New Member old car. replace oil seals Yay or Nay

  1. My model of MX-5 is: NA V Special, Eunos
  2. I’m based near: Chester__
  3. I’m looking for technical help or recommendations on: _Replacing camshaft and front crank shaft oil seals.
    My NA needed a replacement water pump, thermostat housing, Water pump outlet and new front wings. I have been advised to change the cam belt and oil seals. I have the front wings off and all the accessories ( see pics ). The water pump has been weeping on to the crank seal and the area around is slightly corroded ( Pics ). I have heard the seals can be difficult to remove and scratching of the seats must be avoided. The seals are completely dry and dusty. Two questions The NA has a little over 100,000 KM. on the clock. Do I leave well enough alone or do I risk damaging the seal seats. Is there a tool or a method to ease the seals out. Any help would be much appreciated. Allen.

You drill a small hole in the metal ring of the seal, put a self tapper in and pull the seal out. You would rather do it now that next week once you have put it all back together.


thanks Nick, drilling holes sounds a bit drastic. Can it do damage to the seal seat. Allen.

Only if you let it. .

If you don’t know the providence of the seal then maybe better to change it albeit cautiously. I use a seal pulling tool which looks like a mini pry-bar with hooks on the end.
The current one looks pretty dry, I would also change the cam seals whilst you have it apart.

Thanks carl, looks like the yays have it. Allen

I replaced the seals on mine last weekend as a matter of course while doing the cambelt etc. Easy job and well worth doing while it’s all in pieces!

Thanks for the encouragement Mike I’m expecting delivery of the cam and crank seals in a day or two from MX5 Parts. I’ll let you know how I get on. Allen

Hi Allen. Don’t forget that there’s loads of “how to” videos on YouTube to help you along. I always look at a few before starting any job just to see what kinds of issues might arise.

Good call, will do. Allen

Received the last few parts to start the rebuild, the seals come out with a little frustration and a good tip from Nick. One cam seal went in easy and seated good and flat the right hand one twisted slightly, gentle persuasion with a blunt screwdriver did the trick, time will tell !. The crank seal came out OK but the new one was really tight going in. What was surprising was just how clean and dry the space behind the seals was. Next the water pump and thermostat body.

The shiny bits going on, starting to feel as though I’m getting some where now.

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looking good, are you keeping the aircon? if not now’s the time to get rid of the stupidly-heavy compressor that’s sitting idle in the bottom right corner!

This is all looking very familiar. I have to say that my new seals went in fairly easily after a thin coating of oil on the seal surfaces and using the old seals and a small hammer to gently tap them into place. My rebuild has been slow as I’ve got a bit particular about putting dirty parts back on. Everything has been either scrubbed and painted or replaced. I also soaked all the screws and bolts in alloy wheel cleaner, scrubbed them up with a toothbrush and gave them a coat of satin black paint. Next job is to paint the cam cover red…

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Hi Carl, Not give it any thought until now. It hasn’t worked for many years. Was driving around France one particular hot summer, with the hood down it was like sitting in an oven. The aircon was much appreciated with the hood up. I will have to way up if I will ever use it again. I suppose you have to some how fix up an idler pully to support the belt. Any one any ideas how this might work. This is what I like about this club, Good response to posts and members willing to comment and give food for thought. Thanks for your suggestion Carl regards Allen.

Hi Mike, I am cleaning some parts as they go back and will give the engine compartment a clean and polish. As much as I would love to detail the engine, I need it on the road by the middle of May. I may get the cam cover coloured with crackle finish some time in the future. Keep us up to date with progress. Allen.

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More shiny bits and belts going on. Photos show tool I made from a roofing truss tie, used to lock crank shaft to allow work on the cambelt and crank seal replacement

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You just use a shorter drive belt that runs on the crank pulley and PAS pump.

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Yes, I would assume you can use the belt for a non-aircon car like mine.

Hi Allen. I’m not really detailing mine, just tidying. I just replaced the old crumbling exhaust manifold heatshield with a stainless steel one. All new water hoses, pipes scrubbed and painted and I’ve got a tin of XHT red paint to do the cam cover. I’m also replacing the radiator as although the old one seemed ok I thought it best to change it as a precaution while it’s in pieces anyway. It certainly won’t win any shows, but will look better than the oily and rusty mess that lurked under the bonnet before…