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Posted
Posted

Okay, I am hoping this is something silly because I don't get a check engine light, but I don't want to wait until I have to rebuild my transmission to fix the problem if there is one.

 

I bought my truck used almost a year and a half ago. I forget how many miles it had on it, it was a little over 80,000. It now has a bit over 90,000 on it. I use it for towing a car trailer (7,000 GVW), plowing my parent's and my own driveway, and as a pickup truck (you know, to carry sheetrock, etc. in the bed). It really doesn't see much use otherwise. Much of the loaded driving it sees is highway.

 

It seems to me that the transmission sometimes slips on the highway when the torque converter clutch is locked up. There is a difference in RPM between very light throttle, cruising throttle, and unlocked converter at a given speed. From what I understand the computer keeps an eye on this and should pop a code if the trans is slipping, so without an SES light I should be okay.

Near the end of the winter I drove from NY to DC to drop off some parts and I noticed that the transmission temperature got up to 200 degrees. Even on the ride back up, with the bed practitally empty I was running that high. It seemed wrong to me, but again, I didn't get a light.

 

I then had the transmission flushed, and while the fluid didn't seem bad when I checked the level it was kind of dark when the system was flushed. Didn't smell bad but looked ugly.

 

I still notice the "slippage" and the transmission temp will go higher than I think it should. (When I got the truck it would occasionally do the same thing, but I just hadn't paid enough attention to think it was a problem.)

 

Now, when I started it the other day and put it into gear it didn't want to move right away. It was acting like the fluid level was low, which was not the case. Once I got the truck to move it was okay and hasn't done that again, but it's another thing that is getting me worried.

 

One last thing: it feels to me like when I take off from a stop that maybe there is a little bit of slippage, like maybe the line pressure is too low. I don't know.

 

So, what should I look at?

Does it sound like I should have the SES light?

Should I just leave it alone?

Should I try installing one of those shift kit/line pressure increasing kits?

 

TIA

snoman Senior Enthusiast

snoman

Posted
Posted

Kinda sounds like trannyis getting a bit tired. 200 degeres is not cause for concern but if it is slipping some, the fluid will be hotter. From your description is sounds like it has had a hard life and you do not know what it say before you. A shift kits will not realy help it now. You might do a line pressure check and see what it says but you may be needing to spend for coin of it. If it has 3.73 gear and some bigger tires that ncrease the heat and strain on tranny and even stock tires with 3.73's is working that tranny when towing. Not trying to sell gloom and doom here but it is not encouraging at this point.

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Posted
  • Author
Posted
Kinda sounds like trannyis getting a bit tired. 200 degeres is not cause for concern but if it is slipping some, the fluid will be hotter. From your description is sounds like it has had a hard life and you do not know what it say before you. A shift kits will not realy help it now. You might do a line pressure check and see what it says but you may be needing to spend for coin of it. If it has 3.73 gear and some bigger tires that ncrease the heat and strain on tranny and even stock tires with 3.73's is working that tranny when towing. Not trying to sell gloom and doom here but it is not encouraging at this point.

 

 

 

Thanks for the reply.

The tires are stock size, and the gears are 4.10. (Stock)

 

The strange thing is that it doesn't seem to be worse when towing.

It seems to slip even when unladen and on level ground.

 

I guess the big question is going to be how bad should I let it get before I have it rebuilt?

snoman Senior Enthusiast

snoman

Posted
Posted
Kinda sounds like trannyis getting a bit tired. 200 degeres is not cause for concern but if it is slipping some, the fluid will be hotter. From your description is sounds like it has had a hard life and you do not know what it say before you. A shift kits will not realy help it now. You might do a line pressure check and see what it says but you may be needing to spend for coin of it. If it has 3.73 gear and some bigger tires that ncrease the heat and strain on tranny and even stock tires with 3.73's is working that tranny when towing. Not trying to sell gloom and doom here but it is not encouraging at this point.

 

 

 

Thanks for the reply.

The tires are stock size, and the gears are 4.10. (Stock)

 

The strange thing is that it doesn't seem to be worse when towing.

It seems to slip even when unladen and on level ground.

 

I guess the big question is going to be how bad should I let it get before I have it rebuilt?

 

 

 

 

 

You seem to me aware of its function so also long as you monitor it and the temps you can press on for a while. When temps start climbing noticable and it slios a lot worse it is time to looking repairing it. Do not pull it had in drive towing (max effort) and down shift on hard pulls.

battmain New Member

battmain

Posted
Posted

You could just use tow/haul mode all the time. Mine was fine until the dealer replaced the torque converter. When it came back it felt really soft in comparison to when it when in and before it failed. Been using tow/haul most of the time now. That mode will also reduce the tranny temp in heavy traffic. 200 degrees is nothing in traffic. I generally run 160-200 depending on daytime temps. I have a scan tool and in regular mode, it does show a tiny amount of slip.

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