Steering box seal replacement

Discussion in 'How To' started by matty, Jan 16, 2012.

  1. Pinched from Diddymen's resto thread

    Changing the seals on the steering box and re filling with oil

    First off then, I noticed in a post regarding the changes to the MOT one of which meantioned steering box leaks. As my box was removed from the bus I decided to replace the leaking oil seals before refitting.

    First things first, drain what little oil you have into a suitable container before you start.

    remove the red filler plug by carfully prying it out (it just pushes in) and be careful not to damage the O ring in the filler plug
    http://i925.photobucket.com/albums/ad95/diddymen/january%202012/DSC08473.jpg
    next, I removed the top dust cover, thinking the clip sits in a recess on the shaft I removed it before the rubber dust cover - it turned out there was no recess in the shaft for the clip so you can remove the lot together (being careful not to damage them if you havent got replacements)-make a note of where the arrow on the dust seal is pointing
    http://i925.photobucket.com/albums/ad95/diddymen/january%202012/DSC08472.jpg
    with the dust cover removed you can see the extent of the leak
    http://i925.photobucket.com/albums/ad95/diddymen/january%202012/DSC08474.jpg

    http://i925.photobucket.com/albums/ad95/diddymen/january%202012/DSC08475.jpg
    the Bently manual says it is only possible to change the seal on the drop arm side but you can in fact change both. shown below are the two new seals
    http://i925.photobucket.com/albums/ad95/diddymen/january%202012/DSC08476.jpg
    the sizes are:- output shaft - 28x38x7, worm shaft seal - 22x32x7I originally thought there may have been a leak from around the bolts or the shim inbetween the cover, but further investigation proved it to be the seal which was the culpret
    http://i925.photobucket.com/albums/ad95/diddymen/january%202012/DSC08478.jpg
    Undo the 4 bolts and carefully remove the cover, the seal should come away with it and probably the metal shim as well, try not to bang any thing inbetween the faces to separate if it does not part easily
    http://i925.photobucket.com/albums/ad95/diddymen/january%202012/DSC08479.jpg
    you can see the face of the metal shim still on the outer cover showing no signs of oil leaks

    On the steering box under the outer cover you should see a thrust washer/bearing retainer
    http://i925.photobucket.com/albums/ad95/diddymen/january%202012/DSC08480.jpg
    you can take this off to clean up the area, make sure at this point to keep everything clean and avoid getting any dirt in or around the opening or bearing
    http://i925.photobucket.com/albums/ad95/diddymen/january%202012/DSC08481.jpg
    clean everything up, use a scraper very carefully to remove any stubborn dirt from the mating faces of the box and cover (being careful not to scratch the faces), here you can see the cover cleaned but with the old seal still in place
    http://i925.photobucket.com/albums/ad95/diddymen/january%202012/DSC08482.jpg
    The seal is tight in place so will require it to be leavered out be very careful not to scratch or score the cover recess as the new seal will not seat properly and end up leaking again
    http://i925.photobucket.com/albums/ad95/diddymen/january%202012/DSC08483.jpg
    Fill the recess of the new seal with grease (the red stuff in the pics) and put a small smear around the cover where the seal sits
    http://i925.photobucket.com/albums/ad95/diddymen/january%202012/DSC08484.jpg
    you should then be able to push the new seal in by hand from the out side, side of the cover making sure the bottom edge is flush with the inner face of the cover
    http://i925.photobucket.com/albums/ad95/diddymen/january%202012/DSC08486.jpg
    remove any excess grease - I used some high performance aero grade grease as that is what I had to hand

    If you are having trouble getting the seal back in then place a bit of wood over the whole seal and gently tap home making sure it goes in square

    .......and still making sure you dont get any dirt inside the box or around your newly greased seal

    I didnt feel the need to use any jointing compound or sealent on the metal gasket as it was in good condition and didnt show any signs of leaking - and it didnt use any originally.

    If you decide to use some sealer/gasket compond, make sure you keep it to the outer edges to aviod any contanination to the bearing or inners

    replace the outer cover complete with oil seal and gently tighten the 4 bolts (working on opposites like doing a cylinder head) to achieve even tightness. I did mine up by hand and then checked they were done up to 18Nm, I think I had done then tighter by hand so I set my torque wrench to 20Nm to check and left it at that
    http://i925.photobucket.com/albums/ad95/diddymen/january%202012/DSC08488.jpg
    I left the dust covers off at this point whilst I did the other end, then filled up with oil and checked for leaks (then replace dust covers)


    with the input shaft seal done its time to do the output seal, its a little trickier to get out.

    to remove the out put seal first remove the dust cover.

    You will then need to pry out the old seal very carefully, the best way to do this is to use a very small screw driver or a scriber which you use to pierce the seal in the middle (between the shaft and the casing) Some oil seals have a metal insert which will require some force to pierce so go carefully

    once you have got it in, use it as a lever to ease the seal out like so....
    http://i925.photobucket.com/albums/ad95/diddymen/january%202012/DSC08487.jpg
    just as before, be very careful not to put heavy scratches into the shaft of casing where the seal sits when prying the old seal out

    and be careful not to let any bits of the old seal or dirt get into the case or bearing.

    and with it removed you are left with......
    http://i925.photobucket.com/albums/ad95/diddymen/january%202012/DSC08489.jpg

    .Clean out the casing where the old seal was - I use some lint free rag wrapped over the end of the little screwdriver (being careful not to rip through the rag and put scratches in casing)

    Then the same routien applies fitting the output seal as the input seal - fill the groove of the seal with grease and wipe away any excess, I didnt put any around the casing this time instead putting a smear on the outside of the seal where it will sit against the casing (and some on the inside where the shaft goes)

    next wrap some tape around the shaft splines to protect the oil seal from abrasion when re fitting
    http://i925.photobucket.com/albums/ad95/diddymen/january%202012/DSC08490.jpg

    You should then be able to push the seal nearly into place using finger pressure.

    It will probably go so far, then you'll have to tap the last couple of mm home

    you can get special tools to do this but I used a 32mm deep socket which fitted nicely over the shaft
    http://i925.photobucket.com/albums/ad95/diddymen/january%202012/DSC08491.jpg
    you can then gently tap the top of the socket to drive the seal home - making sure you insert it sqarely and evenly.

    The socket doesnt fit neatly over the seal so If using the socket method tap one side down sligtly, then adjust the socket to the other side of the seal tap that down a little.....and so on until it is insert fully like so....

    http://i925.photobucket.com/albums/ad95/diddymen/january%202012/DSC08493.jpg
    last thing is to remove the filler plug again (hopefully you put it back after emptying the oil to prevent dirt getting in) and fill up with new oil to the bottom of the filler plug hole.

    I used EP80 for the oil and mobil28 grease for the seals
    http://i925.photobucket.com/albums/ad95/diddymen/january%202012/DSC08492.jpg
    Last thing to do is check for leaks before you re fit the box to the underside of your bus (as we all know how hard it is to get the drop arm off dont we ;D )

    To check for leaks all I did was to support the steering box with the output shaft facing down wards and leave for 30mins, then, if there are no leaks support it on its side so that the input shaft is the low point, leave for 30mins

    once you are sure there are no leaks you can replace the dust sealsYou may notice that, now you have a steering box with oil in it it may feel a bit firmer ;D

    for interest, if you are thinking of changing the bearings they are:- SKF 3555 927 open cage ball races

    The input bearing should be easy enough to do but the output bearing will need a complete strip down of the steering box

    I would also recommend getting a set of internal bearing extractors and some proper bearing insertion tools if your going to change them

    above all - keep everything clean and avoid getting contamination into the box

    hope that has helped :D
     
  2. Matty

    Thanks for an informative thread, not least for giving the sizes of the oil seals which I can now source with some confidence (that I am getting the right ones).

    The things that I have found a little harder to track down are the dust seals - which not even the major VW suppliers seem to list.

    Can you (or anyone else in this amazing knowledge base) point me at where I may obtain these, be that from a seal and bearing supplier, an OEM or aftermarket supplier or maybe even a VW (or ZF) specialist. Dumb though this may sound, I don't even know how to accurately describe these (even Google doesn't really help).

    Thanks!! H
     
  3. Diddymen

    Diddymen Moderator

  4. Thanks Diddymen! So I'm not being as thick as I thought, if you're not able to find the big dust seal either! If I do track it down (and I am off to my local agricultaral kit supplier tomorrow) I will drop a line here!
     
  5. Diddymen

    Diddymen Moderator

    good man :thumbsup:

    TBH, the out put seal is only a tapered bit of rubber so any dust seal from a bearing suppliers should do the job providing it fits

    .............and its worth getting a new 'O' ring for the filler plug too while your at it
     
  6. Yeah, I will try anything that is even close to being a candidate for the droparm dust cover - and report back.

    I really need a new filler plug as some previous owner has clearly fallen out with mine (and abused it with a screwdriver or other sharp object). Still fits - just looks bad. But O rings are not a problem for me and I usually change them as a matter of course when I have components on the bench.

    Bit shocked at the price of the Input shaft dust cover though, £10 plus for a bit of nitrile and a circlip!

    I did try direct at ZF, they have an amazing array of catalogues and parts lists available for download, and some of these show compatilbility between parts and the range of vehicles each has been used on, but sadly the dust covers are discontinued!

    http://www.zf.com/corporate/en/products/replacement_parts/catalogs_replacement_parts/catalogs.html

    Cheers and thanks again!
     
  7. Diddymen

    Diddymen Moderator

    EDIT

    *** note, due to photobucket, pics are reposted on page 2 of this thread May 2018 ***
     
    Last edited: May 14, 2018
  8. Diddymen

    Diddymen Moderator

    heres how it looked when I took it off

    [​IMG]

    and after a clean

    [​IMG]

    Its worth spending a bit of time cleaning it up whilst its off the bus, not only will it impress the MOT tester (the only other person who will see it other than your self!) but it will also reduce the risk of getting dirt inside when you pop the seals out.

    with the input shaft seal done its time to do the out put seal, its a little trickier to get out.

    to remove the out put seal first remove the dust cover.

    You will then need to pry out the old seal very carefully, the best way to do this is to use a very small screw driver or a scriber which you use to pierce the seal in the middle (between the shaft and the casing) Some oil seals have a metal insert which will require some force to pierce so go carefully

    once you have got it in, use it as a lever to ease the seal out like so....


    [​IMG]

    just as before, be very careful not to put heavy scratches into the shaft of casing where the seal sits when prying the old seal out

    and be careful not to let any bits of the old seal or dirt get into the case or bearing.

    and with it removed you are left with.......

    [​IMG]

    Clean out the casing where the old seal was - I use some lint free rag wrapped over the end of the little screwdriver (being careful not to rip through the rag and put scratches in casing)

    Then the same routien applies fitting the output seal as the input seal - fill the groove of the seal with grease and wipe away any excess, I didnt put any around the casing this time instead putting a smear on the outside of the seal where it will sit against the casing (and some on the inside where the shaft goes)

    next wrap some tape around the shaft splines to protect the oil seal from abrasion when re fitting

    [​IMG]

    You should then be able to push the seal nearly into place using finger pressure.

    It will probably go so far, then you'll have to tap the last couple of mm home

    you can get special tools to do this but I used a 32mm deep socket which fitted nicely over the shaft

    [​IMG]

    you can then gently tap the top of the socket to drive the seal home - making sure you insert it sqarely and evenly.

    The socket doesnt fit neatly over the seal so If using the socket method tap one side down sligtly, then adjust the socket to the other side of the seal tap that down a little.....and so on until it is insert fully like so....

    [​IMG]

    last thing is to remove the filler plug again (hopefully you put it back after emptying the oil to prevent dirt getting in) and fill up with new oil to the bottom of the filler plug hole.

    I used EP80 for the oil and mobil28 grease for the seals

    [​IMG]

    Last thing to do is check for leaks before you re fit the box to the underside of your bus (as we all know how hard it is to get the drop arm off dont we ;D)

    To check for leaks all I did was to support the steering box with the output shaft facing down wards and leave for 30mins, then, if there are no leaks support it on its side so that the input shaft is the low point, leave for 30mins

    once you are sure there are no leaks you can replace the dust seals


    You may notice that, now you have a steering box with oil in it it may feel a bit firmer ;D

    for interest, if you are thinking of changing the bearings they are:- SKF 3555 927 open cage ball races

    The input bearing should be easy enough to do but the output bearing will need a complete strip down of the steering box

    I would also recommend getting a set of internal bearing extractors and some proper bearing insertion tools if your going to change them

    above all - keep everything clean and avoid getting contamination into the box

    hope that has helped :D
     
    paradox, JT1 and Razzyh like this.
  9. Steering box to chassis bracket bolts size are M10 60MM Long with a 1.5MM thread pitch and 17mm heads. Vw sites will charge you about £4 each for these bolts, I got 4 for £2 from a local fastening company. You may end up shearing off these like me if they're on too tight. Every little helps!
     
    Last edited: Sep 26, 2013
    Buddy Hawks likes this.
  10. Baysearcher

    Baysearcher [secret moderator]

    I'm gonna replace the seals on my spare box as its leaking a bit.
    If I google the seal sizes (cheers for posting them!) loads come up.
    Do I need any specific material or will a nitrile rubber rotary shaft seal do? @Diddymen
    Cheers
     
    Last edited: Oct 28, 2014
  11. Diddymen

    Diddymen Moderator

    I don't recall ordering anything special ......pretty sure mine were nitrile :thumbsup:
     
  12. Baysearcher

    Baysearcher [secret moderator]

    Cheers for that mate
    :)
     
  13. Nitrile will be fine...its only a slow speed shaft. Mine are nitrile.
     
  14. Baysearcher

    Baysearcher [secret moderator]

    Excellent, just ordered from a bearing supplier.
    About £6 delivered. Wonder what the normal suppliers sell them for!?
     
  15. Don't think they sell them


    Rebuilt box I think for ££££'s
     
  16. I've found "viton" seals at £4 ish each are they any better? Would I be able to do the lower/output seal without removing the box? Does the lhd (mine) box use the same dimensions of seals?
     
  17. To replace it, you'd need to pull the drop arm off. I wouldn't advise this with the box under the van.
     
  18. hi - really helpful thread - very many thanks - have been trying to follow up the bearings - the part number 3555 927 you give does not seem to be recognised by ZF nor by bearings suppliers - where did you get it from??

    cheers
    Rob
     
  19. Diddymen

    Diddymen Moderator

    I didn't actually change the bearings just the seals, it was a while ago now so cant remember where I got the number from, it would either have been from a part number stamped on the bearings or possibly from another vw site possibly ratwell :thinking:
     
  20. Any one know if the photos can be put back on this thread?
    @Diddymen @matty

    Or any experts actually!
     

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