Engine/Transmission (1994 - 1998) transmission shifting up and down hard with no warning.

[MNeuharth]

Hey guys ive been trying to find an answer to my problem with my transmission on the site for 4hrs with no luck so im posting a new thread.

Let me give you the run down:

So, i had just filled my truck up with fuel and was driving off the fuel lot up to Port Angeles washington from CA(mind you i had been driving it for approximately 700mi without and incident) then suddenly my transmission started to shift up and down really hard. almost banging in and out of gear, and my rpm's were all over the place and my truck pretty much stopped accelerating. It felt as if it was in between shifts and couldnt find the correct gear to be in. So i stopped(obviously), looked around and under the truck for a transmission leaks and so forth. I put the truck in nuetral and checked the fluid level and it was fine. So i let it idle there for a minute and tried going again. this time nothing happened untill about five miles down the road it did it again going around a sharp turn to the right but far less severe than the first time. From then on it didnt do it the rest of the trip to Port Angeles. Then the following morning(after the truck sat all night) it did it again, not alot but just enough for me to notice what was going on and then it stopped and hasnt happened since. (Its been three days since the last episode) I appologize for the lenghtyness of this post but I want you guys to get as much info on whats going on as possible. Any help will be greatly appreciated, MNeuharth

 

[budnate]

plug in with a OBII and see if its throwing any codes, most chain auto parts stores up here have them and will loan them out in the parking lot for a quick scan.

 

[Joe G.]

First of all we need to know what year your truck is. Then we need to know which gears are affected. If OD or torque converter lockup is involved then you probably have a TPS problem. If your truck is a '94 or '95 then an OBII will not help.

 

[JMcCoy]

I agree with Joe. I would look at the Throttle position sensor. I heard you can clean them. I would also clean and gap the rpm sensr on the harmonic balancer. Good luck.

 

[MNeuharth]

Oh ya sorry about that Joe, my truck is a 98 12v 3500 dually 4x4 w/ 213,000 miles on it. And to answer your question about what gears are affected it seams to be between overdrive and through first and second gears and nothing higher than that. Like i said in my first post it only happens right when you initially start accerlating from a slow roll. Like coming out of a driveway or coming out of a slow hard turn and accelerating out of the turn.

Budnate: would it have thrown a code even if the check engine light didnt come on? Im not to familiar with code reading system in my truck. although i know where the plug is that your talking about.

 

[cerberusiam]

You might have to have a scanner to get the PCM codes to show and quite likely there are none serious enough to throw a CEL.



That type of shifting is usually associated with the trans governor solenoid and/or transducer going bad. Could be TPS signal wacked or even a TV cable adjustment problem.

 

[budnate]

when I dealt with mine no lights on the dash but plenty to read when plugged in with the BDII



I am no expert on a 47RE thats for sure but am a decent mechanic, here is some good reading and stuff I learned the hardway digging around, here and the net, sure would have been a ton easier for handout like this to look over.



https://www.turbodieselregister.com...7re-automatic-some-common-troubles-fixes.html

 

[MNeuharth]

Alright, I'll do some checking tomorrow as the parts stores are closed right now. Would it be a good idea to just buy a new throttle position sensor? you know proccess of elimination usually works and $200 bucks isnt alot of money for me spend right now. Oh and i should also mention that im not the best electrition out there. and what they describe in the "47RE, automatic, some common troubles & fixes" section as far as what they are suggesting I do is pretty confusing to me. But I'll give it a shot. Thanks for all the suggestions and input you guys, you all have been very helpful so far and I hope to hear more from others as well. Sincerely, MNeuharth

 

[budnate]

easy stuff to check, check for codes right them down, clear all codes with the checker,



a digital Volt/Ohm meter is easy to use, poke a few wires with some diaper pins and measure voltage and ohms and see if your in the zone or not, the wires are easy to get at under the hood.



B.

 

[MNeuharth]

Alright, B. I do some work on it tomorrow. I'll let you guys know what i find out tomorrow, thanks again, MNeuharth

 

[MNeuharth]

Well guys I plugged in the code reader and all it came up with is: P0622 - Alternator Field "F" control circuit malfunction. What that means im not sure but I did get my alternator tested and it tested bad. Whether or not that has anything to do with my transmission not shifting correctly I dont know but if you guys have any more thoughts on the matter I would love to hear them cause my transmission is still shifting wierd at low speeds and cold transmission temps. MNeuharth

 

[cerberusiam]

If you haven't, you probably need to change out the gov pressure solenoid and transducer. They will definitely cause shifting issues.

 

[Missouri Mule]

The alternator wires can cause noise and cause wierd shifting.

Need to wrap wires in tin foil, there is something else you can do also but forgot what the gadget was called.

Was talking with CTD (98. 5 auto) owner that moved back into the area recentley ( two years) the previous owner had Jasper rebuild the trans. When the 2nd owner moved back to Florida the trans starting to acting up he searched the internet and found a few solutions. Took it to transmission shop showed the owner the solutions the transmission shop owner but some type of elctrical tester on it and found where the interfernce was coming from (alternator wire) wrapped it in foil and tied something in with the wiring which sovled the problem.

 

[MNeuharth]

alright cool i'll check all those things out you guys said and I'll see if it fixes the problem. thanks again and i'll let you know what happens next. How expensive is a gov pressure solenoid and a transducer?

 

[cerberusiam]

The OE sensor and solenoid are about $50 per piece. You can order them here A500 42RE A618 46RE 47RE 48RE Transmission governor pressure sensor 56028196AD,Transmission solenoids.



A kit to upgrade these to a heavier solenoid is around $270 from Suncoast. It should extend the life of the OE stuff plus get rid of some of the issues cause by certain shift kits.



Yes, the alternator is the source of a lot of problems but generally not what you describe. Doesn't mean it can't be but since you replaced the alternator I would doubt its effecting shifting.



All the rewires, filters and tin foil in the world won't solve the problem of noise in the system caused by the alternator. It just covers it up. Skip the placebo fixes and do it right by removing the source of noise if that is the issue.



The solenoids and transducers are the source of a lot of these problems and tin foil won't help.

 

[budnate]

good info, have you checked the voltage on the orange wire from the ECM to the trans yet? erratic Voltage will smoke the elect parts in the trans... mind is fuzzy what all 3 are called right now but I changed all 3 devices for about $140 bucks and installed a resistor to not over volt them again.

The OE sensor and solenoid are about $50 per piece. You can order them here A500 42RE A618 46RE 47RE 48RE Transmission governor pressure sensor 56028196AD,Transmission solenoids.



A kit to upgrade these to a heavier solenoid is around $270 from Suncoast. It should extend the life of the OE stuff plus get rid of some of the issues cause by certain shift kits.



Yes, the alternator is the source of a lot of problems but generally not what you describe. Doesn't mean it can't be but since you replaced the alternator I would doubt its effecting shifting.



All the rewires, filters and tin foil in the world won't solve the problem of noise in the system caused by the alternator. It just covers it up. Skip the placebo fixes and do it right by removing the source of noise if that is the issue.



The solenoids and transducers are the source of a lot of these problems and tin foil won't help.

 

[MNeuharth]

No i havent been able to get into the transmission to check voltages yet as im still on vacation. were leaving tomorrow morning and when we get home(14hrs later) i'll start tearing into it. And by the time i get there is should have some new parts waiting for me when I get there. I think im gonna go with the heavier solenoid from suncoast like cerberusiam suggested. sounds like a better deal.

 

[budnate]

I would highly suggest since your going to be right there anyway. it's not much money and piece of mind knowing there new, do the other 2 solenoids and adjust the bands inside the pan. I happend to have a couple pics when I did mine, when you have the Gov Sol out to swap it, it exsposes the other unit.



good luck, B.



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[cerberusiam]

The lockup and OD solenoids have nothing to do with any of the shifting. They are totally under the control of the PCM and you would know if they did not work. You can replace them if you like but if OD and lockup work now its really just a waste of $$.



If a cheaper solution is wanted than the aftermarket setup, Bor warner has a new solenoid out that is a direct replacement for OE. Supposed to be 30% bigger and stronger than the OE.

 

[budnate]

I see your point, truck has 213K on it, parts are 13yrs old?... . $70 bucks in parts... your right there with the pan off, oil out... yea I wouldn't want do any preventive maintenance either its a waste of time and money,



it was reported the alt was bad who knows what the heck has possibly been hurt with it not providing the proper voltage to the truck and the PCM.

The lockup and OD solenoids have nothing to do with any of the shifting. They are totally under the control of the PCM and you would know if they did not work. You can replace them if you like but if OD and lockup work now its really just a waste of $$.



If a cheaper solution is wanted than the aftermarket setup, Bor warner has a new solenoid out that is a direct replacement for OE. Supposed to be 30% bigger and stronger than the OE.