Author Topic: Gearbox oil seal fitment  (Read 527 times)

Offline KeithJ

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Gearbox oil seal fitment
« on: 28.02. 2021 13:44 »
Been trying to fit a new one and it appears the space between the underside of the circlip and the bearing is just too small to fit the seal.  I've checked all the dimensions so am sure the bearing is fitted to the correct depth, measured the circlip which is few thou thicker than the original one and measured the seal which is also a few thou thicker over the rubbery bit than the old one.  The basic issue appears I can't compress the rubbery part of the seal enough to allow the circlip to "pop in to its grove".  I think it is just an accumilation of tolerances but before I start to thin the seal so I can compress it to fit, is there anything I have missed? 

Thanks.
'59 A10RR + Second engine

Offline Swarfcut

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Re: Gearbox oil seal fitment
« Reply #1 on: 28.02. 2021 16:09 »
  These seals are of varying quality these days and what you have  here is the result.

    Make sure the circlip is an easy fit into the groove, the bearing is correct and fully seated, then its a case of rubbing material from the back of the seal, just enough to leave  a little bit of compression on the seal when the circlip is in place.

 Swarfy.

Offline KeithJ

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Re: Gearbox oil seal fitment
« Reply #2 on: 28.02. 2021 16:14 »
Thanks for the reply.  Yes, have checked the circlp groove which is clear and the circlip fites easily also the bearing is fully home.  By back of the seal, I guess you mean remove some of the rubber until I can just compress it enought to fit the circlip?
ATB

Keith
'59 A10RR + Second engine

Online chaterlea25

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Re: Gearbox oil seal fitment
« Reply #3 on: 28.02. 2021 16:14 »
Hi Keith,
If it's only a few thou? Use a flat nosed punch on the circlips and tap your way around the perimeter until it seats into the groove, using an original circlip makes it a it easier

John
1961 Super Rocket
1963 RGS (ongoing)

Offline KeithJ

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Re: Gearbox oil seal fitment
« Reply #4 on: 28.02. 2021 16:18 »
I did try that and it was just too much to get the circlip to fit.  Tried an original type with a cut out to fit it but still could not squash it enough.
ATB
Keith
'59 A10RR + Second engine

Offline Swarfcut

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Re: Gearbox oil seal fitment
« Reply #5 on: 28.02. 2021 16:53 »
  Keith. The seal carrier  flange needs to be under pressure to provide an oil tight seal against the bearing outer race.

     These aftermarket seals are often very slightly thicker than the OE seals, hence the problem.  So yes, a case of removing the soft rubbery stuff from the back, bit by bit until as CJ suggests the circlip can be forced towards the bearing with a punch and springs into the groove. Rubbing down onto a sheet of fine abrasive on a flat surface is the time honoured way. A little of your favourite sealer will fill any fine scratches in the finished face of the back of the seal carrier.

 Swarfy.

Online JulianS

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Re: Gearbox oil seal fitment
« Reply #6 on: 28.02. 2021 16:58 »
Some repro seals are a very slightly larger outside diameter than the original and do not fit fully into the recess. Check against your original.

Sometimes the old circlips are not quite flat and a new replacement can make fitting easier.

Offline KeithJ

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Re: Gearbox oil seal fitment
« Reply #7 on: 28.02. 2021 17:01 »
Thanks, yes my old clip was bent so I did get a new circlip which has holes in it so makes fitting easier.  Good point on the diameter.  Noticed my seal fits in the diameter below the circlip but slips out very easily when trying to fit the circlip.

ATB

Keith
'59 A10RR + Second engine