Archived Limp Mode?

[Sasquash]

I don't have 1st or 2nd gear. Only reverse, drive and overdrive. No check engine lights. Is this "Limp Mode"? I had to leave my 5th wheel in central Oregon until I get this fixed:{ any ideas? Dan

 

[Jim Fulmer]

Dan you are a smart man leaving the rig behind, I read your sig! If you haven't gotten a hold of Bill try this. I'm going to assume that you have the variable resistor installed at the PCM, if not no big deal. Read the wire from the resistor to the harness, the voltage with the key on should be around 4. 4-4. 5 volts with a multi-meter, if it is high 5. 0 or low 3. 9 it will cause a fail safe start if the voltage is 4. 3-4. 4 there is probably a failed sensor (input or output) and the transmission is telling the PCM there is something wrong so it's trying not to leave you stranded, also I've heard real low fluid level can cause this but I can't conform it.



P. S. Mine did this at 4. 4 volts and I have to install an additional 50 Ohm resistor to get it down to 4. 0-4. 1.



Jim



Oh you should be able to pull it into Manual 2nd

 

[Sasquash]

Thanks Jim,

I checked the voltage, 4. 7vdc. Still no 1st or 2nd gear. I'm heading to Canada tonight and will let Bill K do his magic to it in the morning. Dan

 

[Shooter]

Good chance you fried the 3rd gear clutch pac. The pac is probably welded together. Don't come to a complete stop unless absolutely necessary as the truck is " stuck " in third gear. The reason you still have od is that the power goes through the 3rd clutch pack and then od clutch pack. Take it real easy and no fast starts.



Good luck

 

[Jim Fulmer]

Dan, when you get back post what you found out, was it voltage or a sensor.



Shooter your right, by Dan dropping the 5th and taking it easy he should have been ok, on mine when it did it I could tell that the converter didn't like being pushed in that high of a gear.



Jim

 

[Sasquash]

It's fixed

Well, after a quick trip to our kind northern niebhours, my truck is fixed . Bill said that there was no pressure at the modulator which caused the transmission to stick in third. When the drain plug on the pan was pulled there was about 1/2" of the "fuzzies" on the magnet. . Upon inspection on the bench Bill said that only the third gear pack was really effected, that the back of the transmission looked OK.



Now here's where I was SO impressed with customer service! Bill didn't just fix the damage that was visable. NO, he replaced everything in the transmission including a new torque convertor. That's OUTSTANDING CUSTOMER SERVICE!!! All of this in the second year of warranty.



I also have to thank Darrin, Vinnie and the rest of the staff for their hospitality. Go Canada, 'eh.

Dan

 

[Bob Wagner]

Nothing but the best from Bill and Crew

 

[Jim Fulmer]

That's my buddy! I like the way he looks at it, take care of the customers one at a time. Bill you guys are out doing yourselves



Nice bunch of folks aren't they Dan, good to hear you are back on the road.



Jim

 

[jimk]

Re: It's fixed

[That is great service. If you dont mind why did the third gear clutches go away. The transmission was one year old?

I use to work for Chevrolet a long time ago and some of cheap crap that the service rep would wont to do left a lasting memory with me.

A lot of times the metal will cut the sealing rings. When you get the complete transmission and the cooler and lines are flushed out you are a lot better off in my opion.







QUOTE]Originally posted by Dan Parker

Well, after a quick trip to our kind northern niebhours, my truck is fixed . Bill said that there was no pressure at the modulator which caused the transmission to stick in third. When the drain plug on the pan was pulled there was about 1/2" of the "fuzzies" on the magnet. . Upon inspection on the bench Bill said that only the third gear pack was really effected, that the back of the transmission looked OK.



Now here's where I was SO impressed with customer service! Bill didn't just fix the damage that was visable. NO, he replaced everything in the transmission including a new torque convertor. That's OUTSTANDING CUSTOMER SERVICE!!! All of this in the second year of warranty.



I also have to thank Darrin, Vinnie and the rest of the staff for there hospitality. Go Canada, 'eh.

Dan [/QUOTE]

 

[Jim Fulmer]

Maybe James (inarush76) will chime in here and answer your question. I have ideas but not smart enough to post them

 

[inarush76]

Suspect solenoid caused third gear starts, big truck, direct drive, short life for third clutch. Unfortunately electrical parts can fail at any time with no warning. The fact that the truck drove as far as it did with third gear starts is a testiment to it's toughness. As to the metal rings being cut by the metal, that can happen to any trans that uses metal rings(as do ours before the DTT treatment ) What causes the cut rings is actually metal getting between the ring and the ring land causing it to stick and not spin with the drum causing the ring to wear as it scrubs on the drum's ring bore. This is aggravated by presence of end play allowing fore and aft movement of internal parts. Use of teflon rings, proper bore prep and attention to bushings and endplay greatly reduce this concern. I was a trans tech at Chevy for 8 years and used to (and still do) replaced the steel factory rings in TH350's with teflon. Sealed better, last longer.

Besides the great customer service Bill and crew is famous for, going through the trans complete is a good fundemental move to assure no collateral damage and to clean debris from the failure from the entire unit. Go DTT!Oo.

 

[Sasquash]

Yes, it was caused by the solenoid failing. O'well, you can't predict failure on electrical parts but you can count on DTT service. Dan

 

[jimk]

electrical problems

[Thanks for the reply James, I have seen a few, transmissions that were in pieces or burnt up. I use to work on power shift transmissions on heavy equiment also.

As for the electrical problems that is what plagues my truck from time to time on the transmission. At least for now. I have never been a fan of electral problems.

Jimk













QUOTE]Originally posted by inarush76

Suspect solenoid caused third gear starts, big truck, direct drive, short life for third clutch. Unfortunately electrical parts can fail at any time with no warning. The fact that the truck drove as far as it did with third gear starts is a testiment to it's toughness. As to the metal rings being cut by the metal, that can happen to any trans that uses metal rings(as do ours before the DTT treatment ) What causes the cut rings is actually metal getting between the ring and the ring land causing it to stick and not spin with the drum causing the ring to wear as it scrubs on the drum's ring bore. This is aggravated by presence of end play allowing fore and aft movement of internal parts. Use of teflon rings, proper bore prep and attention to bushings and endplay greatly reduce this concern. I was a trans tech at Chevy for 8 years and used to (and still do) replaced the steel factory rings in TH350's with teflon. Sealed better, last longer.

Besides the great customer service Bill and crew is famous for, going through the trans complete is a good fundemental move to assure no collateral damage and to clean debris from the failure from the entire unit. Go DTT!Oo. [/QUOTE]

 

[icarus33]

Which solenoid causes this scenario. Is it the governer solenoid? I recall that there is a second one, don't have my manual handy as I'm out of town. Just got off the phone with a friend of mine who sounds like he is in limp mode with his truck.

It'll be a week before I get back to check things out on his '96.



Thanks, ic