250/265 gearbox strip and rebuild

Discussion in 'Megane Projects' started by ianplymouth, Apr 28, 2020.

  1. I am not a gearbox rebuild specialist, this is me trying to work my way around jobs to do on my Megane.

    Tools for this first part
    E12 socket
    4mm pin punch
    Hammer
    couple of big screwdrivers or pry bars
    Gear and bearing puller, this is mine.
    49830938401_e186f2ebbc_k.jpg IMG_20200428_152705 by Ian Austin, on Flickr
     
  2. I think this is going to be quite picture heavy :laughing::laughing:


    This is my spare 250 gearbox, as i had already stripped the gearbox i'm rebuilding i thought i would take some pics of this one being stripped, they are the same.
    49831174002_65624fd978_k.jpg IMG_20200428_101535 by Ian Austin, on Flickr

    Remove the switch with the green end, there is a bolt under it that needs to come out
    49831175142_b4da96677c_k.jpg IMG_20200428_101630 by Ian Austin, on Flickr

    use the E12 socket to remove the 19 bolts around the outside rim.

    Before you try and split the box, you also need to remove the pin from the gear selector, it might take a bit to get the leaver off but it will lift off.
    49830335018_44f53e8c6b_k.jpg IMG_20200428_102056 by Ian Austin, on Flick

    once that is off, pry apart the two halves using the four places around the rim, bit like this
    as you lift off the top, you might have to tap the selector shaft down through the hole to get the cover off.
    49830407323_1dbc4df491_k.jpg IMG_20200428_101901 by Ian Austin, on Flickr
     
    richmillions likes this.
  3. Once the top is off this is what you will see under there
    49830409723_3c0dc30c17_k.jpg IMG_20200428_103121 by Ian Austin, on Flickr

    another angle
    49830411018_162abcbbbb_k.jpg IMG_20200428_103132 by Ian Austin, on Flickr

    The next step is to remove the gear cluster
    You need to undo the 13mm bolt on the selector plate, it will need to be pried up to get it off of the dowel.
    the one at the end away from the bolt
    49831178882_b42ebc37c7_k.jpg IMG_20200428_103143 by Ian Austin, on Flickr

    then the arms can be lifted out of the way along with the selector pin and fork, its okay to lift off the hub on the top gear, there are no bits in there that will fly put
    49831180382_201b1d3e7f_k.jpg IMG_20200428_103345 by Ian Austin, on Flickr

    Then its grab the the gear cluster and lift it out, you will have to tilt it slightly to get it out from under the crown wheel/diff, you cant really get the crown wheel/diff out as the gear set is in the way.
    49830947256_fc2d443e3b_k.jpg IMG_20200428_103556 by Ian Austin, on Flickr
     
  4. The Crown wheel now just lifts out.

    Now replacing the bearings on the diff, using the puller, (or if you have a press) pull the bearings off
    49830558263_cba341d14a_k.jpg IMG_20200428_142512 by Ian Austin, on Flickr

    when refitting the bearings, use the old bearing placed on top and tap the old bearing on, gently to start with, going from one side to the other, as it starts to go onto the shaft you can then use more effort to drive the bearing on, once you get the bearing down to the bottom you will here the sound change.
    49831420727_d423d26f6c_k.jpg IMG_20200428_142924 by Ian Austin, on Flickr

    The difference between a standard diff
    49830580203_777db65b66_k.jpg IMG_20200428_103752 by Ian Austin, on Flickr

    and a LSD/cup diff
    49831113111_217051bfb8_k.jpg IMG_20200428_103739 by Ian Austin, on Flickr

    note the pin running across the centre of the drive shaft hole, also the holes with the gears behind on the LSD diff
     
    manugtt likes this.
  5. manugtt

    manugtt RSM Club Member

    And here we go!! I never did open a 6MT gear box, curious the 3 gear axles and selector. I think it is easier to open than olds JB or JC.
    You are a master man!:wink::wink:
     
    ianplymouth likes this.
  6. the reason for my gearbox strip was that 3rd gear was neigh on impossible to engage without it crunching.

    I ordered the bulk ring cluster
    49830679598_f1e5e71ea0_k.jpg IMG_20200428_110442 by Ian Austin, on Flickr

    And the 3rd gear gear
    49830680418_b938e5dc5d_k.jpg IMG_20200428_110426 by Ian Austin, on Flickr

    You need to pull off the bearing from the of the shaft, there is a clip holding the bearing on, well not really holding it on but to stop it moving, then pull the bearing off with the puller.
    Then there is the reverse gear cluster that should pull off.
    there is a collar a washer and another collar left behind, these need to be pulled off with the 4th, bulk ring assembly and the 3rd gear
    49830802183_38ff62b62d_k.jpg IMG_20200428_114141 by Ian Austin, on Flickr
     
  7. The shaft should look like this after all the parts were removed
    49831193346_99ddbc53d6_k.jpg IMG_20200428_110359 by Ian Austin, on Flickr

    The spline part holds the bulk ring really tight so you have to press them on.
    First fit the centre needle bearing
    49831194491_630032a0d6_k.jpg IMG_20200428_110414 by Ian Austin, on Flickr

    The two parts, the 3rd gear and the bulk ring assembly slot together, the 6 tangs fit into the 6 slots
    49831699922_29578bec16_k.jpg IMG_20200428_112321 by Ian Austin, on Flickr

    Both put together
    49830855888_419f568c16_k.jpg IMG_20200428_110512 by Ian Austin, on Flickr

    i had to invert the unit then lower the shaft into them, then use the puller to push the shaft through
    49831723402_130d584179_k.jpg IMG_20200428_112825 by Ian Austin, on Flickr

    now to fit the 4th gear onto the shaft but i then noticed this, i think i should get a new one, although 4th gear i thought didn't have a problem.
    The small teeth are a damaged
    49831505397_24b6528f6d_k.jpg IMG_20200428_121945 by Ian Austin, on Flickr
     

    Attached Files:

    Poppaboost likes this.
  8. This is a lot easier to strip than a mk2 gearbox that for sure, the only other car gearbox i have stripped was in my Rover SD1 about 30 years ago, someone else stripped that one for me and never returned to rebuild it, so i had to piece it all back together without a manual, took about 8-10 builds till it worked right
     
  9. I’d definitely be changing that one too Ian just for peace of mind if nothing else.
     
  10. Yes would be a shame to rebuild and then find its crunching or notchy, just got to try and find one now, as my local Renault parts is closed :cry::cry:
     
  11. Do you know w
    Do you know what the part number for it is?
     
  12. 8200799546
    The 3rd gear one was available from Ebay

    I get a better search on my phone for some reason, better than my laptop, only seems to be available in Poland
     
  13. You make it look easy. How much has it cost you so far.
     
  14. Not sure, with all better quality bearings, seals and the third gear and selector hub, think it's about £300, the forth gear hub is about £100 maybe a bit less, till the parts dept is open i will not know for sure.
     
  15. manugtt

    manugtt RSM Club Member

    One question master, has the bearing some kind of adjustment? I remember in JB gear boxes there are a calibrated washers to attack the bearings of diff. They did need to have a determinate slack.
     
  16. No, there's no adjustment (shims) in any of the bearings, i think the casings are matching and then there machined to a tolerance.

    None of the Renault gearbox's i have stripped has any adjustment, i have stripped other gearbox's and they have shims to adjust the float.
     
    manugtt likes this.
  17. Ian. I could be wrong, but does a bulk ring fit on that 4th gear (tapered part)? How does that look? When I used to rebuild R5 Turbo boxes, a worn bulk ring seemed to be the cause of that damage. The bulk rings have fine grooves on the inner taper, and I found that the peeks, used to become flat, increasing the diameter slightly. Hope that makes sense.
     
  18. No the bulk rings are in the cluster and then the ring locates with the gear, that's the bit thats chewed up, but 4th gear was okay i thought.

    The inside of the bulk rings are now coated with what feels like emery paper
     
  19. No joy on getting the part you need.
     
  20. Not yet, Renault Plymouth are still closed, RPD search didn't show the part.
    Might pull the one from my spare gearbox
     

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