All 2st 2010 Rear shock?

So I swapped out the spring on my WR300. I just estimated the sag, since it's winter and any time in a cold garage is not any fun. Unfortunately, I don't have a preload adjuster wrench. I am just using a heavy chisel and a hammer. Are the preload nuts universal across different shock brands?

Can I borrow a friend's tool from his KTM?

suspect the ktm preload tool will work just fine- pretty simple deal
the chisel and hammer thing is a little nasty!

Motion Pro has a Shock nut driver that has a brass tip. Works great. You can get from your friendly Parts Unlimited Dealer. You want about 8mm preload on spring (or close to it). You are looking for about 103mm rider sag and 33mm static. If you have the correct spring rate for you and your bike. Make sure your forks also have the correct 75mm rider sag (about 42mm static)

I know, but it's all I got...

Hi Vinduro, have been messing with your formula on an '06 wr 250 that has shortened suspension-about an inch i reckon.
Currently have 49static and 75 rider on the fork with 30static and 97rider on the shock with 17 mm of thread showing above the top preload nut- may I ask for your comments?

Once you loosen the lock ring and back it off you can grab the spring with your hand an rotate it causing the adjusting ring to spin to the desired setting then turn the lock ring back by hand and once seated give it one tap with a hammer and screwdriver and it's done. No need to mutilate it by driving the adjusting ring in circles with a punch or screwdriver.

If the suspension has been shortened then you have to refigure the numbers. You want 34% of available travel on rear with 11% in static sag. On front it sounds like you have too heavy a spring about one size. You have too much static to get the correct rider sag. If the forks have also been shortened then you have to refigure that also. You want 14% of available travel in static and 25% in rider sag. If the forks have been shortend an inch or 25.4mm then you want 38.5mm static (+-2mm) and about 69mm rider sag.
If you are short an inch in rear then you have about 295mm travel now. You want 33mm static and 100mm rider sag. So you sound like you are close on rear. Back off to 100mm rider sag and the shock should be good.

thx professor- will peruse the situation immediately following St. Patrick's Day celebrations!