Supercharger rebuild required?

Supercharger rebuild required?

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eltax91

Original Poster:

9,842 posts

205 months

Monday 24th August 2015
quotequote all
Hi guys

I have a mk2 mx5, that has been supercharged. It's running (I think) an eaton m45 supercharger, with a Jackson racing pulley and air outlet. I believe it's from an R53 mini?

When I pulled the air intake pipe off the other day (inboard of the charger) the pipe is cakes in oil. So, I suspect the charger oil is getting sucked through from the nose into the turbine and deposited into the engine.

I've looked in eBay and can find a few kits in the states to rebuild it. They are all nose only lots though, don't seem to include the kit to rebuild the rear bearing too.

I have an engineer FiL who has a bearing press, so rebuilding it should be ok.

Question is, is this a common thing on SC's? Does the oil seal degrade and do this?

Does anyone know where I can buy a full kit from? Nose and rear? Also, anyone know where I can get a technical drawing for it to make the rebuild easier? I've Google but can't find it at all.

Cheers in advance for any help.

Richyvrlimited

1,824 posts

162 months

Monday 24th August 2015
quotequote all
It's unlikely that the seal has gone between the gearbox/midsection and the casing. Where is the PCV system plumbed into the inlet? If you've retained the PCV system, it is much more likely you either have a failed PCV system or your rings are going and allowing pressure to build in the crankcase.

Additionally the casing section is usually under pressure, so IME the nose section oil tends to be pushed out of the seal behind the nose pulley rather than being drawn into the casing.

If it is indeed the seals in the gearbox, replacement is not that easy. During manufacture the bearings are pressed in and the aluminium casing folded over to hold them in place. pressing them out will destroy the retaining ring BTDT, it's too thin & brittle to withstand being bent back.

Jonbondperformace in the states sell a bearing & seal kit, this also includes a large washer that needs to be welded in place to ensure the bearing stays in place (see below).



Also note that the bearings & seals are a protected part, I tried and failed to source them in the UK. the dimensions are about 1/2mm out in all dimensions from the normal sizes, I could only source them from JonBond and another supercharger parts dealer in the USA, (can't remember their name).

It's well worth extracting the rear needle bearings and replacing those along with the single large bearing in the nose section. Especially if the nose has been run dry of oil.

You're unlikely to find a technical drawing, but the aformentioned jobbond has a few youtube videos of replacing some of the bearings. I can talk you through it too if you need it.

Unfortunately all those parts inc shipping & import duty will be more than a good condition second hand blower. Albeit all new bearings will give you much more piece of mind.