Oil seals - question for the engineers, please.

[Steve_N]

I'm in the process of replacing the output shaft oil seal on my 30 year old VP MS3B reverse gear.
The original part is obsolete but is a metal single lip nitrile oil seal 60mmx85mmx8mm.
I'm told that the part that Volvo now supply is a standard rubber-coated metric seal of those dimensions, so I'm planning to source one locally.

The shaft sleeve (£275..) on which the seal runs is in good condition under the seal itself but is coroded outboard of the track of the seal - so it's imperative that the lip of the new seal runs on the good part.

Now to the question.
The 60x85 seals are also available in 6mm: if I were to fit a 6mm seal in place of the 8mm seal would you expect that to move the lip position inward further onto the clean area of the sleeve or would there likely be no difference?

My other options are to get a sleeve made by an engineering shop or to get the existing one turned down by 2mm as 58x85x8 seals do seem to exist too.

Probably unanswerable I appreciate, but thanks in advance for any thoughts..

 

[Grampus]

There are things called 'Wear Sleeves' made by bearing companies like SKF and available from any bearing stockist. I don't know about your particular size but I would guess that it is certain to be a standard size because no manufacturer of gearboxes or engines is ever going to design a dedicated special bearing or seal - designers start by choosing the bearings or seals straight from the catalogue.

Have a look at the SKF.com website under wear sleeves.
galps

 

[30boat]

Have you seen this?
http://www.skf.com/binary/12-147230/457892_tcm_12-147230.pdf
Oops,too late.

 

[Steve_N]

Thanks guys, I'll investigate that possibility.

These are the parts in question by the way.
http://i1051.photobucket.com/albums/s426/Steve928/P3100015_zps857fd0e1.jpg

 

[Steve_N]

The SKF sleeve is looking like a very good option at 20mm width - thanks again.
http://www.barnwell.co.uk/catalog/product_info.php/products_id/55

It's looking tight to accomodate the sleeve's installation 'flange' inside the seal but I don't see a problem in fitting it the other way around - I'd just need to leave off outer rubber dust seal, which is what has caused the corrosion in the first place.

One follow-up question please: do you then use a standard oil seal over the sleeve or does it need a special slightly-oversize one from SKF?

 

[30boat]

The SKF sleeve is looking like a very good option at 20mm width - thanks again.
http://www.barnwell.co.uk/catalog/product_info.php/products_id/55

It's looking tight to accomodate the sleeve's installation 'flange' inside the seal but I don't see a problem in fitting it the other way around - I'd just need to leave off outer rubber dust seal, which is what has caused the corrosion in the first place.

One follow-up question please: do you then use a standard oil seal over the sleeve or does it need a special slightly-oversize one from SKF?

I believe you retain the standart seal size.Better confirm though.
Anyway how expensive would it be to have a new shaft /ring turned by an engineer?

 

[Grampus]

I've only used them to compensate for shaft wear and just used the standard seal running on the new sleeve. You could check with SKF's technical sales support, I 'm sure they have a lot of helpful info.
galps

 

[corinthmistral]

Have used a SKF "speedy seal" on my saildrive prop shaft. Quite straightforward to fit and the stainless is so thin it easily accomodated the original sized seal.

 

[captainboo]

It's looking tight to accomodate the sleeve's installation 'flange' inside the seal but I don't see a problem in fitting it the other way around - I'd just need to leave off outer rubber dust seal, which is what has caused the corrosion in the first place.

One follow-up question please: do you then use a standard oil seal over the sleeve or does it need a special slightly-oversize one from SKF?

I used one of these from Barnwell to repair the output shaft/flange on my PRM gearbox. Due to clearance issues and the need to get the new repair section further down the shaft I fitted it the wrong way round and once the installation flange was removed I then chamfered the lip on a lathe to remove any sharp edge to protect the new seal when fitting.

If you are careful and have no lathe access then the edge could be smoothed with fine wet and dry.

They are designed to be used with standard seal as the metal is extremely thin.

 

[superheat6k]

Had to rebuild the MS3B on my last boat. Couldn't find a manual so I wrote one - here if you want it ...

http://turbo36.files.wordpress.com/2013/01/volvo-penta-ms3b-gearbox-overhaul-instructions.pdf

 

[Steve_N]

I used one of these from Barnwell to repair the output shaft/flange on my PRM gearbox. Due to clearance issues and the need to get the new repair section further down the shaft I fitted it the wrong way round and once the installation flange was removed I then chamfered the lip on a lathe to remove any sharp edge to protect the new seal when fitting.

If you are careful and have no lathe access then the edge could be smoothed with fine wet and dry.

They are designed to be used with standard seal as the metal is extremely thin.

Thanks, I've ordered one. Including the installation 'flange' it is 1.5mm longer than shaft spacer/sleeve but I should be able to leave 1.5mm overhanging, but I'll think about trimming it as you did.

 

[Steve_N]

Had to rebuild the MS3B on my last boat. Couldn't find a manual so I wrote one - here if you want it ...

http://turbo36.files.wordpress.com/2013/01/volvo-penta-ms3b-gearbox-overhaul-instructions.pdf

Yes I've already got your excellent manual, thanks. It isn't the same gearbox as mine though and there are some major differences e.g. your output seal was in a carrier held on by 4 bolts whereas mine fits directly into a recess in the gearbox end plate with no seperate carrier plus the seal dimensions are different. Also the water cooling arrangement is completely different, as is the slip clutch flange.

Are you sure yours wasn't an MS3 - which is what the exploded diagram in your document is entitled?

P.S. I found a Volvo workshop manual for the MS3B (in Norwegian!) here:
boatinfo.no/lib/gear/manuals/vp-ms3b-swe.html

 

[superheat6k]

Yes I've already got your excellent manual, thanks. It isn't the same gearbox as mine though and there are some major differences e.g. your output seal was in a carrier held on by 4 bolts whereas mine fits directly into a recess in the gearbox end plate with no seperate carrier plus the seal dimensions are different. Also the water cooling arrangement is completely different, as is the slip clutch flange.

Are you sure yours wasn't an MS3 - which is what the exploded diagram in your document is entitled?

P.S. I found a Volvo workshop manual for the MS3B (in Norwegian!) here:
boatinfo.no/lib/gear/manuals/vp-ms3b-swe.html

I am sure it was an MS3B, as this was stamped on the dataplate. It was coupled to a TMD40A.

 

[Steve_N]

Just an update and thanks to those that offerred advice.

The SKF Speedi-Sleeve was indeed the perfect solution and this is it fitted over the Volvo part.

The installation lip can be removed if necessary but there was space to leave it on in this instance.

All other parts needed, e.g. seal and various o-rings, were standard non-Volvo parts too.