Re-Manufactured Transmission Intermittent Overdrive

Can you rent a scanner?

Maybe but wonder if I can figure out how to use it, hence what it's telling me.

How many spare parts have you got left over?

Did you follow the instructions correctly?

Did you ensure that the sensitive parts of the transmission didn't accidently get dirty? I am not sure about modern transmissions but older automatic transmissions could really get stuffed up if grime got into the wrong place.

It could just be a simple case of assembly error or grime in a place where no grime should be. You may need to partially disassemble and inspect.

_{Jack - Not a automatic transmission expert!}

Not to my knowledge any parts left over.

I followed instructions on YouTube to the best of my ability.

Oh yeah, I think the sensitive parts are internal.

Was wondering if anyone knows anything on like if a thicker fluid could help or maybe that Lucas Stop Slip would help?

Go to an auto parts store. Most of them will read the trouble codes for you, in hopes of a sale.

Could be a bad solenoid, but who knows?

No trouble codes.

I checked the shift solenoids as best as I could. Even interchanged the A and B ones because they are the same.

What exactly are the symptoms?

Found this....

http://www.twincharlotte.com/transmission-repair-blog/bid/28391/30-Common-4L60E-Transmission-Problems-Repair-Charlotte-NC

Hey... that's a good site, thank you! It said it could be the Throttle position sensor and saw it's only 10 bucks.

The symptoms are just no overdrive after it warms up. Well, after fixing the neutral safety switch I do have overdrive sometimes now but not all the time. I haven't drove it much after that to know for sure but just know sometimes I still have over 2k rpm's at 55 mph and sometimes way less at the same speed. I'm going to check more re-acceleration at that speed.

I would also make sure your transmission fluid is at the correct level....Make sure you have run the transmission through all positions to pump any air out...

To check your automatic transmission fluid, follow these steps:

1. With the gearshift in Park , let your engine run. ...
2. ...with the engine idling and warmed up...
3. Pull out and wipe the dipstick with a clean, lint-free rag; then check the fluid level..

Make sure you are using proper transmission fluid type....Dexron VI... Holds about 10 quarts total....

http://www.wikihow.com/Change-Transmission-Fluid

And inspect really closely for powdered anything that might have come from the rebuild? You may just need to run the thing in some more. I hope you are doing checks with no head wind, level ground, etc. so same rpm's at same speed are observed when in and out of overdrive. Are you sure your brakes are right by now? If they are intermittently grabbing or rubbing, that might affect the tranny operating point.

Ya know that brings up a point of the first time taking off the pan I saw what seemed to me to be too much dust or particles in the fluid. Seems like I shouldn't see any but the guy that bought my original trans said it's not too bad. I took some to show him.

OK, with my brakes and you asking this what I did was to get it rolling slow then put it in neutral and it kept rolling good and slow so don't think anything is rubbing.

Because of you I got the brakes way better than I would have so thanks again.

It was on an another thread folks. A month ago.

https://www.yourmechanic.com/article/symptoms-of-a-bad-or-failing-throttle-position-sensor

I found one online for 7 bucks so will just replace it. i don't mind shotgunning at that price but I am interested inhow it works so will watch it later so thank you for this.

I have had this on several vehicles, it may be due to the trailer hitch electronics, on one Ford it engaged the overdrive and disengaged it as the signal lights or 4 way flashers were operating. On a Buick it was traced to the steering column signal light switch. Both cases were initially diagnosed by activating the brakes lights when the symptoms occurred. When you activate the brake light switch it unlocks the torque converter clutch and the OD clutch. Not sure on your vehicle but it may be similar.

A decent transmission shop should be willing to hook up their equipment & test drive it to run diagnostics for you in real time. I've had this done on three vehicles and they never charged me for it.

1. Why did you replace the transmission ?

2. Was there a driveability issue with the vehicle before you changed the transmission ?

Driveability issues would be, idle, acceleration, hesitation, stalling. Etc.

On some vehicles that use the 4L60E transmission, there are different transmission units that can be mounted to the same engine.

It could be that the electronics in the transmission that you installed, may not be compatible with the ECM in your truck.

I have a 2007 Chevrolet Colorado with a 3 speed + overdrive automatic transmission. I can use a 2007 & a 2008 replacement transmission. The 2009 & 2010 transmission is the same type of transmission & looks exactly the same, except for one little detail, the internal electronics are different and is not compatible with a 2007 year model truck.

It is possible that your replacement transmission is not compatible with your vehicle.

OK, Thanks Everybody.

I took it out on the toll road close to me and all worked great at 65 to 70 mph then between after 10 to 15 miles I started noticing the rpm's started kinda moving up from 2k to 2.5 kinda erratic not corresponding to anything like wind or hills then moved up to 3k and stayed there till after where I was going it cooled down. Then everything was fine for just a short while then no overdrive again all the way going back home.

Everything in is saying heat is the problem with maybe the fluid. It's just no overdrive after it warms up period and good when cold. Not too much heat or anything as far as I can tell though like with a smell or a heat light that I had when the original tranny went out. Also remembering a valve body valve acting erratic in repair video's.

The re-manufacturer assured me it's a direct replacement the same as I had but with an upgraded servo for stronger shifts. The original just started slipping real bad and the fluid smelled burnt is why I replaced it.

OK, the shops said what repair and replacement costs would be, not just a diagnostic so maybe I'll try again just for a free diagnostic, Thanks.

When studying on how to replace it I came across a discussion on the different types of fluids saying that the synthetic Mobile would be thin compared to like maybe the Prestone... I can't remember for sure or find it. This just keeps coming to mind, what do y'all think?

I had a 2005 Chevy Equinox trade in with an intermittent hard shift (3-2 and 2-1 - rarely 1-2). Tranny guy (well respected) put pressure gauge on it and said tranny is bad and needs a rebuild. My mechanic said tranny seems good, but he thinks it's the computer telling it to shift hard. Went to the dealer and they put the scan tool on (different from the one you get at Autozone). They said the tranny is bad.

Additional info on symptoms. When cold, it worked perfectly. When hot, it would work fine, until it got one hard downshift. Then it did it all the time until I shut it off and let it cool down. Sometimes I could drive for a long time with it hot and it would drive fine. If I drove it like I stole it, it would shift perfectly, even when hot. Upshift and downshifts were good. I even tried to force the shift down (manually move shifter) and as long as I drove it like a nutcase, it would shift fine. A bad tranny doesn't act like this. A confused computer does.

I've been in the business since 2002 and I know the tranny isn't bad. This one has solenoids that tell the tranny to shift and the computer is tells the solenoids to shift fast (hard) or slow (soft). The problem I had is a fast shift and since there's no rev matching, so the bands clamp down fast causing it to shift hard. I took it to an independent mechanic who knows electronics and trannys. He told me that it's the computer - it doesn't know how fast to shift - there's a learning mode that learns how the driver drives. He cleared the memory and told me to take it easy and let the transmission learn a different driving style. Well, it worked! I was able to get the car to shift properly and then sell it as a good used car.

Two things to test:

1. Test the overdrive solenoid. First check to see if the computer is giving the solenoid a shift signal. If yes, then either the solenoid is bad (very likely), the valve body is bad (solenoid is telling it to shift and the valve body isn't shifting) or the band is bad (very unlikely, since it was just rebuilt).

2. Since you had the old transmission out, then rebuilt, you may need to reset the memory. If your old transmission was slipping, the computer is programmed to that type of driving style. You need to clear it.

In the good old days, if your transmission wasn't going into overdrive, you could do a pretty simple diagnosis and you could find the culprit. Nowdays, many of these problems are due to the computer - not a bad computer, but the computer tells the transmission to shift hard.

Good luck.