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Crankshaft rear oil seal


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Any experience please re. the kit now being sold by TR Shop which claims to solve the problem without any machining of the crank.

Has anyone used this or knows someone who has? I would be grateful for any info./reports at all. (I'm getting rather tired of keeping the oil industry in business!)

Ian Evans

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Hi Ian,

it is the Christian Marx (Forumite MadMarx) design and actually works.

I've had it for the last two years and know others with it.

However it only stops leaks at the rear crank bearing. The gearbox, diff, rocker cover etc all still leak.

 

It is an engine out job and the seal needs to be fitted correctly. You need a mandrel to align the seal carrier halves (I have one for loan). All very doable.

 

Worth every penny.

 

Roger

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  • 2 weeks later...

Fitted one beginning of the year and completely dry for the first 6 1/2K miles, then quite a bad leak, pulled the engine yesterday and found the spring tensioner that sits inside the viton lip seal had disintegrated into a number of pieces allowing the seal to distort & oil to escape. Hoping it's just a rare one-off incident........

 

Unfortunately having lost PB - I can't post pictures...!

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Hi John ~

 

I also did away with PB. If you click on 'More Reply Options' (bottom right hand corner) and then click on 'Choose File'.

You then access your photo. library. Click on the photo. you want to attach. Click on 'Attach This File'.

 

Click on 'Add Reply'.

 

Make sure your cursor is placed at the bottom of your script otherwise it will appear at the very beginning of the script.

 

I always resize my photo's to make them slightly smaller so they don't take up too much storage space.

 

Hope this helps.

 

Regards ~

Tom.

 

 

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Thanks Tom - that wasn't too painful!

 

Hopefully picture attached with new seal on the left and old seal on the right together with broken spring bits....

post-8404-0-62344900-1509116356_thumb.jpg

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Hi Tom - no I don't have the picture manager programme but thanks for the offer.

 

Hi Iain - can't explain it - she's been really dry for over 6000 - much better than my previous crank with the Landrover seal & scroll removed. For some reason the spring appears to have given up in such a way as to cause an end to be pulled onto the alloy lip seal casing and torn to pieces, most of the parts were still caught inside the lip of the seal but I guess I'm missing about half inch which has probably been ground to a paste under the lip of the viton seal by the appearance of it. (my magnetic sump plug had developed a sudden hedgehog type appearance as well) I dropped the crank in to the machine shop yesterday to check and the journals are all good so it's been polished and going back in today with the new seal.Glad I didn't leave it any longer to sort out.....

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Hi John,

as technology advances we open ourselves to more complication and thus failure.

'KISS' is quite relevant in this case. I wonder how good the scroll seal could be if desiged slightly better.

 

On jet engines many of the airseals are installed oversize (just a gnats) and the rotation grinds them back to a very good fit. All the particles get burnt off.

 

Roger

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As you know Roger the scroll seal works by magic, the alloy 2 piece scroll carrier doesn't actually touch any surface being suspended a thou or 2 above the rear main bearing crank surface and skimming off the excess oil from the surface without touching it. The coarse counter rotation thread turned into the alloy seal curved surface imparting a moment into the oil and propelling it back into the sump.

Whilst you have the engine running there will be no leak, only when the engine is stopped does any excess oils drape around the crank and seep through the small gap between crank surface and the 2 piece alloy seal, there being no inertia to keep the oil attached to the crank and no scraping motion from the alloy seal only a couple of thou above it. Incidentally, if you examine the 2 piece alloy inner oil seal surface where the smallest dia is you should easily see the coarse thread outline. However I have a small collection of seals removed from various engines where because of being badly mounted, or fitted around the crank by sight ! the crank has rubbed the surface smooth, there is no thread form left showing, which compromises the seals function and subsequent efficiency, and allows more oil to transfer around the crank even when in motion which then will cause an oil leak.

The Christian Marx seal which fits behind the existing scroll is excellent, utilising the existing crank surface immediately behind the cranks scrolled surface and preventing ANY passage of oil along the crank surface and leaking out whether the engine is running or not, my recommendation.

 

Mick Richards

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The problem with the rope seals is they are never fitted correctly.

You can reuse the housings, with new rope, but they must be fitted to the housing correctly, and then the two halves should be clamped together on a mandrel that is just a shade larger than the scroll, we had a tool for that.

If this process is not adhered to and the halves are clamped on the scroll of the crankshaft it will tear the rope with the first revolution of the crankshaft.

How do I know I used to work on David Brown engines.

John

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I dont think theres any rope involved on the TR engine, just a 2 thou clearance around the scroll. Theres fibre packing involved but not around the crankshaft.

Edited by peejay4A
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John,

Read my post again, it describes how the oil scroll works.

As Pete says there is no rope, just felt packing which rams down either side of the rear main bearing housing after being soaked in Wellseal. There is no actual contact with the scroll seal when fitted correctly and no rope used anywhere where it could touch a rotating surface.

A major constituent of a badly fitted scroll seal is using a mandrill of the size shown in the manual ! Its the wrong Diameter ! The mandrill supplies by Christian Marx with his kit is correct.

 

Mick Richards

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