Well the title pretty much says it all.

There are two things...
Are you sure it is actually going into O/D?
How far did you adjust the cable, and did the cable adjustment change any of the other shifts?
You may have a cable adjustment issue, which I would certainly check first.
The other thing is...if it has been run long enough with it low on fluid, the band may be scorched. However, the band also applies for 2nd gear, but it uses a different servo to apply 4th. There may be a problem with the servo.
It could also be a valve body issue.
We need to know for certain it is shifting into 4th. Next time you drive it, get it to shift into what you believe is 4th. Once it shifts, without taking your foot off of the gas, pull the shifter down into 3rd, and make sure you feel a definite downshift, and check the RPM rise as it does. If the rpms only go up 100-200rpm, then that is not a 4-3 downshift...it is a lock-up release.
Are you sure the trans is taking off in 1st? It could be taking of in 2nd, and shifting thru to O/D, and the last, late shift you feel may actually be lock-up.(just going thru all of the possibilities, here)

I would suggest you loosen off on the tv cable adjustment, as that can cause the late/sensitive 3-4 shift. You want to move the outer cable housing toward the carb to loosen the adjustment. Do this a couple of notches at a time. Do not loosen it enough for the trans to start slipping, tho. If you do, stop, and tighten the cable adjustment a few notches. Then do not go any farther loose from that point.
How is the cable attached to the carb linkage, anyway? You may have a geometry issue here, as far as the linkage/cable goes.
IF the cable adjustment makes no difference in any of the shifts, you will have a valve body problem, and it will need to come off to fix.

Well, I think it's going into 4th because it's like a 1000 RPM drop. I wouldn't think I'd see that just from a lockup on a 2800 stall. But I will for sure go check it in a minute (put like 50 miles on the car so far today just playing with a cable haha).

defsegx2007-11-12 11:33:24

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.

Shift points are 15-20 for 2nd, 25-30 for 3rd, and no 4th?
This is really frustrating, at this point in time I'm tempted to go let some fluid out just so it will at least cruise right again!
Here is a pic of the linkage:

Linkage pic

(large image modified to link)Adams' Apple2007-11-12 20:03:34

The cable bracket appears to be close enough to work, but the pivot point on the carb itself may be too short.
Now...you say it was working fine until you added "3/4 quart" of fluid. That's not enough to make any difference in it working or not, unless...the dipping stick ain't right. There is a slight possibility that the trans is now overfull, and that will lead to the fluid aerating, which can cause some weired stuff to happen. At this point, you gots nuthin to lose by draining a quart out, and trying that. Stranger things have happened.
If, after you do that, it still doesn't work, I'd have to suggest you drop the pan, and see if part of the band is laying in the bottom of the pan. I'm talkin about nasty black stuff...
While the same band applies for both 2nd and 4th gears, the servo for 2nd has much more apply area(clamping force) than the servo for 4th. The 4th servo also has more of a tendency to leak than the 2nd servo. This will sometimes allow a burnt band to still operate 2nd, but not 4th.

I wouldn't rule out a stuck/sticky valve, either. Adding fresh fluid may have dislodged a piece of trash in there somewhere, and it may be hanging the 3-4 shift valve. If you can, try to locate someplace that sells a product called "LubeGard" transmission additive. A trans shop would be your best bet...I'm not aware of any other place that sells it, but you may luck out and find it at NAPA, or someplace like that. If you can find it, get a bottle of the red..it comes in black, red, green, and silver bottles. It is simply to lubricate, and unstick valves in valve bodies, and trust me...it works. Be prepared tho...this stuff ain't cheap! MY cost is over $8 for a 10 oz. bottle.
One last idear..IF the trans still has the pressure switches on the vb, the 4th pressure switch may be leaking. This will definitely cause no 4th, or slipping 4th. The pressure switch(es) screw into ports on the vb, and signal the ECM that the trans has shifted, and what gear it is in. If yours has been made hydraulic, you don't need them anyway, but some builders leave them in, just to plug the holes. A normal, 5/16" pipe plug will solve the problem IF the switch is leaking.

How's THAT for ruining yer day?

Adams' Apple2007-11-12 20:36:49

Thanks a ton for the reply. It will give me somewhere to start. The distance from shaft to pin on the pivot arm is supposed to be right under 1 1/8" right? I'll check that tomorrow. I might try to drain the pan too, we'll see.

I've also been told the linkage on my QJet isnt the proper setup for a TV Cable, so I have to order an adapter as well. Doing that soon.

Yeah...the stud on your carb is for the kick-down, or passing gear cable on the 350 trans. It doesn't work right for the 700, as the 700 tv cable controls the fluid pressure in the unit, which is very important to the survival of the trans, and the 350 cable only forces the downshift(kickdown), which is way less important. That's where the difference in the geometry of the lever/linkage comes into play. There are adapters to make what you have work for the 700/2004R family of transmissions. I think Jegs, and maybe Year One carry them, but I'm not 100% sure. The places that sell the trans swap set-ups also have them, such as BowTie Overdrives, etc.


btw...changing the filter is not gonna "fix" this issue. It won't hurt, but it ain't gonna solve the problem.
If the filter is stopped up enough to create a shifting problem, ya gotta ax, "Where did all that stuff that stopped the filter up come from in the first place?"

Well I ordered an adapter from transmissioncenter.net. It said on the site "will fit any Edelbrock carb." I got it, and guess what, can't get it to fit. I asked the owner of the business for better instructions or a refund. He said he won't refund my money because it's "been opened." Kinda pissed since it cost me $47 and I can't use it, and because I tore shrinkwrap I can't get my money back. Kinda sleezy business. defsegx2007-11-28 20:49:45

I can look and see if I can find what you need....just need to know what carb ya got....the pic you have posted shows a Quadrajet, but you mention Edelbrock in the above post. I'm pretty sure Edelbrock don't make a trans...
If it's a Quad, I think I can get the adapter, but I ain't promisin nuttin yet....