CD4E Fun

Before anyone asks, yes I have read all the stickies, FAQs and searched the forums and interwebs for pertinent information before posting a new thread. I was not able to find a specific solution to my issue, and thought it wise to ask before throwing tons of money at my transmission. So, here we go:

From what I can tell and have read, the CD4E has 4 physical gears and an overdrive. Since I have owned the vehicle, it has never shifted into overdrive.

The O/D off light does not illuminate, even when toggling the O/D switch on the shifter. Shifting behavior also does not change from toggling O/D switch. (Bulb and socket for this light in the instrument cluster is tested working).

History:
Transmission was reportedly replaced with a used one at roughly 110k miles. It then sat for about 6 months with electrical issues (trans shop didn't reconnect ground wire, battery died, etc) at which point I bought it and got it running.

I broke a transmission cooler line while replacing my radiator. Temporary fix with rubber hose didn't hold up, and transmission started slipping and shifting erratically due to loss of fluid. Drained tranny, properly replaced cooler line, filled with fluid and Lucas. Wife reported that it was acting up (actually turned out to be related to a vacuum leak, my mistake for not duplicating the problem), so I drained out a small amount of fluid as to not have too much fluid in trans. Replaced plug and proceeded to crack the transmission case.

(Are we having fun yet?!)

Drained trans fluid completely, degreased and scuffed/sanded area, sealed with JB Marine Weld. Filled trans with fluid. Shifts fine. But still no overdrive.

I'm guessing that I need to start with the O/D switch and work my way from there. Hoping my issue is electrical/electronic as opposed to hydraulic. The lack of any O/D off light leads me to believe this. Any advice or links to relevant information/fixes is appreciated!

Could be that switch has open or shorted circuit. The 'electrical issues' alluded to seem to point to it.

I'm pretty sure that the CD4E only has 4 total gears. Overdrive is the 4th gear. If the O/D light is on the 4th gear is locked out.

BrApple said:

I'm pretty sure that the CD4E only has 4 total gears. Overdrive is the 4th gear. If the O/D light is on the 4th gear is locked out.

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Aha, that's what I was unsure of. I was looking to find that, but could not tell for sure from the information I found. I haven't driven it in a few weeks since the windshield cracked. I can't remember exactly, but I believe it was shifting through 4 gears. I believe it rides at roughly 2500 rpm at highway speeds (60-65mph). I'll have to take it for a spin and count shifts.

amc49 said:

Could be that switch has open or shorted circuit. The 'electrical issues' alluded to seem to point to it.

Click to expand...

Could very well be. I need to pull the shifter and check the wires and switch out. If I remove the switch and cross the proper wires, it should turn the light on if it's the switch that's bad. If that doesn't work, I may be searching further down the line. If it turns out that the overdrive is working properly, I won't be that concerned about the functionality of the switch.

I'll check everything out and report my findings. Thanks for the guidance and info!

Although an older thread, the trans will run about 2250 rpm at 60 mph in 4th/OD gear. When the OD is off, it should run about 2500 rpm at 35-40. That switch may also affect the torque converter clutch lockup, where in OD at speeds above 35 mph, the TC is locked. That seems to be a electrical issue at the switch, but it could be anywhere from the valve body solenoid to the switch to the TCM.