Agreen
NAXJA Forum User
- Location
- Charleston
Let's see if anyone else has fixed this issue before. And before you go commenting on what fixed yours, read the list of things I've already done.
1998 Sport 4.0 4WD AW4
335,xxx miles
I bought this in 2014 with 230,xxx miles on it and it's had this issue since I bought it.
Under normal throttle conditions, it holds 2nd gear for way too long. 1-2 shift is right on time. Around 2200 to 2400 rpm. 2-3 shift will hold until well after 3000 rpm, sometimes close to 4000. When it shifts, there is no delay. It shifts nice and crisp, but it's just late. 3-4 is right on time as expected, and so is lockup. No issue with downshifts. I can make it upshift to 3rd by slightly backing off the throttle, and I've kind of gotten used to doing it, but it's just not right.
-Fluid level is perfect.
-Always used Dex III
-Fluid is bright red, does not smell burned
-TPS has been checked, and checked, and checked. It's perfectly in spec and operates smoothly through the range.
-The throttle cable adjustment has been done several times. I've even tried playing with it in different directions, but it either drags the shifts out or makes it take forever to shift, so it's been set back to where it should be.
-I have pulled the transmission completely apart and completely overhauled it. I did this about 30k miles ago because I actually converted it from 2wd to 4wd. The 4wd donor trans was in unknown condition, so I used everything from the 2wd except the 4wd output shaft and extension housing. It works well, but the original problem persisted. I also wanted to freshen things up in there since it had over 300k miles on it. Turns out when I pulled the 4wd trans apart to get the output shaft, it was pretty badly burned.
-I also installed a Trans-go HD2 kit while the trans was apart. I used the truck setting, not race. I installed the 1st gear hold as I do a lot of off-road driving and I like the 1st gear hold feature. The trans shifts more firmly now, but still has the original delayed 2-3 shift.
-I have checked the wiring, all grounds, and the harness going to the transmission.
-I put a multimeter on the wires going to the transmission to see if it's calling for 3rd gear. Solenoid #1 is supposed to deenergize, allowing line pressure to shift the 2-3 shift valve to move against spring pressure and shift to 3rd. The TCM doesn't call for 3rd gear until the moment it shifts. In other words, it's not the solenoid or shift valve hanging up, it's the TCM calling for a delayed shift. I even dropped the pan a few days ago and swapped solenoids #1 and 2. I checked their resistance and they were 12.7 and 13.4 ohms. It shifted the same after I swapped their places.
The only thing I can think of is that the TCM has some sort of bias resistor that has drifted over the years and THOUSANDS of miles of use. I've seen resistors (or other electronic/electrical components) change values due to age before, and I'm thinking this is what's happened. Should I take the gamble on a junkyard TCM? Is there ANYTHING that I've missed that I should look at?
:dunno:
1998 Sport 4.0 4WD AW4
335,xxx miles
I bought this in 2014 with 230,xxx miles on it and it's had this issue since I bought it.
Under normal throttle conditions, it holds 2nd gear for way too long. 1-2 shift is right on time. Around 2200 to 2400 rpm. 2-3 shift will hold until well after 3000 rpm, sometimes close to 4000. When it shifts, there is no delay. It shifts nice and crisp, but it's just late. 3-4 is right on time as expected, and so is lockup. No issue with downshifts. I can make it upshift to 3rd by slightly backing off the throttle, and I've kind of gotten used to doing it, but it's just not right.
-Fluid level is perfect.
-Always used Dex III
-Fluid is bright red, does not smell burned
-TPS has been checked, and checked, and checked. It's perfectly in spec and operates smoothly through the range.
-The throttle cable adjustment has been done several times. I've even tried playing with it in different directions, but it either drags the shifts out or makes it take forever to shift, so it's been set back to where it should be.
-I have pulled the transmission completely apart and completely overhauled it. I did this about 30k miles ago because I actually converted it from 2wd to 4wd. The 4wd donor trans was in unknown condition, so I used everything from the 2wd except the 4wd output shaft and extension housing. It works well, but the original problem persisted. I also wanted to freshen things up in there since it had over 300k miles on it. Turns out when I pulled the 4wd trans apart to get the output shaft, it was pretty badly burned.
-I also installed a Trans-go HD2 kit while the trans was apart. I used the truck setting, not race. I installed the 1st gear hold as I do a lot of off-road driving and I like the 1st gear hold feature. The trans shifts more firmly now, but still has the original delayed 2-3 shift.
-I have checked the wiring, all grounds, and the harness going to the transmission.
-I put a multimeter on the wires going to the transmission to see if it's calling for 3rd gear. Solenoid #1 is supposed to deenergize, allowing line pressure to shift the 2-3 shift valve to move against spring pressure and shift to 3rd. The TCM doesn't call for 3rd gear until the moment it shifts. In other words, it's not the solenoid or shift valve hanging up, it's the TCM calling for a delayed shift. I even dropped the pan a few days ago and swapped solenoids #1 and 2. I checked their resistance and they were 12.7 and 13.4 ohms. It shifted the same after I swapped their places.
The only thing I can think of is that the TCM has some sort of bias resistor that has drifted over the years and THOUSANDS of miles of use. I've seen resistors (or other electronic/electrical components) change values due to age before, and I'm thinking this is what's happened. Should I take the gamble on a junkyard TCM? Is there ANYTHING that I've missed that I should look at?
:dunno: