Hey Folks,

I wanted to share my recent experience adding an oil reservoir to my R53.

I bought my R53 last summer with about 280,000km on the clock and with only limited knowledge of the real issues that crop up on these cars, so in the short time I've owned the thing there has been quite a bit of "learning" happening. The main one I will be addressing in this post is super charger gear box oil leakage. This is something that is a bit hard to diagnose because there isn't really a lot of sounds clips I was able to find that definitively show the sound of worn SC gears.

Here is the sound of the car before I fixed it. Notice how the sound is not a rhythmic ticking or a constant humming, but a very metallic sound that jumps around like a thousand tiny hammers bashing against each other. This is the sound of worn out straight cut gears meshing.

This is what the gearboxes looked like when I opened them up. The PTO side was 100% dry and the gears were very worn. You can see how sharp the edges are and all the powdered steel lining the gear case! The belt side of the gearbox had leaked some oil, but was still in pristine condition.Note* I do not know the mileage of this SC. The previous owner may have replaced it with a used unit at about 230,000km, but I'm not exactly sure.




The belt side gears are in good shape!



When I purchased the car it came with an extra super charger unit from a crashed 2004 R53 with a broken gear housing on the water pump side. I hammered out the PTO shaft that drives the water pump and swapped that intact gear onto the intact SC housing that was in the car. So, now I had a workable supercharger. The only issue is that the seal at the PTO is from the old dried up SC and was running without lubrication for quite some time. I am guessing this means that seal will leak even faster than normal. Since accessing the fill hole for the PTO side of the SC is impossible without full disassembly I decided to add a SC oil reservoir.

I added a hose fitting to the PTO side gear chamber. This is a brass 1/4" NPT hose fitting. This fitting has a tapered thread that requires a special tapered tap. That taper causes the hose fitting to seal tighter and tighter as it threads in. The size fitting is *almost* to large for this gear box, but it does just barely fit. You can see that it doesn't intrude into the gear chamber, so there is full clearance for the gear. I think the wall thickness of the gear box is about 6-8mm, which allows for a good number of threads to be engaged. I was able to put pretty significant torque on this fitting with no issues. I think a smaller fitting would be more appropriate, but this one was easy to get from the local parts store and it worked fine.


Make sure to buy the appropriate drill bit with the 1/4" NPT tap as it is over 1/2" and probably won't be in your workshop already.


From here I just used some standard 1./4" fuel line from the local shop to connect up to this Suzuki GSX1000 brake fluid reservoir I found on Amazon. It is very small, light, cheap and the fitting works with 1/4" hose.



For now I have the resevoir mounted to the intercooler bracket, which is not ideal as it gets shaken like mad along with the engine. There is an empty mounting boss of the firewall to the left (viewing the car from the front like you would with the hood up) of the coolant reservoir. I will move this over there next week when I have a bit of time. Routing the hose was no problem as it can snake through the maze of vacuum and coolant lines under the intake manifold easily.

Here you can see the oil fitting tucked away under the intake manifold. There is just enough clearance to fit everything comfortably.


Reservoir mounted to the IC tab. I drilled and tapped an M6x1 hole through the tab and ran the mounting screw in from the underside. You can see the hose here beside the reservoir fitting- uncut at this point. You can see the route the hose takes here as well. I'll draw some arrows and lines in to clarify the path when I have access to Adobe Illustrator tomorrow.



Conclusion:
1. So far I have already found a flaw with this system. I did not build in an air breather so the fluid from the reservoir cannot flow into the gear box as the gear box is fully sealed. So there is a big air pocket inside the gear box right now. I will fix this by running a 1mm ID plastic straw down the hose into the gear box. This vent technique is the same as what the Brits call a strawpedo, or around here its part of a beer bong hahaha. I'm hoping to find some tiny tube today to ventilate this thing and then it should be good to go!
2. I did not build a feed line to the belt side of the SC. This is certainly possible, but I figured I should keep it simple and just do the hard to access side for now. It is possible to easily add oil to the belt side gearbox with a syringe and some 1/4" OD hose as that fill plug is accessible with no disassembly.
3. I'll update this with the new reservoir location and breather tube function soon.
4. Check your super charger oil before it is too late!!

-Brad

 

I'll be interested to see if this fixes your noise issue because it sounds like worn timing chain/guides to me. Keep us updated, please.

 

Yep it definitely fixed the noise, although I still have the noise from the dual mass flywheel to deal with.

 

This is quite an interesting DYI! Please keep us updated, the supercharger maintenance is about to begin in the next few weeks on ours, already order the kit with all the seals and the oil.

 

I'm no expert but my concern is that as designed, the cavity is not intended to be full of lubricant. It is designed to provide optimum lubrication without the risk of cavitation. Would be interested to hear from someone knowledgeable about this sort of stuff.

 

I was thinking about that, it should only be filled to the drain plug, completely filling it may put more strain on seal or even the gears since have to turn fully submerged instead of just dipping into the fluid. It would be nice to be able to top off the fluid by just pouring it in the reservoir, but how can you check the level in the s/c. Maybe if you could include some kind of dipstick.

 

There is 100cc oil in the larger chamber and only 25cc in the smaller chamber. It would be tough to get a dipstick to register such a small amount. Besides, removing the supercharger is fun!

 

I received the small hose to create a breather for the SC, but the reservoir has been slowly empyting into the SC as the car is driven, so I haven't bothered to try inserting it yet. Curiously the oil in the reservoir has turned light grey and has some very small suspended particles in it. There must be some amount of flow happening up into the reservoir. The metallic particles are a bit disconcerting, but perhaps that is normal. I cleaned out the gear case, but maybe I left some gunk behind.

I agree it isn't designed to be run full up, but I decided to take the chance. The risk of running dry seems worse to me than the risk of cavitation or some other issue. I typically only city drive the car so the RPM is usually under 4000, which might mitigate such a risk to some degree I can only speculate on. There is still room for the oil to expand as it heats up, so that isn't an issue at least.