The Stovebolt Site Forums The Shop Area General Truck Talk oil/lubricant change frequency

I should know this but just wondering what others feel as to how often to change the oil, in the motor, gearbox & rearend? I realize the dirtier the environment you live in, the more frequent it should happen, but for most of us city dwellers...

235
SM420
3.55 rearend.

Since I was a kid I go by the old standard , 3 months or 3000 miles, for oil changes. I realize that oil has gotten better, etc, etc and can probably go a lot longer between changes but $30 per oil change is pretty cheap insurance. It has served me well since high school.

Transmission and rear end only need to be topped up when they are low.

Agree with Otto on the 3000 mile oil changes (even though with a filter you could probably double that and still be safe). Prefer checking trans and diff 3-4 times a year because the trans tends to leak a little toward the diff and overfill it. Outright changes of gear oil only happen with milestone events such as swapping the 4.11 for the 3.55 which I did last week.

It's a little off topic but just gotta say the 3.55 with 235 seems a match made in heaven. Also have a set of tall 16" tires and a set of 15"s to adapt for highway or city/mountain type driving.

With a draft tube which only works well at highway speeds and only if it isn't clogged with crud, 3,000 mile oil changes should be seriously adhered to. Crankcase contaminants will degrade the oil at a much higher rate that an engine which has a proper PCV system.
Even engines built later than the mid-fifties with full flow oil filter systems and PCV systems need to be changed every 3,000 miles.
Modern engines of today do not require 3,000 mile oil changes. It has nothing to do with what kind oil is put in them.
It has everything to do with the advent of computer controlled electronic ignition, fuel injection and timing.
Carburetors, and points points wear out significantly over a short amount of time and cause increase of oil contaminants in the crankcase.
I have driven 6 modern work trucks over the years for up to 187,000 miles without ever needing new spark plugs. They likely didn't need new plugs when they were sold at auction (many of them did need new transmissions however). Try that with a Stovebolt or any other vehicle which has a carburetor and points without Triple A.

Thanks guys. What if you only put an average of 2,000 miles on your rig each year. Still change every 3 months? For me that's every 600 plus miles. I use Valvoline VR1 30W high zinc racing oil. My 235 is a '62.

With today's modern oil, which is far superior to the oil available 70 years ago, you'd be fine changing it once a year. The truck isn't seeing severe service so once year is ok.

My custom, with a similar low annual mileage situation, is to just change it every 6 months or thereabouts. Not saying that’s correct, but 3 months seems like huge overkill.

Y'all aren't driving your trucks often enough.

I thought of this article when i read the headline..


https://www.thedrive.com/news/motor-oil-age-doesnt-matter-as-much-as-mileage-study

I won't say how long i go in between oil changes ...........like Carl says.....I don't drive my stovebolt enough

I have a constant loss system on Ol' Roy. It always has fresh oil in it!

I did change the motor oil today and checked the levels of both the rear end and gearbox, which both were up at perfect level and were both very clear. The motor oil on the other end was pretty dark and ready to be changed with about 1600 miles on it. Thanks for the encouragement.

I can relate to this.

hello I would like to get some advice I have a 235 1960 engine in my 55 chevy 3200 it doesent smoke and I have just recently did the PVC upgrade. But around 1300 to 1500 miles my oil is pretty dirty I change the filter every time Wix 51100. I am thinking my oil pan is very dirty any thoughts on this. thanks

Dirty oil means it's doing its job. Pull your pan and take a gander at everything in there. Maybe it's dirty, maybe it isn't. If you're worried, do Jerry's crankcase flush with diesel fuel in the linked post.

I use the old rule of thumb and change oil every 3000 miles. It's cheap insurance. If you're more comfortable changing your oil every 1500 miles, do so. It isn't going to hurt anything and it costs less than $50 to do it.

https://www.stovebolt.com/ubbthread...4761/54-235-engine-work.html#Post1544761

Awesome Jerry I will do that at the next oil change. Thanks Just one question do I add the Diesel fuel to the 5 quarts of oil or to 2 quarts of oil to total 5 quarts

I'm not Jerry but the total will be 8 quarts so the connecting rods slosh around in the liquid.

THANK YO SO MUCH OTTO.

Thanks for the link, Otto. Yes the whole point is to turn the oil into a semi-solvent and then splash it around violently inside the crankcase. That only happens if the level of the liquid in the oil pan is close to the centerline of the crankshaft. It does a lot better job of scrubbing things than you'd ever be able to do by dropping the oil pan and scrubbing with a brush and solvent. Overfill the crankcase by about 3 quarts by adding Diesel fuel to a full fill of fresh oil.
Jerry

THANKFUL FOR YOU GUYS YOUR A REAL BLESSING

I change the oil by calendar. In the Fall and in the Spring.

When I worked at a Chevron station in high school in 1960, we used to idle an engine with an oil/kerosene mixture to supposedly clean things up. (We didn't sell diesel.) I forget the ratio of the two but I do remember being leery of the practice. Also, the standard practice back then was to change the filter every other oil change.

I've never changed transmission or rear end oil.