Crunching The Gears

[Nemo2000]

I have noticed recently with my petrol RAV 4.2 (2000 reg, about 42K miles) that when taking it out first in the day, despite being very careful with the clutch etc, it tends to crunch the gears on almost every change, but after about 5 minutes driving the problem goes away. Is there any logical reason for that? I suppoe that it is linked somehow to the engine having warmed-up, but why would that affect the gears/clutch?

[anchorman]

Sometimes the clutch can fail to clear when the engine is cold. Try engaging reverse when cold and if the gears grind it is the clutch.

[crofter]

Hi Nemo.

One cause of what sounds like "clutch hang up" can be oil on the assembly and when the engine is cold the oil is sticky and so you do not have a clean seperation between engine and gearbox.

When the engine warms up it becomes less so and the clutch will appear as normal

Have a look underneath and see if you can see any oil there.

Del

[Nemo2000]

"Sometimes the clutch can fail to clear when the engine is cold. Try engaging reverse when cold and if the gears grind it is the clutch."

Anchorman - does that signify any potential problem, or is it just merely a 'fact of life' with the RAV that need not be a cause for concern?

[Tech01]

As previously written up, good idea to check that box is filled with 75W-80, and not the heavier 75W-90. Makes gear changing easier, particularly when cold.

Also check clutch pedal adjustment (without mats/carpets!), and set to published figures.

Chris

[anchorman]

If you just feel it roll over the gears when it is cold that is acceptable but if it grinds like you are try to force two moving gears together that is a problem. It should be virtually silent when warm. I told you to try reverse because it has no synchromesh to assist with a clean change so you get a proper feel for what is happening. If it does grind you need to do some checks before pulling the box out. Like Chris says, the easiest thing to check is the pedal. It should be virtually no resistance (other than the return spring) for the first 6-12mm and then feel firm right to the floor. The dimensions are pinned in the tech section and be sure that mats don't stop you getting the full stroke. If somebody has added the wrong oil (too thick) it can actually cause the gears to be turned by the drag so that needs to be changed if in doubt. If all that is OK it is probably the clutch components sticking when cold and that could well be oil but not definitely and even if it is you might not see it with the box in - it only needs to be damp. It could be distorted or simply bggrd. Either way it is a big job and you should only attempt it if you have some reasonanble knowledge and some good help to get the box out and back in.

[Nemo2000]

>>>"The dimensions are pinned in the tech section...."

Umm, where exactly please? I've looked, but obviously in the wrong place, as I can't find

[Davrav]

>>>"The dimensions are pinned in the tech section...."

Umm, where exactly please? I've looked, but obviously in the wrong place, as I can't find

Just like at home - someone tidies up and then nothing can be found....................

Anyway, look here:

http://www.toyotaownersclub.com/forums/index.php?

showtopic=109888&st=0&p=996864entry996864

4.2 up to 2002

Gasoline

Top left of page 2

[anchorman]

Thanks Dave

I've mended the link to SDS sheets.

[Nemo2000]

Thanks for the links.

I have checked the pedal now as best as I am able. The initial 'slack' is about 5-6mm, so in within the 'B' figure. Allowing for the carpet thickness, and depending *exactly* where on the floor/bulkhead one measure too, then the 'A' figure (pedal to floor) is about 167mm, so OK there too. However, I'm confused from the diagram exactly what the 'C' figure of 25mm is meant to be for - can someone explain to please?

The pedal seems firm when pressed all the way to the floor and the limit stop on the pedal arm makes contact with the bulkhead.

[anchorman]

Its the minimum bite point to ensure the clutch clears properly.