MX5 rear main seal Problem or Fine

drift76 · Postby **drift76** » Mon May 30, 2011 8:13 pm

Just did a rear main seal on my MX5 and when i put it in the seal went about 3mm past being flat (as in it went further than the other seal) the seal that i pulled out was flush and this seal isnt as its pushed in further
Am i in the sh*t as the car is back together(still a way off starting), am i in for another seal???

93_Clubman · Postby **93_Clubman** » Thu Jun 23, 2011 11:57 am

FWIW, Bigdog's advice in the following re the front crank seal is that it needs to be flush & not pushed all the way in:
viewtopic.php?f=29&t=38848&p=570951#p570951

Postby **NitroDann** » Thu Jun 23, 2011 12:11 pm

So long as both the outer and inner sealing surfaces are both parallel and smooth it makes no difference at all. Im a mechanic and I cant remember the number of engine seals ive done. Average something like 20 a week.

Dann

bigdog · Postby **bigdog** » Fri Jun 24, 2011 1:16 pm

Well, my front seal was certainly inserted parallel, but it was seated to the rear of the housing. My understanding is that the crank can then grab on the seal and turn it causing it to leak. FM make an insertion tool to avoid this problem. The rear seal doesn't seem to have the same issue from what I can see, so you should be fine. The front seal caught me out, as every other engine I have built the seal is seated fully to the rear.

Postby **NitroDann** » Fri Jun 24, 2011 1:30 pm

Sorry I thought 'the seal cant be rubbing against its rear face' went without saying.
Maybe not.

Dann

zossy1 · Postby **zossy1** » Fri Jun 24, 2011 1:37 pm

NitroDann wrote:So long as both the outer and inner sealing surfaces are both parallel and smooth it makes no difference at all. Im a mechanic and I cant remember the number of engine seals ive done. Average something like 20 a week.

Dann

I love you ND, but I'm calling shenanigans on this claim. 20 seals a week? You mean to say you are doing a combined total of 20 front and rear main seals a week? Or does this include cam seals too? And I'd guess most are clutch or timing belt replacements?

You must work 100 hours a week! ;)

Postby **NitroDann** » Fri Jun 24, 2011 1:56 pm

Every timing belt job has at least 2. Jesus a vectra has 5.
Every leaky diff has at least 2 that get done, every second auto falcon has a leaky rear gearbox seal.

Dann

zossy1 · Postby **zossy1** » Fri Jun 24, 2011 2:07 pm

NitroDann wrote:Every timing belt job has at least 2. Jesus a vectra has 5.
Every leaky diff has at least 2 that get done, every second auto falcon has a leaky rear gearbox seal.

Dann

To call Jesus a Vectra is particularly cruel! Jesus saved the world from their sin. The only thing a Vectra saves is mechanics (from going broke) ;)