Leaky rear engine seal

Submitted: Wednesday, Mar 08, 2006 at 21:13
ThreadID: 31559 Views:1713 Replies:9 FollowUps:16
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When I bought the GQ the rear engine seal was leaking.

So the mechanic pulled the box out and we replaced the thrust and spigot bearing and the seal. We dicovered that the flywheel was warped and running 2mm out of round but I had it all put back together and we went off on our big trip.

After 10,000km the rear seal starting leaking again. We arrived home and after 20,000km I had the box removed again and replaced the flywheel, clutch and rear seal. Had an in-depth discussion with mechanic re the fitting of a speedi-sleeve. Mechanic reckoned that there was no play and that sleeve wasn't necessary.

8000km later and we have a recurring leak. Now the box will be out for the third time next week and we will be fitting a speedi-sleeve. I am paying for the sleeve but nothing else.

Is there anything else we should look for because I am getting sick and tired of having this recurring problem on the ever reliable 4.2 diesel

Cheers
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Reply By: 120scruiser - Wednesday, Mar 08, 2006 at 21:25

Wednesday, Mar 08, 2006 at 21:25
Use a genuine seal and not cheaper after market ones.
I switched to genuine seals a few years back on customers cars and have not had one come back.
Cheers
120scruiser
AnswerID: 159399

Follow Up By: Willem - Wednesday, Mar 08, 2006 at 21:29

Wednesday, Mar 08, 2006 at 21:29
Thanks mate. Will advise mechanic
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Follow Up By: GUPatrol - Thursday, Mar 09, 2006 at 07:42

Thursday, Mar 09, 2006 at 07:42
Yep,
Best advise.
Also check the breather valve on top of the rocker cover to make sure its not putting extra pressure when venting.
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FollowupID: 414058

Follow Up By: 120scruiser - Thursday, Mar 09, 2006 at 08:06

Thursday, Mar 09, 2006 at 08:06
Good point GUPatrol.
We have had 2 magnas in 2 weeks with blocked up PCV valves and it is amazing where and how much oil comes out of an engine. One was only partially blocked and it stilled poured out of every orifice.
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Reply By: Steve M - Wednesday, Mar 08, 2006 at 21:39

Wednesday, Mar 08, 2006 at 21:39
Never heard of not having to use a speedi-sleeve because of lack of play. I am a diesel mechanic and have used speedi-sleeves succesfully to stop leaking because of the groove which is created on the crank seal area due to wear.

I had a XF falcon (which had an inherant problem with rear mains) so I got a "Taxi Kit" which involved using a heavier duty seal and speedi-sleeve to increase the pressure on the seal by increasing the seal area diameter (slightly) to apply more pressure on the seal. Probably didnt keep the vehicle long enough to know if this was worth it though.

Steve M

AnswerID: 159402

Follow Up By: Willem - Thursday, Mar 09, 2006 at 08:37

Thursday, Mar 09, 2006 at 08:37
Thanks Steve

Having not had the mechanical training to know if the mechanic is telling me porkies, I am at a disadvantage. Only two mechanics in town. One is an aggravating bastard and the other the one I use. He works for a business selling tyres and comes in when there is work. So I have to rely on his wisdom when it comes to mechanical things beyond my capability
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Reply By: Wayne (NSW) - Wednesday, Mar 08, 2006 at 21:42

Wednesday, Mar 08, 2006 at 21:42
Willem,

Might want to invest in wing nuts for the gear box. Makes it a lot quicker to unbolt and replace.:-))

When the clutch is back on the motor have it checked for run out before the gear box goes back on.

Wayne
AnswerID: 159404

Follow Up By: Willem - Thursday, Mar 09, 2006 at 08:24

Thursday, Mar 09, 2006 at 08:24
Yes Wayne :o)))
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Reply By: Patroleum - Wednesday, Mar 08, 2006 at 22:20

Wednesday, Mar 08, 2006 at 22:20
Willem,

Another thing people don't think of is crankcase pressurisation from blowby. 2 things can happen. Firstly, the engine is worn and has excessive blowby-under load crankcase pressure builds up and forces oil thru the seals, maybe a new,tight and sharp (On sealing Edge) seal can just tolerate this and shortly after it leaks. Second. Engines have some way of breathing combustion gases back into the inlet manifold to be reburnt, often a hose on the rocker cover, these can block up causing crankcase pressure. If it's in the rocker cover check hose and fitting to r.cover. As 120 Cruiser says genuine seals are a must. I only use genuine seals and rocker cover gaskets.

Good luck

Greg
AnswerID: 159414

Follow Up By: cokeaddict - Thursday, Mar 09, 2006 at 06:13

Thursday, Mar 09, 2006 at 06:13
Hi Dad,
What Greg said above ..... Sounds like it to me mate. I modified the rocker cover breather on mine and found out a few days later the sump was pressurising thus pushing oil out past the seals (front and rear). I put the breather back to its original place and leaks stopped.

Well worth looking at.
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Follow Up By: Willem - Thursday, Mar 09, 2006 at 08:19

Thursday, Mar 09, 2006 at 08:19
Thanks Greg

Hi Son, lol

Cheers
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FollowupID: 414063

Reply By: Barnray - Wednesday, Mar 08, 2006 at 22:52

Wednesday, Mar 08, 2006 at 22:52
Willem has the crank been checked for runout. I remember you had mentioned the flywheel runout before. Barnray
AnswerID: 159420

Follow Up By: Willem - Thursday, Mar 09, 2006 at 08:28

Thursday, Mar 09, 2006 at 08:28
Banray

I take it you mean crank wear.

According to the mechanic everything is fine. The truck has 308 on the clock but the engine is still running sweetly, not using oil, and starts first go every morning with no prolonged cranking
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Reply By: nowimnumberone - Thursday, Mar 09, 2006 at 12:28

Thursday, Mar 09, 2006 at 12:28
Is there anything else we should look for because I am getting sick and tired of having this recurring problem on the ever reliable 4.2 diesel
yes a new mechanic
AnswerID: 159478

Follow Up By: Wombat - Thursday, Mar 09, 2006 at 13:24

Thursday, Mar 09, 2006 at 13:24
I was thinking the same thing Nudie, although apparently the only other one in town "is an aggravating bastard".
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Follow Up By: Willem - Thursday, Mar 09, 2006 at 19:05

Thursday, Mar 09, 2006 at 19:05
Like you Wombat
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Reply By: kesh - Thursday, Mar 09, 2006 at 14:56

Thursday, Mar 09, 2006 at 14:56
But Willem, its a Nissan, what more do you expect. I seem to recall you also bought a Cruiser which was promptly discarded. Why?
Never forget the old adage, you only get what you paid for.. AHOS.
I reckon the previous owner of that unit is still smiling, more than now the happy owner of a..............?
kesh
ps. You didnt accent "the ever reliable 4.2 diesel", wonder why?
AnswerID: 159517

Follow Up By: Willem - Thursday, Mar 09, 2006 at 19:07

Thursday, Mar 09, 2006 at 19:07
You bored or on the P*ss again?
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Follow Up By: kesh - Friday, Mar 10, 2006 at 19:57

Friday, Mar 10, 2006 at 19:57
Neither, Willem, but like a lot of people who offer good advice to you it so often seems to me that you have difficulty in digesting it.

Now going back to "tors", (I seem to remember shortly after you aquired it)you discovered early on that the flywheel had a 2mm runout. I know nothing whatsoever about the 4.2 Nissan diesel, but I can tell you that the Land Rover flywheel has an allowed limit of 0.05mm (0.002") run out, and the Land Cruiser 0.20mm (0.008") runout.

So here you are seemingly happy with 40 times the L/R and 10 times the L/C limit runouts.

You put it all back together, hell man, what do expect the inertia of that wobble is going to do to the main bearings at 3000rpm? Nothing? Ever picked up the flywheel and noticed its weight?

I could warrant that your crankshaft has been flexing like it was never designed to.

Sorry Willem, its the mechanics chain I should have rattled, not yours, but I hope you get the mains clearances checked and runout brought to specs before the next adventure
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Follow Up By: Willem - Friday, Mar 10, 2006 at 20:31

Friday, Mar 10, 2006 at 20:31
kesh

My apologies for being snarky but you do have the ability to wind me up.(refer to this and previous posts)

I am no mechanic but am able to 'fix' things from time to time. I take your point on the flywheel wobble but the vehicle came like that.

Fortunately/unfortunately I live in a small country town with limited facilities and have to rely on advice from qualified trades people who are used to doing things the bush way. I am sceptical of the advice sometimes and try and work around the problem without causing bad feelings likje trying to tell a mechanic how to do his job.

This time round we are going to be more specific in our endeavour to repair the problem.

I will keep you posted

PS My old diesel seldom gets to 3000rpm...lol
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Follow Up By: kesh - Friday, Mar 10, 2006 at 20:59

Friday, Mar 10, 2006 at 20:59
The bloody "cabin fever" seems to get to me this time of the year.
Ready enough to go back to work, but still too hot for this ole feller to handle!

My other blight is that some strange gift allows me to do any sort of mechanical work I might need to do. (engines, gearboxes,diffs, steering pumps etc.) A legacy from the old man was a very comprehensive W/shop, lathes, mill, instruments, etc. Allied to the fact that I cut and polish gemstones as part of the income, instead of replacing injectors I make laps and recut nozzles, seats etc. Made up an injector test bench and discovered quite a bit about injector/pump tuning.

I've never known a bad mechanic because I have never taken any of my vehicles to one. But I have seen plenty of results of their incompetant workmanship.

Yeah, I know, 3000rpm was just a figure. My 75 L/C (bought new) has never been over 3000 yet (unless it was in the showroom) I picked it up in the city with 5km. on the clock, and it never went back for any service (including that first 1500 or whatever it was)

Lets know how it goes.
kesh

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Reply By: Member - Lindsay S (Int) - Thursday, Mar 09, 2006 at 23:53

Thursday, Mar 09, 2006 at 23:53
Willem
I have never stripped a Nissan 4.2 but a crank seal alone will not cope with the oil being flung from the spining crank surface. Most automotive engines have a 'slinger' or thin metal disc ahead of the seal which as the name implies slings the bulk of the oil into a groove formed by the seal housing or sump and block. The chamber thus formed has a drain channel in the lower part which allows the oil to return to the sump. If this is blocked or partially restricted the build up of oil will 'flood' the seal. From one skaap to another it may be worth checking.
AnswerID: 159624

Follow Up By: Willem - Friday, Mar 10, 2006 at 08:41

Friday, Mar 10, 2006 at 08:41
Thanks Lindsay
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Reply By: Kiwi Ray - Friday, Mar 10, 2006 at 04:41

Friday, Mar 10, 2006 at 04:41
hi Willem
You might like to check the end float of the crankshaft, if it is too much this can cdeate oil leaks
Ray
AnswerID: 159639

Follow Up By: Willem - Friday, Mar 10, 2006 at 08:41

Friday, Mar 10, 2006 at 08:41
Thanks Ray

Will check that too
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FollowupID: 414272

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