AutoShift Problems – now general discussion on AutoShift and Clutch Systems

[rv_safetyman]

Well, I wish this was an April Fools post, but sadly it is not.

Perhaps I should blame this all on TomC!.  We have driven over 50K miles and the only problem I have had with the AutoShift has been a loose connector.  In a recent thread, TomC mentioned that there his dealership has had some issue with the AutoShift.  My bus must have read that post and took it as gospel.  The following are some modified excerpts from my blog.

Yesterday as we drove through Pueblo, CO, we noted that the transmission did not down shift as we slowed down.  We made it through town OK in tenth gear and then continued on to this rest stop.  I did quite a bit of trouble shooting and determined that the transmission computer had failed.  I had a backup computer, but it was at home.  I have been carrying the replacement parts with us for the past several trips, but in the rush to get on the road for this trip we left them home.  We were a bit over 100 miles from the house so we decided to unhook the service truck and drive to the house to get the computer.  We left at 12:30 and arrived back about 5:30 after taking a detour to for a stop to get a backup disc from our printer who is going out of business.

The next day we took off and the transmission would not shift.  The transmission has gone into limp mode where it will not shift.  I did quite a bit of diagnostic work with my Pro Link computer reader and called the local Eaton transmission representative, a very helpful person.  We did quite a bit of trouble shooting, and we are both very puzzled as to what is going on, but we have no alternative but to be towed home.  

Being towed home is no fun.  I will start a thread on that subject later.

The problem is solvable, but will take a lot of trouble shooting and exchange of parts.  Fortunately I have access to all of the electronic parts.  Just more work.

Jim

[Eagle Andy]

Well Jim , Iam sorry to hear of your problems , at least you were a little closer this time . Good luck and hope your on the road soon

[luvrbus]

Jim, have you told Sonnie about this yet lol 


good luck

[rv_safetyman]

Hi Clifford.  No, I have not called him to hear the "I told you so".  Still having Internet problems, so I have to fight that dragon first.  Doing this at the library.

Jim

[luvrbus]

Sonnie and both know how you electronic guys get that great fuel mileage LOL but I hope you get it worked out without any big expense man you got more patience than I do when it comes to electronics.

good luck

[Hard Headed Ken]

Jim,
 As you know I'm installing an Eaton Ultrashift with my Series 60 swap. I think the Ultrashift is very similar to the Autoshift except the Ultrashift has a centrifugal clutch. I spoke with a local fleet owner who has about 70 trucks, 16 of which are Ultrashifts. He has had some problems with XY shifter motors going bad, then with a few weeks the trans computer will fail. To me this would indicate lower voltage output from the switching transistors, or just higher amperage draw from the motors because of wear either way the result will be higher amperage draw from the XY motors. The motors are replaced and the switching transistors in the TCM are already weak and fail shortly afterward. I don't have a service manual yet for my transmission, but I don't see any external relays for controlling the XY motors, so that means they are switched by the controller. My previous experience is that when an ECM or maybe TCM in this case switches a reasonable heavy amp load they don't hold up very well. I haven't measured the current draw of the XY motors, but I'll bet it over 10 amps. It takes a serious switching transistor to handle that load. Not to mention the heat generated by the transistor. I'm considering adding external 20 amp relays that will be control by the same output that controls the XY motors. Instead of the TCM switching transistors driving the amp load of the XY motors all they have to do is drive the relay coils. Of course this is all just a guess.

Ken

[Dreamscape]

Jim, Sorry to hear of your problems. Hope you get it fixed and you can continue your trip.

Paul

[scanzel]

I deal with computers every day at my job. PITA ! I think I will stay with my mechanical 6 speed Spicer after all. Just the way I feel, more electronics more problems when something fails.

[belfert]

Jim, sorry to hear you are having more problems.

Computers and electronics have for the most part greatly improved our society, but there are some negatives too.  The postives mostly outweigh the negatives.  20 years ago a lot of us were tied to a desk computer and an office, but now we can work from just about anywhere.  There is the downside of working more hours and always being reachable.

[rv_safetyman]

Thanks for the comments.  I always seem to push the envelope and every once in a while I pay the price.  However, in the past few months I seem to have really been punished by the computer gods

The current issue should not be a killer, but it will take time to work through the trouble shooting process. 

At least now it is home and I can pick away at it as my metal state permits

If any of you folks who favor MUI put a hex on me, will you please remove it

I have made the observation several times, but all of my problems began right after I obtained "classic" plates for the bus.  I think she took offense at that classification!

Jim

[bobofthenorth]

Jim does your towing company have a frequent hooker discount? 

Sorry - couldn't resist.  I feel your pain.  And I agree with Clifford - you have way more patience than I do.

[DaveG]

Hey, I'm just glad your engine still runs good!

[eaglespirit]

Really sorry to hear of your problems, but it makes me feel about the furnace not working & having to pay extra for electricty at Albuquerque.
BTW I really enjoyed your seminar, good info! Left a day early to avoid the next storm & it worked.
Good luck.
Jim

[Gary LaBombard]

Jim,
So sorry to hear of your latest bus problems, man it is starting to scare me at my creeping age just how much I will get to enjoy our bus if I ever do.  I will not install the electronics and engine upgrades you have had the courage and knowledge to do, I just will use our ole Eagle as the way she was born and take my time getting from place A to Place B.  I know you are looking for more performance etc. especially where you live and understand that, and also your knowledge as an engineer or if you aren't one you sure should be one with all you have done & know.  I will keep ours as simple as I can for maintenance and without depending upon a lot of sensors that I admit are great when they work great, but man, I would not have your patience with the problems like you have experienced in the past year, you got to be one heck of a guy.  What I should be saying is you are one heck of a guy.

Good luck with this, sure miss you guys and hope to see you on the East Coast again soon.   Stay safe.

Gary

[James77MCI8]

Didn't you just replace the ECM on the engine. This might be a good place to start trouble shooting. My rig is all mechanical and I am no expert but when troubleshooting I always go back to the last thing replaced andstart there. Good luckeither way and I do admire your tenacity.