lack of gear box oil

[Gavin Housh]

Have any of you noticed that on the 125 Sachs motor when you pull out the drain plug in the bottom of the motor very little oil is left in the gear box and I mean only a trickle is left in there. It seems that under race conditions all the oil gets in the clutch case and never goes back into the gear box. Is this the way the engineers desinged the motor? Do we need to drill some holes in the case to allow the oil to move more freely between the two sections of the motor? I've noticed that if you fill the motor with the recomended 600cc of oil and then open the oil level plug on the clutch cover you have to pour in a considerable amount of oil to bring it up to the level hole. This leeds me to believe that we may need more oil to keep the gears properly lubricated in the gear box. I've talked to other Sachs motor owners that tell me that they have also noticed a lack of oil in the gear box so I assume this situation exists on all the 125 Sachs engines. What gives?

 

[Kip Kern]

I put 700cc of oil in the box as this covers the lay shaft end. This was recommended from the old "Keeping Track".  I also use a lighter viscosity,10w 40w, most folks use heavier oils.

 

[john durrill]

We use to use ATF in the early 70's for gear oil. It seems to me it was something we were told would work by the folks at PENTON.
It worked well and solved the clutch drag at check point problems we had too. I used it for thousands of miles over a 5 year period.
Maybe Doug could shed some light on the subject.


 

[OUCWBOY]

I was wondering about this issue also. On the 175 KTM motor you get two different answers to that question in the shop manuel. One says 1400cc's and the other says 1800cc's. If anyone would know it would be Doug.

[Doug Wilford]

Thanks guys, I don't have all the answers. The best and way to change oil on the Sachs is to remove the left side cover, you can get more oil out, you can inspect and clean out any metallic residue and it is a whole lot easier to put the 700cc of oil back in.  We did use ATF for years, compared to the 90 W that Sachs recommended the trannys worked like a jewel.  Now I use the Golden Spectro 80W which is actually a 10w-30.  To heavy an oil will cause a hydraulic lock when upshifting and cause missed gears.   The selector rod moves in a very small area and if sealed by heavy oil it will hydraulic lock.
 I don't think tomuch oil will hurt the 175 tranny I would go with the higher quanity, if you notice some abnormal leakage, drai a little out.


Edited by - Doug Wilford on 09/18/2001  9:28:30 PM

[Dave Hefterich]

CZs have the same situation. They take a small amount of oil 600cc. When you pull the drain plug only a trickle comes out  All the oil is in the left case so you have to lean the bike over to get it out. The only difference is that CZs have a dry clutch. According to Bertus CZ this is normal.  Once the engine is running the trans. slings the oil into this area. I guess it is sort of like a dry sump in that only enough oil is there to lubricate not to cause drag.I am sure that with the reputation for reliability that CZ engines have the system works.