: 88 Brougham Tranny problem



88landyacht
07-02-07, 12:23 AM
I have a problem with the tranny on my Caddy, Don't know what model of tranny it is, but the 307 (5.0) is powering it, but any way, here goes:

After the car has warmed up a bit, the tranny acts like a manual transmission that the driver forgot to push in the clutch when coming up to a stop sign/light, and right at the lowest rpm, when she's about ready to bog (or convulse), she downshifts into the next gear, what causes this, and what can be done to fix this??

Keeping in mind, the car sat dorment for almost 2 yrs before I got her....... :confused:

Jonas McFeely
07-02-07, 07:45 AM
I had/have the same problem as you with my '85, Though mine doesnt sound as severe. I am willing to bet, from all of the research ive done and people whove told me, it is more than likely your Torque Converter Clutch Solenoid.

Apparently its about a $150 part plus install. Funny you post this because mine is going in next week to get new trans fluid and filter and to get the TCC looked at.

88landyacht
07-02-07, 08:31 AM
The TCC soleniod, hmmmmm, I'll have that checked out, cause she won't shift down going up a hill either, sometimes I have to down-shift her manually, BUT......................If thats the only thing wrong with her, I am not going to complain!!

Jonas McFeely
07-02-07, 08:53 AM
Yeah, i am willing to bet its the TCCS. Mine sometimes give me fits going uphil,though in Florida there isnt too many of them.

Does it act up more when your A/C is on? Mine always does,when i turn the A/C off it rarely messes with me.

jayoldschool
07-02-07, 09:12 AM
The TCC soleniod, hmmmmm, I'll have that checked out, cause she won't shift down going up a hill either, sometimes I have to down-shift her manually, BUT......................If thats the only thing wrong with her, I am not going to complain!!

It sounds like the TV cable is not adjusted properly. If it is not correct, the trans won't downshift. Check the manual for the proper adjustment method. This is very important to get right. The bowtieoverdrives.com site probably has info on it.

Cadillac Giovanni
07-02-07, 11:51 AM
If you're mechanically abled in the least bit of any way, you could probably change the solenoid yourself. You can pick up the part for about 60 bucks from your local GM dealer and save the installation fee. The solenoid is toward the front of the tranny once you get the pan off. Then it's just a matter of a few screws and plugging it in.

However, get the TV cable checked out first. It may be one, or both of those issues.

88landyacht
07-02-07, 12:07 PM
Is that anything like what was called a "modulator valve" back when?? cause I replaced one of those when I was 16 on my 1970 Skylark I had back in like 1980-81, But back then, that thing poured white smoke out my tail pipe like the water going over the Niagra Falls!!

And I believe, if I remember correctly, it was on the right side of the tranny.............

Cadillac Giovanni
07-03-07, 06:30 PM
I believe the modulator valve is what is connected to the TV cable inside the transmission in order to help the transmission select the proper gear for the current conditions. (I think, I may be entirely wrong.)

The torque converter clutch solenoid is the valve that controls when the torque converter locks up in order to better transfer power at higher speeds. I think it locks it up at around 40 on the Broughams. When it goes bad, it can lock up too soon, causing the car to have trouble accelerating, because it's like trying to take off in high gear. The other problem it causes is for the clutch to unlock too late, which makes the engine drastically drop RPMs at the last downshift, and even stall if it's bad enough.

Terribly easy fix though. If you did a modulator valve, you could change one of these.

88landyacht
07-03-07, 10:01 PM
I believe the modulator valve is what is connected to the TV cable inside the transmission in order to help the transmission select the proper gear for the current conditions. (I think, I may be entirely wrong.)

The torque converter clutch solenoid is the valve that controls when the torque converter locks up in order to better transfer power at higher speeds. I think it locks it up at around 40 on the Broughams. When it goes bad, it can lock up too soon, causing the car to have trouble accelerating, because it's like trying to take off in high gear. The other problem it causes is for the clutch to unlock too late, which makes the engine drastically drop RPMs at the last downshift, and even stall if it's bad enough.

Terribly easy fix though. If you did a modulator valve, you could change one of these.


Yeah, but that was 27 years, and 2 back injuring accidents ago!!..........

Cadillac Giovanni
07-03-07, 11:29 PM
Well, still, very easy. If you can lie on your back under the car you can do this. If not, no big deal, like it was said, it costs 150 bucks to have it done, and 60 bucks worth of that is the part itself.

3141592654
07-04-07, 08:25 AM
All of the regular RWD Caddies got this transmission in 1988. This is one of the reasons that I decied to go with the THM 400 in my rebuild project. VERY SIMPLE...one wire, one vacuum hose, and NO lock-up clutch. They forgot to put the forth gear into it, though! :rolleyes:

pi-