So here is one for the guys doing maintenance on their own vehicles.
I am sure everyone that have adjusted their Patrols tappets before have always found this one tappet that just doesn't want to stop clapping hands. No matter how hard you try to get the clearance perfect, it just sounds like one is set incorrectly.
Well....I might have found the problem to this.
While building a TD42 engine I did a close inspection on the rocker shaft and the individual rockers and found that the area that presses on the valve itself, has a very shiny dent in. This is very slight on most of them and you could barely feel it, but on two of them, the dent was quite deep and very noticeable.
Now the problem comes in when setting the valve clearance with a feeler gauge. the blade is as broad as the rocker and the area that is dented is about 6/7mm. This means that if you set your air gap to 0.30mm and the dent is another 0.2mm deep you end up with a 0.5mm tappet clearance.
The fix was very simple, I used a flappy disc on my angle grinder, and very carefully polished every rocker until the dented area was flat again like it should be. It is really not a big job to remove the whole rocker shaft when the tappet cover is off and anyone that has a little bit of DIY skill can pull it off.
- visible dent in rocker
- rocker_dent.jpg (172.56 KiB) Viewed 289 times
- The end result
- rocker_fixed.jpg (200.94 KiB) Viewed 289 times