100 series problems

[stew1978]

I'm heading off to the simpson desert in July and there appears to be a couple of issues I need to get looked at before I go. They are:

1) The main seal is leaking but not a heap. I'm going to try that stop leak stuff and see what effect it has but should I get it fixed. Is it likely to fail in a big way at short notice?

2) The next problem will take a little explaining. My 100 series is an auto. From time to time it seems to have a problem dropping down to the lower gear/s. Doesn't happen often but still concerning. It usual occurs like this. You are driving along and increasing speed but not going fast, maybe 25-40klm/h. The engine revs (only for a second) like it is about to drop down to a lower gear but doesn't and everything returns to normal. The next thing you notice is when you put your foot down to speed up the car wont drop down to a lower gear. You can put your foot right to the floor and nothing but a very slow speed increase. Same thing happens when you stop. It seems to start off again in 2nd or 3rd.

To be honest my second problem has me worried. I am extremely worried that my transmission is going to crap itself. Don't have $2K-$3K to fix it right now.

[Modified Toy]

Go buy a Throttle position sensor most common problem for driveability concerns on landcruisers pretty cheap off toyota to.

[drr]

The Auto in my cruiser was doing exactly the same thing. I don't think it will be a throttle position sensor issue. The auto is shifting through the gears on acceleration but it does it so quickly that you're constantly driving on the torque converter in a higher gear than what you should be in regardless of throttle input. It makes the car very sluggish. All I did was adjust my kick down cable up a lot, nearly to the end of the thread. I believe the problem is the line pressure relief valve inside the auto getting stuck at very low pressures. Adjusting the kick down will bump the pressures up a little and stops it from playing up. Sounds a bit dodgy, but has worked fine for me and still shifts fine and doesn't hold gears for too long either.
One way to check to see if that's the problem is to wait until the car is playing up, pull over and put it in park. Open the bonnet and pull the kick down cable a few times as far as it will go. It should fix the problem temporarily, sometimes it takes a couple goes at it.

[UPPY]

When was the last time the auto was serviced?

[popeyehj60]

is it a 4 speed or 5 speed auto

[oldmate]

The transmission should drop back to first when you get below 15-20kph.

On the 4 and 5 speeds shifting is controlled electronically, and has nothing to do with the throttle cable.

It could be one of the two solenoids in the transmission that control the 1 to 4th gear selection, or it could be an electronic signal problem elsewhere. The solenoids are expensive so you will want to make sure the wiring is checked first.

If you have the 4 speed, then try selecting L gear manually. THis overrides the electronic control. If you're adventurous, disconnect the solenoid connector (on the passenger side of the box near the pan). This disconnects the electronic control and you can select the gears manually by the shifter. L is 1st, 2 is second and D is overdrive (4th). Doing this will eliminate a mechanical problem with the box as the problem.

[drr]

On the 4 and 5 speeds shifting is controlled electronically, and has nothing to do with the throttle cable.

The 4 speeds use a "kick down" cable which controls the line pressure. The line pressure won't affect shift timing on an ECT but it did something for mine, it may have unblocked or unjammed no.1 shift solenoid (a faulty #1 solenoid will cause it to start in 3rd when in drive, O/D will still work). I was about to start ripping it apart but it hasn't played up since I adjusted the cable (about a year ago now), and I'm too lazy and tight to fix something that's working.

[stew1978]

Took the car to a auto specialist who said the first step to most problems is a simple service. Agreed to that and guess what, all fixed. Hasn't happened since and that was 2 weeks ago. He said that if the service didn't fix it the Throttle Position Sensor was the next step. He did say that some of the readings from the sensor were a little strange (only getting to 70%, what ever that means) but he said he didn't think it was a problem. Don't like the idea of something on the car not working properly though.

Got a quote to replaced the seal. $700. Toyota service centre wanted $1000. My local mechanic worked for toyota for 25 years so happy for him to work on the car. Just need to get some cash together.

[stew1978]

I spoke too soon. Time to get the Throttle Control Sensor changed. Anyone done this before?