Hello all, I am new to this forum and I need some assistance.

I just obtained an 1984 Eldorado that is having a problem shifting. When I first started driving it shifted fine. Now, it will not go from 1-2 until it's almost full rpm. The same with 2-3, I am not sure about the 3-4.

I was on the road when this happened, so I paniced alittle, and removed the cable from the linkage that went down to the tranny. This seemed to allow it to shift sooner, so I could at least get home, I never when fast enough to get to forth.

The fluid is full, it's not burnt, and it's not slipping either. Could this just be a kickdown linkage problem? How do I check? Is there something else I can check? I really don't want to take to a transmission place, because I think it will cost a fortune....

Also, the check engine light came on, and it has error code '29'.

Any help is greatly appricated. :bonkers:

Not too sure on the code as of yet, but there might be a vacuum line running down tho the trans. Check and see that it didnt fall off, or the hose split.

The code is...

Shorted Fourth Gear Circuit

Vacume lines look ok....

Verify vacuum thru the hose to the modulator, if good, replace the modulator. Its rare but I've seen the governor drive gear strip, its plastic. If stripped the governor weights wont move .

I had an '83 Eldo that developed the same problem. On mine, there was a broken spring inside the trans. I believe it was on one of the shift accumulators. I had a GM mechanic fix it. I think it was accessible through the trans pan, without having to remove the valve body.

The code is...

Shorted Fourth Gear Circuit

I assume this is a HT4100 engine.
You might need to adjust the TV cable. There is no downshift cable (although the TV cable looks similar). There is a procedure for this listed in the service manual.

The error code is curious - maybe it is caused by the problem or it might be an actual short (or a bad 4th gear switch) and it is contributing to the problem.
That circuit should remain open until the car shifts into 4th gear.

Also, on this cars - vacuum is not used in the transmissions at all. No transmission vacuum lines, no modulator valves.

I'm not a transmission expert - maybe someone else can chime in.
Peteski

I cleared the error, and it didn't come back. I only live a short distance to work (about a mile and half), and I have been driving it. It goes into 2nd at about 25mph and into 3rd at about 45mph. I didn't go fast enough to see if it will go into 4th.

It is a the HT4100 engine.

Is the TV cable adjusment something I can do in the driveway (without dropping the pan)?

I've never done it but you don't need to open up the transmision. The adjustement takes place where the cable is attached to the bracket on the top of the engine.

If you don't have a service manual, try searching this site for "TV cable adjustment". I'm sure someone described it here at some point.

Peteski

Found it....

"The TV cable only rachets once....the first time you go to WOT after "adjusting" it. With the throttle closed you release the lock on the TV cable housing at the mount beside the throttle body. PULL the housing of the cable away from the throttle body while holding the lock release button/tab down. You should feel it move as you pull it with the lock tab pressed. Release the lock tab while still holding the cable housing out firmly. NOW go to WOT with the accelerator. You will hear the TV cable go zzziiippp as it rachets and self adjusts. That is all there is to it."

...I hope it is as easy at sounds. I also just found an old Chilton book in the garage, that basically says the same thing as above. I'll try it tomorrow, and will let you know if it worked.

Vince

Did you verify vacuum to the modulator? The 2nd gear shift seems high at 25 mph. thats assuming light throttle. The cable you removed at first is the TV cable. With it removed, the trans will shift too early and left disconnected, will damage the trans.

I adjusted the TV Cable as described, but it didn't help. I only drove about 5 miles with it disconnected, then reconnected it. It can be done without even removing the air cleaner.

The vacuum line looks like it's connected, it's a solid line hooked to bottom of the TB. I didn't varify that there was vacuum to it. Started to check it with more detail tonight, but had an unrelated problem with a heater hose that I had to fix.

I have to work outside on it, and it's cold here in New Jersey, so my daily time window to work on it is very short.

I have an appointment tomorrow with a 'National Transmission Chain' in the local area. I will post what the fix was, I just hope that it's not major.

Did you verify vacuum to the modulator? The 2nd gear shift seems high at 25 mph. thats assuming light throttle. The cable you removed at first is the TV cable. With it removed, the trans will shift too early and left disconnected, will damage the trans.

Carnut,
I don't think that that year and type of car has a vacuum modulator for the transmission. TV cable substitutes for both, the modulator and for the downshift cable.

I wonder if it is possible that the TV cable somehow got disconnected at the transmission. Probably unlikely. So, there must be another problem.

Peteski

Transmission guy says that it's an internal problem. This also a non-modulated transmission.

Also, code 29 came back as I was taking there, in third gear.

At any rate, I told him to fix it. Looking at $1500 to $1700.

I'll post the final outcome....