Aisin transmission ?

[Ozymandias]

Unfortunately it doesn't change the lockup speed for the Aisin.

Uh that's sad, so the good old 48RE is smarter than this brand new unit.

 

[Ozymandias]

Wait a minute, it doesn't even lock up in Second gear?

 

[AH64ID]

Wait a minute, it doesn't even lock up in Second gear?

Not in 4LO.

For some reason the programming for TQ Lockup is not using TOS like a 48RE does, but rather it appears to be using wheel speed and has the same criteria for lockup in HI or LO rang...~20-22 mph.

The 48RE is just simpler and doesn't care about any gear changes after it, so HI/LO doesn't effect TOS. I really hoped the Aisin was this way, but neither my 18 or 22 will lockup any slower in 4LO.

I'll bet it an engineering oversight with ow its a stand alone controller, which actually surprises me a little since it would need a VSS input for operation instead of just a TOS speed sensor like the 48RE uses.

 

[Turbo Terry]

Whats the highest transmission temps you have seen slow mo dirt road driving . Your not pulling your camper all the time your hunting right . In 4 h not 4 low . I would just watch the transmission temps and stop if it really started to go up and put it in neutral high idle and let it cool . When it got to about 190 would be on the side of the road. I see folks go backcountry here pulling way heavy 5 th wheelers slow over steep grades in a panic because the transmission alarm goes off. I tell just find a wide spot pull over set the brake neutral and fast idle let in cool down . Works for them it seems . But it does really scare them and freak them out in the middle of now where being from Illinois Nebraska etc etc flatlanders mostly sorry

 

[Turbo Terry]

I have got pretty hot a time or two pulling grades hauling 3000 lbs pulling 2000 lbs . When the chimes and bells go off it’s pretty scary

 

[AH64ID]

Whats the highest transmission temps you have seen slow mo dirt road driving . Your not pulling your camper all the time your hunting right . In 4 h not 4 low . I would just watch the transmission temps and stop if it really started to go up and put it in neutral high idle and let it cool . When it got to about 190 would be on the side of the road. I see folks go backcountry here pulling way heavy 5 th wheelers slow over steep grades in a panic because the transmission alarm goes off. I tell just find a wide spot pull over set the brake neutral and fast idle let in cool down . Works for them it seems . But it does really scare them and freak them out in the middle of now where being from Illinois Nebraska etc etc flatlanders mostly sorry

I've seen the pan temps get up to ~200°, but I'll usually downshift to 1st or go to 4LO if they are getting that warm. The TQ converter outlet temps (CTS3) will get a bit hotter when unlocked and that's how I normally determine when to downshift. Even at 200° the ECM isn't close to full fan command for too hot of trans temps.

No, I'm not always towing while hunting but the road in/out of camp has some long and steep grades and sometimes it's slow and slick with 6 chains on (reference Jan 2024 on the TDR Calendar) and the temps will really climb easily.

The truck has plenty of power at 15-18 mph in 2nd gear to pull the grades, but the temps climb too quickly and I often do a lot of the pull in 1st and the trans doesn't get nearly as hot. It takes so long for the trans to cool at idle that I prefer to keep moving a little slower at 2500 rpms in 1st, which actually really helps temps stay down. I'll also use 4LO on the really steep/slow sections which for my normal hunting area is only about 1/4 mile out of the 50 miles of dirt.

If you're alarms and warnings are going off you need to downshift sooner.

 

[Turbo Terry]

Yes I agree when the alarms go off your almost a bit late 200 f is about right . I also think really good Amsoil atf helps a lot also , I pull the dip stick and check red color and no burn smell also. Easy to change 7 quarts of fluid almost anytime which is about 2/3 to half the fluid . Must burn a lot of fuel running high rpm’s in 4 low. Good thing you got a big tank

 

[AH64ID]

At the speeds and weights that I'm using 4LO in to keep the trans cool it's all 4-6 mpg, even in 4HI slightly faster.

These things burn a lot of fuel with an unlocked tq converter.

 

[petersonj]

I don't understand why the automotive industry is stuck on torque converter automatic transmissions for our trucks. In my opinion, by now, the trucks we drive should have been equipped with something like a heavy duty application of an 8 spd dual clutch (wet clutch) automatic transmission. No torque converter lock-up to manage and no excessive heat generation from an unlocked converter!

For those who are not familiar - the dual clutch transmission (DTC), also called a direct shift gear transmission (DSG) provided by Volkswagen since 2002 has been refined and is a very reliable and very smooth shifting transmission. It has been called the dual clutch transmission because there are two automatically operated clutches in the transmission. One clutch works in conjunction with odd numbered gears and the other clutch works with even numbered gears.

The transmission gear selector can be placed in "Drive" and be operated like any other automatic, or the gear selector can be moved into a manual position to toggle into any preferred gear and be kept there from about 1,000 rpm to redline. Essentially, the transmission performs like a manual transmission gearbox, but the clutching is automatically done for the driver whether operating in the automatic mode or the manual mode.

A well designed DCT / DSG transmission for our trucks would make every driveability problem mentioned in all of the previous posts disappear, and would make the truck be a pleasure to drive.

- John

 

[Turbo Terry]

I just went out and went on a lonely road no traffic and put my truck in 4low and drove it around using the steering wheel shifter in 2nd and 3rd gear up a couple good grades and down .Ten miles a hour speed rpm’s I dont remember about 1500 I think this a sweet pulling spot for the truck . transmission temps went up a wee bit but stayed at 163 normal 30 degree day. But the problem I really see is you don’t really know if you in lock up or not. Would be nice to have a light or something wouldn’t it. So as I recall from last summer hauling heavy load and using the exhaust brake in tow haul mode the brake would drop off at about 12 miles per hour which means the torque converter went out of lock up If that’s true and run at any thing above 12 mph you should be locked up. Hard to tell the lock up it’s very faint. My old 99 DTT built transmission you could really feel it and it was at 20 mph . Oz says his is at 8 mph which is pretty low Then theres tow haul mode wonder how that enters into all of it.A transmission man might be able to put a lock up light on the transmission but then there’s the warranty. Maybe you can plug something into the port that would tell you lock up . Interesting topic as we wait for spring in Alaska 2 months away

 

[Ozymandias]

Not in 4LO.

For some reason the programming for TQ Lockup is not using TOS like a 48RE does, but rather it appears to be using wheel speed and has the same criteria for lockup in HI or LO rang...~20-22 mph.

The 48RE is just simpler and doesn't care about any gear changes after it, so HI/LO doesn't effect TOS. I really hoped the Aisin was this way, but neither my 18 or 22 will lockup any slower in 4LO.

I'll bet it an engineering oversight with ow its a stand alone controller, which actually surprises me a little since it would need a VSS input for operation instead of just a TOS speed sensor like the 48RE uses.

That's interesting as the ECM knows that the truck is in 4Lo and changes the fueling table and reaction to throttle input. But apparently doesn't tell the transmission about it.

 

[Bug Out]

Certainly glad you chimed in John. Don’t really know when mine was built but at almost 23 k miles now it shifts like a dream. No issues .Also I have a warranty and max care no worry’s

If you do the trans service (oil drop)yourself etc, MAKE sure you reset the codes BEFORE you shift into gear. When you change the oil, it throws a code and causes the AISIN trans to shift like GODLIZZA who wants to break your driveshaft in two. Once you plug into the OBDII port and clear the code, your golden.

 

[AH64ID]

I just went out and went on a lonely road no traffic and put my truck in 4low and drove it around using the steering wheel shifter in 2nd and 3rd gear up a couple good grades and down .Ten miles a hour speed rpm’s I dont remember about 1500 I think this a sweet pulling spot for the truck . transmission temps went up a wee bit but stayed at 163 normal 30 degree day. But the problem I really see is you don’t really know if you in lock up or not. Would be nice to have a light or something wouldn’t it. So as I recall from last summer hauling heavy load and using the exhaust brake in tow haul mode the brake would drop off at about 12 miles per hour which means the torque converter went out of lock up If that’s true and run at any thing above 12 mph you should be locked up. Hard to tell the lock up it’s very faint. My old 99 DTT built transmission you could really feel it and it was at 20 mph . Oz says his is at 8 mph which is pretty low Then theres tow haul mode wonder how that enters into all of it.A transmission man might be able to put a lock up light on the transmission but then there’s the warranty. Maybe you can plug something into the port that would tell you lock up . Interesting topic as we wait for spring in Alaska 2 months away

The TQ converter will stay locked down to 12, under the correct conditions, but it won’t lock that low. It needs to be at 20-22 mph to lock.

I use my CTS3 to know when the TQ converter is locked.

That's interesting as the ECM knows that the truck is in 4Lo and changes the fueling table and reaction to throttle input. But apparently doesn't tell the transmission about it.

Yes, it’s interesting for sure.

If you do the trans service (oil drop)yourself etc, MAKE sure you reset the codes BEFORE you shift into gear. When you change the oil, it throws a code and causes the AISIN trans to shift like GODLIZZA who wants to break your driveshaft in two. Once you plug into the OBDII port and clear the code, your golden.

In my experience codes only happen with a filter change. Just a fluid change won’t throw a code.

 

[bcbender]

I'll bet it an engineering oversight

As a development engineer this can happen and infuriates me all the time when things aren't checked completely. [one of the main reasons I got into this field] I always thought the wired failing in the rear doors of the 3rd gens was also engineering oversight as they did not fully understand the usage cycle of that door and should've spec'd out a higher strand count wire.

It takes so long for the trans to cool at idle that I prefer to keep moving a little slower

That's been my experience as well.

That's interesting as the ECM knows that the truck is in 4Lo and changes the fueling table and reaction to throttle input. But apparently doesn't tell the transmission about it.

That is exactly why I was asking, I have not used 4lo but a few times but assumed the transmission shift schedule and lockup algorithm would be gear based not speed based as internal [pre transfer case] relative velocities are the same.

MAKE sure you reset the codes BEFORE you shift into gear.

I guess I need to research this, I will be doing a filter in Oct. I assume Alpha-OBD can take care of it, Itll be a good time to do the brake fluid aswell.

Catching up......