tuners; transmission control inputs

That sounds so much like what mine started to do. Then it progressively got worse and I needed a new TC.

Everyone pointed to it being an electronic issue since the PCM was commanding it to unlock. But in the end the TC was on its way out. I think there is some weird deal that tells it to unlock and relock, or some kind of fail/safe deal.

No codes, no blinking lights, and the only way I finally got BTS to send me a new TC was when I watched AE and looked specifically when it was 100% locked and there was slippage rpms.

There was also oil in the main harness plug on the passenger side of the tranny that went to the valvebody's. That made me think that oil was leaking through the trans and into the plug, then the excess oil in the plug was making the TC unlock and lock. I changed those out as well when I changed the TC. I don't think that was the issue but it is something for you to look at as well.

It did take months of it unlocking and relocking for it to finally start showing the increased tranny temps. It would sometimes only do it once and then not do it again. Only when you are accelerating and usually when the tranny got warmed up a little bit.

Also, I was running Swamps tuning...

^^ Yeah, your experience has been making me question the mechanical side of this issue. According to Mark K, the PCM will command an unlock if it detects excessive slip--then speeds are then out of parameter and it wants to lock back up. I can almost command it to happen at 56-60mph in top gear by feeding it a little throttle. At that speed is when it would almost be in a lugging condition as well. Its been doing it for about 3 months now.

On another note, the solenoid block plug you ref'd had oil on it but I don't think there's anything wrong with it (resistance of all solenoids are in spec).

I understand you may have AE? If so, we need to make a few laps in this old turd...lol

Mandkole! Yall waaaaaayyy over my head. Are you running a 5 speed auto in your 2000 7.3?

No, just the 4 speed auto (4R100)

Ok!

Mine was right around 55-60 mph too lol.

A friend of mine has AE right now. Lol. You should give Derek or curtis a call and have them run your truck!

Mandkole, I have AE software that I won't be using for the next few weeks due to work travel.
Depending on where 'Northwest' is I can meet you along the I-5 corridor, or mail the CD and dongle to you for the time being.
Shoot me a PM if you are interested.

UpstateDieselGuy said:

I'm thinking you could clean house doing some freelance tuning for some of the tuners out there! lol I would presume that you cannot do so legally though.

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Nobody told me I couldn't. I don't see any legal issue. I see a few other issues, tough.

I don't have time, I don't have the desire, I don't have the equipment, and I don't have a truck.

Layson said:

Everyone pointed to it being an electronic issue since the PCM was commanding it to unlock. But in the end the TC was on its way out. I think there is some weird deal that tells it to unlock and relock, or some kind of fail/safe deal.

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I don't remember the failure mode software really well because that was someone else's responsibility, but as I remember it the software looks at slip very often. The loop time is 0.008 seconds, so it can look 125 times per second. I think it was on the 1 second loop, but I don't remember. Even at once per second it can detect that the converter isn't locking when it should and unlock it. It will then try to lock again. After a couple tries it gives up and should set a code.

Layson said:

No codes, no blinking lights, and the only way I finally got BTS to send me a new TC was when I watched AE and looked specifically when it was 100% locked and there was slippage rpms.

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Usually that is a converter problem.

Understandable. Enjoying life after a career is important.

I'm still working full time, just not in engineering.

Dirtclod said:

I have the same size tired on my 01. I have a new tranny with HD upgrade. My mechanic who installed it said its the same build that goes in th motor home. I know I need some tuning and as soon as I get my truck out of the shop from a crash and finish my fuel system and injector orings I'm going to dp tuner to get their 16 pos. ok Mark my question for youo you recommend dropping gear to 410? Or fix with tuning? My front left wheel hub assembly is messed up and I ain't spending a dime on that 50. I'll just get a d60 from a guy that's pm'd me. Before I do that I'll need to know what gear. Any advice is greatly appreciated!

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just a fyi, from the ball joints and u-joint out to the tip of the lockout, including all brake components, a d50 is the same as a d60 axle..

















i very much agree with the fellers below.. mark is an awesome asset to the forum!

V-Ref said:

Mark

Your a great resource to have on these forums. Your posts are always informative and enlightening. Thanks for your contribution here.


Sent from my iPad using Tapatalk

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TyCorr said:

Agreed Tim! I always read when I see his name in the reply.

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Dmstrucks02 said:

Yep, always good information to soak up

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live life full throttle

Layson said:

Mine was right around 55-60 mph too lol.

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I've run the AE and monitored slip RPM-- its slipping. Cruise is 50-75 slip rpm and more aggressive running is 300-400rpm. It should kill the motor by grounding it on in gear with brake on and it just drops a couple hundred rpm.

The trans needs to come out, TC replaced, maybe a new pump and everything looked over. Adding up all the little things its done, everything is making more sense now. Good news is that its not dead yet, but I need to baby it so I can make a plan to get it out soon.

Sucks to hear that. Good but bad kind of thing....


It is just odd that our BTS trannies are about the same age and from the same batch years ago. Ended up doing very similar things when they went out...

^^ yeah, Im glad Ive had the opportunity to study it closely because a TC would probably not fix it by itself. The slow TC failure is likely more due to the pump leak. In talking with my trans guy, he said that pumps can be an issue with 4R100s. Unless it was modified, the pump is likely not a BTS issue, but rather a component issue.

When the trans eventually goes in, we will be looking at it closely to see the source of a BTSs awesomeness...

For now, need to get some thoughts on a converter.

I would get a John Wood from Vision Diesel. Then get one of his billet input shafts too. The one in our truck is stock.....