winter. Shell X100 was a modern detergent oil, available as single or multi viscosity. Detergent oils are not that new and by 1960, nondetergent oil was getting pretty hard to find. Dad leased a Shell Station in 1960 and I'm pretty sure Shell did not have a non detergent automotive oil. At least we did not sell one.

If a person wants to use non detergent oil in the trans, how about air compressor oil? Available at your friendly hardware store and very good oil.

Bill

 

[panjang]

Thanks 65beam. I should have mentioned not to use EP gear oil anywhere it is not specifically recommended.

EP additives provide boundary lubrication where oil film is removed by high pressure contact. This is desirable in the case of hypoid or worm gears, but can result in some types of synchromesh cone clutches not having enough friction to work properly.

Some old rear axles with spiral bevel gears can also be damaged by the chemical action of EP additives. Problem is, I think it's now pretty hard to find non-EP gear oils.

Another non detergent type of oil, which contains little more than anti-foam additives, is "hydraulic" oil, - e.g. the Shell Tellus range for hydraulic systems using mineral oil, rather than special fluid - but I don't really believe there is any harm in using a detergent engine oil per se.

Some engine oils have more EP additives than others, so diesel or "heavy duty" oils should probably be avoided for use in transmissions where engine oil is recommended.