Morris Minor Owners Club

Just changed oil on all dampers. All were very contaminated with black sludge metalic particles. Photos show a before and after cleaning of a front unit.
I drained the oils by removing the top lids and then flushed them 3 times with Gunk by repeatedly operating the arm and then removed the valves and cleaned them. After rebuilding each one was refilled and flushed 3 times, by operating the arm, with 10wt oil.
To gain a comparison of different oils one of the fronts was filled with 10wt and the other with 5w/30 oils with very little difference in effort to operate.

What different oils have members used and what differences if any were seen?

I have used straight SAE 30 engine oil through to EP 90 in the Minor front dampers and SAE 20/50 in the rear dampers.
The straight SAE 30 grade oil gives a nice firm but not harsh ride. The EP 90 gives a really hard ride.
I would recommend that a straight SAE 30 oil is used in both the front and rear dampers.

What's 10wt oil? Never heard of that grade before!
If I remember correctly, mine are probably due a refresh, I used motorcycle fork oil. SAE20? Or even hydraulic jack oil, same viscocity.

olonas wrote: ↑Sun Jun 18, 2023 11:33 am What's 10wt oil? Never heard of that grade before!
If I remember correctly, mine are probably due a refresh, I used motorcycle fork oil. SAE20? Or even hydraulic jack oil, same viscocity.

Castrol fork oil is 10wt (Halfords) amongst other brands. Alternatively Moss sell their own brand of “lever arm shock fluid” and Dynolite make a lever arm shock oil too. They are supposed to be “anti-foam”.

philthehill wrote: ↑Sat Jun 17, 2023 10:38 pm I have used straight SAE 30 engine oil through to EP 90 in the Minor front dampers and SAE 20/50 in the rear dampers.
The straight SAE 30 grade oil gives a nice firm but not harsh ride. The EP 90 gives a really hard ride.
I would recommend that a straight SAE 30 oil is used in both the front and rear dampers.

Thanks Phil

svenedin wrote: ↑Sun Jun 18, 2023 12:16 pm

olonas wrote: ↑Sun Jun 18, 2023 11:33 am What's 10wt oil? Never heard of that grade before!
If I remember correctly, mine are probably due a refresh, I used motorcycle fork oil. SAE20? Or even hydraulic jack oil, same viscocity.

Castrol fork oil is 10wt (Halfords) amongst other brands. Alternatively Moss sell their own brand of “lever arm shock fluid” and Dynolite make a lever arm shock oil too. They are supposed to be “anti-foam”.

Thanks Stephen

"Castrol fork oil is 10wt (Halfords) amongst other brands."
SAE10W. Where's the "t" from? No such grade as wt.
I use Castrol Fork Oil, SAE20W. SAE20/20W is the recommended alternative to Armstrong Super(Thin)Shock Absorber Fluid. Section L4 of the workshop manual.

wt is weight.

" Oil weight is a term used to describe the viscosity of an oil, which means how well it flows at a specific temperature. The Society of Automotive Engineers (SAE) assigns a viscosity number, or weight, to oil based on its flow at 210 degrees F, which is roughly the standard operating temperature for most motors. "

John ;-)

olonas wrote: ↑Sun Jun 18, 2023 11:33 am What's 10wt oil? Never heard of that grade before!

This is a bit of a can of worms...
I think it's general confusion amongst people, including some retailers, as to the 'weight' of an oil.
The W in a Lubricating oil grade actually stands for 'Winter' :
https://www.castrol.com/en_gb/united-ki ... rades.html

So we're used to seeing Engine Oils such as 10W/30 for example. These are graded on Society of Automotive Engineers (SAE) standards.

Hydraulic oils these days are usually to ISO standard, which have a different number system.
However, within the Automotive sector, they often ignore that and stick with SAE...even when dealing with non lubricating oils..

Castrol Fork Oil, since that is the one mentioned earlier, actually comes in several grades, 5W, 10W and 15W that I know of, possible more.
That's 3 different weights of oil, all of which have winter additives so they don't thicken up like a simple 5, 10 or 15 grade oil would.


Whereas Dynolite Shock Oil is to ISO 68....