neuroclast

Well the title pretty much says it all.

My situation: I purchased the car a month or so ago, it has a 700R4 with everything hydraulic. Even the lock-up of the TC is hydraulically controlled. Well, it wouldn't lock up, and my friend suggested I check the fluid level. Sure enough, it was about 3/4 of a quart low! Well, I filled it up to normal levels, and now it has another problem. It won't stay in 4th gear.

If I accelerate at a normal speed up to like 60, it stays in 3rd until I let off the gas, then drops to 4th and as long as I don't give it much gas stays there. But the minute I give it just a little gas (not much) it drops back down to 3rd. When I'm up around 70+, it won't even hold 4th at just enough gas to hold cruise. It keeps dropping down to 3rd. Let alone bridges, it drops to 3rd there when it sees them a mile away.

I really have no idea what's causing this. I thought maybe the TV cable, so I adjusted the slider in and out and it seems to do it either way.

Any ideas?

Thanks
-Josh

neuroclast

Ok, I tried a few things. It's DEFINITELY staying in 3rd, not 4th.

If I accelerate at a moderate speed, it won't shift out of 3rd into 4th. I got all the way up to 85 and still it was in 3rd, until I let off the gas completely then it dropped to 4th. As soon as I hit the gas a little though, straight back down to 3rd.

I tried to loosen the cable and it didn't make it better, also tried to tighten it and while the shifts got hard it also didn't make a difference.


This is really frustrating, at this point in time I'm tempted to go let some fluid out just so it will atleast cruise right again!

comp

neuroclast

mrvette

As long as your are SURE from the rpm/ratio/speed calculations that you are in 4th, and not 3rd, you could be having the TC lock and unlock from engine vacuum controll for some such adjustment/trigger ile that is outta wack....you should adjust the throttle cable to be tighter than Dick's hatband at full throttle, and still allow full throttle...
I do it by pushing the D shaped metal piece into the plastic to let the cable slide out toward the tranny a bit, release it, then force the throttl open, it will eventually pull the cable length adjustment into position...if forced open from under the hood, NOT by the gas pedal....

the TC lock is controlled electrically ...but that hudraulic valve is the interface from electric to hydraulic....


NOW, I suspect you are locking and unlocking, BUT, having said that, from reading your post a couple times, you MAY be having an extreme example of the way MY 700 acted in my '72 shark.....

it tended to downshift when over 1/2-2/3 throttle....no matter what...

another thing I hated about that tranny and am SO glad I did another swap to the 200 4r last fall....

cured THAT problem....I can do 130 at close to full throttle in overdrive now...instead of winding the **** outta my engine....it's a 336 rear diffy BTW....stock tire height....

neuroclast

Well I can try to tighten the slider back some I guess. The tranny is locking and unlocking when it DOES go into 4th, the only problem is BARELY ANY throttle sends it back to 3rd, and it won't shift to 4th without me letting off the gas (atleast at up to 85-90 mph).

mrvette

YUP, an exaggerated version of MY symptoms.....even here in the Florida flatlands tallest elevation in the state being some 300'....it was a PIA to live with.....I have 336 gears, my car WAS a Muncie 4 spd...

wonder what your ratio is??

wonder whos' shift kit, if any, was installed.....IF any, I bet it'a a superior/fairbanks.....

which is what MY 700 had,

I have been a trans go supporter for decades now....which is in my 200 4r, which I dearly LOVE for it's overall road manners....

neuroclast

I have a 3.55 rear, 2800 stall w/lockup, transgo kit.
So you didnt get it fixed when you had the 700R4? I really don't want to have to live with it like this, and I don't have the money to change to a 200.

couperdecar

try this link : http://www.bowtieoverdrives.com/hot/

3/4 Throttle Valve
Product: 3/4 Throttle valve
Price: $34.95

When cruising in overdrive (4th), your transmission will downshift into 3rd gear if the throttle is more than half way depressed. With the 3/4 Throttle valve, your transmission will not downshift into 3rd gear until the throttle is at least 75% depressed. This allows for cruising at higher speeds in overdrive.



I've got the same car ('79) and LUV the 700R.
You ABSOULUTELY should also have an adjustable cam mounted on the throttle linkage on the carb - that the TV cable goes to. Its by adjusting this 'cam' that you shift into the next gear earlier or later.

neuroclast

Well, my problem is it slips to 3rd w/maybe 10% gas. If it was 50% I'd be happy

couperdecar

And you have the adjustable cam on your throttle linkage?

neuroclast

Here is what I have:

couperdecar

Nope - you don't have it. And you need it. Let me go on BTO site for awhile and see if I can fine it.

Artsvette73

I think the problem is in the cable.
I see the alignment with the cable and the throttle shaft is at an angle. It should be straight. I don't know if you have a stock manifold or not but I do see a spacer plate. Which will compound the problem. And the adjustment of the cable looks pretty far out. Have you looked to see if your throttle has full travel? The throttle plate shaft and the point where the cable hook up is critical.
http://www.cpttransmission.com/ Read the tech article.

couperdecar

OK - try this link : http://www.tvmadeez.com/1905_cam/

These pictures show the guy installing the cam onto his throttle linkage.

What they don't show is the actual cable hooked up , but once you get it you'll see the slot that the cable hooks into.

neuroclast

So what does this actually do? I can already adjust the cable length at the black plastic snap, does this do something else?

couperdecar

probably you'd be way better off to read the BTO explaination than mine

Heres a quote from BTO : (from this link: ) http://www.tvmadeez.com/article/index.php

The sole purpose of the TV valve is to direct TV Feed fluid into the orifice shown with the red circle. The volume and pressure of this TV Feed fluid, being directed into this passage, will progressively increase, as the accelerator pedal is being depressed.This increasing TV feed volume and pressure entering into this feed passage is directed to all of the transmissions pressure regulating and shift control circuits.This increase in volume and pressure is not designed to increase in a progressive straight line; it's heavily biased towards increasing pressure and volume more rapidly during the initial movement of the Throttle valve and to have delivered its full influence by slightly over half throttle opening.

I've colored the important part in red. 'Thats' what the cam is for.
Go on the BTO site and do some reading. There's lots and lots of interesting and good info there .

EDDIEJ82

Desfegx I'm gonna try to help you out here. I still think you should read the bowtie overdive article it's the best one out there and the most easiest one to understand.

See the arm on the carb that the tv cable is hooked to? That arm was designed for a downshift cable, not a tv cable. The geometry is wrong and it doesn't pull the cable at the right angle or speed in relationship to the rpm increase of the motor while going down the road.

The tv valve in the trans controls the shift timing and also the fluid pressure that is applied to the clutches with the rpm increase of the motor. If the tv valve isn't in the right spot in relationship to how far you have the gas pedal mashed, the correct pressure will not be applied to the clutches to make them grab correctly. Kinda like riding the clutch on a standard car and never letting it out fully. You understand that if you always ride the clutch on a standard car it will burn it out. Same thing for the clutches in the 700r4.

Bowtie overdrives makes a kit that corrects the geomotry and the pull of the cable OR you could figure out all the angles and bulid it yourself.(I'm not a salesman for Bowtie, it's just the easiest one to hook up) There are resources on the web to make your own.
http://www.transmissioncenter.net/subject.htm
http://www.tvmadeez.com/article/index.php
http://purplesagetradingpost.com/sum...o/700R4p1.html

Also I doubt if the guy that installed this trans didn't know how to hook up the tv cable, he didn't have a clue how to hook up the lockup kit. Yes it is hydrolic but it is controlled electronically.

I'll try to help you anyway I can as will the rest of the guys on here. But read the articles first so you can understand what we are talking about. If you don't want to try to understand this trans to work on it yourself, you would be best to take it to a repair shop while it is still working. Just my opinion and everyone has one.

neuroclast

Well thanks guys, that helps a lot. transmissioncenter.net sells a bracket that does the same thing as the cam I think, only it's by itself so I don't have to buy the whole kit. I'll purchase that and see what it does.

I know I'm a newb to autos but I really appreciate the time and patience.

Thanks
-Josh

markdtn

I would not drive the car until you get the TV cable sorted out. It does not take much time at all to burn up a trans if it is not adjusted correctly. It needs to be level at the throttle connection. You should be able to use a bracket from a 83-86 Chevy truck or Caprice (to 89?) with 305 or 350, 700R4, and Q-jet.