What do I call this rubber seal?

[skotl]

I'm reconditioning a lawnmower (don't ask) and I've done a decent job on the gearbox except that it's leaking oil around the drive shaft. On closer inspection, the shaft goes through the gearbox and is held in place by two rotten rubber seals (kinda washer-like). These have a 1/2" inside diameter and are around 4mm wide.

Major question is what should I be searching for, to find the replacement parts?

Secondary question is how to removed the knackered seals. I have fashioned a scraper type tool, and have even attacked them from within with a blowtorch, but there are still remnants inside the gearbox / shaft assembly.

 

[MoreWellie]

might be too late for my approach of screwing either one or two self tappers in to the seal and pulling on them, if two then they would be on opposite sides to stop the seal twisting as it came out

obviously not a good idea to screw right through them if there is a bearing behind

 

[normspanners]

Action seals in Birkenhead are fantastic for shaft seals they have something like 2mil seals in stock from as small that you can hardly see to 2mtr dia ones ! and cheap too.

 

[rikrobson]

What make is it. There's a Lawnmower place in perth that can get oem spares. they do all the usual makes

 

[rikrobson]

Auto Garden
Address: Whitefriars St, Perth PH1 1PP
Phone:01738 631223

 

[slim_boy_fat]

How about Gits oil seal? http://www.gitsmfg.com/shaft-seals/

 

[skotl]

Auto Garden
Address: Whitefriars St, Perth PH1 1PP
Phone:01738 631223

Cheers - it's a Victa (Australian). Although you can get some parts here they are laughably expensive - I bought some of the gearbox / clutch bits from Victa in Oz and even with shipping and customs it was half the UK price.

That said, I'm sure these seals will be cheap enough

 

[penfold]

I think I had one of them when I was a nipper; does it have a cast alloy deck housing?

 

[skotl]

Is it one of the victas with the b&s engine with drive shaft out the side to a belt (with these seals gone)?

I think I had one of them when I was a nipper; does it have a cast alloy deck housing?

Exactly!

 

[skotl]

In that case, if you want oem you can order for the engine from the code number rather than trying to source victa parts - in fact, most good garden machinery emporiums will probably have them on the shelf and identify them from "it's the seal for the drive output shaft on a x.hp briggs".

That's a thought - cheers!

 

[rikrobson]

Auto garden do b&s stuff as if got spares from them before. The only carry a limited stock and order the parts in as required.

 

[rikrobson]

If you can get the offending seal out and size it up you find something near enough

 

[skotl]

If you can get the offending seal out and size it up you find something near enough

s'knackered because it appeared to be glued(?) in and I've had to scrape it out in 1,000,000 tiny rubbery bits. Don't hold out much hope of getting a decent seal with its replacements...

I even used a blowtorch thinking that would just melt the rubber bits, but they just laughed at the flames

 

[rikrobson]

You'll need to dissolve the rubber out or mechanically abraded it. But you'll need to cleanup the seat. How big is the seal?and how big is the part?

 

[skotl]

The seal has a 1/2" internal diameter (which is the diameter of the axle, of course). I think it's around 4mm across, but it's inside a housing so quite difficult to get to.

What would I use to dissolve i? The housing seems like cast, presumably aluminium.

 

[anjum]

Some seals have a metal "band" in the outer edge. If so, you'll need to prise this out.

 

[rikrobson]

It depends on what its made of. A hydrocarbon (toutlene, Xylene or acetone), brake cleaner would be a favorite. Silicone based rubbers dont dissolve though, but they shouldn't break up either.
some rubbers are resistent to solvents unfortunately.

if the seal is intact then you will need a pick or two to get it out. get one into the meat and try and pull it out enough so that the other one can be inserted behind the seal. one its behind the seal it should pop out or you'll be able to get the original pick in behind too and then run them round the circumference pushing out the seal.

once out you'll get the correct dimentions. outer and inner diameters and thickness.

 

[rikrobson]

if the seal has gone then it needs replacing, no matter how hard it will be.

 

[skotl]

I gather the originals are beyond measuring...

The trouble with extraction is usually because the former inside the seal is steel, which rusts and expands, almost vulcanising the 'rubber' into the alu housing and the steel former. Then, picks aren't a whole lot of good - it's either massive perseverance and risk damaging the hole/shaft, or split the cases to get the shaft out so the seals can be driven out.

That sounds likely - TBH this was a winter project to be ready for spring () so I'm going to spend another couple of weekends on it and if it's not going to work then I'll just have to buy a new mower the whole thing only owes me about £70 so far anyway...

 

[DAPPH]

Bung up a photo or three of the seal & surrounding area from inside & outside the casing if possible .
They may neoprene or nitrile rubber seals .

As said some seals have a metal rigidity rim inside the outer casing of rubber & your better off splitting the engine apart to get better access .
If there is a lip perhaps use a six inch nail or coach bolt with the rim filed or ground square to the axis give you a pulling lip . Hold it in the lip with a set of mole grips and gently lever the grips away from the casing with a flat bar on some wood
Or if you can match up the bore of the casing hole & work from inside to the outside of the casing with a washer . Use a couple of washers & a socket to make a pulling bridge then slowly tighten the nut on the thread to gently ease the remains out . Put the new seals back in the same way and make sure that the lips face the right direction