Oil Change necessary?

[badgertom]

Every year I change the engine oil and gear oil on my 1982 R65. A couple of years ago I changed both to synthetic oil. This year I only put on 450 miles. Although the manual says to change oil every season ( I think they may mean regular oil??), I wonder if I should change the oils this year. Synthetic oils are very expensive with a quart at about $18-$19. I ask a mechanic and he says that as far as the gear oil is concerned
I don't have to change it. At the time I did not mention the motor oil to him. So, should I change the motor oil?....and leave the gear oil?

[Tony Smith]

Firstly there is absolutely no reason or advantage in using synthetic oils in your situation, save your money and don't buy them.


Yes you should change your trans fluid yearly regardless of use.  Most oil manufacturers recommend changing engine oil at least 6 monthly ESPECIALLY if only lightly used.

[montmil]

Occasionally, synthetic oils, being as slippery as they are, can sneak past OEM engine oil seals and drips appear. Changing back to conventional oil usually stops the floor spotting. I you really like synthetics, maybe try the semi-synthetic oils available for motorcycles.

Ride more often. Keep that oil circulating.

[Barry]

Every year I change the engine oil and gear oil on my 1982 R65. A couple of years ago I changed both to synthetic oil. This year I only put on 450 miles. Although the manual says to change oil every season ( I think they may mean regular oil??), I wonder if I should change the oils this year. Synthetic oils are very expensive with a quart at about $18-$19. I ask a mechanic and he says that as far as the gear oil is concerned
I don't have to change it. At the time I did not mention the motor oil to him. So, should I change the motor oil?....and leave the gear oil?

I agree with your mechanic on the gear oil. Absolutely no need to change it at that mileage unless it's been contaminated. You can change it every few year.  But you need to check that the gearbox oil hasn't had any ingress of water so I always at least look at the oil to make sure.

In the engine I use full synthetic and this year my mileage will be under 2000 miles but I still change it annually because the oil gets contaminated with combustion by-products and water especially if used in the winter on short runs. In fact synthetic oil tends to have a high detergent content so it cleans better and therefore goes black quicker. The oil itself doesn't wear out but the additives do. On my early model filling to half way on the dipstick takes less than 2 Litres so it's hardly expensive. I kind of agree about very expensive synthetic being a something of a waste in low mileage use but you don't have to pay a fortune for synthetic these days.

I don't agree that synthetic brings no advantages at all although it depends to some degree on the grade.  I'm using 5W40 and there is no question that the thinness of a 5W when cold is an advantage especially in the winter. I also see no disadvantages in that I have experienced no leaks.

[badgertom]

After using synthetic oil can I change back to regular oil? (both engine and gear oil). I was told by a you should NOT change back to regular once you have used synthetic. If so why not??

[Tony Smith]

After using synthetic oil can I change back to regular oil? (both engine and gear oil). I was told by a you should NOT change back to regular once you have used synthetic. If so why not??

Advertising puff to keep you locked into buying a very expensive oil that you do not need. For mine I'd be looking for a good mineral oil with lots and lots of ZDPP additive.

Admittedly I do live in a temperate climate, my sop to temperature related viscosity is that I use Penrite 20W60 in summer and Penrite 20W50 in winter, of course some people are unfortunate enough to live in a climate that requires thinner "winter" oil.
 
I am yet to be convinced that there is any advantage in a full synthetic oil for an airhead, and as Monte pointed out, a frequent byproduct of using the stuff is an increase in "territory marking".

[Barry]

After using synthetic oil can I change back to regular oil? (both engine and gear oil). I was told by a you should NOT change back to regular once you have used synthetic. If so why not??

The idea that mineral and synthetic oils don't play nicely together when mixed is a 40 year old urban myth that dates back to early ester synthetics. Leaving aside odd stuff like Castrol R all modern oils are compatible. How else could semi-synthetic oil be made.

Same goes for the idea that modern synthetics are not compatible with seals. The reality is that full synthetic oil has a higher detergent content so if you switch to synthetic it will clean up any existing deposits in the engine which may cause oil leaks if the seals are worn.  That just means you have bad seals and not that the synthetic is incompatible with the material the seals are made from.    

There are several reasons why I switched to semi synthetic or synthetic oils.  Synthetic oil is fundamentally better and needs less additives to perform as a multi grade. It's accepted that most wear occurs when engines are cold so I worry about how thin my oil is when it's cold rather than how thick it is when it's hot. Only synthetic can resolve that problem with 0W and 5 W oils. I'd happily use 0W40 in my airhead and may do so in future. Us oldies are pre-conditioned to be aghast at the idea of using a 0W oil but it's a misconception and a misunderstanding of oil designations.  Even 0W oils are still too thick when cold and don't lubricate efficiently.

There is an urban myth or misconception that modern oils like 0W40 are vastly thinner than  20W50.  The reality is they are only slightly thinner when hot but more importantly they are vastly thinner when cold.  

I do accept though that in very hot climates these cold viscosity issues are hardly worth worrying about. and the focus switches more towards oil that is thick enough when hot.

[Einar]

I wouldn't change. Synthetics are durable and with that milage it's a drop in the ocean.
One reason to change on a yearly basis regardless of milage is that the oil might lose some of its fluid properties (viscocity at temperatures close to operatings limits) but this in my opinion is less a problem with synthetic/modern oils.
I use mainly synthetic in my air and oilheads, I have changed back and forth between mineral/semi-synthetic/synthetic and not had any issues so far, despite the many recommendations to be consistent with oil type and change frequence.
My 2 cents.

[montmil]

Not quite as wordy and long-winded as The Snowbum but still a sure cure for insomnia. [smiley=zzz.gif]
Lots n' lots of oily stuff.

Bob Is The Oil Guy
http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=cfrm

[Semper Gumby]

WooHoo another ADOT!

HI BadgerTom.

Change the gear oil.  Gets rid of any moisture.  Also if you have a moisture leak into lets say the drive shaft then you will find it when the oil you are changing comes out milky (contaminated with water) in which case there is something else you need to fix.

So changing oil in the tranny, drive shaft and final drive 1)removes moisture, and 2)  helps identify trouble in a timely manner.

But if you'd like to leave water in your gear box, drive shaft and final drive then go ahead.  But have you priced replacement parts for those bits recently..  

Btw - I change out the gear oils twice a year when I change from summer to winter oils in the fall and when I go back to summer oils in the spring.  But then I ride a lot and my bike lives outdoors.  But then again I'm at 130,000 miles on the original gearbox so I must be doing something right.   8-)


Now on the matter of your synthetic engine oil - Yes it is a better oil than the Dino oil I use and Yes you can let it ride for more than a year with low mileage.  Because it wont let the acids build up that will start to cause corrosion.  But keep an eye on your oil consumption and look for leaks.  1980 was the tuning point for Oil Seals.  After 1980 all seals made had to be compatible with synthetic oils.  Before 1980 ugh Good Luck.  I have had experience with this when I tried Synthetic oil in my 03/1980 bike's gearbox and was rewarded with a nice clean twelve inch puddle of really clean expensive gear oil on my garage floor underneath the shift shaft seal.  

And in true keeping of every ADOT I will now tell you what oils I use:

Engine - Summer Valvolene VR1 20W50 - Winter Valvolene 10W40 Motorcycle oil. Both of these are Dino Oils with lots of anti-wear Zinc (ZDDP) that I can buy at Autozone when I am traveling about the country.

Gearbox, Drive shaft, Final Drive - Summer Valvolene Durablend SemiSynthetic (Dark Blue Bottle) 85W145
- Winter Valvolene Durablend 80W90.

I'm in Atlanta GA and I ride year round.  Your results may vary.

Regards,