[Steamguy]

Guys,

I haven't seen this problem mentioned before, so am creating this post. My truck's at 100,000 miles and most of its on-road work is towing, so both my mechanic and I felt it's time to do a fluid and filter exchange on the transmission. I used to turn a wrench, but I have advanced arthritis, so working on my own stuff anymore is no longer an option. Fortunately I found an excellent mechanic who's even more fussy than I am about how things should be done.

Before the exchange, the transmission was behaving normally. Now however, after driving half a mile, I lose the ability to shift manually. This means that when towing, I can't toggle down to 3 and hold it for the hill. So the transmission will 'hunt'. then shift down to second, then as the fluid cools, shift up normally and try to lock the torque converter in a higher gear. Which leads to it 'hunting' again, and then the shift to second again. I only discovered this halfway to our last camping destination, when I went to manually shift down... and no reaction. The grade logic seems to be working normally. Proper downshifts going downhill when on the brake, and so on. Proper and solid upshifts, properly matched to load.

Other clues: I have a very, very, early '04, and one of the "easter eggs" in the system is that the ring that indicates your gear when in Manual Mode will disappear when the transmission is beginning to overheat; at that point, you lose Manual Mode. However, it otherwise shifts normally. After I got home, the next day I drove the truck and when I left home, I shifted into 2 manually and took off down my gravel road. Normally, it would just stay put there, even on the roads into town. I got a half mile, and the indicator went out, and the transmission shifted as normal, as if it wasn't in Manual Mode.

Weird, huh? Anyone have any experience with this? Or maybe we have a transmission tech on here that's seen this before.

 

[Steamguy]

Update:

Left the truck with my mechanic for a few days, to let him puzzle through it. He checked wiring and connections, all the possibilities he and I could think of. All are good.

It's still doing it.

 

[dubyam]

Locking out manual shifting is, generally with Titans, a symptom of overheating. I'm not sure if your early truck (complete with Easter Eggs) does this or not, but later models do. I'd start by putting a gauge on the output side (in line with the fluid lines is likely the easiest and best spot) and check the trans temp. Beyond that, it's possible your valve body was damaged or some such, during the fluid change, but your trusted mechanic would have to be pretty ham-fisted to damage it. Also, I don't think the filter is a change-out item, so if he tried to get it out, that may be the root of your problem.

Unfortunately, I suspect you're in for a trans rebuild. But it would help to know temps and what he did in there before shelling out for one.

 

[Arachnid]

Do you know if he flushed it, or did a drain and fill?

 

[Steamguy]

Do you know if he flushed it, or did a drain and fill?

He did a drain and fill, using the 'pass-through' method others here have used with good success. Open one of the cooler lines, and add clean to the filler tube at the same rate as the old drains. And he did use Matic-J.

Yup, transmission rebuild may be in order. But on a truck that's only worth maybe $5,000 on a trade-in, it's really, REALLY tough to justify $2500 worth of work.

At this point, I'm swinging into looking at a new-to-me truck, for next year. I was going to delay for a couple years longer, but I'm moving that schedule up. This has been a good truck, but it has roughly 70,000 miles of towing work on it.

At nearly 14 years old, it's showing its age:

• Clear-coat peeled on a patch of the roof (doesn't bother me, really)
• Worn out driver's seat (still feels okay so this doesn't really bother me)
• Intermittently working rear passenger window(s)
• Cam chain follower rattle on startup
• Mushy brakes (this is my biggest annoyance about the truck - nothing will fix it; and now it needs brakes again.) You have to hit the [email protected] brakes twice anytime you want to stop, and them working this way when towing gives me nightmares. Serious nightmares; wake-up-in-a-cold-sweat type.
• And the biggest 'tell' for this old Apprentice Mechanic: the oil pressure drops at hot idle.

Yup, time to let someone else deal with it. I have probably the oldest truck on the board, and probably the longest ownership. But it looks like time has come to trade it.

I had a succession of 'beaters' when I drove 100+ miles a day commuting; I'd get home and get to wrenching on the the car/truck, so it'd be ready to go to work the next morning. Last on that list was a Jeepster Toledo that tried to kill me on a daily basis, and when I was done with it, my hair was much more gray, and I swore off beaters forever. 30 years later, I'm still sticking to that promise.

If something else develops with the truck to resolve this, I'll let you guys know.
But my old trusty, dusty, blue friend, you've broken my heart too many times...

 

[Bobby Hamrick]

I was troubled trying to decide to change or not to change tranny fluid. Just bought the Titan with 193k. Talked to many people and decided it’s A fat No. many situations like you are in now developed by fluid change. I’d expect high detergent fluid has broke down seals by dislodged debris. This is one case the old, “if it ain’t broke don’t fix it” adage stands tall.
I have a long list so it’s fine with me.
All shocks
Rear dope and clean vent plus modify it to be better
Oil n filter
Bleed off all old brake fluids and replace with new.
Spark plugs and air filter
Brake pads and turn rotors while I’m there
Serpentine belt

Anything y’all may have learned from above work please feel free to share.

 

[LUBECAKES]

The only time you avoid a fluid change is when the fluid has gone black. That's because black fluid is full of spent clutch material and other debris, which in some cases can be the difference between the clutches working properly or slipping.

 

[cajun56]

I haven't been on this forum long and this 2005 Titan I bought from original owner with 174,900 miles. Trans oil was never changed and he was towing air-boats from south LA, to Michigan! The oil was brown looking in trans, so I did the oil swap as per on these forums and had no problems with my transmission at all. I still use truck to pull two different trailers and now at 183,600 miles with truck. Next up is a trans-go shift kit for it.
My brother is a mechanic by trade, so he has a friend with a transmission shop who will rebuild my trans, when it needs it.

 

[Steamguy]

The only time you avoid a fluid change is when the fluid has gone black. That's because black fluid is full of spent clutch material and other debris, which in some cases can be the difference between the clutches working properly or slipping.

I remember seeing a sample of what came out of it. It wasn't black, but it was well on its way. The screen was changed because it had a (very light) coating of crud from the fluid breaking down. This truck has always been reliable, still is - if you don't need to shift manually. It's been parked since I last drove it to tow my trailer, and it'll stay that way for a while yet. Winter's coming, and I'll take it to work once or twice just to exercise it before I have the snows put on.

I agree with the opinions above, likely some junk got caught in the valve body, but in taking a hard look at the numbers, it's just not worth putting $2500 into a $4000 truck. I'll let the grade logic deal with the gear selection, and I'll baby it for a couple years more. I'll do the brakes in a month or so, mostly because I couldn't have it on my conscience to sell a vehicle with known safety problems.

Part of the back story here is that my permanent job of 17 years ended back in January. If they'd just kept going for another year and a half, I could have retired. I've been back at my old contracting business which has provided intermittent income, but no insurance. I've had a steady gig since July (thank God) and these folks are making positive noises about making me permanent. Which would come with health insurance! Hooray!