5.9Excursion

I'm curious to know when a stock tranny locks the convertor when driving? Is it only after it has shifted into overdrive? Does it unlock the convertor anytime the break pedal is touched?

Never driven a stock dodge auto truck and I'm trying to program my trans controller to have one calibration shift just like stock.

Thanks!

06RAM2500

Locks @ 50 mph or up to 60 depending how much pedal is applied and if it's in overdrive. If out of overdrive, it'll lock up @ 35. Either I/O overdrive unlock is @ 40 mph.

coparam4x4

Mine unlocks at 45.

Nate-03 D

When you guys are saying it "unlocks" what exactly is it doing?

What's going on then at about 55mph when your at 2k rpms or so under normal acceleration and the rpms drop to about 1500? Is the TC unlocking then?

5.9Excursion

So it only locks the torque convertor when the transmission is in top gear? No locked up T/C during any shifts (like the 3/4 shift)?

My current setup shifts from 3 to 4 around 50 mph (light pedal), just wondering if a stock setup would lock it up just after this or before the shift...

Thanks

92'1stGen

Mine shifts:
2nd at 10 -13
3rd at 20 - 21
4th at 37 - 38
Locks the TC at 45
Unlocks the TC at 42 if your off the accelerator
You can keep the TC forcefully locked all the way down to 40 by keeping on the accelerator atleast slightly, at 39 it unlocks.
That's in regular D with no Tow/Haul on and 4.10's. It may be different points for 3.73 but I don't know for sure, never driven one with those.

RamWheelsBy4

Yes that is the TC locking in OD.

Hvytrkmech

45 mph in 4th is normal lock up speed for light to moderate acceleration without being in tow haul. It could be a little higher speed depending on gear ratio. In tow haul the T/C on an 06 will lock immediatly after the 2-3 upshift in 3rd, then unlock shift to 4th and relock.

If you are at WOT and not in t/h mode the trans will still lock the 3rd gear upshift. As far as deceleration goes the 48re will stay locked regardless if you are on the brakes or not, down to 45mph then unlock. In tow haul it will stay locked in 4th then downshift to 3rd and relock for engine braking.

It is a very different stategy from the 4R100 you had in your excursion.
Ford likes to unlock them as soon as it see's a brake light signal, Dodge does'nt.

Dieselnick

What year is your 5.9/48re?

Nick

5.9Excursion

03-04 year range. I'm using the ATS standalone valve body and controller so I have to program all the shift points and the torque convertor lockup strategies. Anything is possible, just didn't know how the stock trucks worked. Thanks for all the info...

Dieselnick

My '04 w/3.73's locks at 48mph in od and 33 in tow/haul. On deceleration it unlocks at 41 in od and 28 in tow/haul. The 04.5 to 07 engines made their peak TQ 200 RPMs higher than the 03-04 305/555's, so their lock-up speeds would be higher w/the same gearing.

Nick

Sprinter17

Also you shouldn't get lock up until it reaches operating temperature, or close to it, and above 45mph. When you reached your speed and everything stops shifting, if you tap your brake pedal, it should unlock and rpms go up about 150.

CrazyFloyd

I know this is a stupid question but how can y'all tell when it locks and unlocks?

CamperAndy

There is an RPM drop when it locks but a lot of people have modules like the Edge with Attitude that you can see the shift points and TC lock status as you drive.

CrazyFloyd

So I take it that when my truck shifts into overdrive and the rpms go up first then down it is engaging. If thats the case then mine engages around 50-55 mph.