Lost Overdrive

I have lost overdrive in the riv... at 60mph I am crankin almost 3K on the tach. I can downshift to 3 and not get any change in speed or rpm.

what can cause this? trans runs and shifts fine otherwise.

Sounds like a bad TCC solenoid - that's tourque converter clutch. Or the converter itself has gone. Have you checked and/or changed the fluid lately?

The symptoms describe a situation with no 4th gear. Loosing TC lock-up would not cause 3k RPM at 60 MPH.

true AA, I reread and agree. But I've no idea what will cause that.

What if you go around 50 and tap the brake while you still have your foot on the gas for cruising. Do you get a little jump in RPMS, the TCC disengaging?

As to why it won't shift into 4th, I have heard the 4th gear drum is a weak point in these. When my transmission was rebuilt an 'improved' one was used. Unfortunately that's my only guess.

I agree with Aaron and Derek. Interesting question is do you get TC lockup in 3rd? It sounds like you aren't getting 4th gear at all so you wouldn't get lockup in that gear. The TC should engage at around 30mph when the car is in third gear. There could be more than one issue here.

Here's an example of how tuning software could make a transmission last for a longer time in a crippled state. You could program the TCC release to hold in 3rd gear under extreme throttle at higher speeds. Wouldn't be as fun to drive, but fuel economy would be better, and the TC wouldn't burn up as quickly.

In a sense, you could use TC lock-up as a 4th gear.

I will test to see if I get TC lock/unlock today.

will not having 4th or no TC lock hurt the trans or anything else? Am I looking at yet another trans failure. It was rebuilt a year ago. I dont really want to sink another 1.2K into this car.
funny thing is that this is just a daily driver. no perf mods at all and I dont even beat on the car.

Do you have any warranty from the trans rebuild? Most rebuild shops around here offer a 3 year warranty as I recall. I had mine custom built, so no warranty, but the price was right too. (it was a transmission guy who did performance builds off-hours for cash...)

warranty is up.. figures. it was only a 1 yr.

I did test the TC lock and there does not seem to be any in OD. at 65mph, i tap the brake and there is no change in rpm.

as an FYI, I also no longer have cruise (it was working before...).

blackrose613 wrote:

as an FYI, I also no longer have cruise (it was working before...).

Could be a faulty throttle position sensor or some other sensor screwing up causing your issues then. Just a guess on my part from some experience. Noticing any other odd behaviors, like speedometer jumping or anything?

spedo is fine. other than no OD and no cruise, the car is actually running well now.

things recently replaced: ignition switch and neutral safety switch.

could a TPS really cause this?

blackrose613 wrote:

spedo is fine. other than no OD and no cruise, the car is actually running well now.

things recently replaced: ignition switch and neutral safety switch.

could a TPS really cause this?

I'd like to think that anything that causes 2 problems would set a code and light the MIL...

But if not, now that you mention it, something I could see messing up OD and Cruise would be the "neutral safety switch". On these transmissions, it's much more than that, it tells the PCM exactly what gear the shift lever is in... If it was installed incorrectly, I think it could cause a Cruise Inhibit and prevent OD. Again, though, why no light? Do you have a scanner?

i took a 160 mile round trip this past Friday pretty much of a straight line there and back. on the way a good portion of the road is on a steady incline and the car with its new ac-delco oxy sensor did me proud by behaving like a good girl. i was doing 85 to 90 on sections with a little over 2 grand on the speedo.
on the way back I'm navigating the town making my way to the interstate on- ramp. i get to the on-ramp and see a few cars all ready on the interstate coming up fast ,but i think i can gun her and beat em onto the right lane which they are on. i gun it and sure enough the riv picks up speed with the s/c whine making my nuts tingle. i quickly look back and the cars seem almost disappointed that they couldn't celebrate a victory over the dude merging the on-ramp. i continue up the hill that follows the on-ramp and i notice that the speedo reads just a line above 3grand? no prob I'm going up a hill why should i be alarmed? further down the road on a flat section the speedo still is in the 3,s, i travel a few more miles,tapping the brakes,flooring it a little to see if i can snap her out of it, nothing happens. so i pull over,shut her down,wait a min or two,start her up and accelerate...i hit 80 again and overdrive comes on smooth and easy...mystery? has this happened to anyone ? would a bad valve or sensor cause this???

Perhaps you had had the gear selector in 3rd instead of OD ?

If you are sure that it was in OD, then I would definitely drain fluid, replace filter and refill just as a precaution.

Bert

If it only happened once, then I would do as Burt said.
On my mine it started happening every-time / all the time.
Brought it to a Trans place and they replaced the TCC solenoid.

interesting. i just replaced the filter and fluid last week along with a bottle of lucas stuff and while she shifts better and runs smoother I'm sure that i was in -d- at the time. hey rick what did they charge you for the TCC solenoid install? is it just a matter of dropping the pan and replacing the part on the valve body?

No, The various Solenoids are under the side cover on the driver's side. requires removing the left side drive shaft and then the left side cover.
Then access to all the stuff is easy.

thanks fellas ! good to know..ill watch her progress and check all that out...........

robo, just my opinion, but instead of the Lucas stuff for the Trans, you might want to try the TransX.
Have had very good luck with that product for occasion sticking of components.
The Lucas is just too thick to help loosen things up.

you might be right rick. it was recomended to me and i have used it for years but the parts place didnt carry it so i tried the lucas. it does slow things down quite a bit. but damn the tranny is super smooth with it. but my prob began before changing the fluid and adding the lucas...ill pick up a bottle of transx ,but i hate to have to lose all that fresh fluid. im not sure that the transx would work with the lucas syrup?

Then I would definitely dump the fluid you have along with the Lucas product and add some TransX before paying the big $$$$ to change the solenoid.
The only reason I went with a complete Overhaul was that i had a warranty.

maybe. but if the solenoid is at the location you mentioned ,i can do that myself..i think?

Yes, anything is possible.
Just look in the FSM and it spells it out, IIRC.
The only reason I didn't do it myself at the time is I had an extended warranty that I bought after buying the car.
Got more than my money's worth out of that.

thank you friends. i am going to tackle this myself when i get my new scanner in sometime mon or tue....

robotennis61 wrote:

thank you friends. i am going to tackle this myself when i get my new scanner in sometime mon or tue....

I admit I thought the tranny had to be dropped to access the valve body... This is still a pretty big job with some things I still don't understand, but I thought I'd post the FSM info for the 4T-65. Hopefully the 4T-60 is easier, or you have the appropriate manuals. For instance, step three calls for installing a top-mount "engine support fixture" even though you're going to be using your jack to support the transmission later on. Supposedly you can rent them...
Also, if I were going to undertake something like this, I'd research beforehand everything in that valve body that should be replaced with upgraded or aftermarket pieces while I was in there! Like the boost/reverse valve & sleeve assy, and the actual TCC valve & O-rings...


1. Disconnect the negative battery cable.
2. Remove the park/neutral position switch.
3. Install the J 28467-360 fixture.

4. Raise the vehicle. Support the vehicle.
5. Remove the left front tire and wheel assembly.
6. Remove the inner splash shield.
7. Remove the tie rod end from the knuckle assembly.
8. Remove the stabilizer shaft link from the lower control arm.
9. Remove the ball joint from the steering knuckle.

10. Remove the drive axle from the transmission. (Which is a job unto itself, you can't just unbolt it from the trans & hub like in the old days.)

11. Remove the pinch bolts from the steering gear intermediate shaft (one of which appears to be under the dash.)
12. Remove the intermediate shaft from the steering gear.

13. Position a transmission jack under the transmission oil pan. Raise the jack until lit supports the transmission.
14. Remove the three frame-to-body bolts on the left side of the drivetrain subframe.
15. Lower the transmission jack and the transmission in order to gain access to the case side cover.

16. Pre-clean the outside of the side cover with engine cleaner if necessary.
17. Remove the oil cooler pipes at the case.
18. Remove the case side cover bolts.
19. Remove the case side cover.
20. Clean the case and side cover gasket surfaces.

21. Disconnect the transaxle wiring harness
22. Remove the TCC solenoid locking clip, solenoid & valve assy.

Installation Procedure

1. Install the new gaskets on the case.
2. Install the case side cover.
3. Install the new side cover bolts & tighten the side cover bolts to 11 N·m (98 lb in).
4. Install the oil cooler pipes to the transmission.

5. Raise the transmission so that the frame bolts can be installed.
6. Install the three frame-to-body bolts. Tighten the bolts to 112 N·m (83 lb ft).
7. Remove the transmission jack.

8. Install the intermediate shaft to the steering gear.
9. Install the pinch bolts at the intermediate shaft.
10. Install the drive axle to the transmission.
11. Install the ball joint to the steering knuckle.
12. Install the stabilizer shaft link to the lower control arm.
14. Install the tie rod end to the knuckle.
15. Install the inner splash shield.
16. Install the left front tire and the wheel assembly.
17. Lower the vehicle.
18. Remove the J 28467-360 fixture.
19. Install the park/neutral position switch. Refer to PNP Switch Replacement
20. Connect the negative battery cable.
21. Inspect for leaks.
22. Check the fluid level.

23. Mix a double Old Fashioned.
24 Consume and repeat.