Rear oil seal leak. Advice required.

[zeds4ever]

  I'm sure I'm bloody jinxed with this car, turns out now that I'm getting tell tale signs of the rear oil seal on crank is leaking. Been using Castrol Magnatec oil & it has started since then. Whilst the motor was rebuilt a few years ago it has done no road miles & I have been starting it  up & running about once a week. Is there an additive that I can put in oil to help overcome this or do I have to replace the damn seal. If so what is the best method to do this & what is the best seal to use. Car is fitted with Auto trnsmsn.

 

                                                              Regards: Alan. 

[peter mc]

it a box out and have a look , the oil you use wont cause a leak , but a seal thats not fitted right or a leak around the rear cap  because its not fitted right is the most likely cause ,  you can still get the nissan seal at your nissan dealer

[nizm0zed]

^^^

indeed, however you forgot the all important check for a groove around the seal surface.

If that groove is present, the only way to absolutely fix it completely is to get it machined and sleeved.

Otherwise it'll always leak oil, some more than others.

 

the 'dodgy' fix (for crappy old dunger cars, NOT zeds) is to use a thicker mineral base oil, it'll eventually carbon up and plug the leak somewhat, but its really not good for them...

[Riceburner]

If its got a wear mark where the seal was I've heard of fitting the new seal slightly further out than where the old one was, could be worth a shot if your feeling lucky

[zeds4ever]

Thanks Fella's for your reply, so gathering from your responses I have to take the gear box out & check the seal more closely. The bottom line is that I will have to take the motor out Remove sump & crank shaft to refit Nissan seal. Is this correct or is there an easier method that will be just as effective. Once again many thanks for the advice.

 

                                                              Regards: Alan. 

[nizm0zed]

you dont need to remove the engine to replace the seal, it can be done in car if you drop the sump a bit off the back.

However, you will need to remove the gearbox and flywheel to access it.

 

As Pete suggested, there is the chance the seal isnt seated correctly, creating a leak.

If there is a groove around the crankshaft you need to work out where you want to go from there,

either try to move the seal position a little bit, as suggested by Gareth (however, no guarantee of sucess)

maybe try a different brand, although all seals for that should be made to one specific size, some tolerances can make for a seal that is a bit tighter, its all guesswork, trial and error though.

Or, if the groove is bad, you then need to consider removing the crankshaft and either replacing it with another, or getting the seal surface machined down and a sleeve pressed over it.

That last one is obviously quite extreme, so its more of a last resort, however, it is also a very permanent fix, if done correctly.

 

no matter what, if you put a new seal in there, make sure you coat the seal lip AND the crank surface generously with Vaseline, to ensure the seal has good lubrication.

Running a dry seal on a surface is a good way to burn the edge off them, creating a nice little pool of oil under your car...

 

Edit:

You know what, i cant actually remember if you need to drop the rear of the sump??

I honeslty cant remember if it was just a pressed in seal, or whether it was in a carrier plate??

someone will confirm that.

[peter mc]

just the gear box  remove the clutch and flywheel and the seal can be removed , no need to remove sump only if thats leaking do you take it off 

[zeds4ever]

  Thanks Alan & Peter, I will do what you suggest. I think the crank should be no problem tho as it was machined & balanced when the motor was rebuilt. Think it might be what was mentioned with regard to seal being dry which was as a result of the motor not being turned over for quite a while. Three years aproxmtly. Your help with this is much appreciated.By the way Pete even tho you have given away building motors it brightens my tired old eyes to see that you are still around to lend your immense knowledge about motors to other people such as myself, all the best with your future endeavour's what ever they may be.

 

                                                Kind regards: Alan. 

[peter mc]

thanks mate . but I'm building more motors now than i ever have  just not working for my self , I'm working under Les Collins , and learning how to do it better ever day , he is a true datsun engine man

[zeds4ever]

Good to hear Pete,I'm sure the fella's on the Forum will be pleased to know that. I find it hard to believe that you are still learning about motors tho. LOL.

 

                                                                Regards: Alan.