runs but wont go

Bill 340 · February 02, 2012, 06:50:24 PM

OK here is a weird one, series 60, 746 Allison provost 1994, starts and runs fine, put in gear step on throttle it comes to a complete stop, still running, just wont move, will Idle along about 1/5 mph. reverse the same, was running fine earlier today, then decided at every stop light it would bog WAY down and finally pick up and run fine, for about 30 miles, THEN decided it will not play anymore, and now , every time you step on the pedal forward or backward it stops SUDDENLY. put in neutral and rev it up fine, put it in any gear and it wont rev past 10,000 or move in either direction.let it idle in gear and it seems fine, Now this afternoon backing up to the shop when in reverse the rear drive axle locked and jumped a little, Now lets hear the Ideas, the shop does not have one Yet, all help here is appreciated, and will update you all when the problem is found.

robertglines1 · February 02, 2012, 07:10:11 PM

ck oil color in transmission. choclate=water cooler for trans leaking=broke trans. Not sure if your is one that has liquid cooled trans or not. Black or burned smell=burned clutches in trans. Bk had problem a few years ago with one. First thought was fuel but farther I read sound like trans especially jerk. Sucks. Bob

luvrbus · February 02, 2012, 07:20:44 PM

Does it have a retarder ? could also be a broken axle or bolts sheared on the ring gear cage

robertglines1 · February 02, 2012, 07:24:35 PM

Clifford beat me to it. Do you feel bus torque when you apply power. Guess you could pull drive shaft and eliminate rear end. or prove it to be problem.

Ed Hackenbruch · February 02, 2012, 07:33:24 PM

Electronics? sensors?

Cycletek · February 02, 2012, 07:42:10 PM

What is your air pressure?

robertglines1 · February 02, 2012, 07:46:20 PM

Actually his onboard computer should give him fault codes from his DDEC IV.I believe that should be his system Maybe DDEC III. Both should have. Hope it is something simple. Also My 98 has a Jake disable switch.I would assume his does also on ddec 3 0r 4. Just general info. Good luck. Bob

Bill 340 · February 02, 2012, 07:54:40 PM

did not check codes yet, air pressure normal, feels just like you are parked against a wall, wants to move but cant, No tel tale lights nos pro driver notes either, twice there was a loud clunk when backing up. but it drove fine for 200 miles aftyer that, drive avle seems to graband lock when reversing?

Cycletek · February 02, 2012, 08:05:13 PM

Sounds like it lost a tooth off the ring gear and it grabs it every so often or a carrier bearing coming apart spragging and tying up the rotation of the carrier. Very interested in what you find out!

robertglines1 · February 02, 2012, 08:06:37 PM

Guess you pretty well figured it out your self. just has to be differential prob. Ck by pullin drain plug and see what falls out. Off wall ideal brakes seized?? loose shoe in drum? look thru inspection holes from rear. Bob

Bill 340 · February 02, 2012, 08:14:46 PM

will let you all know when its discovered, till then all suggestions are appreciated. till the problem is found all ideas are welcome, thanks Bill

robertglines1 · February 03, 2012, 04:11:01 AM

Simple non $ ck lift tags and try. If it works ask me will explain. problem about that time frame. Discovered in research on my current build. I know doesn't make much sense but doesn't cost anything either. Bob

Ed Hackenbruch · February 03, 2012, 06:31:55 AM

Low on tranny fluid?

TomC · February 03, 2012, 08:31:20 AM

Sounds like a rear end problem-maybe a blown thrust bearing. Those big rear ends are expensive-suggest you not drive it anymore until you pull the pumpkin out and inspect it (also VERY heavy).

On another gear front-we have a fairly new truck in with a Series 60 that stripped the smaller gear on the bull gear (engine gear train for the overhead camshaft). Luckily the driver stopped immediately and nothing additional was ruined. As compared to another driver that with his Mercedes-Benz 4000 engine, dropped a valve and continued driving the 5 miles back to the yard. Ultimately was a $15,000.00 engine mistake. Good Luck, TomC

Bill 340 · February 05, 2012, 12:40:52 PM

Well its still at the shop. they didn't have a chance to look at it till Monday,, they did have to move it, AND it started like always, put it in gear, it went forward like it should, put it in reverse and it backed in the shop as it should. Now seem since it cooled down it wants to drive normal, even when it was acting up. if you got it moving it shifted Thur all the gears fine, just if you stopped it would lock up on every take off, the engine temp was 198 the trans temp was 200, Any more thoughts, I am sure the shop could use a few hints as its their first of this kind, thanks Bill