Limping along with Mr. Allison

[johnhicks]

We had the brain-dead Allison ECU replaced at a Freightliner shop in Atlanta.

Things didn't exactly go swimmingly so we decided that we needed to go to an Allison shop and not just a truck shop; I reasoned that since the brain box came from W. W. Williams and we were closer to W. W. Williams in Montgomery that W. W. Williams in Atlanta especially considering the Atlanta traffic we would proceed to W. W. Williams in Montgomery. So I plotted our route there.

It appeared, according to the topo map, that we would encounter many hills, even some that were called mountains, on the direct route and with an ailing gearbox that didn't look like a good way to go.

We toddled down to FDR SP south of LaGrange, Ga., and stayed the night. Actually we had a two-night reservation but getting Mr. Allison in good shape was a whole lot more important than sitting in a campground.

We launched for Montgomery this morning and had a relatively uneventful trip with Mr. Allison only once taking a dump and arrived at W. W. Williams just in time for lunch.

After lunch the tech came out and asked "Where's you port?' I replied, "Don't have one."

The tech said "I'll find it." I said "Good luck, I'll help you look."

After a lot of rummaging around the tech said "They hid it too good. Let's go for a ride." I believe there's no port at all; neither the chassis manual or the engine manual make mention of any sort of port. There is no port.

Mr. Allison huffed and puffed and blew up his back feathers and hunched and hissed and spat and took the tech for a ride and threw codes that don't even exist.

The decision was "Park over by the fence; we'll fix you in the morning."

When I tried to back out to get over by the fence Mr. Allison had decided we didn't deserve reverse gear either. But we made it through the neighboring business' parking lot.

I think this tech's going to fix it. I'll post his accolades when he does.

[mel s]

Originally Posted by johnhicks

We had the brain-dead Allison ECU replaced at a Freightliner shop in Atlanta.

Things didn't exactly go swimmingly so we decided that we needed to go to an Allison shop and not just a truck shop; I reasoned that since the brain box came from W. W. Williams and we were closer to W. W. Williams in Montgomery that W. W. Williams in Atlanta especially considering the Atlanta traffic we would proceed to W. W. Williams in Montgomery. So I plotted our route there.

It appeared, according to the topo map, that we would encounter many hills, even some that were called mountains, on the direct route and with an ailing gearbox that didn't look like a good way to go.

We toddled down to FDR SP south of LaGrange, Ga., and stayed the night. Actually we had a two-night reservation but getting Mr. Allison in good shape was a whole lot more important than sitting in a campground.

We launched for Montgomery this morning and had a relatively uneventful trip with Mr. Allison only once taking a dump and arrived at W. W. Williams just in time for lunch.

After lunch the tech came out and asked "Where's you port?' I replied, "Don't have one."

The tech said "I'll find it." I said "Good luck, I'll help you look."

After a lot of rummaging around the tech said "They hid it too good. Let's go for a ride." I believe there's no port at all; neither the chassis manual or the engine manual make mention of any sort of port. There is no port.

Mr. Allison huffed and puffed and blew up his back feathers and hunched and hissed and spat and took the tech for a ride and threw codes that don't even exist.

The decision was "Park over by the fence; we'll fix you in the morning."

When I tried to back out to get over by the fence Mr. Allison had decided we didn't deserve reverse gear either. But we made it through the neighboring business' parking lot.

I think this tech's going to fix it. I'll post his accolades when he does.

johnhicks
Entertaining story!
No port... ... and you you apparently don't have the make, model and year of whatever "Mr Allison" is in either.
Mel
'96 Safari

[johnhicks]

It's a 93 HR Imperial, Oshkosh XC chassis, MD 3060 w/WTEC II controls.

The tech's conclusion after the ride was that the new ECU was defective and he ordered one to be delivered from Birmingham so we're waiting.

[t55watson]

I have not had very good luck with tranny tech's. With no port all they know how to do is throw parts at it, on your dime. Good luck.

[mel s]

Originally Posted by t55watson

I have not had very good luck with tranny tech's. With no port all they know how to do is throw parts at it, on your dime. Good luck.

t55watson
X2!

In June of '02, (at 39,457 miles), I paid Interstate Detroit Diesel, (in Bloomington, MN....an "authorized/certified Allison shop/dealer").... $1,567.19 to have a "Do Not Shift" problem diagnosed and a bad wire from the chassis battery to the Allison VIM replaced!

Although my coach has a diagnostic port, the tech "threw parts at it" for 3 1/2 days before he found and replaced the 15' piece of 14 gauge wire... .
(Fortunately he didn't leave any part IN when it didn't solve the problem).

The original bill was $2,137.43!
When I flatly REFUSED to pay that much for their "certified Allison tech to LEARN how to fix an Allison transmission", they dropped $570.24 off of the bill.... (which, BTW, only made me feel slightly less SCREWED)!

Mel
'96 Safari, M3060 Allison, 134k miles

[johnhicks]

Followup...the tech confirmed that the original ECU, which first starting having problems last winter, was bad, and I coincidentally developed a brand-new problem of a bad turbine sensor. He tapped the wiring bundle and I now have a port. Fixed tomorrow we hope.

[johnhicks]

The latest is that the C1 clutch is "burnt, welded"; our tech, the Allison distributor and an Allison rep are saying the same thing. Apparently C1 isn't used until fifth gear, which is when things were going wild. It's not like second opinions are readily available.
The good news is that we're not going to be charged for anything to this point. The bad news is that we'll need a reman transmission, which is the least expensive option.

[Elictrix]

"Apparently C1 isn't used until fifth gear" ?
C1 is not used in 5th.
See clutch chart for your transmission.

[94-Newmar]

Originally Posted by johnhicks

The latest is that the C1 clutch is "burnt, welded"; our tech, the Allison distributor and an Allison rep are saying the same thing. Apparently C1 isn't used until fifth gear, which is when things were going wild. It's not like second opinions are readily available.
The good news is that we're not going to be charged for anything to this point. The bad news is that we'll need a reman transmission, which is the least expensive option.

Uh..... find another shop. Unless you've got 500,000+ on the ticker I doubt highly you have a clutch problem in any fashion unless you've run it dry pulling 20k lbs up a 10% incline for 20 miles.

Have a new shop drop the pan and inspect the harness bulkhead from the WTEC controller, test the harness from the bulkhead to the solenoids, test the solenoid for that circuit. Keep in mind with the WTEC-II all your solenoids are powered from the shiftpad - that can be 40 foot in length or more.. through aged wiring..

The WTEC-II in these years was HIGHLY sensitive to transient noise from the alternator. The 3 sensors each being a twisted pair of wire run at 40+ feet in length caused a lot of cross-talk as the wiring aged. You will obtain all sorts of errors, from 2011, 2015/2016, 2112, etc etc - generally all sensor errors - which in reality is the transmission harness failing. Speed sensors, turbine sensors and engine rpm sensors rarely, if ever, go bad. I had similar problems and ended up re-manufacturing the entire transmission sensor harness as it's no longer available. All my problems magically disappeared.

Did he have the Allison DOC program on his laptop hooked up while you went for a drive? The DOC program is fabulous for invasive real-time testing.

[anotherone]

Originally Posted by 94-Newmar

Uh..... find another shop. Unless you've got 500,000+ on the ticker I doubt highly you have a clutch problem in any fashion unless you've run it dry pulling 20k lbs up a 10% incline for 20 miles.

Have a new shop drop the pan and inspect the harness bulkhead from the WTEC controller, test the harness from the bulkhead to the solenoids, test the solenoid for that circuit. Keep in mind with the WTEC-II all your solenoids are powered from the shiftpad - that can be 40 foot in length or more.. through aged wiring..

The WTEC-II in these years was HIGHLY sensitive to transient noise from the alternator. The 3 sensors each being a twisted pair of wire run at 40+ feet in length caused a lot of cross-talk as the wiring aged. You will obtain all sorts of errors, from 2011, 2015/2016, 2112, etc etc - generally all sensor errors - which in reality is the transmission harness failing. Speed sensors, turbine sensors and engine rpm sensors rarely, if ever, go bad. I had similar problems and ended up re-manufacturing the entire transmission sensor harness as it's no longer available. All my problems magically disappeared.

Did he have the Allison DOC program on his laptop hooked up while you went for a drive? The DOC program is fabulous for invasive real-time testing.

Dang you really know your stuff. And at 5 in the morn I guess my dog woke you up too. Sure glad guys with your smarts are watching over us . thanks!!!!

[johnhicks]

Well guys, I'm at the Allison distributor's shop and an Allison rep was on the phone with the tech diagnosing the problem. Where "find another shop" would you suggest I go? Joe's Shadetree Mechanics?

There is no port to plug in to. The tech hooked up some wires and got input speed, turbine speed and output speed. Input speed is around 600, turbine speed is around 300 (I'm told it should be around 600) and of course output speed is 1, or nil. As I understand it, the clutch is burned, stuck, dragging, which can make turbine speed go low; the tech saw as low as 100 in neutral idle. He said solenoids have been replaced in the past, which may mean nothing or everything. I can drive forward in neutral and reverse is fighting something that wants to make me stop or go forward. Of course I'n not doing this for any length of time or distance.

I understand what you mean about old wiring but it's not intermittent as may be expected.

I've been here since Monday and they've actually worked on it for several days and not charged since no fix was achieved.

Once again, here's the sequence..

The old original ECU made the keypad blink since last January. After a little while it stopped blinking and worked fine the rest of the day.
Several weeks ago, rather than blinking it flashed a couple of times, shut off, illuminated "do not shift" and wouldn't do anything. It wasn't completely dead and didn't totally inhibit cranking. After idling 15 to 20 minutes it would come up and work normally the rest of the day.
We were about to fly south for the winter and the local diesel shop essentially said "what's an Allison" so I decided to head for the nearest truck shop that claimed to be an Allison dealer which was around 80 miles away. We made it there uneventfully at around 65 mph.
Me, that shop, and the Allison distributor agreed that according to the codes I was seeing it was an ECU problem. I also talked with two guys who rebuild ECUs and they said the ECU was brain-dead.
So we get a new ECU, have it programmed according to the number, and all hell breaks loose. It was fine on a test drive on local roads although shifting rough, but on I-285 around Atlanta it's inhibiting shifting and staying in third, fourth and even fifth, which leads to some exciting moments.
The next shop, where we are now, sticks a new ECU in since that's the only new thing in the system, and it acts the same way. Also, for the first time, it won't do reverse unless it does.
And then we get into turbine speed etc...

[johnhicks]

BTW, all the excitement happens above 60mph. We can tootle around at 55 mph and nothing happens other than hard shifting. Or iow, fifth and sixth.

[94-Newmar]

From the service manual:

NVL Neutral Very Low — The ECU has sensed turbine speed below 350 rpm. This can be caused by a dragging C1 or C3 clutch, a failed turbine speed sensor or more commonly due to crosstalk between solenoid and turbine speed sensor circuits caused by direct wire-to-wire short or by water in the electrical connectors. See Section 4 for corrective action. When attained, the C4 and C5 clutches are applied to lock the transmission output.

Did the tech see any turbine speed being reported at all when the engine was not running?
You would never get to 55mph before it failed.

Any 22xx or 25xx errors stored in the ECU?

From the service manual:

Main code 53 indicates a failed offgoing speed test. The speed test during a shift is designed to ensure neutral is attained during shifts to neutral. This test compares engine speed to turbine speed. If neutral is selected and turbine speed is found to be much lower than engine speed, the ECU sees this as neutral not being attained. The transmission is commanded to Neutral with No Clutches and Code 53 XX is set. Additional codes could be logged for other shifts where “X” indicates the range from and “Y” indicates the range to.

Any 53xx errors? IF the C1 or C3 clutch is dragging the controller has no choice but to set a 53xx code immediately after shifting from N to 1st.

Im certainly not bashing your current repair shop, but honestly if the C1 or C3 was welded and/or just dragging you would have a bounty of errors that would immediately set a beeping alarm, inhibit any further shifting (DNS), immediately stop adapting, set at least 4 different error codes and from N to 1st it would fail immediately falling back to neutral on the display. There are tests the ECU constantly does between the turbine sensor and engine speed sensor for oncoming ratio speeds, range verification ratio tests and of course offgoing ratio tests.

I still say there is an issue in the controller harness in some fashion. Being a twisted pair of wires for each sensor and the 40'+ in length, these things are ridiculously sensitive to even having corrosion on the wire, even missing shielding somewhere from a rodent chewing. If it were me, I would make a new twisted pair to run from the 3 sensors back to the ECU and quick connect them in place of the OEM. Just leave them laying on the floor - no need to run them in the harness yet. This takes less than an hour to do and certainly eliminates the possibility of crosstalk and/or corrosion or rodent damage.

[johnhicks]

The only code stored is 3500; the tech had things apart.

The tech checked with a VOM but I'll suggest the bypass wires. Thanks very much!