My Ram truck has started randomly dis-engaging from gear while driving. I’ve never noticed it when the trans. is cold. It doesn’t slip; when it works its fine. When it drops out of gear, its instant and acts like its in neutral. It will re-engage, after a number of seconds goes by and I feather the throttle a bit. It started when I was at highway speed, but now will do it in about any gear. Is this a common problem, and could it be electrical? I’ve replaced the filter, checked the fluid (looks fine), and pulled a cooler line and it has plenty of pressure. The truck also has an enormous trans. cooler added to it, and it has 155,000 miles. Can anyone help?
Did you check the fluid level with the gear selector in PARK?? It’s very important that the gear selector is in PARK when checking the fluid level. When you refilled the trans did you use Chrysler’s ATF+4 fluid??
Ooh, sorry, brain was MIA on last post. This Chrysler has to be in NEUTRAL when checking fluid level, not park. Sorry if any confusion.
Yes I knew it had to be in neutral or there is no line pressure, and yes I used Chrysler fluid. As I said it seems so sudden I would guess its electrical but the last tranny I rebuilt was a 904 so I’m not familiar w/ all the electronics, especially on mopar’s. Also at a point I was wondering if the pump was weak since once dis-engaged, feathering the throttle for 5-10 sec.'s seems to be what gets it back in gear, almost like it only then has enough pressure to hold the gear? But that’s why I’m on here- IDK. Stumps me since it never slips when in gear.
If the fluid is up to level & in good shape then the next thing I’d say you need is to get it on a scanner. Is the check engine light on? There are basic OBDII codes that might be set & provide you some info & many auto parts stores will read those for free. If there is no check engine light you might have to drop an hour’s labor cost on a local transmission shop to get it on a scanner.
The only way to really check the pressure, btw, is with a gauge.
Yea, lets get a gauge on it and see what the pressures look like. You said you changed the filter, was it changed before or after the problem started??
wait so you are driving and it seems like it’s in neutral… like the rpms ramp up suddenly but the vehicle doesn’t accelerate?
could this be slipping you are describing? maybe one (or more) of the gears is shot
Thanks all for your responses. Yes, the fluid is full and looks ok. I changed the filter after the problem, believing that might be the problem. I am trying to get it to a shop so they can scan it- tranny shops seem to all do that for free. And yes, while I’m driving it will INSTANTLY did-engage, randomly, and then will re-engage after a few seconds. It DOESN’T slip- I know what that feels like I am no stranger to bad transmissions or mechanics in general- its my field. The way it happens makes me think it’s electronic, like a solenoid acting up, a loose connection, etc. At first I thought it was like the pan would get too low and run out of fluid til more drained into it, but fluid was full, and now has a new filter w/ no change. It happens in basically any forward gear, so it’s not just one. And it happens after its warm, not when cold. Just wondering if this is a common problem w/ usual fix; or if anyone has had this same issue?..
This won’t be an electronic issue. Everything you describe point directly at the pump. These transmissions are known for their internal leakage problems. It’s going to need to be pulled and disassembled.
Okay so if it is the pump, and I want to do this myself, I’d buy a re-man pump, seal and gasket. On a shoestring budget, would it be worth my while to put in a reman. torque converter and maybe buy a kit and go through the clutches and bands while I’m at it? I don’t want to pay $600+ to have it rebuilt, I can take it in and out, and I don’t mind playing w/ snap ring plyers… Will I benefit by just doing the aboved named stuff? I’m not actually keen on taking down the valve body myself…?
This really isn’t a DIY transmission. It first has to be diagnosed. Me telling you it sounds like the pump is the best guess I can give you under the circumstances. I don’t have the vehicle here in front of me to actually look at and run tests on the trans. That’s the only way I could tell you for sure what’s wrong. You can’t just throw a pump and some clutches and steels in this trans and everything will be fine. Like I said before, this particular transmission is known for it’s internal leakage issues. These issues HAVE to be addressed during overhaul. These aren’t things you are going to find in any ATSG book. This trans has a separate overdrive unit bolted to the back of the trans. Special tools are required for removal, disassembly, reassembly, and installation of the unit to the case. It’s going to be impossible for you to build this yourself on a shoestring budget.
k well it aint getting rebuilt right now. Its in Minnesota, I’m in N.C. I just want to get it so I can limp it down here w/o towing it, so if it ends up being the pump, I’m sure I’ll at least try to slap one in and see if it makes it here. Once it is I can worry about an overhaul if needs be. Used trannies for this truck go for about 850 or more, and thats out of the question too. If I had my way I’d be bolting in a 383 or 440 with a 727 and whatever t-case I needed and put an end to everything thats wrong with the truck. I have 3:55 gears so I wouldn’t miss o/d too much; but I have to say the fuel injection on the 5.9 magnum is beautiful it gets 19-20 mpg highway! If I could get f.i. on a big block and have that mileage nothing would be stopping me from doing it!
maybe I could put a smallblock 727 behind the 360 instead? I’m sure its the type of thing not many people even think of doing, but a p.o.s. electric nightmare vs. one of the strongest a/t’s ever meade seems a simple choice to me! I’m a believer of improving things that are shit, not just maintaining the status shit.