Intro/clutch chatter when warm (solved!)

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scotttie
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Intro/clutch chatter when warm (solved!)

Post by scotttie »

Hi all,

 I’ve owned my syncro for just under 2 years. It’s a RHD 2.1 DJ Reimo hightop conversion which the previous owner supposedly found in a field by nearly reversing a tractor into it (it was hidden in the hedgerow). This does tie up with the MOT history showing no test between 2012 and 2019. The PO liked to restore Minis in his spare time so took on this challenge of getting it back on the road. Recon engine, some bodywork repairs and a respray later, I purchased the van. Gearboxes went off to Aidan/Neil Fox and VC to Ian with the plan of getting the van ready for a 6 month rock climbing trip around Europe this summer (didn't quite work out for obvious reasons…)

 Back to the main reason for this post: Clutch Chatter!

 For a while now the van was suffering with a clutch judder/chatter when engaging the clutch in 1st, G or R. However this symptom was only apparent after everything had got up to operating temperature. This problem seems to be commonly associated with oil contamination on the friction plate which will then seep out of the friction material when everything is heated up. With this in mind it was time to get the gearbox out to inspect and replace the clutch.

 SPOILER: if you don't want to read this small essay on how to remove a gearbox, skip to the bottom for the cause of the chatter!

 I know many of you are already fluent in removing a syncro gearbox, but for those that are not (me included), I have documented the process thanks to the help from Neil, Ian and Jes.

 BEFORE YOU START make sure you have a well stocked supply of biscuits. This is vital to the day running smoothly.
 Image
 
  1. Safely jack up rear of vehicle on axle stands or ramps. I brought some ramps from halfords I was really pleased with for only £45!

    Image

  2. Disconnect starter and leisure batteries (if leisure is not isolated)
  3. Remove prop and engine/gearbox protection bars. The “drain pipe” protection tube for the gear linkage is bolted to the o/s prop rail so remember to unbolt that as well (some models didn’t have this?).
  4. Unbolt gearbox end of prop and allow that end to rest on the floor to one side. There is a lip on the gearbox prop flange so if the prop doesn’t fall down once the 4 bolts are off, push the prop toward the front diff to release it. You only need a few mm to get it over the lip.
  5. Unbolt the x2 nuts and bolts that hold the gear selector lever to the side of the gearbox and rest the gear linkage on the floor to one side.
  6. Unbolt the CV joints, cover with a bag and cable tie the bags up.

    Image
  7. Tea break.
  8. Unplug the reverse light switch and diff lock switch
  9. Disconnect the vacuum lines from the diff lock actuator. There are two vacuum lines, disconnect on from the actuator and one from the rubber elbow then they can't get put back the wrong way around.
  10. The clutch slave cylinder! Luckily my slave bracket had a notch taken out of it which makes life a lot easier when removing the bolt closest to the engine (Aidan I believe I have you to thank for that!). There are x2 nuts and bolts that hold the slave to the bracket. Remove those and tie up the slave. I am not sure how you remove the bolt if your bracket hasn’t been modified but I am sure someone can share some wisdom on that.
  11. Remove the p clip holding the clutch line to the slave supporting bracket.
  12. The metal coolant pipes that go over where the engine and gearbox meet are bolted to the top of the gearbox. Unbolt this along with the accelerator cable bracket.
 There are two things still connected. The breather tube at the front of the gearbox and the starter motor cables. These are easier to get at once the gearbox is lowered slightly.
 
  1.  Engine support. The engine is supported by engine mounts at the rear and the gearbox at the front. When the gearbox is out the engine (flywheel end) will want to fall down. Support the engine through the lifting eyelets on the crankcase with a ratchet strap over a bar across the engine bay:


    Image


  2. To lower the gearbox we used a piece of ply on a trolley jack with a ratchet strap around the gearbox. The trolley jack was centred around the blind hole in the bottom of the gearbox which is roughly the balance point. Be careful not to catch any cables/wires in the ratchet strap when it goes over the top of the gearbox, otherwise they will get pulled down with it!


    Image
 
  1. Tea break.
  2. To remove the gearbox you can either unbolt the rubber mounts or unbolt the mounting brackets from the chassis (3 bolts each side). We opted for the latter so that the gearbox position would stay the same and not run the risk of introducing any unwanted drivetrain vibrations from altering the alignment.
  3. With some slack in the ratchet strap supporting the engine, you can now start to lower the gearbox. When you have enough room, remove the banjo bolt holding the breather line to the gearbox and disconnect the starter cables.
  4. Disconnect the engine from the gearbox by undoing the two nuts at the bottom and the two nuts and bolts at the top. Note the top right bolt is an 8mm allen head bolt that also goes through the starter motor.
  5. Continue to slowly lower the gearbox whilst also pushing it toward the front of the vehicle, making sure nothing is catching on the gearbox or getting pulled in the engine bay. When the gearbox is nearly free, make sure the ratchet strap supporting the engine is tight. Once the gearbox is free, lower to the ground and you’re done!


    Image


  6. Tea break and stuff face with biscuits.
 Clutch inspection & conclusion

 The bell housing was bone dry and there were no signs of oil coming from the crank seal. Release bearing looked good. With the pressure plate removed it looked pretty much brand new. The flywheel looked good with no cracks or heavy blueing. The friction plate also looked good and had a lot of life left. However, on closer inspection of the friction plate, the springs were very loose and there were signs of rust coming from the springs.
 
Image
 The clutch fitted was the LUK late 2.1 clutch. From what I understand this later clutch had a higher clamping force than the early one and was introduced 89 onwards. The later clutch is meant to be compatible with all years but as my van is 88 we fitted the earlier clutch kit made by sachs. 

 The history of the clutch is unknown and it could well have sat in the van whilst it stood in a field for several years. I can only assume that the age combined with the lack of use caused the friction plate springs to fail. I do not think the failure had anything to do with the LuK clutch or the fact that it was the heavy duty version. What I am not clear on is how heat was a factor. Potentially the fiction plate is more grabby when warm and the failed springs were unable to cushion the clutch engagement.

 With everything back together following the process above in reverse, a quick test drive down the road and the chatter was gone! Clutch engagement was very smooth and the peddle was lighter which must be due to the lighter clamping force of the early clutch.

 Massive thanks to Neil, Ian and Jes for all their help! (feel free to add if there is anything I missed)

Cheers,
Scott
______________________________________________________________________
2.1l T25 Syncro Reimo hightop

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silverbullet
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Re: Intro/clutch chatter when warm (solved!)

Post by silverbullet »

It was a syncronauts day trip. Plenty of quality banter and decent tea (Yorkshire) was not in short supply. A bit of swapmeet parts exchange too, well worth the mileage.

Notable moments: Jes rocks up last, puts on some 1970's yellow overalls, takes them off again, didnt touch a spanner :D

Gave the Leibniz Dark a good hiding too.
85 syncro Caravelle twin slider Oettinger T3200E-6
90 SA Microbus supercharged wbx/UN1 project

http://www.025motorsport.com

jes*b
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Re: Intro/clutch chatter when warm (solved!)

Post by jes*b »

I believe my interventions were limited but significant . Overalls were Sealink issue off the old man .

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silverbullet
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Re: Intro/clutch chatter when warm (solved!)

Post by silverbullet »

To be fair, you did slide under the van and the box lined up a treat.
Vintage workwear. My Castrols are just about ruined.

Did the fancy German work shorts escape unscathed?
85 syncro Caravelle twin slider Oettinger T3200E-6
90 SA Microbus supercharged wbx/UN1 project

http://www.025motorsport.com

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