Easy to replace front crank shaft seal?

[StageLeft]

I know, I know. I should start paying you guys

93 sentra. It was diagnosed with a big oil leak 8k miles ago and I'm thinking it would be nice to deal with it. The mechanic said the front crank shaft seal and rear main seal were gone. I figure that perhaps replacing one only would curb the problem, since the rear main seal is a massive repair and I don't want to pay for it.

SO:

1) How easy is it to replace the front crank shaft seal? I can't find a how-to on the internet, and I'd be willing to buy a haynes if it meant that I could do it with a standard tool kit and a barely working knowledge of where the engine is in the car.

2) How the hell can my front seal be gone, when I had it replaced a year ago (20k miles)?! That sucks!

 

[CraigRT]

have you tried any Nissan forums like SE-R.net or any others?

i find they can always offer fantastic help on matters such as yours.

 

[BatmanNate]

Depends entirely on the motor. However if you're due for a new timing belt (should be every 40 or 60k I don't remember) then have them do it while they're in there and it won't be much extra cost at all. The parts are all cheap, it's just probably a pain in the ass to get to.

 

Skoorb;
Want real advice ?
Email or PM me.

 

[notfred]

if you had it replaced a year ago and it's dead again:

1) It's fine, and the rear main seal is your only remaining problem.
2) It was installed incorrectly.
3) Your crankshaft bearings are shot.

you will have to pull the timing cover and timing chain/belt to get to the seal.

 

[StageLeft]

I'm scanning deja now...yes real advice this time Roger. The octane mixing was a real question as well until the end

I will PM

BTW the car uses a timing chain, so no replacements of a timing belt!

2) It was installed incorrectly.

Well it was done at a nissan dealer, so if he couldn't install it correctly I sure as hell can't. I wonder if it's just the rear main seal then...hopefully the crankshaft bearings aren't shot, whatever that means in the grand scheme of things!

 

[Antisocial Virge]

If the front seal is leaking after only a year something else is wrong. It might have been a burr on the crankshaft. Front seals all depend on the vehicle, last one I did was on my 5.0L F150 and it was a joke. FWD depending how much room you have to play with and the type of seal might be brutal.
Now if its the rear seal *shudder* good luck

 

[notfred]

Originally posted by: Skoorb
hopefully the crankshaft bearings aren't shot, whatever that means in the grand scheme of things!

If they were, you'd likely hear some type of grinding noise coming from the motor. Also, it'd be time for a new engine.

 

[StageLeft]

Originally posted by: notfred

Originally posted by: Skoorb
hopefully the crankshaft bearings aren't shot, whatever that means in the grand scheme of things!

If they were, you'd likely hear some type of grinding noise coming from the motor. Also, it'd be time for a new engine.

Other than a very subtle peculiar rattling I sometimes hear when under power (and I've had this for thousands and thousands of miles, and a mechanic said it was not the timing chain, and he couldn't even hear it on a test drive), the engine runs like a champ. So if it's not that, and we assume that the fronk crankshaft is good maybe it is the darn rear seal.

 

[Bluefront]

I've replaced this seal on a sentra before. It's not very hard. The hardest part is removing the crankshaft bolt....you need a 27mm socket. Since the crankshaft pulley was recently removed, it should easily come off with a couple of screwdrivers/pry-bars.

Then you carefully pry out the old seal with a screwdriver...or a seal remover tool. It's easy to replace. You push it in by hand to start it, then tap around the edges until it's flush with the case (put some grease on the seal). The pully itself is the sealing surface...you'll see two sets of marks on it where the seal edges ride. Clean this off with some very fine sandpaper...like 600 grain. This is where you may find a problem. If there are wear grooves right here, caused by the seal, the pully may have to be replaced.

I've done this job in my driveway....it's pretty easy for me. Difficult to say how hard an amature would find this job....but I bet you could do it.