Ain't Got No (satisfaction) Fourth Gear

[ynwa]

So I've done a ton of work on the little bus (my project post is waaay overdue for an update). However one lingering issue (among others, hehe) is that I don't remember ever feeling 4th gear in my auto. This post is possibly a vehicle for a series of condolences which I will also appreciate, however there might be something out there in your collective minds that might just do the trick.

Here's the skinny. Initially I was having issues with a high RPM 3rd gear shift so I performed the following so far.
* Changed the tranny fluid and poured in a can of Seafoam. Ran that for a couple of weeks with some burns up to 80 on the hwy.
* Drained (also drained the torque converter based on another good post).
* When I received the van the 'throttle kickdown linkage' was disconnected (bolt fell out probably). So I reconnected it. It was set to a very narrow setting, like 15mm.
* After reading Gbear's post I tested it at 32mm and had slipping from 1st to second so backed it off again.
* Just before our trip to Carmanah I dropped in a bottle of Rislone trans repair.
* Bus ran fine although trying to drive 100 in 3rd was a stretch at 3,500.
* I've just backed off the linkage even more so I'm probably closer to 25mm gap from 'nub' to cable housing.
* Shifting is happening a bit quicker but still seems to slip from 2nd to 3rd at high revs (need to back off the pedal).
* I've tried to set the 'free play' in the kickdown but I really can't tell what's freeplay and what's worn out plastic linkage.

I recently blanked the EGR so my TPS is moot. I'm just using generic Motomaster ATF.

Bring the condolences. :)

[Growlerbearnz]

OMG the internet ate my homework! Try again:

I'd suspect the OD solenoid on the gearbox isn't getting power.

Solenoid.JPG (140.28 KiB) Viewed 4791 times

The wiring diagram alleges that there's a coolant temperature switch that only lets it operate once the engine is warm. I have no idea where that switch is, but it sure seems to work that way. Anyway: with the ignition turned on and engine warm (but not actually running) if you climb under the van you should be able to hear the solenoid clicking if someone in the cab turns the OD button off and on. (I'm guessing the OD off light on the dash works.)

If you can't hear it clicking in and out, I would try applying 12V directly to its connector. If it clicks then, I would leave it connected and go for a drive to confirm that you have 4th- and then figure out where the break in the wiring is. Once the engine is warm, the gearbox should drop into 4th at about 55kph if you're being gentle.

The TPS doesn't do anything gearbox-related. It's there for the glow plug controller only.

The full throttle kickdown cable adjustment (that 32mm one) mostly effects full-throttle gear changes. If your 1st-2nd shift is playing up, check the cable adjustment at idle (1-2mm free play). That said, 1st-2nd is always a bit mushy, it can take about a second to complete the shift if you're driving normally. 2nd also does this weird thing where it feels like it's slipping, but locks up if you put your foot down a bit harder. I have no idea what it's doing, but they all do it to some extent.

[ynwa]

Oh, man, that's exactly the glimmer of hope I was looking for! I'll let you know how it goes over the weekend. You're replies are nothing less than heroic!

[ynwa]

Hey! So I checked the wiring and there was power to the Sol with engine warm and ign on.
I suspect this means that the Sol is toast? My dash light works fine.

I'm going to check RMI and see what they have.

[Growlerbearnz]

That's the conclusion I'd draw as well. Replace the solenoid and keep your fingers crossed. Could you hear it clicking as it was turned off and on? I mean, it might be physically jammed so it'll click but not actually do anything, but if it was silent then that's definitely a problem.

[ynwa]

Ya, it was silent as I had someone flicking the button. I also gave it a few 'love taps' from a wrench but nothing shook free. :) Sure hoping for 4th gear sometime in the near future.

[ynwa]

Hey! Great news! I've got 4th Gear, wahoooo!!! It was the OD Solenoid. Such a small little thing affects such a major issue. Pulled one off a wrecked L300 and was quoted over $300 for a NOS part.

Only thing I notice now is that the gears shift pretty close to each other. This is probably normal but thought I would check. 2rd to 3rd has always been a bit 'slushy'. Feels like it's slipping but from what I've read this is sort of normal?

Anyway, great news if anyone else has this issue and is wondering about the trans. After checking for voltage at the SOL connector, try a used SOL.

Cheers.