Gearbox input shaft oil seal fitment

Discussion in 'Mech Tech' started by DIY_Bodger, Nov 29, 2021.

  1. Hello all and thanks to all the regular contributors - been getting good advice here for months without having to post. However - I'm now a bit stuck on what should be an easy task....

    2.0 Type 4 CJ Engine. Just fitted a new clutch and as a precaution decided to replace the oil seal that goes between the clutch and gearbox shaft.

    Wish I'd never touched it - old seal was practically welded in and in the end I had to spend days picking it out with various tools.

    Tried to install the new seal following Bentley instructions - would not seat no matter how much persuasion I gave it. Ripped it out and noticed there was still a piece of old seal in place. Thought I'd cracked it so cleaned that out and tried to fit the second seal - again no joy and seal damaged so now a THIRD seal is on order!

    My thoughts with this are:
    • There is still some of the old seal in the housing (I was fairly certain I'd got it all out but maybe not)
    • I am doing something wrong here just oiling the inner lip and pressing the seal in, then trying to tap it in with a home made drift
    • A long shot - it's the wrong seal. Some suppliers on a well known internet auction site say the 113311113A seal doesn't fit a 78 with a CJ engine, but most of the others say this seal with fit all air-cooled so I think the seal is right

    One thing I noticed on a photo of the Elring seal is that there is a clockwise arrow on the seal - is this just to show rotational direction of the shaft, or should I be twisting the seal in clockwise to initially seat it?

    Can't believe how much time I've spent on this already. Any advice appreciated.

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  2. Zed

    Zed Gradually getting grumpier

    What do you mean by "it won't seat"?
    Along with the part number, the one you took out probably had the sizes stamped on it if you still have it.
    No you don't need to twist it.
    It would probably be a lot easier with the bell housing off, but that's another level of frickery...
  3. Thanks for the reply Zed. When I said it won't seat, I should have said it won't seat fully - i.e. it sits about 5mm above the surrounding metal and then won't budge any further even if I go from a tap to a thump. I'll inspect it again for any remaining old seal when the new one arrives and if this one goes the same way I'll probably have to take the bellhousing off as you suggest. Jeez - I was hoping to be putting everything back together this week and it looks like I'll end up taking it further apart.

    Don't have the original part any more but think I checked it a few weeks back before I ordered the first replacement.

  4. I couln't get that seal out with the gearbox on a bench and a selection of pulling devices to hand , I had to take the bellhouse off and get at it from behind... quite easy to do if there's no oil in there.... get a good look at it then and clean up any bits you find
  5. Reassuring that it's not just me who had a problem with this. I'll try the above and report back in due course.
  6. Right size seal?
  7. Once you take the bell housing off, thats a gasket needed ...

    The seal has an almost 12mm wide metal ring on the outside which grips the gearbox nose cone - the 12mm bit of . " 22.2x40x12mm ".

    If you pick bits of rubber away without getting the metal bit, there will still be a metal ring in there, the step in the hole in the bell housing is big enough to exactly fit that seal. So its going to go down 12mm. : The 17mm is the height to the tip of the seal back up the shaft.

    I use a reasonable quality about 4mm shaft screwdriver as a lever, trying to hook that behind the metal ring , and if I feel concerned, I push a metal shim between the screwdriver and the drive shaft to avoid scratching ..

    If that doesnt work, carefully driving the metal ring in towards the shaft should collapse it and loosen its grip .. Use that shim to stop chewing the drive shaft if you miss..

    To drive it home , using the old seal is usually a good idea, the metal ring on the outside works nicely, or a suitable sized socket. And then the metal "nose" bolted into the bell housing with the three bolts and the cross-drilled drain hole pointing down will go over the seal, it actually has three projections that rest on the seal when it is properly home.
  8. MorkC68

    MorkC68 Moderator

    ^ why not get proper oil seal hooks to avoid damaging and sealing surfaces?

    The oil seal is called a Radial Oil Seal (aka a Chamban seal) with the arrow typically identifying the direction of shaft rotation but they can also act as a seal on a hydraulic cylinder / actuator. We have boxes of them at work.
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  9. I tried varous bodges , levering screwdrivers ...self tapping screws and pullers, then bought a small seal puller.. broke it.. then spent a few quid on a gasket ..half an hour job done

    Sent from my SM-T580 using Tapatalk
    theBusmonkey and snotty like this.
  10. I managed to yank mine out (eventually) the first time around, but taking the bellhousing off makes it a lot easier. You can make your own gasket.
  11. Zed

    Zed Gradually getting grumpier

    I've seen quite a few that you might think would leak but don't. If you up end the gearbox driveshaft down and leave it for half an hour you'll find out.
  12. Arrrghhh! Wish I'd looked at these latest replies this morning. Managed to find loads more bits of the old seal under some rare sunlight this morning (been working outside in overcast conditions previously). Hit the same problem again of course the new seal won't sit flush with the surrounding metal.

    Mike - I bet you've hit the nail on the head re that metal ring. I don't remember pulling that out and I bet it's still in there. Looks like I'm down another seal then but at least I have a likely solution available.

    I'll get yet another seal and try and remove the metal ring. Hopefully that will be it done but if not it'll be gearbox removal time. The window for working outside on the drive may be starting to close now until the spring so this might have to go on hold for a while.

    Thanks for all the help guys.

  13. theBusmonkey

    theBusmonkey Sponsor

    Right @DIY_Bodger , the only really effective way of replacing that seal is to remove the bell housing.
    I'm sure it's doable without doing so, but how good is your patience haha.
    As prev mentioned the seal has to be removed completely, and the outer sealing surface to the bell housing is a daft tight fit! Often aided by a teeny bit of corrosion underneath that OD.
    As you have a type 4 motor, you'll have an 091 bellhousing just like this:

    Now this is a diesel one so will look a bit different to yours but the parts are the same.
    1, is the oil thrower. There to help prevent oil from reaching the seal. It's a press fit into the housing, but can displace. You won't know this until you've got the seal completely out. If it's displaced, it can get chewed up by the input shaft and then bits of metal can run through the crown wheel. Not common, but it does happen. There's only .5mm clearance between the rotating shaft and the thrower, so it has to be central.
    They need gluing back in or an oversize one hammering (pressing lol) in.
    2) the seal. You know that! Once the bell housing is off, lever it out with a seal remover, from the clutch side of the casting. It can be drifted out from behind, but beware..displace the oil thrower and..blah blah.
    Before you install the new one, touch up the leading edge of the orifice :rolleyes: with a dremel or wet and dry etc to remove any burrs. The seal can pick up on insertion and twist off centre.
    This is usually another press job to be honest but if you're confident with a hammer and dolly, go for it. Lube the outside lightly with oil.
    Lube the inside lips with grease before...
    3, release bearing guide sleeve. This is a bearing surface, so must be in good condition.
    There should be 2 drilled holes, one hole should face downwards. If any oil gets past the thrower and seal combo, it should then just drip to the bottom of the housing without contaminating the clutch.
    IMG_20211201_135331.jpg Arrow point to hole.

    The reason you save yourself a load of grief by removing the housing is because the input shaft is in the way of easily removing the seal, and drifting the new one in square.
    Plug the breather hole on the front of the box, stand it up, remove the housing and see what you see...
    If you want seals I have a fresh bag in stock of the correct SABÓ quality brand for about £2.30 each.
    Bell housing gaskets £1.90
    And the guide sleeves, correct INA not cheap repro, are £9.70.
    If the thrower is loose, I have oversized ones, but fitting will involve a press assuming the old one hasn't gouged out too much material as it span...unlikely as I said:thumbsup:
    It's worth touching up the shaft forks whilst your there so they roll nicely against the back of the bearing. Grease the tips of the forks, but not the guide tube.:thumbsup:
    Your profile doesn't show a location, but if you're in the UK and close to East Midlands Airport you could always drop by the workshop and borrow the tools to DIY in the workshop here...sometimes the shortcuts don't always pay off:(
  14. Brilliant info there BM and thanks for the workshop offer. I'm in Wiltshire so not exactly around the corner but not a million miles away either. I think for now I'm going to persevere with the gearbox-attached method and try and get that metal ring out but if that fails I may end up referring back to your post and getting in touch for those parts.

    After spending a couple of hours today picking bits of seal off that metal ring that needs to be removed anyway (i.e. two hours pointlessly wasted, not including the previous days messing around) I'm stepping away from it for a while. On the plus side, I was worried I'd scratched the housing scraping that seal off but now turns out any damage will just be to that metal ring.

    Plenty of jobs I can do inside the van over the winter with the door closed and the electric heater on, so no danger of me being short of stuff to do!
    theBusmonkey likes this.
  15. theBusmonkey

    theBusmonkey Sponsor

    Ha! Tell us about it, always something to be done...
    Those seals can put up a fight. I have broken type Sealy AK7000 seal removing tools before now and that's with the things on the bench!
    Look closely at the one you have in hand. That's all you're trying to remove. No more, but no less. This metal ring thing discussed is I suspect just the outer part of the seal that's broken away from the centre and is there to give the sealing lips some structure.
    Edit, you can gouge the sealing surface of the bell housing if you are not careful. That's why cleaning it up after removal and taking a view is important;)
    Good luck. If you need anything specific in the future just drop me a pm...Neil
  16. Zed

    Zed Gradually getting grumpier

    Sometimes the simplest jobs (on the face of it) are sent from hell in reality. :)
    I remember me and Flakey changed my flywheel oil seal simply because we could get at it. What we didn't know was that the builder had fitted a slightly deeper (or might have been shallower) seal so it avoided damage on the flywheel. After our work it leaked like a sieve. Oh how I laughed as I took the type-4 engine out in a rocky car park and worked all that out. It wasn't even leaking before we changed it. :rolleyes:
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  17. There's a lot to be said for leaving things alone but in this case there was a spray pattern of gearbox oil on the housing above the seal. It looked like it had been there a long time (almost dried on) and probably a PO had replaced the seal and not cleaned up the oil from a previous leak/spill. Problem is, once you've seen oil which looks old, do you assume it's old and not replace the seal, or replace the seal just in case? I couldn't ignore it so I elected to replace. OK it's turned into a nightmare but when it's done I should have peace of mind and not risk leaving a leaky seal in.

    Typically, when I did the one at the front previously (to the shift linkage) it took 10 minutes from start to finish.
  18. theBusmonkey

    theBusmonkey Sponsor

    In that case as it's had an unknown leak ideally you need to have a look at the input shaft. Depends on how deep you want to go tbh.
    I personally subscribe to the 'if it ain't broke don't...' school but if you're in there anyway. :rolleyes:

    The seals can score the seal surface of the shaft and then no matter how many times you replace the seal it just won't!
    The shaft is meant to be a little loose, so don't worry about that as it is supported in the clutch assembly and pilot bearing.
    As I say, depends how deep you want to go;)
    You did replace the pilot bearing when you did the clutch didn't you...if the end of the shaft is nice and clean and straight sided and un-scored, then with fresh grease you'll be reet:thumbsup:
  19. For now I'm going to do the bare minimum and monitor it for leaks. Can always do it 'properly' in the spring if necessary. Yes to the pilot bearing - well, it will be yes once the seal is in first. From the way the oil was sprayed (top left of the casing) my best guess was that the sleeve had been put on the wrong way round and some point in the past and instead of oil dripping from the bottom it got sprayed upwards. Anyway it didn't look fresh at all so fingers crossed.

    Hopefully an easy job now once I get that old steel ring out and fit the new seal. I'll put an update on here when it's done.
  20. Update: New seal hasn't arrived yet but the sun in shining so what the heck I thought let's get that metal ring out. Screwdriver, hook and plastic waste pipe to protect the shaft. A few minutes later and success. The old seal is fully out. Thanks to Mike for pointing this out, and for all the other contributors. If/when I have the gearbox out I'll come back here and refer to this thread to replace all the gaskets/seals properly. It's so obvious now that there was no way a new seal was going to fit over that steel ring but as you all know, once a job 'gets to you' you can easily get tunnel vision and stop thinking rationally.

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