Overdrive, transmission issues (1 Viewer)

[Natev22]

Hello,

I recently purchaed a 99 land cruiser. I noticed on the highway, the overdrive does not seem to function properly.

At 55mph I'm at 2800 tpm. It revs up to over 3000 rpm as I approach 70mph. I push the overdrive button and the OD OFF light turns on but there is really no change to the RPM. Maybe it increases by 100 or so but it's barely noticeable.

This is a stock truck with stock tires.

I'm hoping there is a quick fix. Any input is appreciated.

Thanks

 

[flintknapper]

Hello,

I recently purchaed a 99 land cruiser. I noticed on the highway, the overdrive does not seem to function properly.

At 55mph I'm at 2800 tpm. It revs up to over 3000 rpm as I approach 70mph. I push the overdrive button and the OD OFF light turns on but there is really no change to the RPM. Maybe it increases by 100 or so but it's barely noticeable.

This is a stock truck with stock tires.

I'm hoping there is a quick fix. Any input is appreciated.

Thanks

There is no change in rpm because you are not in Overdrive (for whatever reason). With OD on....at 55 mph (assuming stock tire size) you should be at about 2,000 rpm (or pretty close) if OD is working. If you were then to press the OD OFF button and the trans shifted out of OD...then yes, 2500 rpm or a bit higher would be what I would expect.

If you are not seeing significant rpm changes when pressing the OD OFF button (at highway speeds) then it isn't functioning.

Quick Fix: Not likely.

The fact that pressing the button lights up the OD OFF light in the dash...suggests that the button itself and that part of the circuit is working. So your issue is downstream of that (if electrical) and if not electrical....then an issue with the transmission.

 

[Natev22]

Thanks for your help. That's pretty much what I was expecting. Where do I start to diagnose this?

 

[BnvS]

Isn't overdrive like the 5th gear? Would you look into the solenoid? But now think about it. Change out the transmission fluid/flush first and see if that does anything.

 

[flintknapper]

Thanks for your help. That's pretty much what I was expecting. Where do I start to diagnose this?

How good of a home mechanic are you?

 

[medtro]

Hello,

I recently purchaed a 99 land cruiser. I noticed on the highway, the overdrive does not seem to function properly.

At 55mph I'm at 2800 tpm. It revs up to over 3000 rpm as I approach 70mph. I push the overdrive button and the OD OFF light turns on but there is really no change to the RPM. Maybe it increases by 100 or so but it's barely noticeable.

This is a stock truck with stock tires.

I'm hoping there is a quick fix. Any input is appreciated.

Thanks

Were you on flat ground or going up an incline? Strong head wind?

Was your CDL on? CDL on will change your shift pattern.

Did this happen all the time or just one time?

Do you have enough ATF in the tranny?

 

[Natev22]

I am a decent mechanic. But right now I just have my driveway and very little time due to two small children and a busy work schedule.

It's definitely doing it all the time. Even on a downhill.

CDL is not on. I will check the ATF level today.

 

[flintknapper]

I am a decent mechanic. But right now I just have my driveway and very little time due to two small children and a busy work schedule.

It's definitely doing it all the time. Even on a downhill.

CDL is not on. I will check the ATF level today.

^^^^^^

Understand.

Just so we have a 'base' to work from, check the fluid level and condition of the fluid. Fluid level should be checked with engine/transmission warmed up.

Shift through all gears or take on a short drive. Then in 'park' (on a level surface) engine idling, check the fluid level. Remove the dipstick, wipe it off, reinsert, withdraw and note fluid level on dipstick. There are notches on the dipstick that indicate both the hot and cold levels, but a transmission should only be checked when warm and idling.

Note also the condition of the fluid. Is it bright red when wiped on a white paper towel? Does it smell burned in any way.

IF the fluid level and condition are good we will turn our attention elsewhere.

 

[Natev22]

It is between the 2 hot marks after a 10 minute drive but it's not red not even close. More brown than red.

 

[2001LC]

I'd also suggest flushing all 12qts of transmission fluid out. I'd use Mobil 1 full synthetic MV ATF, in 98-02.

Also worth noting; ECT (Engine coolant temp) is important, to transmission shifting. The transmission will not go into higher gear, until operating temp reached. So knowing what ECT, may yield clues!

Note: Dash gauge is near useless for ECT. As it only tells when very cold or very hot.

 

[DTCsk8er]

I'd also suggest flushing all 12qts of transmission fluid out. I'd use Mobil 1 full synthetic MV ATF, in 98-02.

Also worth noting; ECT (Engine coolant temp) is important, to transmission shifting. The transmission will not go into higher gear, until operating temp reached. So knowing what ECT, may yield clues!

Note: Dash gauge is near useless for ECT. As it only tells when very cold or very hot.

This ^^. Seems like it's unrelated to this issue, but worth mentioning. I noticed on mine that it won't shift into the higher gear until the engine is at temp.

 

[flintknapper]

This ^^. Seems like it's unrelated to this issue, but worth mentioning. I noticed on mine that it won't shift into the higher gear until the engine is at temp.

It is a design feature. The transmission (A343F)) will NOT go into OD until the coolant temperature (NOT the AT fluid) reaches 130°F.

So if the sensor is bad.....that could indeed cause the condition. It isn't the most likely cause....but it does make the list.

 

[Natev22]

Ok I've been driving the 100 on and off for a few weeks now. I don't think it's an overdrive issue, I think this thing just isn't shifting into fourth gear. The transmission fluid is pretty brown.

Is my transmission bad?

 

[flintknapper]

Ok I've been driving the 100 on and off for a few weeks now. I don't think it's an overdrive issue, I think this thing just isn't shifting into fourth gear. The transmission fluid is pretty brown.

Is my transmission bad?

No way for us to know until you get that fluid changed *full fluid change*.

You should be able to feel the transmission shift through each gear *under fairly hard acceleration* or at least see the shift points on your tachometer. IF it isn't going into fourth gear it should be discernible.

But...IF your fluid is so degraded *and it sounds like it is* that the transmission is just slipping into each gear....then you'll have a tough time diagnosing further until you have fresh fluid. It could be a shift solenoid or something internal as well....but I wouldn't jump to any conclusions.

 

[2001LC]

Ok I've been driving the 100 on and off for a few weeks now. I don't think it's an overdrive issue, I think this thing just isn't shifting into fourth gear. The transmission fluid is pretty brown.

Is my transmission bad?

I'd do full 12 qt flush with Mobil 1 ATF in 98-02 100 series. If 03 Toy IV, if 04- up Toy WS ATF.
But first, I'd also monitor engine coolant temp and AT temp. Than again after full 12qt flush.

 

[ramangain]

Agree with the troubleshooting that if the fluid color is brown, you need to do a full tranny fluid flush. It take a couple of hours to methodically do it correctly with triple checking everything the first time, but can be done with simple hand tools.

 

[zhloea]

Will replace all Solenoids be a stupid idea for preventive mantainace? Is it difficult or risky to do that? ( My lc100 have a little hesitant shifting but nothing is really serious )

 

[Rebin Rajan]

Hello,

I recently purchaed a 99 land cruiser. I noticed on the highway, the overdrive does not seem to function properly.

At 55mph I'm at 2800 tpm. It revs up to over 3000 rpm as I approach 70mph. I push the overdrive button and the OD OFF light turns on but there is really no change to the RPM. Maybe it increases by 100 or so but it's barely noticeable.

This is a stock truck with stock tires.

I'm hoping there is a quick fix. Any input is appreciated.

Thanks

Hey, did you manage to identify the issue. I have a similar issue with my LC100 2006 model. 4th gear doest engage