'93 Prado LJ78 Transmission problem (1 Viewer)

[PradoLJ78]

Hi everyone, new member here, Kevin from Ireland. I bought a '93 LJ78 last week. It's a 2LT-E and a343f transmission. Needs a small about of bodywork/welding but overall pretty good.
Main problem with it is transmission. If I put it in "D" its very hesitant to take off even under revs so I'm forced to start off in "L" and manually shift up to "2" and "D" as I gain speed. It shifts fine from "L" to "2" to "D" with a noticeable drop in RPM with each change but once it goes into "D" it doesn't seem to climb through gears.
The previous owner said everything was fine until their "mechanic" removed the engine to diagnose an overheating issue. Any ideas? I'm thinking of ordering a full set of solenoids, filter and fresh ATF for it. Thanks in advance.

 

[ATL Cruiser]

If the transmission shifted fine before the engine was pulled, but not after:

Your kick down cable is probably mis adjusted. That would have been disconnected when the engine was pulled. There is a procedure for adjusting this in the FSM.

Or it's low on fluid. I don't know if your mechanic disconnected the transmission cooler lines when the engine was pulled. If he did, it would have lost a bunch of fluid.

 

[PradoLJ78]

Its showing the fluid level full when its hot i.e. after a good drive. It looks brownish and there is a slight burnt smell off it

 

[PradoLJ78]

The O/D OFF light is flashing on and off intermittently as I'm driving also.

 

[PradoLJ78]

If the transmission shifted fine before the engine was pulled, but not after:

Your kick down cable is probably mis adjusted. That would have been disconnected when the engine was pulled. There is a procedure for adjusting this in the FSM.

Or it's low on fluid. I don't know if your mechanic disconnected the transmission cooler lines when the engine was pulled. If he did, it would have lost a bunch of fluid.

So I put up about 60 miles on it today. O/D off light flashing once everything has gotten warm. I've learned this is like an EML, crossed TE1 and E1 with ignition on. O/D off light didn't flash as I thought it would even when I pressed O/D button. Engine management light put up a code 6.

 

[nomadtribe]

Hi @PradoLJ78

Herewith a link to the error codes - Toyota 2LTE error codes - https://forum.ih8mud.com/threads/toyota-2lte-error-codes.201623/

In addition, I have attached a screenshot for the O/D error codes. O/D must be on in order to read the "blinks". In some cases I found that the truck must be moving (bit strange).

If the oil is brown and a burning smell is present, a good flush will be in order. Check out the post from @GTSSportCoupe that he created - Flushing auto tranny in BJ74 - https://forum.ih8mud.com/threads/flushing-auto-tranny-in-bj74.961259/post-10690422

There is a "speed sensor / RPM sensor" on top of your transfer case. It is a bugger to get too, but you may want to check it out. Inside your transmission to transfer case housing runs a small lube pipe that oils the shaft and keeps the sensor end lubricated. If this is blocked, the sensor may get damaged.

Hope this helps.

 

[PradoLJ78]

@nomadtribe thanks for that, I'm going to try to flush the transmission over the next few days. I can't flash the O/D Error codes because O/D won't engage.

 

[nomadtribe]

@nomadtribe thanks for that, I'm going to try to flush the transmission over the next few days. I can't flash the O/D Error codes because O/D won't engage.

Hi @PradoLJ78

Have a look at this diagram. It will provide you with an overview of the relevant O/D switches, etc. that you can check.

Overdrive & Electronic Controlled Transmission for 1990 - 1992 Toyota LAND CRUISER LJ78 | Japan sales region, , 17730675-910803

Looking for genuine OEM Overdrive & Electronic Controlled Transmission for 1990 - 1992 Toyota LAND CRUISER LJ78 (Japan sales region, , 17730675-910803)? Check on MegaZip at discounted price from manufacturers' warehouses in Japan, USA, UAE. Detailed diagrams & catalogues. Worldwide shipping...

www.megazip.net

Stupid question - did you remove the battery terminals for a minute or so to reset the codes?

 

[GTSSportCoupe]

Maybe check the trans lines to the rad cooler and make sure nothing is kinked or restricted anywhere.

I think there's a 'kick down' cable that needs to be connected to the throttle body too; make sure that's ok. (or am I getting confused with my friend's hdj81? haha).

Try the flush and see how it goes too. The filter is just a screen and can be cleaned; you just need to buy a gasket for it is all.

 

[PradoLJ78]

Hi @PradoLJ78

Have a look at this diagram. It will provide you with an overview of the relevant O/D switches, etc. that you can check.

Overdrive & Electronic Controlled Transmission for 1990 - 1992 Toyota LAND CRUISER LJ78 | Japan sales region, , 17730675-910803

Looking for genuine OEM Overdrive & Electronic Controlled Transmission for 1990 - 1992 Toyota LAND CRUISER LJ78 (Japan sales region, , 17730675-910803)? Check on MegaZip at discounted price from manufacturers' warehouses in Japan, USA, UAE. Detailed diagrams & catalogues. Worldwide shipping...

www.megazip.net

Stupid question - did you remove the battery terminals for a minute or so to reset the codes?

I haven't done that yet, i know the batteries were flat for quite some time before I collected it off the previous owner. Ill pull the dome fuse for a few minutes and see if it resets. As far as I can tell the kick down cable is connected at the throttle end not sure about below. I'm hoping to get it up on the lift later today or tomorrow

 

[PradoLJ78]

Removed the dome fuse for 10 minutes but the code O/D off light still flashes after driving for a short while. Ill try the flush and see how it goes. Also want to change the ecu temp sensor and see if this does anything, its awkward to get at by all accounts.

 

[nomadtribe]

Removed the dome fuse for 10 minutes but the code O/D off light still flashes after driving for a short while. Ill try the flush and see how it goes. Also want to change the ecu temp sensor and see if this does anything, its awkward to get at by all accounts.

For the ECU Temp sensor, I ended up removing my intake manifold

If you count the flashes from the O/D, you will pinpoint your issue.

I have tried to upload a manual that covers the O/D codes in detail, but it is 70mb.

Will try to load this into google drive and PM you the link.

 

[PradoLJ78]

So I dropped the pan off the transmission today to check/replace my shift solenoids in case they were the issue. Once I had it apart I realised the solenoids that I was sold were completely wrong for my trans! Went ahead and cleaned out the filter and flushed out the fluid. Took 12-13 litres I would say before it came clean.
It seems to drive smoother on the road and not sound as loud, not as jumpy between gears but I'm still having an issue when I put it into drive where it won't go through the gears. I imagine next port of call is the ECU? A mechanic local to me maintains the torque converter is causing the problem and I need to replace it and the autobox .

Here's the old solenoids on the bottom compared to the new ones I received, completely different.

 

[Tigris]

Dang...

This brings back memories of my shifting issues. I went down the same path (check things, flush fluids, replace solenoids) and then found the culprit to be the ECU, the electrolytic capacitors were all shot. Rebuilding the ECU resurrected the truck. My KZJ78 now shifts nicer than the wife's new fancy car.

With yours being an LJ of similar vintage, I would highly recommend pulling your ECU and taking a look. In fact, replacing the capacitors with genuine modern components is still very recommended regardless if you have issues or not as a great many of the capacitors that Denso sourced at that timeframe were compromised during production (bad electrolyte formula).

Best of luck!