Driving to work the other day and the CEL came on. Turned out to be P1740 which means the computer didn't see the expected drop in rpm when the TC locked up. I was in third gear under light throttle and everything felt normal at the time. I was unloaded as well.

I just turned over 69,000 miles. I've never had a hint of trouble from this tranny except for the 2-3 shuttle, so I cleared the code and it hasn't come back. That was 2 1/2 days ago with two days of normal daily driving since then.

I'm not the original owner. Tranny mods I can see are a Mag-Hytec double deep pan and a blue torque converter of unknown brand or specs. The fluid is about 10,000 miles old and looks and smells new.

This puts me in a real pickle. I'm leaving in a week to drive 3400 miles (moving from Alaska to Utah) and will weigh just over 21,000 pounds. We've shipped our other vehicle and are living in our travel trailer at the moment. I can't really afford (time wise) to put the truck in the shop or to be without it at this point. I'm in the military and can't delay the trip either.

I've read many threads about this. Most of them say this the beginning of the end for the tranny. It looks like there are so many things that could cause this that I can't begin to guess which parts to throw at it on my own. I do have the upgraded governor pressure solenoid waiting to be installed at the next pan drop, but I don't think it is related and likely wouldn't solve the problem.

I'm inclined to risk it. First and only time code appeared, hasn't come back, and drives normal. What would you guys recommend?

Thanks,
Stew


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I threw this same code over a year ago with roughly the same mileage on the truck as yours. Like yours, my transmission never shifted better. Since then, I have been watching it (listening for lockup, etc.) and can detect nothing unusual. I have a cheap OBD reader tool that I got off Amazon. For some reason, it won't clear a 1740, but it's completely dormant (i.e. no CEL). Being in Calif, I was afraid it might prevent my smog test from passing, but it didn't. One theory with mine is that I threw this code when my batteries started failing. I was told that failing batteries can throw all kinds of codes. I have since replaced the batteries and I haven't done a thing about transmission. It continues to shift just fine and the CEL has never gone on again.

I read all those doom and gloom posts about this code but just about every one of them also had symptoms at the time the code was thrown. If it were me, I would get it checked out before a trip like that. But, I have a feeling (from your description) that it may have been one of those flukes.

Good luck with your trip and thank you for your service.

 

Thanks. Nice to read something besides doom and gloom. The local tranny guy said he wouldn't worry about it as long as it was an isolated incident. I'm going to press on.

Stew


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