Hello Scotty and team!
My Honda is a 5-speed with 220,000 kms on it.
This summer I replaced the clutch to solve what I thought was noise from a worn out release bearing. Except for the clutch fork and the pivot bolt, which were in decent shape, I replaced the whole clutch system including the hydraulics. The rattling improved considerably but was still there when you first press in the clutch. No rattling at any other time when cruising in any gear at any speed. Only when changing gears. I also had this new, weird problem where the clutch would occasionally grab when first starting up. Perhaps 9 times out of 10 a smooth launch but then the tenth time, the clutch takeup would continue a bit past the normal friction point then suddenly grab lurching the car to a start. Not a pleasant experience at all. This had me really puzzled.
Just this week ETCG posted a video about thrust bearings and how much wear is permissible. For a K24 engine the specs for crankshaft end play are 0.45 mm or 18 thou. I checked my end play and got a whopping 0.90 mm (35 thou) which is way beyond spec. I now suspect that the problem I have is not with the clutch but rather "crank walk". That would be the source of the rattling I feel and hear and possibly the cause of the occasional clutch grab. I have no oil leaks.
My question to you is: Is the solution as straightforward as installing two new thrust bearings like ETCG or is the engine done? I'm prepared to remove the oil pan and oil pump and do an inspection for internal damage.
Thanks!
I would instead look for a problem with the clutch slave cylinder. If it doesn't retain the correct pedal adjustment because of an internal leak, the clutch pivot fork may be rattling against the cylinder plunger from time to time. Also check the clutch master cylinder and bleed the system of air if present.
Hello and thanks for the reply! I already did all that and the adjustment is all to spec. Did you notice the excess crank end play I reported? Could that be the cause?
That is a very odd occurrence if it turns out to be the crank thrust bearing. Since you mentioned your end play is about double the specification, it could definitely be a contributing factor. Can you pull the pan as you said and get access to the offending bearing? I'd love to hear how this works out. Thanks for the info. As far as the grabbing issue, I can only surmise that the clutch disc itself may be getting hung up and not sliding on the trans input shaft splines properly. Just a guess. What was the condition of the old throw out bearing, pressure plate and pilot bearing?
The throwout bearing was intact but had broken tabs. I posted a query about this on the Honda Element Owner's Club earlier this year: https://www.elementownersclub.com/threads/element-with-bad-5-speed-manual-transmission.167503/
The clutch disk was actually in good shape with signs of wear but you could still see the grooves in it - lots more material available IMHO and I even considered reinstalling it with just a new release bearing. The pressure plate and flywheel were also in good shape with only a couple of heat spots but no scoring and no cracks. Those I also considered reinstalling with the old disk.
As stated, the rattling condition improved but was still there when you first press in the clutch and you could even get the rattling sound sometimes when you held in the clutch all the way and revved the engine to 2-3k. I thought it may be poor quality release bearing that came with the Exidy kit (too loose) so bought an OEM which had a slightly smaller inside bore and installed that one (so this meant that I removed the clutch twice!). I reused the original clutch fork, pivot and spring which seemed intact and showed normal signs of wear. The old clutch never grabbed; just rattled allot and the condition occurred all at once this spring. Step three was to replace both clutch slave and master cylinder. No change.
The K24 Honda engines have a large main bearing bed plate as opposed to the classic individual main bearing caps so there's actually a whole lot to accessing the thrust bearing and I am actually not sure if I can even properly take it down while the engine is still in the car with parts still attached to both ends of the crankshaft.
These Honda engines are not known for worn thrust bearing issues, even when driven over 400,000 kms! I welcome any more input you may have to offer.
Thanks!