Front Crankshaft Oil Seal

[David Mutch]

Hi all, me again! Having quizzed you previously about oil leaks, I have had another look and am fairly sure that my major leak (there are probably many other smaller ones!) is the result of a busted front crankshaft oil seal. I'd like to have a go at fixing this myself, but would appreciate something of an idiot's guide, as it's not something I've attempted before.

 

On looking at it, I see one possible immediate problem, in that I believe that my cooling arrangement is somewhat unconventional. There is no standard BMC water pump fitted, but instead there is a Jabsco pump driven by an extra pulley bolted/welded to the crankshaft pulley. I was wondering whether people could tell from the pictures below whether this is going to make it difficult to get the crankshaft nut/pulley off?

 

Also, I was wondering whether, whilst I've got the timing cover off, whether it might not be a good idea to replace the timing chain/tensioner, as I have no idea how long it's been on there. Not noisy at the moment, but given the effort involved in getting to the thing, I thought it might be worth just doing it whilst I'm there?

 

Cheers

 

[Chalky]

Timing chain and tensioner are a quick and easy job once the cover is off. On my car I changed the sprockets as well. On the petrol (I don't know the diesel) there's a simplex and duplex chain depending on year, both are easily available. The kit for 2 sprockets, chain, tensioner, seal, gasket and lock washer cost about £40. If you do buy a car kit check that the timings are compatible - the key way positions do change for different engines. The tensioner is hydraulically operated and it requires setting when it's installed but auto adjusts after that. There have been mixed reports about the quality of some of the replacements. If the petrol and diesel parts are common check on the MG forums for where the better parts come from.

 

The crank shaft nut is 1 1/8". I loosen it by removing the king lead so it won't fire (petrol), putting the socket and a T bar on a chassis rail and cranking the engine. This loosens it! Diesel will require a different method to make sure that the engine doesn't run afterwards.

 

Fit the new seal into the cover and fit it on the front of the engine with the bolts loose. Lightly lubricate the seal then fit the pulley. This will centre the whole lot before you tighten the bolts up and reduce the chance of a leak.

 

A twin pulley version of the front pulley is available. It's used by MG owners in the US to add aircon to the car. there's also a ribbed belt version used to attach a super charger.

Edited June 30, 2016 by Chalky

[Tony Brooks]

I hope that I am wrong but that looks a right bodge to me.

 

It looks as if the standard BMC starting handle dog has been turned down and bodged to fit the extra pulley but in the same way as Chalky explained how to loosen the nut the pump would tend to undo the dog nut. Although they were usually fitted with a tan washer maybe the tab washer was not man enough so it seems they fitted a rectangular plate behind the dog nut with a hole in one side that they secured to the engine pulley with a hexagon set screw. They then welded the dog nut to the plate.

 

As there is only one position where the extra set screw can fit over the years wear may have taken place that can no ,longer be tightened up so it is even possible the pulley is a bit lose on the crank.

 

I have a feeling the 1.5 timing cover seals push in from the front so as long as you follow Chalky's advice about loosening all the timing covers crews and freeing it from the gasket you may be able to change the seal with out taking the timing cover off. However given the BMC's propensity to leak oil I think that I would take the opportunity to fit a new gasket. Check the crankshaft has not been scored by the seal. If the crank is grooved a new seal might turn out to be a temporary solution.

 

 

PS remember to refit the oil thrower and I think it has a right and wrong way round because it is slightly dished at the edge.

[David Mutch]

Timing chain and tensioner are a quick and easy job once the cover is off. On my car I changed the sprockets as well. On the petrol (I don't know the diesel) there's a simplex and duplex chain depending on year, both are easily available. The kit for 2 sprockets, chain, tensioner, seal, gasket and lock washer cost about £40. If you do buy a car kit check that the timings are compatible - the key way positions do change for different engines. The tensioner is hydraulically operated and it requires setting when it's installed but auto adjusts after that. There have been mixed reports about the quality of some of the replacements. If the petrol and diesel parts are common check on the MG forums for where the better parts come from.

 

The crank shaft nut is 1 1/8". I loosen it by removing the king lead so it won't fire (petrol), putting the socket and a T bar on a chassis rail and cranking the engine. This loosens it! Diesel will require a different method to make sure that the engine doesn't run afterwards.

 

Fit the new seal into the cover and fit it on the front of the engine with the bolts loose. Lightly lubricate the seal then fit the pulley. This will centre the whole lot before you tighten the bolts up and reduce the chance of a leak.

 

A twin pulley version of the front pulley is available. It's used by MG owners in the US to add aircon to the car. there's also a ribbed belt version used to attach a super charger.

Thanks Chalky. You make it sound reassuringly simple!

 

I hope that I am wrong but that looks a right bodge to me.

 

It looks as if the standard BMC starting handle dog has been turned down and bodged to fit the extra pulley but in the same way as Chalky explained how to loosen the nut the pump would tend to undo the dog nut. Although they were usually fitted with a tan washer maybe the tab washer was not man enough so it seems they fitted a rectangular plate behind the dog nut with a hole in one side that they secured to the engine pulley with a hexagon set screw. They then welded the dog nut to the plate.

 

As there is only one position where the extra set screw can fit over the years wear may have taken place that can no ,longer be tightened up so it is even possible the pulley is a bit lose on the crank.

 

I have a feeling the 1.5 timing cover seals push in from the front so as long as you follow Chalky's advice about loosening all the timing covers crews and freeing it from the gasket you may be able to change the seal with out taking the timing cover off. However given the BMC's propensity to leak oil I think that I would take the opportunity to fit a new gasket. Check the crankshaft has not been scored by the seal. If the crank is grooved a new seal might turn out to be a temporary solution.

 

 

PS remember to refit the oil thrower and I think it has a right and wrong way round because it is slightly dished at the edge.

 

 

I fear you're spot on there Tony. Would replacing the pulley with one of the double pulleys Chalky mentioned be an option to fix the bodge?

[Chalky]

On the MG forums the Americans talk about something called a speedy sleeve that you put over a worn shaft to get it to seal. I've never used one but they swear by them.

[Flyboy]

To me the pulley looks the wrong size for the belt. The belt looks like it's bottomed in the pulley groove.

Edited June 30, 2016 by Flyboy

[Manxcat]

On the MG forums the Americans talk about something called a speedy sleeve that you put over a worn shaft to get it to seal. I've never used one but they swear by them.

Speedi-Sleeves

SKF make them, I use them reclaiming certain Land Rover parts.

Saves trying to make a smooth shaft to get a oil seal to seal against when the old oil seals have worn the shaft.

 

SKF website

http://www.skf.com/uk/products/seals/industrial-seals/power-transmission-seals/wear-sleeves/skf-speedi-sleeve/index.html

 

I get them from my local bearing stockist, but you can get them online from various places, try these

http://www.bearingboys.co.uk/Speedi-Sleeves-Shaft-Repair-3289-c

 

HTH.

[Tony Brooks]

Thanks Chalky. You make it sound reassuringly simple!

 

I fear you're spot on there Tony. Would replacing the pulley with one of the double pulleys Chalky mentioned be an option to fix the bodge?

 

Personally I would see if Calcutt can supply the proper water pump pulley and bolt. I suspect, but do not know, that the ones Chalky was talking about may have the second pulley nearly the same size as the engine pulley. If so I would be concerned that it would drive the raw water pump fast enough at idle and low speed. If I turn out to be correct you could always try fitting a smaller pulley on the water pump.

 

Brain fart - old age. It may drive the water pump too fast at high speed so look at fitting a larger pump pulley.

Edited June 30, 2016 by Tony Brooks

[David Mutch]

On the MG forums the Americans talk about something called a speedy sleeve that you put over a worn shaft to get it to seal. I've never used one but they swear by them.

Thanks for the tip. I'll look into that if it turns out to be necessary

To me the pulley looks the wrong size for the belt. The belt looks like it's bottomed in the pulley groove.

Yes, the pulley doesn't seem to be right for the belt. However, the belt was on there four years ago when I bought it, and hasn't needed changing yet (thankfully, as I can't for the life of me find one the right size) so I figured if it ain't broke...

Speedi-Sleeves

SKF make them, I use them reclaiming certain Land Rover parts.

Saves trying to make a smooth shaft to get a oil seal to seal against when the old oil seals have worn the shaft.

 

SKF website

http://www.skf.com/uk/products/seals/industrial-seals/power-transmission-seals/wear-sleeves/skf-speedi-sleeve/index.html

 

I get them from my local bearing stockist, but you can get them online from various places, try these

http://www.bearingboys.co.uk/Speedi-Sleeves-Shaft-Repair-3289-c

 

HTH.

Thanks!

[David Mutch]

 

Personally I would see if Calcutt can supply the proper water pump pulley and bolt. I suspect, but do not know, that the ones Chalky was talking about may have the second pulley nearly the same size as the engine pulley. If so I would be concerned that it would drive the raw water pump fast enough at idle and low speed. If I turn out to be correct you could always try fitting a smaller pulley on the water pump.

Thanks Tony. I'll look into that.

[Tony Brooks]

Thanks Tony. I'll look into that.

 

Note my edit to this, had a senior moment but I would still try to fit the "standard" pulley but you will probably have to move the water pump back.

[Flyboy]

I don't know if it's feasible but there is a double waterpump pulley availble for the MGB. Would it be possible to drive the raw water pump from there if there's room.

 

 

I've just realised the op doesn't have a std. water pump so this won't work.

Edited July 1, 2016 by Flyboy

[pete.i]

 

I hope that I am wrong but that looks a right bodge to me.

 

It looks as if the standard BMC starting handle dog has been turned down and bodged to fit the extra pulley but in the same way as Chalky explained how to loosen the nut the pump would tend to undo the dog nut. Although they were usually fitted with a tan washer maybe the tab washer was not man enough so it seems they fitted a rectangular plate behind the dog nut with a hole in one side that they secured to the engine pulley with a hexagon set screw. They then welded the dog nut to the plate.

 

As there is only one position where the extra set screw can fit over the years wear may have taken place that can no ,longer be tightened up so it is even possible the pulley is a bit lose on the crank.

 

I have a feeling the 1.5 timing cover seals push in from the front so as long as you follow Chalky's advice about loosening all the timing covers crews and freeing it from the gasket you may be able to change the seal with out taking the timing cover off. However given the BMC's propensity to leak oil I think that I would take the opportunity to fit a new gasket. Check the crankshaft has not been scored by the seal. If the crank is grooved a new seal might turn out to be a temporary solution.

 

 

PS remember to refit the oil thrower and I think it has a right and wrong way round because it is slightly dished at the edge.

 

Yes that's good advice. If you get it wrong it makes a hell of a mess of the oil thrower. Mine had a kind of serrated edge (not a good description but it's all I could think of) I don't know what it catches on but it does catch something and that nagles the edge of the oil thrower ring/disk up.

 

Don't know if anyone else has mentioned this or if you already have it but it doesn't hurt to link it again. This is the "workshop manual" for that engine.

 

http://the-norfolk-broads.co.uk/downloads/bmc1500L-diesel-workshop-manual.pdf

[Tony Brooks]

I don't know if it's feasible but there is a double waterpump pulley availble for the MGB. Would it be possible to drive the raw water pump from there if there's room.

 

 

I've just realised the op doesn't have a std. water pump so this won't work.

 

This may well be of use to others but a bit of caution is required. I think there are at least three different water pump flanges on 1.5 diesels, one with just three bolts so it would be important to make sure it fits the hub on the engine.

[David Mutch]

Thanks all. I have often wondered exactly why the cooling system is set up like this. Is it because the standard BMC water pump wouldn't be man enough for a keel cooled system like this? Just wondering whether it would be possible to change back to a standard water pump setup, as the Jabsco setup causes endless issues.

[RLWP]

Thanks all. I have often wondered exactly why the cooling system is set up like this. Is it because the standard BMC water pump wouldn't be man enough for a keel cooled system like this? Just wondering whether it would be possible to change back to a standard water pump setup, as the Jabsco setup causes endless issues.

 

Most BMCs use the standard water pump for a keel cooled system. Are you sure you haven't got two circuits?

 

Richard

Edited July 1, 2016 by RLWP

[David Mutch]

 

Most BMCs use the standard water pump for a keel cooled system. Are you sure you haven't got two circuits?

 

Richard

 

Absolutely. Just the one

[RLWP]

 

Absolutely. Just the one

 

It may be a leftover then. Some of the BMCs have a heat exchanger in the Bowman tank, so the original water pump circulates coolant through the engine and heat exchanger. The Jabsco circulates either raw water or keel tank coolant through the other side of the heat exchanger

 

Our BMC 1.8 and others with keel cooling use the standard pump

 

Richard

[David Mutch]

 

It may be a leftover then. Some of the BMCs have a heat exchanger in the Bowman tank, so the original water pump circulates coolant through the engine and heat exchanger. The Jabsco circulates either raw water or keel tank coolant through the other side of the heat exchanger

 

Our BMC 1.8 and others with keel cooling use the standard pump

 

Richard

 

Thanks. No heat exchanger on my engine, and the original water pump has a blanking plate with a fitting for the coolant pipes. The coolant circulates through pipes which go out of one side of the boat, around the back of the swim, and back in the other side. I just wondered whether the drop in the system / the volume of coolant that had to be moved might be too much for the BMC pump?

[Tony Brooks]

Back in the day many 1.5s used direct raw water cooling with only a Jabsco pump. However once pushed hard they seemed to fur up the internal hotspots and crack heads or worse.

 

If the OP has a direct raw water cooled engine I would advise a swift charge to heat exchanger cooling even though I do not like it on canals.

[David Mutch]

Back in the day many 1.5s used direct raw water cooling with only a Jabsco pump. However once pushed hard they seemed to fur up the internal hotspots and crack heads or worse.

 

If the OP has a direct raw water cooled engine I would advise a swift charge to heat exchanger cooling even though I do not like it on canals.

 

The engine isn't raw water cooled. It's a closed circuit, which uses pipes on the outside of the hull to dissipate heat from the coolant.

[Tony Brooks]

 

Thanks. No heat exchanger on my engine, and the original water pump has a blanking plate with a fitting for the coolant pipes. The coolant circulates through pipes which go out of one side of the boat, around the back of the swim, and back in the other side. I just wondered whether the drop in the system / the volume of coolant that had to be moved might be too much for the BMC pump?

 

In that case forget the Jabsco, fit the normal water pump and direct that round your external pipes. That way you do away with the somewhat unreliable rubber impeller. I am assuming that you already have a header tank for the system, be it the exhaust manifold casing.

 

I can assure you that the normal BMC engine pump can shift sufficient water through 1 to 1.25" bore hose and 4 x (say) 3/8 to 1/2" bore keel cooler tubes in parallel. If you have a very long run of 1/2" external tube then it may not. I am sure we had some boats with about 7 or 8 metres of 1" bore pipe running to the keel cooler without overheating problems.

 

It seems your cooling system is another bit of a bodge but if it works then fine.

[David Mutch]

Here you can see the coolant pipes going round the back of the swim, below the anodes and prop

[David Mutch]

 

In that case forget the Jabsco, fit the normal water pump and direct that round your external pipes. That way you do away with the somewhat unreliable rubber impeller. I am assuming that you already have a header tank for the system, be it the exhaust manifold casing.

 

I can assure you that the normal BMC engine pump can shift sufficient water through 1 to 1.25" bore hose and 4 x (say) 3/8 to 1/2" bore keel cooler tubes in parallel. If you have a very long run of 1/2" external tube then it may not. I am sure we had some boats with about 7 or 8 metres of 1" bore pipe running to the keel cooler without overheating problems.

 

It seems your cooling system is another bit of a bodge but if it works then fine.

 

I'm yet to find something on this boat that wasn't a bit of a bodge. Endless hours of fun fixing it all over the last few years!

 

Edit - Yes, there is a header tank in the system. I'm a little concerned that the pipe run might be a bit longer/wider diameter than that. I don't know what the inner diameter is, but the outer diameter must be at least 1 1/2", and there are two runs of maybe 5m each

Edited July 1, 2016 by David Mutch

[Tony Brooks]

If you decided to use an engine water pump I think it would be fine. I am not so sure that you have the surface area to cool the engine uder high powers but if it was OK on the Jabsco it should be OK with the engine pump.