rear main help

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mudgroup
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rear main help

Post by mudgroup »

gay all...

need some advice on a rear main seal that doesn't want to stop leaking...
has been replaced 4 times...
hopefully someone here can help with what cases a rear main seal to let go..... doing my head in... and also the current engine builder
• mix of early / late motor components (ie fj - ek) ?
• input shaft bent ?
• gear box ?
• crank bent ?

and also... how do you deal with an engine builder.. that can't solve the problem...
i don't want to take it back to him... but have invested in this guy and the engine.. which is still under warranty ?

stu 8)
but what about speed ?
if you're important, people will wait!
newman
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Re: rear main help

Post by newman »

Stu,
The best advice I can offer is find a mechanic who is really familiar with Holden sixes, I'm lucky that I have my wifes uncle who has been in the trade for most of his life (he's in his sixties now) and he has given me plenty of advice regarding my grey motor. :wink:
Mick 8)

P.S. I will ask him over the weekend when I see him.
mudgroup
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Re: rear main help

Post by mudgroup »

thanks mick.
working on these engines, as described my engine builder, isn't 'rocket science' but is a lost art i think...
have had some success with his engine in the wagon.. but this one has everyone stumped ! it goes very hard.. so no dramas there..
yeah... any advice would be great... thanks 8)
but what about speed ?
if you're important, people will wait!
EffCee
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Re: rear main help

Post by EffCee »

The issue here is a lot of people have either not learnt how to do a "rope type" rear main oil seal or have forgotten how to do it properly. You must soak the rear main oil seals in oil for at least 24 hours before assembly. If this is not done, the seal, which is really tight when fitted correctly, overheats and "burns out".

The second thing to do when fitting the seal up is to ensure that the seal is properly seated. There is a tool for this, however they are easily replicated or you can use the crank if need be. The rear seal is pressed in, and using a piece of pipe or similiar roll the seal in to ensue that the seal is in correctly. Sit the crank back into the block, and tighten the rear main cap only, just short of the required tension. Remove the rear main cap and the crank. You will note there is some excess rope seal. Trim this off, leaving approx 0.5mm of the rope seal sitting proud of the crankshaft mating surfaces. Install the bearings, and crank back into the block, when fitting the rear main, use a gasket sealant ( a good silicone sealant) in between the cap and the block face to assist the seal.

I have seen some seals that have been rotated after they have been pressed in, to avoid having the seal ends in the parting line between the block and the crank, but if this is not done correctly then this can cause issues as well.

One other thing for your engine builder to check on, ensure that the seal locating pin is still in place and that the seal is not spinning inside the rear main groove.

Keith
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Re: rear main help

Post by mudgroup »

keith.. thank you for your advice.. and i have passed it on...
thanks.. stu
but what about speed ?
if you're important, people will wait!
mudgroup
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Re: rear main help

Post by mudgroup »

well.... this thing has me stuffed! rear main replaced again and still leaking. have full refund from engine builder but still no running grey. so... cashed up ready to buy something running, or ready to find someone else to pull apart and get it right. it runs really well, just leaks rear main.... heaps. any advice re engine rebuild in geelong or melbourne would be great... or anyone looking to offload a decent running engine. stu 8)
but what about speed ?
if you're important, people will wait!
hagar
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Re: rear main help

Post by hagar »

In all engines, especially modified ,the engine needs to "breath" if there is excessive crankcase pressure the oil will be forced out where there is least resistance .Early engines were just vented later they were vaccumed so check oil breathers etc. Has anyone checked the seal area for "run-out" ,put a dial on it and check end float while your at it,has the block been line -bored ?if so was the seal tunnel bored at the same time to keep it on centerline. A piece of rope rubbing on a lump of cast needs all the help it can get to create a seal ,the materials have changed ,we cant use asbestos any more and graphite doesnt seem to work as good . Cheers Gary
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Devilrod
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Re: rear main help

Post by Devilrod »

Hey Stu is the crank excessively worn where the rope seal sits? Could be why it won't stop leaking.
Speed and Style........... One day I'll get the speed bit.
mudgroup
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Re: rear main help

Post by mudgroup »

gary / dr...
just to confirm.. this engine is stock...and trying to revert to stock specs as close as possible... allowing for a grind here and ther..
i have been assured that all measurements are as they should be.. but after a discussion with another builder yesterday... the crank grind doesn't seem as easy as it sounds... i always questioned and passed on comment from the forum .... but... lets say we still have the same problem...... maybe time for a new crank.. but it will be sent to another builder to check... if no good... then thanks to bumper... have another to look at ! thanks for the advice...
ute still goes well... engine is great... its just like a big black alsatian when it leaves its mark !
stu 8)
but what about speed ?
if you're important, people will wait!
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Devilrod
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Re: rear main help

Post by Devilrod »

As you know mine wasn't much better. I spent easter resealing the motor and box. I noticed while replacing the rear main a bit of a groove where the old seal had been. I've put a rope seal in and its definitely better but not perfect. Auto was worse!! At least its not consuming a litre of fluids every second week... :shock: :mrgreen:
Speed and Style........... One day I'll get the speed bit.
tm 50
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Re: rear main help

Post by tm 50 »

Mud group If your still chasing an engine buider , give Joe a call BnB engines westall rd clayton 95479674
mudgroup
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Re: rear main help

Post by mudgroup »

dr... yes i remember... a word of warning to anyone following dr to this years nats.... :lol: :lol: :lol:
thanks tm50.. but trying someone in geelong.... 8)
but what about speed ?
if you're important, people will wait!
mudgroup
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Re: rear main help

Post by mudgroup »

drip... drip... drip...
calling all grey engine builders... where do you get your rear main seals from ?
new block, everything fits up and measures they way it should... but it still leaks..
seal not spinning... just getting saturated with oil... current guy blaming the seal... and it is the only one he can get...
his next thought is to use a red rope seal... and pack it out with a spacer ???

goes like a rocket though... and can't get enough of it...

maybe its time for an upgrade.... how does the roadster go dr ?
anyone want a matt black ute !
#thisutehasdunmyheadin

stu 8)
but what about speed ?
if you're important, people will wait!
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Devilrod
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Post by Devilrod »

The roadster goes drip ................ drip. :mrgreen: but other than that great for a motor recoed in 1977! :shock:

I managed to slow down the leak in mine from the rear main but not stop it entirely.

You could always make a tray with a bit of foam that catches all the oil and rinse it out every so often.... Seen it before!!!! :shock:
mudgroup
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Re: rear main help

Post by mudgroup »

ahhh.. just the word.. 'roadsterrrrr'... how cool does that sound off the tongue ?
oldskool has had some exposure recently dr... looking good 8)
but what about speed ?
if you're important, people will wait!
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