transmission trouble?

Question

I own a 1984 firebird with a 305 V8 and the 700r4 tranny it isa 4-speed automatic. Whenever i drive it, it doesnt want to shift out of first gear until like 3500 rpm and it keeps on continuing through all the gears. But what ive figured out is if i pump the gas pedal really hard a few times before i turn on the car, then it runs perfectly. I talked to some of my buddies and they said it was either a modulator valve, the T.V. Cable, or the governor, i think its the valve. Does anybody know if i can do it myself and do i have to drop the tranny, Please give me detailed instructions. thanks

what side of the tranny is the modulator on ? and is it easy to get out ?

Answer 1

Modulator ??? Shift control Module???
Some people have no business answering these types of questions.........They will only send you on a wild Goose chase.

I've been a tranny tech for 21 years, so here is the straight goods on your problem. First, no modulator valve. The Governor, although it controls the up shifts, is not the problem. You said when you pump the gas pedal hard a few times, it runs normally. So what does pumping the gas pedal have to do with the transmission??? The T.V. Cable !!!!
The cable goes into the transmission, where it acts on the throttle valve line up. This consists of 2 valves. One is the plunger, which has a return spring on it. The other valve in this line up is a free floating valve (no spring). Any debris or contamination in the tranny can/will cause this valve to hang up and the result is late/hard shifts. This problem can be corrected by installing an aftermarket spring on the valve, but it needs to be done by a professional. Keep in mind that installing the spring will correct the symptom, but not the root cause of the problem.....
Contamination/Debris.............

Answer 2

First off the 700R4 trans does not have a vacuum modulator. The only communication between the engine and the trans is the T.V. link. A lot of people incorrectly refer to it as a kick down cable. My only guess (keep in mind it is only a guess) is that you have a clogged filter. It would be a cheap and easy thing to try. If that doesn't help you will need to take it to a trans shop. 700's are the most tempermental transmissions out there. I run one in my car (not original) and I have replaced it several times now. I have more than twice the factory horsepwer and most of the failure is because of that. 700's have one of, if not THE, lowest first gear of all production transmissions. For this reason it should shift sooner not later. You could have a clogged port in the valve body or one of the channels inside the trans. maybe even a piece of dirt in the valve the T.V link controls. The pump is very high pressure. Arround 200 psi. (mine pushes 235 psi. when I checked it but it's a custom build) This is really not a transmission to get into if you have never had one tore completely apart before. A lot of small shops don't even like to work on them so if they seem hessitant when you ask about it you might be better off to go somewhere else. The problem is 99% chance of being inside because these don't sound like symptoms of the T.V. link being out of adjustment. Good luck.

Answer 3

Before you go dropping the tranny, I'd go with the simple stuff first. Check the fluid for the proper color and fluid level; if it is brown or burnt looking, that could be the root of the problem. In that case a fluid and filter change is in order. Secondly, as another answerer pointed out, I'd check any vacuum lines going to the tranny (if you have any) for cracks or damage, and make sure they are seated properly. After doing some minor research, I don't think this style transmission has a modulator valve. My advice is to pick up the Chilton manual specific to your year car from your local Advance Auto, Auto Zone, or similar store; it will have troubleshooting tips and detailed instructions, with photographs, of the proper procedures. Or, better yet, take it to a trans. specialist for evaluation.

Hope this helped.

Answer 4

there is not enough room here to give you detailed instructions,,it would probably be the longest answer yahoo has ever seen on here,,you need to go get a transmission builders opinion on it before you go and start spending money on it,,and for all those who don't know,,a 700r4 does not have a modulator valve on it,,they never have ,,i own a repair shop ,in Tennessee,,and we do this kind of work all the time,it sounds like you need advice from someone who can test drive the car,,and i cant do that,,just get a professional opinion,,before you spend any money,,i hope this help,s,,good luck with it,,and have a good labor day.

Answer 5

Heres what I would do. I would change the Shift control module, Then drop the Transmission pan and change the filter and clean out the pan. Then I would check all the linkage between the fuel system and transmission for free operation. Also Lucas makes a great Transmission additive for reduction of friction and wear.

Answer 6

crawl underneath the car and look to where a vacuum hose connects to the transmission. This is where the modulator valve is. Remove it and take it to a parts store. There are bout 3 different ones depending on what the color band it has on the base.

Answer 7

Sounds like a valve

Answer 8

Get yourself a transmission manual and have at it. Yes you will have to drop the tranny. I wouldn't recommend trying this alone especially if you are depending on this car as your only transportation.

Answer 9

Trans filter or vacuum module.

Answer 10

go to your local garage for help it better having a expert looking at your car then see what happen rather then spending on a fortune on the thing that u don't need