Check Transmission Fluid - May have over heated it

[Romer]

Some great info about heat with the tranny in 4th gear vs Overdrive. I ordered the Blue Tooth OBD II reader to be able to monitor

Coming back from Moab, the floor started to feel warm and something smelled hot, not quite burning when we got home.

I was towing my 4000 lb trailer over the MTN passes. The weather sucked over Vail pass and I wanted to keep the speed up going up the pass, I neglected to down shift which I do know better

I am concerned I over heated the Tranny fluid. With the skid plate system I wanted to make sure I knew what to look for before I checked it. Not sure if even checking it will show me its good and maybe I should just exchange the fluid to be safe.

Thoughts?

 

[gaijin]

I'd replace the fluid just for peace of mind if nothing else.

You'll need the TechStream software and cable if you DIY, or simply have the dealer do it.

HTH

 

[Willy beamin]

Better safe than sorry

 

[Rigger]

Yes - change the fluid.

 

[Romer]

I'd replace the fluid just for peace of mind if nothing else.

You'll need the TechStream software and cable if you DIY, or simply have the dealer do it.

HTH

I wasn't aware of needing the Techstream. I'll just have it done.

Peace of mind is something I am big on for my vehicle. I changed the head gasket out on my 80 when it was still good so I wouldnt have to worry about a failure. Those that had an 80 know what I am talking about. Toyota never admitted an error with the original headgaskt, but they redesigned it and I don't recall one of the new designs having ever failed

 

[BTUMAN]

I have the Bluetooth reader and have the transmission temp as a readout. While towing my Kimberley about 4 hrs over mostly flat land, the transmission temp does increase while under load (including up hill). However it was great to monitor it and see it return to the radiator temp. very quickly. I saw it go as high as 250 just for a minute. It is definitely very sensitive temperature reading as it moves up and down a lot. It was obviously dependent on the gear and rpm.

I would say if you ran it hard pulling and with the hills and didn't know you were at that 250 F for a long time, the fluid may have broken down a bit. I would recommend the BG fluid flush and fill or you will not get all of the old fluid out.

That's my thoughts.

 

[Romer]

I have the Bluetooth reader and have the transmission temp as a readout. While towing my Kimberley about 4 hrs over mostly flat land, the transmission temp does increase while under load (including up hill). However it was great to monitor it and see it return to the radiator temp. very quickly. I saw it go as high as 250 just for a minute. It is definitely very sensitive temperature reading as it moves up and down a lot. It was obviously dependent on the gear and rpm.

I would say if you ran it hard pulling and with the hills and didn't know you were at that 250 F for a long time, the fluid may have broken down a bit. I would recommend the BG fluid flush and fill or you will not get all of the old fluid out.

That's my thoughts.

Thanks. I already dropped it off. I will be able to monitor next time to better balance the operation. Both the heat in the cab and the smell when we stopped tell me this is the most conservative approach

 

[linuxgod]

I have the Bluetooth reader and have the transmission temp as a readout. While towing my Kimberley about 4 hrs over mostly flat land, the transmission temp does increase while under load (including up hill). However it was great to monitor it and see it return to the radiator temp. very quickly. I saw it go as high as 250 just for a minute. It is definitely very sensitive temperature reading as it moves up and down a lot. It was obviously dependent on the gear and rpm.

I would say if you ran it hard pulling and with the hills and didn't know you were at that 250 F for a long time, the fluid may have broken down a bit. I would recommend the BG fluid flush and fill or you will not get all of the old fluid out.

That's my thoughts.

Keep in mind there are two transmission temps. The lower one is measured at/near the pan. The (typically) higher one is between the torque converter and the radiator. Make sure you have both (formulas below work in EngineLink and should be translatable to other apps)

• Toyota A/T Pan Temp. PID 2182. Formula ((((A*256+B)*(7/100)-400)/10). Range -40 to 300. Units are F.
• Toyota A/T TC Temp. PID 2182. Formula ((((C*256+D)*(7/100)-400)/10). Range -40 to 300. Units are F.

 

[gaijin]

Thanks. I already dropped it off. I will be able to monitor next time to better balance the operation. Both the heat in the cab and the smell when we stopped tell me this is the most conservative approach

You can double check on how thorough a job they did when you see how much ATF-WS they bill you for.

A complete empty and refill should be more than 6 quarts. If they only bill you for a little more than 2 quarts, then all they did was drain the pan and refill it - leaving more than 4 quarts of the old fluid in there.

HTH

 

[chilibit]

I am a little rusty on this but on my 80 I thought it took something like 2-3 times the stated capacity to do a thorough flush and replace. This is the result of not actually being able to drain the unit. Sort of a dilute and drain approach because of the torque converter. Is my memory faulty?

 

[Romer]

I am a little rusty on this but on my 80 I thought it took something like 2-3 times the stated capacity to do a thorough flush and replace. This is the result of not actually being able to drain the unit. Sort of a dilute and drain approach because of the torque converter. Is my memory faulty?

Yup, they used 10 quarts to replace the 6. The price was stated on a coupon before I started at $350. My skid plates gave them a reason to stop and scratch their heads

 

[blatant]

Wouldn't a dash light have come on?

 

[Romer]

They asked that question as well and it did not. Very likely my fluid was fine, but I am anal about PM. It could have been hot for a while but not yet at the point the light trips. On my 80, once the gauge read you were starting to get the Anitifreeze hot it was too late. This way I will know I have good fluid as I monitor the temps while towing using the data to teach me the best way to tow over the MTN passes, the flat lands were not an issue. Anyone who has done Vail pass going east and then a few minutes later the 12 mile steep climb to Eisenhower tunnel understands that is the hard spot.

Going west on these passes is easier and gradual up hill, down hill has the grade. Since I will be doing these trips several times a year to get to destinations, I want to be sure I am doing it as efficiently as possible with a known good baseline to start with

 

[gaijin]

Romer, can you share how much your dealer charged for this service?

TIA

 

[Romer]

I did above, it was $350. Seemed like I could have gotten a better deal if I shopped around, but it is one of two places I trust in this town to work on my vehicles, the other is Slee

 

[Canyonero]

I did above, it was $350. Seemed like I could have gotten a better deal if I shopped around, but it is one of two places I trust in this town to work on my vehicles, the other is Slee

Romer-the Toyota dealership on Arapahoe?

 

[Romer]

No, I went to ToyCar Care on Arapahoe and Potomic. They have all X Toyota Mechanics there are work on Toyota and Lexus. The GM and I hit it off about 10 years ago talking about our 40's. Pretty much the same crew since then

About Toy Car Care| Auto Repair Centennial

 

[Canyonero]

No, I went to ToyCar Care on Arapahoe and Potomic. They have all X Toyota Mechanics there are work on Toyota and Lexus. The GM and I hit it off about 10 years ago talking about our 40's. Pretty much the same crew since then

About Toy Car Care| Auto Repair Centennial

I know right where it is, thanks. I've been looking for a place closer than Slee where I can take my truck. Sounds like that's the place.

 

[bjowett]

A wise decision.

 

[txtortoise]

I saw BTUMAN's transmission temp formulas. Should I assume I have to input the custom formula in the OBD Bluetooth Scangauge, since I don't see a default readout for those or am I missing something on the Scangauge.