Rear Main Leak

Submitted: Tuesday, May 18, 2004 at 09:30
ThreadID: 12961 Views:4076 Replies:3 FollowUps:0
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Hi all just looking at options for leaking rear main on VN commodore 5litre V8.
I have not had to repair this before and am led to believe that the crankshaft has to be released to replace the seal, is this correct and is there any other way.
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Reply By: Baz (NSW) - Tuesday, May 18, 2004 at 10:14

Tuesday, May 18, 2004 at 10:14
Falcon has the same problem, i know it's a big job in the falcon, i assuming it would be a big job on the holden as well, i had a 302 ford it was around $500, that was a while ago though 88 or 89. I've always wondered why they have'nt addressed this problem.

AnswerID: 59047

Reply By: roblin - Tuesday, May 18, 2004 at 10:31

Tuesday, May 18, 2004 at 10:31
I am unsure of the rear main seal composition for the 5litre however if it is an old rubberised rope seal (as opposed to a circular rubber seal in its own housing) there is an alternative. The first V6 VNs had the old rope seals and were known to leak after awhile (I know, I had one and had to fix it). Holden sold repair kits that consisted of a length of rope type main seal, a couple of wedges, sump gasket and some sealant. Thos ewho own old fords may recognise this repair.
Simply done: you lift the engine (in the engine bay but after disconnecting the mounts) sufficiently to allow you to remove the sump. Don't forget to drain the sump oil first though!
REmove the rear main bearing cap so that you can access the seal. With a suitably sized punch, you drive the seal up and around the crank until it is fully compressed - thereby making a tighter fit around the crank. You then apply sealer to the new rope seal and force the seal into the space left after drinving the old seal in. Cut the new length of seal of flush with the upper bearing cap the drive the supplied plastic wedge in against the seal to ensure a tight fit. The wedge is on the other side of the seal to the crankshaft. Place a new length of rope seal in the bottom bearing cap, trim to fit and replace bearing cap - torque appropriateley then reassemble motor. Yes, this was a Holden sanctioned fix!!!!!!
If you have a rubber pressure seal, I believe the seal is embodied in a cast seal housing that is able to be withdrawn from the back of the motor without lifting the engine from the car. You just replace the seal and bolt the housing back on.

For the first fix, the gearbox can stay in place - you just lift the whole lot up sufficiently to enable the sump to be taken off.
The second fix will require the gearbox and flywhhel to be removed I believe.
I have done the first fix but not the second. Allow yourself a day to do it although it should probably only take you 4 hours at the most if you have all of the tools.
AnswerID: 59049

Reply By: Willem - Tuesday, May 18, 2004 at 11:31

Tuesday, May 18, 2004 at 11:31
When we bought our VR V6 wagon a couple of years ago I enquired about this leak and was told by a Holden trained mechanic " yeah they all leak there, don't worry about it". So I haven't worried about it and it does not leak much. If it becomes a fountain then we might swap it for something else :-)

AnswerID: 59060

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