transmission got a little heated going over the Siskiyous.

[BIGNASTY]

If your talking about Anderson Grade? SB I 5, that's not really much of a grade !!

 

[cerberusiam]

The 05 works completely different than than earlier trucks, it does not have an OD lockout so it will shift back and forth all the time at those speeds on a grade with switch backs. It probably wasn't going into OD just drive and locking the TC. To get it to hold 2nd gear you need to manually downshift to 2nd gear. To get it to hold drive you need an OD lockout box so you can turn on TH and keep it out of OD.

 

[EMAC2]

The original technical paper which describes development of ATF+4 states it was tested for 500 hours at 100 degrees C (311 degrees F) and still retained acceptable performance criteria required by Chrysler.

You can read the full report HERE.

John L.

Isn't 100 degree Celcius 212 F?

 

[SnoKing]

Isn't 100 degree Celcius 212 F?

Yes! Chris

 

[JLandry]

Isn't 100 degree Celcius 212 F?

My mistake. I mistyped and have corrected my original post to state 155 degrees C per the technical paper.

John L.

 

[mbirch]

I think it's rather presumptive of Bignasty to know the exact location of MY travels, but no, it was not on I-5 that I encountered problems. The first time it happened was after leaving the coast highway above San Francisco on highway 29 between Calistoga and Middletown. One of the other times it happened on highway 49 in "Gold Country" on the other side of the valley, and I can't remember the exact location the other time it happened. Prior to this trip to California I went 11,000 miles circumnavigating the United States and had no such problems, BUT, I had the shift kit installed between those two trips.

 

[SDputter]

On a long grade that I pull my 15K 5er a dozen times a year, mine will drop into 2nd at closer to 40 mph. TC unlocks at that point and I used to cross my fingers when I didn't have a temp gauge because I would keep the rpms up (like 2800) to only reach 35 mph. I know the oil had to get hot but mine never kicked it into a higher gear, lock the TC and lug the motor. Then Cerb enligthened me on the fact I can manually shift into 2nd to get the TC to lock up. As Cerb recommended, I'm careful about making this shift. When I get below 45 mph, I'm waiting for the downshift, when it happens, I back off the throttle completely and as it is spooling down, I manually shift into 2nd. I slowly get back into it waiting for the transmission to make up it's mind and lock the TC. It takes a couple of seconds. When it does, I can then accelerate back upto 45 mph without turning to many rpms (maybe 2500). Everything has seemed real smooth everytime I have done it and now that I have a gauge, I see little transmission temp increase. Likewise, when you get to the top of the hill, back all the way off and let it spoil down before putting the lever back into drive.

Cerb's the best!

 

[Motorhead]

I think Cerberusiam is wrong in stating that second will lock the converter in second on a stock trans. Best is to get rid of the L-O-O-S-E, STOCK torque converter with a tighter style and if needed, install a floor switch or something so that you can momentarily lock the converter when holding the trans in second gear. A spinning, Not Locked up converter will make lots of heat.

 

[mbirch]

While my trailer is 9.2K and not 15K it still shifts frequently on steep switchback mountain roads which I am sure is making the temp rise in the transmission. I am used to the predictable shifting pattern and when it doesn't shift as it should it is pause for concern, even the wife can notice the difference. If the change in shifting is due to the trucks electronic sensors trying to save the transmission due to higher temps, it seems like an overtemp light would come on to notify you of problems.

I will agree that it seems as if Cerb knows alot about transmissions and it must be frustrating trying to teach someone like myself about the "magic" of how an automatic transmission works, I just can't seem to fully understand the darn things.

 

[cerberusiam]

You are thinking 2nd gen 47RE, they would not lock in 2nd gear without modification. Every 48RE I have ever driven from 04-06 has locked in 2nd manual. I have to think the 07 would follow the same pattern and probably the 03 also but have not tried them. The 48RE will even lock in 1st manual with a switch. Stock transmisison have a less than stellar lockup algorithm in 2nd and drive, they are design only to lock with little load. Tough to get to that point on a grade without some playing with the throttle but once they lock it will hold pretty good. With higher efficiency TC its becomes a lot easier as there is less throttle needed to accelerate and hold speed so they lock sooner and more vigorously.

Some type of lockup controller is nice to have but is really not needed in most circumstances if one understands the operation of the lockup programs.

While my trailer is 9.2K and not 15K it still shifts frequently on steep switchback mountain roads which I am sure is making the temp rise in the transmission.

Yes it will, and, yes it does. Nature of the stock transmission and programs. The TCM will change shifting algorithms before the trans temp light comes on, its attempt to keep the light from coming on.

With steep switch backs where you cannot get to speed and maintain it, nothing much to be done other than pick a low enough gear and lock the TC. A lockup switch will allow even more of a range of speed in 2nd manual and not unlock, a good TC will come close also if you regulate the acceleration correctly. I have pretty much quit using a lockup switch with a tighter TC. Few places I cannot drive in 2nd or drive and keep the TC locked with careful foot work.

 

[sag2]

Lock up switch, less than $10, great converter, more than $1,000 plus install. Sounds like no brainer to me.

 

[leaky gasket]

Would it be possible to install a tattletale light on the TCC to show when the converter is locked up?

 

[spin05]

so im thinking after taking this all in, im not too worried about it. Im pretty sure i was in 2nd gear and not locked up. I will try the manual shift down method next time. The truck took on the grapevine no problem and the other hill outta redding. Also a big long hill on hwy15 i think it was that goes to Barstow/vegas and never got above 210 deg or so. It also never did that mild surging either so i think you may be right on the fan. So in your guys opinion the fact that its a bit over filled that could cause foaming wouldnt cause the surging??????.

 

[SnoKing]

Would it be possible to install a tattletale light on the TCC to show when the converter is locked up?

transmission solenoids have battery voltage on one side and the PCM grounds the other side to pull them. So a LED with 1000 ohm resister in series with battery voltage on the positive side and connected to the PCM lead on the ground side should work. 1-2 hour project. OD solenoid works the same way. Chris

 

[leaky gasket]

Thanks Chris, i'll give this a try.

 

[daryl]

Where and how do you connect a lock out switch. I have been looking online and I can find a trans controller for $400 to $600. If I can find a cheaper fix, let me know.

 

[cerberusiam]

Where and how do you connect a lock out switch.

A lockout switch is a completely different animal. This discussion aroound keeping the TC locked to keep it cool. That in itself has problems because becasue a lockup switch with no other mods will stack shift the trans right into OD.

 

[AEdelheit]

Will the torque converter LOCK in SECOND gear? I thought the trans will only lock the converter in 3rd and 4th.

It will only IF the shifter is in second gear, otherwise it will only like in 3rd and 4th.

 

[p-Bar]

Check out the Derale brand through JC Whitney has an electric fan on it thermostatically controlled . under 200.00

 

[cerberusiam]

It will only IF the shifter is in second gear, otherwise it will only like in 3rd and 4th.

Actually there is nothing stopping it from locking in auto 2nd either, other than a calculated relationship. Enough speed, low enough engine load and APPS readng and they will lock in 2nd auto.