Gear problem

[Skyhawker]

Hi all, would really appreciate some advice. I have a Toyota Alphard 2.4l Automatic which essentially has the innards of the 2001 Previa.

Today whilst driving over certain speed I felt that the gear disengage so the car was revving but didn't pick up anymore speed. I then went down a gear and it worked ok. When the car changes gear it isn't smooth. When I reversed the car also vibrated badly.

I checked under bonnet and have discovered oil on what looks like a cable that runs from a bolt at side of engine and terminates on the body of the car. I hope that makes sense. There is quite a bit of oil. Engine sound like running fine. Any ideas? Is this serious trouble?

Please see attached photo

[finlo]

Top up the ATF and get the leak seen to.

[Skyhawker]

The ATF level is fine.

I have found the source of the oil, please see photo attached. Can this cause the issue with gears?

The ATF was golden colour. Can this be? Is it not supposed to be red?

[Steve_D]

Please don't take this the wrong way but are you certain you were dipping the transmission and not the engine oil.

As you say most ATF types are red so we first need to know the type and spec. of the ATF that should be in there.
If it is Dexron 2 or 3 then it should be red meaning your next move is to drain the old fluid and change the filter (if it has one) then fill with new fluid.

If this task is not in your skillset then find an auto transmission specialist in your area rather than a main dealer.

Steve

[anonymous-user]

Skyhawker said:

The ATF level is fine.

I have found the source of the oil, please see photo attached. Can this cause the issue with gears?

The ATF was golden colour. Can this be? Is it not supposed to be red?

That "leak" looks to be comensurate with a slow weeping of engine oil from the cam cover gasket. Engines are not perfectly sealed, they all "leak" a bit over time. Oil can wick through tiny voids and holes in gaskets and seals and then runs down anything it finds, such as wires, pipes and bits of engine structures!

I suggest cleaning off that part of the engine (probably wiping with a cloth would do it, but you could use some wd40 or similar to help breakup the oil baked on oil deposits) and monitoring it over the next few months. Unless it is actually dripping then there is no issue with it, and it wouldn't be worth the cost of removing and changing the cam cover gasket etc


Your real problem, the gears slipping is more serious and almost certainly unconnected to that small oil weep! (i have seen a transmission control ecu damaged by oil wicking up the loom from an engine oil leak,into the ecu)

Slipping gears in a transmission has 3 main possible causes:

1) The transmission is receiving false information from a damaged sensor or wiring loom (causing it to fail to apply the correct controls)
2) The transmission is unable to generate enough internal oil pressure to prevent the clutches and brakes inside from slipping (low oil, knackered oil pump)
3) The brakes and clutches in the trans are worn out. They have a high friction surface, if this is worn down, no amount of oil pressure can prevent slipage


In all cases, once some basic checks have been done (trans oil level check, visual check of looms and sensors etc) it'll probably need a mechanic and access to suitable transmission knowledge to find the root cause. In the case of 2) & 3) above, it is likely on an old car to be uneconomic to repair