Front Main Seal replace

[vercingetorix]

I have been monitoring an oil leak for some time now and finally located it by de-greasing the engine. It seems to be coming from the front main seal and then blowing backwards over the rest or the engnie and front cross member. While I was looking I noticed that there was some coolant leakage from the same area, I assume the water pump.

My question is Can I replace the front seal at the same time I do the water pump without pulling the engine?

I have done some searches and the opinions are sort of divided and the ones that say its easy do not give a blow by blow description of how to do it, or where to find the info.

Any input appreciated.

Best,

H Houghton

PS

I also need to know the proper size of bolt that holds the fan shroud. The PO tied it on with zip ties! This ranks right up there with the lawn sprinkler fittings I found when I replaced all the vent hoses on the gas tank.

[Nissanman]

No.1

Water pump.

Easy enough to do, just be careful getting all the fasteners out.

If they are corroded, it may be wise to renew them with a stainless bolt kit from a vendor.

No. 2

Front main seal.

The design of the crank is such that the main seal runs on the O.D. of the crank pulley.

That means that once you remove the crank pulley, there is ample room around the inside circumference of the seal to hook it out with the appropriate tool.

Re-insertion of a new one could be achieved without removing the radiaiator.

If you are doing the water pump, may as well pull the rad. and give yourself better access.

Note the condition of the surface of the crank pulley where the seal rubs.

If it is badly grooved, the new seal will have an issue from day one.

Either have a speedi-sleeve fitted to the pulley OR re-insert the new seal to a different depth that the old one was.

Then the lip on the new seal will have a fresh surface to seal against.

Strongly suggest you use a shop manual to get some baground info. before you start:nervous:

Pic. shows seal and crank diameters.

[JimmyZ]

N-man is right but you'll need to remove radiator for clearance when using a puller on the crank pulley.

It would also be nice to be able to use an impact wrench when removing the pulley's nut. You might have to settle for chocking the flywheel so that a breaker bar can be used.

2c

Jim

[GreenZZZ]

If you are in there, consider doing the timing chain as well, and do expect to break a water pump on timing front cover bolt or two.

[JimmyZ]

No kiddin' about the bolt breakage thing. Had a long one from the F-cover snap once. That sucked!

He ought to get by with the seal and W-P, I'd rather leave the chain for another day. Seems to me that the chain lasts as long as the rings do. (Unless improperly installed.)

Get some anti seize too. Use it on bolt threads and the engine side of any gasket. Makes the next time around easier.

Red loctite the crank bolt though.

[Rockr69]

I just did one on a l24 maxima, DO pull the rad. You can use a steering wheel puller for the damper just get bolts at hardware store with big fender washers. When it came time to break damper bolt loose, because I don't have air, I positioned breaker bar against frame rail and using the starter, spun the engine. Broke right loose. DO change timing kit, guides and tensioner etc., and oil pump. You will be glad you did. I guess I got lucky and didn't break any bolts, but have on other applications. I mean if your in there might as well do it, right?

[vercingetorix]

Do i have to remove the timing cover to get the seal out? I thiought that the bottom of the timing cover also seals the front edge of the oil pan gasket and I would avoid that can of worms if I can.

Best,

H Houghton

[vercingetorix]

Also as to changing the depth of the seal, is there no seating ridge??

[Nissanman]

The seal can be removed without removing the timing/front cover.

Fiddly, but achievable.

If you do anything on the timing chain etc. then the front cover does have to come off.

4 x 6mm bolts clamp the sump to the front cover.

Not something that I have done on an engine still in the car:eek:

The crank seal is usually pressed in till the front edge is flush with the cover, it doesn't bottom out on anything as such.

There is a weeny ledge about 20mm in, but if you press the seal in that far I'm guessing it will have gone in too far.

The depth of the cover at the hole is only about 8mm and the seal is about the same width.

You may not need to adjust the seal depth, just inspect the crank pulley suface with this in the back of your mind:nervous:

Pic. shows front cover seal area and sump bolts x 4.

I just happened to have an L24 front cover next to my 'puter!!

[GreenZZZ]

Do i have to remove the timing cover to get the seal out?

Nope! Break fewer bolts that way.

[vercingetorix]

Nope! Break fewer bolts that way.

So Comforting!!

[rtaylor]

And if you pull the timing cover, it is advisable to loosen the pan bolts as well. I did not do that and when re-installing the timing cover, due to the tight fit of the timing cover between the pan and the head, the head gasket got pinched, which then caused an oil leak and I had to pull the head to install a new head gasket.