FJ62 A440f AT oil temp light - Rodney response (1 Viewer)

[jhanger]

I mentioned a problem in another thread but thought I'd repost it here with the response I received from Rodney so that everyone can see:



Problem: driving the cruiser to work after installing the Extreme Valve Body from Rodney @ Wholesale Automatics, and so after driving for almost an hour, I was nearing my destination and slowed down from 70 to 35 as I made my exit and lo and behold the AT Oil Temp light comes on. F@@&@!!! See my many previous posts about this. So I realized that this only happens when I slow down after cruising for some time. My lines have been triple checked and the flow rate is fine. I have a new external trans cooler in front of the radiator (I used Georg's recommended brand). The radiator was replaced OEM last year. I also just had a new torque converter installed with the valve body. I am at a loss. Could the trans cooler in the radiator be not working? As I said, the flow rate is fine. I'm running synthetic fluid. Rodney's valve body came with a new screen and the old screen looked fine but I replaced it anyway. I'm thinking of installing an aux fan in front of the aux cooler. I am running stock 4.11 gears on 33" tires. I have 4.88's but they are not installed yet as I am wavering on those versus 4.56. I have no plans to ever go bigger on the tires so 4.88 might be overkill. Thoughts??

so I sent this same note to Rodney and his response was great so I thought I'd share it with everyone here:

Hi James its Rodney from Wholesale Automatics,


This is in fact normal, When the torque convertor lock-up comes on it stops the oil flow through the torque convertor and because the convertor is basically stuck between a hot engine and a hot oil pump the oil in the torque convertor over a very long time normally more than 45 minutes will get quite hot even though the oil temp light and oil temp gauge if you have one says that all is still normal. But when you slow down and either stop or come into a town the lock-up will release and the super-hot oil will then go past the temp senders and this is what you are seeing. Only 2 ways to fix, 1/ put one of our Heavy Duty Billet torque convertor in that allows for the flow to continue while the lock-up is on “or” every now and then when on a long trip slow down to under lock-up speed for a few minutes to flush the hot oil out and then continue. Took me 2 years to find this problem and find the cure.

 

[cruisermatt]

Interesting. Good tech.

 

[Cruiser Jimmy]

So their valve body cuts off the flow of oil? I'm pretty sure the stock one doesn't. Did WA (or your domestic dealer) recommend their TC at the time of the valve body purchase. It's a small hassle to drop a new one in but probably worth it.

If the oil stays in the TC and cooks, your lockup clutch is going to be affected by this process. And not in a good way.

 

[62LostInMn]

I have the Extreme Valve Body in my '88 62 and run 31x10.5 tires, otherwise the drivetrain is stock. It's been installed about 4-5 years now and I have an aux cooler in front of the radiator. I've never had the trans temp light come on, other than briefly at start-up which is a normal check. I've pulled my 16 foot fishing boat (probably 2500lbs fully loaded) to Canada a number of times driving 65-70 mph, and that is about a 7 hour trip. The last trip in August was pretty hot too. My fluid still looks perfect.

Something doesn't sound right. There are a ton of these VB's installed and I would think someone else would have seen this by now.

Anybody?

FYI - I'm planning 4.88's and 33's this coming spring. I'm OK being a little deeper than stock.

 

[Randy88FJ62]

35's, 4.88 gears, F250 Aux Trans cooler, and stock gearing: I get up around 230 max on a bad long hill. Normal operating temps are 190°F

 

[RockDoc]

I've had an extreme VB (with stock TC and aux cooler) for about 8 years and have never had this happen to me. I agree that if part of you ATF is getting hot enough to trip the light, that's not good. Could the clutch in your new convertor be slipping?

 

[Cruiser Jimmy]

@jhanger as most of us do we assume your temp light is working properly. Maybe hook up an aftermarket temp gauge to confirm.

Also the clutch in the TC can be replaced and even upgraded.

 

[jhanger]

My AT oil temp light has been coming on for many months almost every time I drive for more than hour. It started a few months after I replaced my original transmission with one I bought from Georg. It seems to happen every time my overdrive continually kicks in (strong headwinds, gentle hills, etc). My fluid would end up burnt. I did the Rodney flush, replaced the aux cooler and checked the lines. Still happened. I started researching on here. Decided to replace the torque converter. The first TC installed made a strange noise so it was warrantied for another new TC. While at the tranny shop I decided to pull the trigger on the extreme valve body. First day on the road and she drove great. Lock up while going up hills. Barely used overdrive at all. No light until I came into town. Shot it with an IR temp gun and the hottest temp I found was 190 halfway up the trans pan. Cue my question and response from Rodney. So I have a new valve body, a new TC, synthetic fluid, and AT oil temp light that comes on. I've got to get this figured out.

 

[SteveH]

Is it possible the AT fluid temp sensor is defective? 190F pan temps should not turn on the light. If that were true, mine would be lit up most of the time. I would worry about your trans. if I saw temps like 235 or something in that range.

 

[Cruiser Jimmy]

Based on your forth to last statement, my gut is telling me you're fine. If you're getting 190 degree with an IR temp gauge then you are sitting right where you need to be.
From my first hand experience: My temp light came on while I was driving above lockup speeds for a sustained period, different from your situation. The lockup in the TC engages and disengages between 47 and 55 mph. If you have a burnt lockup clutch (which I did) then it's slipping and you are cooking the fluid in the TC and feeding it back to the trans which will initiate the a/t temp system. My Autometer temp gauge was installed right before the outlet of to the cooler, a good location for the highest temps. My temps (highway speed) were consistently at 220 and higher. It was only until I got back into the city and drove under 47 that the temps came down.

 

[Cruiser Jimmy]

I can't remember if I mentioned this but the temp light comes on at 305 and turns off at 247. At 305 I felt the tranny humps heat.

 

[Cruiser Jimmy]

But when you slow down and either stop or come into a town the lock-up will release and the super-hot oil will then go past the temp senders and this is what you are seeing.

I hope I don't make you paranoid, I really want to help you out.

Based on this statement from Rodney and after thinking about it more I wonder if your oil pump bearing is out of spec. In the attachment you'll see the front plate of the pump.
It's not pictured but there's a bearing on the inside of the shaft. That bearing keeps Hydro pressure in the TC area. If it's out of spec it can lead to slippage also. The bearing is replaceable and orderable from company's that rebuild trannys, not from Toyota.

BTW, that is pretty easy to fix.

 

[dpw]

So, I think I’m on the right thread based on my initial searches of what’s going on but time will tell.

So I’m still learning my new & first FJ62 (first posted about it a few weeks ago). Instead if shipping it to me I decieded to risk a fresh road trip and flew up to OR. I’m now road tripping it home to with my 4yo daughter. I’ve been getting to know the vehicle while enjoy the countryside down to the Ventura/SB area. It has preformed great for the past week (both on and off road)until today....

After putting in a long highway session (~3hrs) I slowed down quickly as I came to the first stop light of town (I did down shift the AT into 3). As soon as I stopped I noticed the smell of burning oil. Then I see the AT Oil Temp light came on. The light changed and I pull through the intersection and off to the side and shut her down.

Besides the smell and AT Oil Temp light it drove fine.

After crawling under I see lots of oil (I assumed it was oil at least) all around the undercarriage just forward and mostly to the passenger side of the rear diff.

I couldn’t find any ruptured hoses.
I checked the oils and break fluid and they were normal.
BREAK: took little girl #2 in the bushes.
After some time for things to cool down I opted to drive it down the road (~5mi) and camp out for the night.

It drove fine through all get gears with no AT light and I didn’t see additional oil leakage like before. (There was still a good bit of residuals down there from before but nothing flowing)

My plan is to take it to a local auto shop in the am for a closer look before continuing my trip. (Nothing close by on the Crusier Mechanics post either)

There’s a Toyota dealership 20miles away (in the wrong direction) that I’m considering as well.

Background:
•The rear engine seal was just replace last week.
•It has a trans cooler.
•It had pretty much sat in a garage for the past 5 years so this road trip is the most it’s seen in a while.

Any thoughts/suggestions? I’ll post some photos of the adventure once I make it home to not jinx myself anymore than I already have!

Cheers,

 

[Spook50]

This is interesting. I'm all stock except for the aux cooler, and I have a fairly long stretch on the highway to get to work. On my way home I stop on the offramp because of a light, and I've never seen my temperature spike under those conditions, even before the aux cooler. Is this something exclusive to the upgraded VB? It's on my list for a future upgrade, and if I can find a good shop around here, have them install that and a billet torque converter as well, and I figure that'll help it last me until I can afford to go the Vortec route.

 

[dpw]

So, I think I’m on the right thread based on my initial searches of what’s going on but time will tell.

So I’m still learning my new & first FJ62 (first posted about it a few weeks ago). Instead if shipping it to me I decieded to risk a fresh road trip and flew up to OR. I’m now road tripping it home to with my 4yo daughter. I’ve been getting to know the vehicle while enjoy the countryside down to the Ventura/SB area. It has preformed great for the past week (both on and off road)until today....

After putting in a long highway session (~3hrs) I slowed down quickly as I came to the first stop light of town (I did down shift the AT into 3). As soon as I stopped I noticed the smell of burning oil. Then I see the AT Oil Temp light came on. The light changed and I pull through the intersection and off to the side and shut her down.

Besides the smell and AT Oil Temp light it drove fine.

After crawling under I see lots of oil (I assumed it was oil at least) all around the undercarriage just forward and mostly to the passenger side of the rear diff.

I couldn’t find any ruptured hoses.
I checked the oils and break fluid and they were normal.
BREAK: took little girl #2 in the bushes.
After some time for things to cool down I opted to drive it down the road (~5mi) and camp out for the night.

It drove fine through all get gears with no AT light and I didn’t see additional oil leakage like before. (There was still a good bit of residuals down there from before but nothing flowing)

My plan is to take it to a local auto shop in the am for a closer look before continuing my trip. (Nothing close by on the Crusier Mechanics post either)

There’s a Toyota dealership 20miles away (in the wrong direction) that I’m considering as well.

Background:
•The rear engine seal was just replace last week.
•It has a trans cooler.
•It had pretty much sat in a garage for the past 5 years so this road trip is the most it’s seen in a while.

Any thoughts/suggestions? I’ll post some photos of the adventure once I make it home to not jinx myself anymore than I already have!

Cheers,

So, I ended up bringing my FJ62 to the dealership in Monterey—partly because of the nearby attractions for the kiddo (as I suspected it might take some time) but also because I couldn’t find anything else to the south.

Bottom line is that they couldn’t find any active leak, nor could they tell where the leak came from because of all the resdiual oil on the undercarriage.
All the fluids looked good but the transmission fluid was a little bit down.

They recommend that I pressure wash or steamed clean the bottom and keep an eye on it.

I pressure washed the bottom but also called the shop that did the rear main seal replacement the other week. First thing he said was, “Well, that guy has been living in a garage on a ranch the past 5 years and likely hasn’t seen over 45mph in as many years. You likely ran it too hard, for too long, and too soon so it lifted its relief valve to vent as it got too hot”

That was the biggest day of highway diving since I got it, but my biggest surprise was why the dealership didn’t think of the transmission vent?!

I wasn’t aware of such a vent but would think the dealership would be.
That being said, the dealership did have it for two hours and didn’t charge me anything which was pretty awesome of them.

It drove fine today with no issues but I did baby it more than before especially on highway hills. It made it home so I now have time to learn how this vehicle works.

I think my plan is to investigate the previous posts on this thread regarding highway driving as well as to confirm my aux tranny cooler is working as it should be.

Rgs,
Dave

 

[Cruiser Jimmy]

So my initial thought is that you were driving at highway speeds right from OR to CA right? This is speeds above 45 to 50 mph. The Torque Converter(TC) is in lockup at that point. If the TC has a burning up or burnt lockup clutch then you are cooking the oil while you are continuing to drive at these speeds which would explain the light coming on. This will eventually burn the Co, C1 and C2 clutch packs. Feels like you need a reman'ed TC.

 

[jhanger]

Update: everything has been running fine since re-gearing to 4.88s until yesterday. No excessive overdrive/AT Temp issues until I decided to haul an empty 14’ trailer about 60 miles down the highway. It did not like it at all. A dozen times in overdrive but tranny never got hot driving 55-65 mph. My destination was a mile off the highway, so I exited and then parked the rig. I came out two hours later and there was a small puddle of ATF and a smaller puddle of gear oil two feet away as well. The shifter was HOT. I unhooked the trailer and drove it another mile to my house and parked it overnight. This morning had another small puddle of ATF. Checked the ATF levels (cold, then hot) and it was low. I added 3/4ths a quart of Mobil 1 Syn. ATF fluid and then watched it drip on to the ground almost immediately. After re-reading the Rodney response above, I immediately think it’s my TC cooking the oil and then I didn’t drive it long enough at lower speeds for it to be cooled down. But then the immediate drip this morning makes me think it’s something else or a combination of issues. I think a tow to an actual cruiser mechanic shop in DFW might be in order...to be continued

 

[brownbear]

I can't remember if I mentioned this but the temp light comes on at 305 and turns off at 247. At 305 I felt the tranny humps heat.

Just for some tech info.

The A/T Fluid Temo Sender in FSM

Says to check in heated container or oil. At 25 Celcius it should have 3.38 K ohms.
At 120 C it should have 0.55 Kohms.
So it probably turns on the light at 120.

It doesn't say in the FSM an on and off value.

I'm not a fan of warning lights. I'd take off a light and put in gauge to read myself.

 

[Cruiser Jimmy]

I'm not a fan of warning lights. I'd take off a light and put in gauge to read myself.

Thanks for the tech info/help.

Yes, not a fan of the warning light either. would rather see the gauge too.

 

[cc93cruiser]

Just for some tech info.

The A/T Fluid Temo Sender in FSM

Says to check in heated container or oil. At 25 Celcius it should have 3.38 K ohms.
At 120 C it should have 0.55 Kohms.
So it probably turns on the light at 120.

It doesn't say in the FSM an on and off value.

I'm not a fan of warning lights. I'd take off a light and put in gauge to read myself.

Thanks for the tech info/help.

Yes, not a fan of the warning light either. would rather see the gauge too.

Anyone know what npt size/thread pitch etc the oem temp light sensor in tranny is? Would also like to look at getting a direct bolt on temp sender unit for temp gauge install.