oil leak bukh DV20

[worane2]

G'day folks,
I have a rebuilt Bukh DV20 I have just bought on ebay.
It had a slight oil leak down the bottom of the back cover.
I have a workshop manual which is rubbish when it comes to oilseal details.
This morning I have split the gearbox off the rest on the motor. I removed the clutch type housing forward of it at the same time. It has a series of rubbers in there which I assume are the clutch.
The bottom of this section was full of black engine oil.
Now in front of this , still attatched to the engine is a cast iron "basket" which the rubbers slot into.
Question.... I take it the oil seal I am looking for is behind this cast Basket.
I do not like the idea of pulling the fueling system apart.
Anyone have any ideas and even better, a generic set of part numbers for this oil seal? I hope some one is into these repairs. I am no mechanic.

 

[worane2]

I just drove 80kms. to borrow a puller that is smaller than the one I have which does not fit.The result of digging my way forward into this motor is , I have at last found the offending oil seal and I am now waiting for the shops to open tomorrow for a replacement.

 

[Twister_Ken]

Font of all UK Bukh wisdom is the importer in Poole. Very helpful, very happy to answer questions. Probably closed for the bank holiday, tho'.

01202 668840

 

[worane2]

thanks and duely noted. What holiday is that?

 

[Ben Dockrell 22]

G'day folks,
I have a rebuilt Bukh DV20 I have just bought on ebay.
It had a slight oil leak down the bottom of the back cover.
I have a workshop manual which is rubbish when it comes to oilseal details.
This morning I have split the gearbox off the rest on the motor. I removed the clutch type housing forward of it at the same time. It has a series of rubbers in there which I assume are the clutch.
The bottom of this section was full of black engine oil.
Now in front of this , still attatched to the engine is a cast iron "basket" which the rubbers slot into.
Question.... I take it the oil seal I am looking for is behind this cast Basket.
I do not like the idea of pulling the fueling system apart.
Anyone have any ideas and even better, a generic set of part numbers for this oil seal? I hope some one is into these repairs. I am no mechanic.

Might be useful to take photos of the motor and gaskets ect ect just to make things easier,though the guru may not need it

 

[Poignard]

Gaco SM 35.50.7 according to my BUKH parts manual.

 

[worane2]

Thanks . My workshop manual has no references at all for seals.
Since writing the above earlier today I have found my way in and removed the offending seal. It has just the markings as you state.
Good to know it has the correct seal in it even if it is leaking oil. Cheers Nick.

 

[Poignard]

Thanks . My workshop manual has no references at all for seals.
Since writing the above earlier today I have found my way in and removed the offending seal. It has just the markings as you state.
Good to know it has the correct seal in it even if it is leaking oil. Cheers Nick.

There is a very good Parts Manual for the DV10/20. As well as listing all the parts the numerous drawings are very helpful when you are stripping and re-assembling the engine. The downside is the cost of the manual! Mine was £25 about 15 years ago. Possibly it's available on-line for free (as is the Workshop Manual)

 

[RobBrown]

Here

http://www.earlhill.de/download.html

Guess which engine I've got!

 

[SimonJ]

Bukh 20 rear cranshaft seal

I did the job earlier this year on my engine - taking advice from BUKH in Poole on the method.

Remove seal after pulling coupling off by screwing in a couple of self tapping screws then pulling out with pliers or similar.

When replacing seal do not put in too far. You may need it in a positon slightly different to the one you removed to avoid a worn part of shft. Push it on square - I used a socket of suitable size to fit. Be very careful it does not go in too far - it could go beyond the housing & then you have a probelm!

When torquing up the half coupling nut it does not, BUKH say, need to be torqued too hard - otherwise it will never come off again if needed. I think it was 40ft lbs but it may have been less. And do not like me forget to put the washer in behind the nut which I found when I replaced the engine!!

The front seal is much easier but you need to remove flywheel. I have some ideas on that too!

 

[Poignard]

http://www.earlhill.de/download.html

Guess which engine I've got!

Thanks for that. It will take up a lot less room on a memory stick than as a book!

 

[VicMallows]

I did the job earlier this year on my engine - taking advice from BUKH in Poole on the method.

Remove seal after pulling coupling off by screwing in a couple of self tapping screws then pulling out with pliers or similar.

When replacing seal do not put in too far. You may need it in a positon slightly different to the one you removed to avoid a worn part of shft. Push it on square - I used a socket of suitable size to fit. Be very careful it does not go in too far - it could go beyond the housing & then you have a probelm!

When torquing up the half coupling nut it does not, BUKH say, need to be torqued too hard - otherwise it will never come off again if needed. I think it was 40ft lbs but it may have been less. And do not like me forget to put the washer in behind the nut which I found when I replaced the engine!!

The front seal is much easier but you need to remove flywheel. I have some ideas on that too!

A bit confused. I think you are talking about the gearbox output seal? (done that one ... easy once you manage to get the half-coupling nut off!). OP was talking about the engine output seal which obviously requires removal of the gearbox.

I need to do the gearbox INPUT shaft seal, so makes sense to replace the engine side seal at the same time, so also welcome as much information/experience as possible.

Vic

 

[SimonJ]

A bit confused. I think you are talking about the gearbox output seal? (done that one ... easy once you manage to get the half-coupling nut off!). OP was talking about the engine output seal which obviously requires removal of the gearbox.

I need to do the gearbox INPUT shaft seal, so makes sense to replace the engine side seal at the same time, so also welcome as much information/experience as possible.

Vic

Sorry if I confused (or am confused!) I was talking about the rear engine crankshaft seal for which of course the gearbox needs to be separated off from the engine. Is doing the gearbox seal much the same? Not sure about that! Mine has not leaked so I have not touched it!

 

[worane2]

I replaced the rear engine crank shaft seal just before reading your email Simon.
The seal went in quite easily. I pushed it in about three mm. beyond the face of the casting. Is this too far?
Regards Nick.

 

[SimonJ]

Hi
I hope you all assembled now 3mm would have been good. Apologies, my attention to this interrupted by a wedding and a load of other stuff. Trust all working well.

 

[VicMallows]

Is doing the gearbox seal much the same? Not sure about that! Mine has not leaked so I have not touched it!

Simon, Having (at last!) removed my BUKH20 gearbox (BW7) - see other threads - I can now comment on replacing the input shaft oil seal...............

Contrary to the impression (and picture) given in the BUKH workshop manual, in order to replace the input seal it is necessary to split the gearbox as this seal (unlike the output one) is pressed in from the INSIDE. Splitting the gearbox is easy enough, the only point of note is that you need a very short allen key for the top two bolts. Nothing internally is disturbed.

I have found that my (massive) oil leak is not in fact due to the seal, but due to a fracture in the alloy near the STB engine mount holes. I find it incredible that the rear end of the engine is supported on the light-alloy front gearbox casting .... why not on the cast-iron engine block?

NOW LOOKING FOR ADVICE ON A GOOD WELDER to repair the alloy casting in Solent area, preferably Chichester Hbr area.