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
    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
    autronix and ROSS BATTEN like this.
  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
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  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
    autronix likes this.
  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
    autronix and manugtt like this.
  5. 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. 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
  21. Did you have any bother removing the outer race from casing/housing?

    I've had a read through a manual for the pk6 box which reads fairly straight forward.
  22. One of them is a right shite to get out, the others weren't to bad, the difficult one i drilled some holes in the flywheel side of the casing, there are three marks there, then used a pin punch to tap the race out, i can take a picture later if you want.
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  23. That would be great. I'm at the stage where I'm wondering is it worth buying a reconditioned box or opening mine up and replacing the bearings.

    Did you work from a repair manual? I've found one for a pk6 box but nothing for the pk4.
  24. I bought a secondhand gearbox as my 3rd gear went, this is the gearbox that was originally in the car when it was made.
    I was rebuilding it to be a spare incase the one that's in there goes wrong.
    I have had to replace the third gear, the 3rd/4th baulk ring assembly, but i also see that the forth gear also needs replacing, would all be done except that my local Renault garage has been closed for a long time, i do need to get down there to order the part, then i can start to put it back together.
    I have replaced all of the bearings and seals the the best ones i could.

    Sorry i didn't work from a manual, i am an engineer by trade so this stuff is easy for me, the only thing i have used is the parts diagram

    Aldo likes this.
  25. I'm at the stage where my box is giving a faint whine. Not overly concerned at the moment but I imagine itll get worse.

    I'm in the marine industry so don't have a great deal of experience with car transmissions.
  26. Mine just started crunching into third when i was at the Nurburgring, drove it back okay but by the time i got to the UK i had to do 2nd to 4th gear changes.

    I think from what i have heard, that the whine is the first motion shaft bearing, you still have to strip the box to change the bearing though.
    Mine was on about 110k miles when 3rd gear went, be worth changing the oil, to make it last a bit longer.

    I am a self employed Marine Engineer, where are you based ???

    The Mk3 gearbox is a lot easier to strip than the Mk2 one
  27. Have you made any progress on this
  28. IMG-20200904-WA0005.jpeg

    This all looks a bit familiar...
  29. no, i have been really busy with work and my gearbox i bought from Ebay is still going strong when it needs changing then the other one will be finished toot sweet :laughing::laughing::laughing:
    Azza likes this.
  30. Nice to see your still keeping your hands dirty with renaults pal i drove mine for the first time in weeks today damn weather is keeping me too busy got some 630's mapped scaled in tonight bought 2 months ago hows the 265 going now ? The r26 at the limit now so pistons an rods for xmas :weary: then another kinugawa china charger 3 bar map sensors from a 250 an a shit load of boost :sunglasses:
  31. Just finished a job for a friend, stripped his engine as he thought he had ring land problems, the valve guides were very badly worn and i think the rings were also not great.
    The bores were dark with burn oil so honed them.
    Its all up and running so the owner will get it back very soon.

    Think i have another one coming soon, as that guy wants me to forge it for him, so that's Christmas and new year sorted :laughing::laughing::laughing:

    Mine is going great, had a couple of issues with the actuator, that i think i have now sorted.
    But the main thing now is the fuel pump, we think its maxed out, maybe a bit tired, so looking to sort this out after a double header at Donington and Snetterton mid December.
  32. Excellent pal glad your keeping busy im on call at xmas :disappointed: so thats knackered but the extra cash will buy shiney engine parts for my standard meg :tearsofjoy: what pump are you running atm ? And do you have an afr guage hooked up yet ?
  33. Also is your fuel system returnless ?
  34. Working Christmas :laughing::laughing:
    Did that a few years ago well many years ago, I worked Christmas night well should have started at 10pm, was told not to get in till 2am, went home at 7-30 boxing morning, made nearly a weeks wages for 5 hours :laughing::laughing::laughing:

    You need to do the work if its for shiny bits

    Not going to bother with an afr gauge, it was spot on on the dyno so it's going to be fine :sob::sob:
  35. Still standard fuel system, only upgrade is the 630 injectors, but with 120k miles (nearly) the standard pump must be getting tired.
  36. Afr guage is a must pal youll be able to tell if your pump is on the way out. Ive got one on the wish list with the other shiney parts the mk2 pump is good for some hammer we tried to go over the boost limit on my forged meg an the ecu consistantly dumped fuel into the mix to save the engine 7afr at times what map sensors are you running an what boost is it still doing 370bhp ?
  37. I fitted the dw65c in my mk2 that was way more than it required, the mk3 one is different, once i can get the pump out and see what i can fit in there then i will do a thread on it.

    Its running the standard map sensors, they are the ones you need for yours if your boost goes over 1.7bar, the mk3 ones are rated for 2.5bar, i think i'm running around 26psi atm, once the fuel pump is sorted it might go up a bit more :laughing::laughing:

    Its running 388hp atm did get to 399.8 but that was the injectors maxed out, there good for 450hp, so that shows that the pump is struggling.
  38. Hi Guys
    Sorry for the delay in any movement on this thread, i couldn't get the part required for this rebuild, as in previous posts 4th gear needed replacing.

    Once the first lockdown lifted my work took over in a big way, so as things have slowed up a bit, well a reasonable amount atm, i will be able to complete the rebuild, although as the weather is getting colder a few jobs have come in.

    So today i have ordered the 4th gear from my local Renault stealers, well to be fair it doesn't seem that bad at £101, but could take a few day to arrive as it's coming from France.

    So as i think i might have some time on my hands in the next few weeks, this thread might get finished :blush::blush::blush:
    manugtt likes this.
  39. autronix

    autronix RSM Club Member

    thank you Ian for this gold mine. top job as always !

    is this the correct gears layout?

    49830947256_fc2d443e3b_k - Copy.jpg
  40. Sorry can't get the link to work

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