Sudden onset trans issues?

[thezentree]

I'm on a camping/four wheeling trip with some friends and drove 7 hours on hilly interstate to get here yesterday. As of yesterday afternoon, which has been the hottest day this year so far, on the road my transmission has been acting up. It's started stuttering in OD with moderate load around 1500-2000 rpm. I think it's the torque converter trying to decide if it wants to unlock. Turning OD off stops the stuttering.

Trans temp is also a lot hotter that it usually is (scangauge). I don't think I've ever seen it get above 175 before and as of yesterday it's consistently 190-200, even on flat ground and not pushing it. 4lo/1st gear it's hovering around 175 but even driving gravel FS roads at 25mph the temp is spiking back to 190-195.

The fluid is still red and doesn't smell burnt but this is not inspiring confidence. The way this is all of a sudden starting makes me think that the trans isn't quite dead and that there may be another issue causing this.

Any ideas? Or do I just need to get home before I melt the clutch packs and just have it rebuilt?

 

[VernySanders]

I just had the same issues but even worse. I dont know what my temps were because I dont have that fancy gadgetry but my trans felt like it was slipping and shuddering the entire truck would shake. Ended up being a clogged trans filter. I dropped the pan changed the filter put topped off with new fluid and a Lucas oil transmission fix and shes been running like a top. I had a lack of pressure / lack of fluids flowing through the trans causing the slip. You could also slightly hear my trans pump on idle.

 

[Mark_BC]

If its overheating then that means you arent moving fluid through the radiator or cooler, whichever setup you have. So there is either a problem with the radiator or the transmission preventing it from going. As verny says maybe a clogged filter? I wouldnt know, never dropped the pan before.

 

[alumarine]

190 to 200 is not overheating.
Have you checked the level?

 

[mtbtim]

190-200 degrees on flat ground and not towing is high. Normally you would only see those kind of temps if you're climbing a grade. If you're also monitoring your coolant temp, what temps are your running?

Start with the obvious and check your fluid level and make sure that's good. Since it's pretty common that people don't know the correct way to check their automatic transmission fluid level, I'm going to cover that and I don't mean any disrespect. Are you checking the fluid on level ground, engine running and the shifter in Park? At a normal operating temp of 158-176 (according to the FSM) your level should be in the hot range. If you're checking it cold, then you should expect the level in the cold range on the dipstick. I prefer to confirm the correct level when the trans is hot because this seems to be a more accurate reading.

If you're fluid level is good, and you're still experiencing the symptoms you're describing, I would suggest you stop driving it. Tow it to the nearest town and rent a U-haul and trailer and get it home where you can inspect things further. Your trans might be toast already, but if it isn't, continuing to drive it will put the last nail in the coffin and then you'll be stuck on the road or the trail and looking at an expensive and labor intensive replacement.

 

[thezentree]

Made it home, but that torque converter is trashed. It was hard to tell what was going on with it when I was aired down and on corrugated gravel roads, but getting it aired up and on the highway made it quickly apparent that all is good when cruising with the torque converter locked up, but as soon as the trans gets loaded, it starts stuttering until the TC unlocks and as soon as it does, the trans temp spikes.

I made it home (7hr drive ) by manually shifting it and turning OD on/off to keep the TC locked as much as possible. When it was locked the trans temp stayed around 175, even over a 5 mile long mountain pass.

Fluid level is good, the fluid is red and doesn't smell burnt so I am hopeful that the transmission itself isn't trashed but I guess I'll know more when I drain it to pull the torque converter.

On a side note, this was the first real four wheeling trip I did with it and I am SO impressed with how well it did. Such a great trip. I can't wait to get this transmission crap fixed and go back.

 

[thezentree]

Figured I'd update this in case anyone else runs into similar issues.

I'm no longer convinced my transmission or torque converter is dying - I think it was actually a combination of badly needing a tune up (the shuddering) and that trip coincidentally falling on the first really hot weekend since I installed my aftermarket front bumper (the high ATF temps). The bumper blocks a lot of air flow to the radiator (most of them seem to), especially the lower portion - right where the transmission cooler is.

Since the trip I've done spark plugs and wires, installed a new radiator, changed the ATF and filter, and installed an aux ATF cooler. The shuddering stopped as soon as the plugs and wires were done. The new radiator and ATF didn't seem to make much of a difference, but it's peace of mind I guess. The aux trans cooler though seems to be keeping the ATF temps around 160-180 in stop and go traffic, so I'm going to chalk this one up to a combination of minor issues suddenly coming to a head and seeming like one really big one.

So, uh, :bolt:

 

[rightyouareken]

Glad to hear it's working out to not be a problem!