1996 T444e 175hp partnered with AT545 on a 3600 Thomas vista chassis. 308k miles on everything.
Coming around a slow, flat curve, pulling a trailer on the interstate a clatter started from the engine/transmission area. I pulled over immediately to look things over and this is what I THINK I have ruled out so far:
Turbo- Removed the hoses and it is dry inside and doesn't have any play.
Removed the serpentine belt and found nothing loose. The fan clutch feels strong, all pulleys feel tight. The clatter remains with motor running and belt removed.
Injectors seem okay-Using a laser thermometer, all the cylinders seem to be registering the same temps while the motor is at idle.
I purchased a Scangauge D and ran through a diagnostics test and no codes are displayed.
So I find a youtube video that has a sound a lot like my problem and the video claims the flex plate is broken as the problem therefore I make the decision to separate the transmission from the motor and inspect the flex plate.
Here is that video:
After removing the part and inspecting it, I learn that my skoolie does NOT have a flex plate but something far more robust. More of a flywheel. It must weigh in the neighborhood of 35lbs and is in very good condition.
I am now reinstalling the flywheel and ancillary parts associates with it and will start the motor without the transmission attaches to see if I learn anything meaningful but basically I'm stumped at this point.
No unusual smoke coming from the exhaust to report.
I appreciate any suggestions as to what should be ruled out next. I've been here 11 days now and everybody is being super cool but it's time to move on.
A shop rescue is cost prohibitive.
Also, I want to get this out to anyone reading this:
I have been all over the bus's undercarriage for more than a week now and seen everything from all angles and I'd like to pass on that I found 5 significant bare wire wear spots so far that I will be cleaning and coating with JB weld then covering with fresh loom. some are heavy gauge wires going to the starter and some are sensor wiring going into the transmission. I would expect all older bus's may display the same wear issues and would benefit from an inspection.