Machined a low cost bolt on kit to refill the supercharger oil w/o removal or mods
About 3 years ago I was installing a new clutch and replacing all the typical wear items on my R53. While waiting on parts that I forgot to order, I designed and made a bolt on kit, so I could refill the supercharger with oil without removing it from the car.
The center of the kit is a machined billet aluminum plug that replaces the PTO and nose OEM Drain/fill plug on the supercharger.
There are drain and fill tubes that run from the nipples to the bottom of the car. One to drain off excess oil and a second tube that runs up to the radiator cowl area to fill.
All you have to do is fill a syringe with the correct amount of GM Eaton supercharger oil and inject it into the fill tube with the drain tube capped. Once filled you take the cap off the drain tube allowing excess oil to drain off. Then you are done and the supercharger has a safe level of oil again.
Simple, and with no tools, I top it off every 3rd oil change. My mini has 178k miles on it, 150k miles with an M7 overdriven pulley and its running great quiet and no issues.
In an effort to earn some side money to help pay for the restoration of my 1976 Mini, I made a little square space site and put this together into a kit.
If your interested in trying out the kit its for sale at
I would love to answer any questions or hear any feedback. It's been working great on my mini for the last 3 years.
I've received some good questions, and thought it would be good to share to better explain the kit:
1) How do I remove the old oil? How is the correct oil level attained and not over filled?
A) The old oil doesn't need to be removed. It is supposed to be a sealed lifetime oil, thus no reason to remove any of the old oil remaining in the sump. The supercharger PTO is only two gears splashing around in a 1 inch deep pool of oil. The only thing that matters is that there is oil PRESENT. The oil level is self regulating when you fill it.
B) With the kit you inject the appropriate amount (or more if you want, it's doesn't really matter) of oil into the upper fill line with the drain line capped. Once injected you remove the drain cap and let the excess drain away. The gear box now has the correct amount of oil in it. There is no possible way to over fill, as long as the drain line cap is removed and the line is drained.
2) What about the tubing, do I need to remove them each time refill?
A) The tubing is very robust it's temperature range is -100° - +500° F. The same tubing has been installed on my R53 MINI S for 3 years with no issues. It's just as pliable and soft as new.
B) The tubing stays in place to allow you to top off the supercharger whenever you would like. The fluid in the supercharger cant physically drain below the fill plug, so there will never be a fluid loss below the appropriate full point.
3) Is there a video of the process?
A) A video could be done, but it's simply injecting the oil into the supercharger, essentially over filling it (very boring to watch!). Then removing the cap on the drain tube. The oil drains to the correct max fill point with no fuss. Fin
4) How did the original oil disappear or the oil level go down?
A) The shaft of the input gear that turns the PTO gear box is part of the lobes of the supercharger. On the shaft is a seal to seal the High vacuum environment of the supercharger compressor from the PTO gear box. As that seal wears the vacuum is able to slowly over time draw oil past that seal, and it's burned in the engine. Eventually resulting in an empty or low oil level in the PTO gear box or nose of the super charger. This results in excess wear on the gears and bearings of the supercharger, eventually leading to a failure and stoppage of the water pump which is driven by the PTO gear box.
2005 MCS with LSD 1976 Mini City 1000
Megan Rear control arms, TSW springs, Webb Motorsports Camber Plates, ALTA PSRS, HAI, M7 16%, Engine Dampener, Helix Short Shifter,
RSPEED Rear Sway Bar
Last edited by The_R1_Kid; 04-02-2017 at 09:14 PM.