TC not fully unlocking on 1998.5

[VMac822]

So, after 278,800 miles, my  virgin 100% stock automatic has had its first hiccup.  A couple days ago when I came to a stop it kept wanting to lurch forward, dragging the engine down. It doesn't kill it but it is lugging.  I did some Googling but am not finding anything with the exact symptoms I'm having. I think it's the TC solenoid so I ordered one and will try replacing it.

 

During normal driving the trans essentially operates normally, when the TC locks at its usual time the engine RPM drops, and it unlocks and relocks as I let off and back on the throttle.  Basically, everything works normally but it acts like the torque converter suddenly went from 80-whatever percent efficiency to like 95%.  It's great to drive and has nice snappy solid shifts when accelerating from a stop. But, I'm sure that's hard on the torque converter.  So I parked the truck to avoid possible damage.

 

In my investigation, if I unplug the multi pin cable from the trans and start it, the problem clears.  Once I reconnect it and begin driving the it's fine until it locks again, then it is stuck like that until I repeat the cable unplugging process.

 

I drained some of the trans fluid to look at it, it's nice and clear.

 

I need to do some digging but I need to look at doing a proper trans rebuild/upgrade.  I want to have mine rebuilt versus swapping in a built trans and using mine as a core.  It's survived towing many tens of thousands of miles and handled some power upgrades for 120K miles (100-150hp over stock).

 

Does anyone know a good trans builder in Eastern WA or NE Oregon?

 

Vaughn

[IBMobile]

8 minutes ago, VMac822 said:

Does anyone know a good trans builder in Eastern WA or NE Oregon?

Yes, Call @Dynamic.   He rebuilt  @Mopar1973Man and my transmissions.   8311 N. Glenarvon Lane Newman Lake, WA 99025 - (503) 880-5451  He is listed in the vender section. 

[Mopar1973Man]

Yup good man for the job. @Dynamic did all the upgrades and beefed it up good.

[VMac822]

Great, thanks guys, will get in touch!

[jlwelding]

On 6/1/2022 at 2:49 PM, VMac822 said:

I want to have mine rebuilt versus swapping in a built trans and using mine as a core.  It's survived towing many tens of thousands of miles and handled some power upgrades for 120K miles (100-150hp over stock).

I will never give up my trans, motor, or rearend ever again. My old truck was a 5 speed, it was jumping out of 5th gear just every now and then. I made the dumb mistake and took it to a so called big shop and exchanged it. Me being dumb I didnt know I could have fixed it myself. Anyway 4 transmission later and two under warrenty(I just sold it) and I just heard the last trans is now jumping out of 3rd. That trans only had 10k on it but was 3 months out of warrenty. Never again.

[Mopar1973Man]

Jumping out of gear is because of bad bearings on the main shaft. As torque is applied to the shaft it moves and kicks the stick out of gear. Basically most likely using too thin of fluid and allowing it to overheat. Max trans temp should be no higher than 220°F. Yes you should install a trans temp gauge but do not install fast coolers because it moves the temp sensor too far from the gears and will show cooler. But the fluid around the gears is still hot.Temp sensor must be as close as possible to the gear teeth for proper temp measurement. Mine I bung close as possible to the PTO gear.

 

I've seen my last trans over 240°F towing my RV to Pittsburg Landing near Oregon. I was only running 15 MPH on dirt road running 7% grade. Even my heat shield in place. Even running downhill didn't cool because of reverse torque running down hill. This is why trans temp is required and why fast cooler should not be used.

[VMac822]

So I spent most of the day working on the truck, having all kinds of fun bathing in ATF and fighting with the shifter and kickdown levers, the rod thingy inside with the C clip, wiring connectors and so forth.  Installed the new TC lock solenoid and nada. . .did not solve the problem. Didn't help (or hurt) one bit.

 

Any speculation what is going on? Electrical issue? What is happening mechanically? I don't believe it is the TC is locking, I have been driving it like this for a few days and there was no burnt smell or any metal on the pan magnet to speak of.  

 

I looked over the wiring at the APPS and reseated it, and checked grounds.  Should I remove the Trans relay and see how it acts?

 

As I mentioned, the TC lock/unlock is working normally per programming, the truck acts like the torque converter is running at 95% plus efficiency.  Anyone know if it will hurt it to keep driving it?

 

I need to get this figured out soon, because I have a camp trip planned for the coast in a couple weeks.  If I need to rebuild the trans I need to make sure it's not an electrical problem outside of the trans, I would hate to rebuild it in a rush only to have the same issue when I put the trans back in.

 

Once my trip is over I can have some down time and get it rebuilt.

[Great work!]

Monitor the orange black wire in the middle PCM connector by back probing or a piercing probe connect  a volt meter, other lead to ground using alligator clip or similar. Need long leads or tape meter to window. Should be 12v or more when converter unlocked and close to 0v when locked. Test drive and watch for bouncing readings. Other electrical is pinched melted or cracked insulation in the wiring inside the tranny or outside. Are you sure it's not jumping in out of limp mode that justs leaves in 3rd gear all the time . A test light works too. On the mechanical side was there any screens in the TC solenoid or valve body they need cleaned. Other problems is sticky or worn out spool valves in the VB (common) or severe restriction in the cooling lines or coolers , blow it all out. And finally a torque converter that is failing inside (falling apart).

[IBMobile]

When my torque convertor failed it would not lockup and the trans temp would be very hot going up hills pulling my trailer.

 

 

[Hutch24v]

I also recommend Dynamic. He just did rebuilt mine and couldn't be happier. 

[Silverwolf2691]

W-T mod is something to look into as well. AC noise is murder on 2nd gen electronics.