Crankshaft rear oil seal - upgrade or not ?

[Superaquarama]

Hi Guys,

 

Just embarking on the engine part of our resto, There's been quite a bit in the past about the rear oil seal upgrade, with or without the need for crank machining, so am just wondering what the current thinking on this is ?

 

I've never had any probs with previous TRs leaking from the rear of the crank but presumably the upgrade's more effective. Only thing is that the original scroll system has nothing to go wrong, whilst the conventional seal upgrade can always fail, with attendant engine removal.

 

Would add that the car won't be used competitively.

 

Any opinions, anyone ?

 

Thanks,

 

Anthony

[Ashley James]

Mine has the standard seal and I've just rebuilt the engine, it's probably not bone dry, but it seems good enough, so I've just done another the same with a bit more power and that has a standard seal too.

 

If you haven't had any trouble I wouldn't change it.

[foster461]

The nice thing about the Marx rear oil seal is that it does not mess with the crank or the function of the scroll seal. It requires a slight modification of the alu housing to take the viton seal but its function is to supplement the scroll seal and catch the few drops that would otherwise get past it, I have one ready to go on my engine when I get to that stage. I think there may now be a complete kit that doesnt even require the modified housing.

 

Stan

[Jersey Royal]

Hi

 

I have fitted the Marx seal.

 

http://www.tr-register.co.uk/forums/index.php?/topic/30330-tr3a-rear-crank-oil-seal/page__hl__marx

 

Although the engine is now back in and running, i have only run it in the garage, as i still have bits and bobs to complete

before shes road worthy.

 

However, the engine has been up to temperature and so far no oil on the floor.

 

Cheers

Guy

[PeteT]

Hi Antony,

 

I fitted the Revington split seal which requires the original scroll to be machined off. The machining cost as much as the seal kit and guess what? The engine is currently out to replace the seal which leaked like a sive from day one. Could be my clumsy fingers, i'll know more when I remove the bottom end. If I had my time again I think I would plump for the Marx solution. Hope that helps.

 

Regards, Pete

[stuart]

The Land Rover type seal where you have to machine the crank does need very careful machining and they do very often leak. The Marx one seems to be a much better bet as it retains the original as well.

Stuart.

[Don Elliott]

I bought a modern oil seal replacement kit for my 1958 TR3A from Ken Gillanders in So. Calif. but it came from Racetorations in UK. This was in 2000 after losing a litre of 20W50 oil every 600 miles for 10 years. This had been happening since 1990 and to be environmentally correct, I wanted to stop the oil leakage so I took out the engine and had the crank re-ground for the new rear oil seal. I re-built all the babbitt inserts and for the next 7 years, it still leaked a litre of oil every 600 miles. In 2007, I changed the rings after having the liners re-honed by an engine re-builder whom I trust.

 

Since installing the new rings, I now drive 2500 miles before having to add any oil and I've switch to Castrol 10W30 from the previous Castrol 20W50. I have been adding DPPT Plus every oil change as well.

 

So the excessive leakage I had for 17 years had nothing to do with the rear oil seal. It was the rings that were permitting "blow-by" and this was pressurising the sump and it was leaking out the overflow vent pipe just behind the fuel pump. I suspect that the new liners installed with new pistons and rings as a set in 1990 had not been honed, therefore the rings never "bedded in" properly - hence the blow-by.

[Dick]

I have ran with the standard sealing arrangement for some 40 years and whilst not bone dry there are no drips. I have also rebuilt at least a dozen engines all with the standard seal with no issues.

 

Personally I would never fit the conversion as I believe that there is not enough wrong with the original.

 

Many cars of this period use the TR system....it works and there is nothing to go wrong....assuming that the engine can breath and has not excessive piston / ring wear....which would challenge any sealing arrangement.

 

I believe that everyone should enjoy their car as they wish and if modifications are part of that then so be it, but also believe that for normal use many mods. are of limited if any benefit and just compromise a well proven design....

 

.Making it go faster within reason and not compromising reliability I am into......coming up for 300,000 miles now and apart from normal wear and tear and failure due to youthfull exuberance (along time ago) I have never had a car that has been so reliable....which is probably why I have kept it this long.

 

Just my personal and inexpert opinion,

 

Dick.

[Superaquarama]

Many thanks, everyone, just the sort of info I was looking for.

 

So I think I'll stick to the original system and save a bit of money as well !

[TR24178]

I wish you b*ggers had come to this conclusion before I had the scroll machined off!

 

I had read so much on here that condemned the original system, this is the first posts I have found to support ST's original design.

[Guest ntc]

Can park mine with the original seal on your posh drive and no leaks

[JJC]

I've got one of each and despite an early false alarm over the Land Rover one they both work just fine. JJC

[TR24178]

We already have leaks on our notsoposh drive Neil, we got home from an HRCR touring assembly a fortnight ago and the Citroen decided its 73 year old petrol tank should start to leak!!

 

John

[RogerH]

Hi John,

if you are not happy with the machined scroll area then you can go backwards and fit a split collar over it to bring it back to size and fit one of Marx's seals.

 

Roger

[TR24178]

Roger

 

I am sure it will be ok if assembled carefully, perhaps we try to do too much to these old girls, reinventing the wheel!!

 

John

[RogerH]

Hi John,

I'm not sure what gives me the bigger grin - driving the car or making something original that works.

 

Roger

[Fireman049]

Does anyone sell the Mad Max oil seal in the UK?

 

Tom.

[MadMarx]

Does anyone sell the Mad Max oil seal in the UK?

Tom.

 

Tom,

 

that would be me I guess.

 

I'm happy that there is many interrest to keep the project going.

The week before I've send 25 housings to USA (Joe Alexander - ARE). So there is a good respond on this solution.

As far I heard only of one failure. He got a free of charge ring to replace and was happy with it after.

 

Take care if you use a centering tool that the dimensions are different as shown in the workshop manual.

The factory did print id wrongly...the mandrel must be smaller than in the manual.

The new made mandrels take that in account.

If you use your own ones...turn them down to fit.

Proper size is 71.57mm instead of 71.66mm. (maybe a reason why so many scrolls leak)

 

I can't recommend to center the housing on the crank.

The gap between crank and housing is 71.57 - 71.38 = 0.19mm. This would be the measure which could be the housing offset.

Not a problem for the Viton seal but the scroll doesn't like it as the crank does flex and will grind out the scroll housing. While I did the rework many of the old housings I found 70% of them worn out.

That was the reason to make NEW housings as they will stay within the tolerances.

 

Cheers

Chris

Edited November 20, 2012 by MadMarx