I'm faced with something I have never run across before and I sincerely hope there is someone out there that might have a clue as to what I should do. I own a 1988 Dodge Dakota 6 cylinder automatic, today while driving home all of a sudden the truck acted as if it was in neutral and started to coast to a stop. When I tried to use any gear including reverse it would not move. I turn the motor off and waited about thirty seconds started again and it went into gear fine and I started to move forward by the time I reached about 30 km an hour it again stop working and I coasted to a stop, this processed I continued until I managed to get the truck off the highway an to a safe area to park it. I have check the fluid level in the transmission and it is at the right spot, everything sounds fine when it is moving well at least up till the time it starts acting as if it is neutral. I am mechanically inclined and not afraid to tackle anything I understand but in this I'll admit I'm over my head. If anyone has an idea what I'm dealing with please let me know.

 

You didn't state how many miles, last time trans was serviced.

This trans should have a filter and it could be clogged.

 

Trans was serviced 37,000 Km ago is that too long?

 

I would advise taking it to a reputable trans shop. They will have to scan the computer for codes. If it's showing no symptoms right up until the failure, it may be electrical. Definately not a DIY job though.

 

Was the filter changed at that time?

 

Honestly I couldn't tell you I assumed it was but now I'm wondering. As for taking it to a trans shop I'd love to but would rather avoid the $85 tow bill if I can. This way I have nothing against changing the filter if there is a chance to repair it.

 

Chances are changing the fluid and filter at this point will get you nowhere.Also if you change the fluid you will remove evidence of certain tranny parts beginning to fail like bushings or internal pump parts.Some tranny guys like to see what's floating in the fluid and laying in the pan.I know I do.

 

It doesn't seem to be acting like a tranny that's coming apart. Chrysler love to use lots solonoids, at least in the later model stuff. I'm not sure how electronic that one is. Changing fluid and filter in a trans that already has problems usually ends up in disaster. It only gets worse. The $85 tow bill is the least of your worries right now. You could be looking at thousands. Why waste even more.

 

maybe look on your trans service reciept, see if there is a pan gasket and filter posted on it. if not, they used a flush machine hooked into the cooler line which i don't have the most confidence in.

you failed to tell us if it's a 3 speed or 4 speed, i don't even think 4 speeds were invented in 88. does it have an 'OD-OFF' button anywhere on the dash? if it's a 3speed, the only solenoid it has is the lock-up, and will have one wire going to the back of the trans pan area. it might not even have that though. a 4 speed would have two solenoids in it. either trans would have a 3wire neutral start connector.


your description is of a clogged filter. if it was mine, i would drop the pan and replace the filter, add new fluid(idling in neutral) until it's full. you will be able to drive it for a while, maybe forever....no one has a crystal ball.
a person had the same problem with the same type trans in a jeep in here in the last month. he said it (new filter) fixed his problem. hearing nothing back, we would assume it's still working.

as it is, it's already not working, you can't possibly hurt anything by changing the filter.

let us know if you need help.

 

This should be a Chrysler Loadflite A-998 three speed or A-500 four speed overdrive transmission. I would probably recommend at least trying to change the fluid & filter, but it might not do any good.

Other than a clogged filter, here are some possible causes:

1. Low hydraulic pressure
2. Leaking/damaged valve body
3. Hydraulic pump failure
4. Broken planetary gear

These transmissions are notorious for breaking or seizing planetary gear sets due to incorrect oiling. The factory planetary didn't have a chamfered edge and didn't allow adequate lubrication.

Does the trans whine as this problem is occuring?

 

the 999 and the 998 are derivitives of the classic old 904...a 3 speed trans, the only difference being more clutches in the front and rear drums. the A500 is the 4 speed based on this unit.

if the pump or planetary gears failed, there would be no driving under any circumstances.

if i ever saw a failed planetary gear, that didn't have a clogged cooler, it would be my second one. what chamfer exactly are you talking about? the intermediate shaft will seize in it's support before gears fail. (way before)

this particular trans will definitely whine, as the oil filter is clogged and the pump is starving for fluid(cavitating)


the 87's had the 3 speed(i'm kinda sure) and the 90's had the A500(i'm positive), so somewhere between the two the 4 speed started. when the A518's (based off a 727)first came out, they had initial oiling issues. the 500 and the 518 share nothing internally except atf. those problems are long gone now.

 

found this too:
http://forum.doityourself.com/showth...hreadid=156867


when you are shutting off the truck, the stuff stuck on the filter falls off, letting it drive for a while, til more stuff sticks on the filter.

you might have done some damage, driving it with no fluid going to the pump.

spend the $20-30 on a filter and see where it gets you.

 

Sorry about the previous post, some of the infogot cut out somehow, but I corrected it... it should have said the trans would be the A-998 3spd or the A-500 4spd... and yes, you are right the A-998 was the standard trans until 1989 when the A-500 was also introduced into the line, and in '90 the A-998 was replaced. As for the mysterious chamfer, the overdrive planetary and bearing failed due to poor lube to the planetary pinionsand direct clutch thrust plate flexing from spring load. To resolve the problem, you had to file a 45 degree chamfer on the inside edge of the planetary, install a new thrust bearing, and an updated direct clutch thrust plate. The early unit didn't have an index groove, and the updated unit had a machined bevel on the bearing surface. By '90 the factory chamferred all planetaries for the A-500. The only reason I mentioned this was because of a Chrysler bulletin that was issued, and some of these would exhibit the same symptoms as mentioned when the trans was at operating temperature. How they "un-seized" temporarily, I could not tell you.

 

Thanks for your help I changed the fluid and filter and all is well.

 

awesome!


(and none of that stuff above applies to you)

 

question i have a 1988 dodge dakota 4x4 3.9 v6 automatic transmission my trans doesn't want to shift gears unless i take my foot off the gas..i saw i had a pan gasket leak so i changed the gasket and the filter. but when i looked in the pan there was what looked like some kind of broken gasket and the pan gasket wasn't broke. i cleaned it out finished installing the new filter and gasket. and it is still doesn't want to shift someone please help i'm going to loose my mind.