jchaussee

As it says. When I am going down road and when it shifts from first into second ( automatic, 700r4) it shifts hard and the rear end kinof breaks and wants to slide. This normal? Messed up? Anything to look into?

Thirdgen89GTA

iTrader: (5)

The First answer is get a lighter foot, yours is too heavy.

If the First answer is not true, then and its an Auto with a B&M or other crap "shift kit" then yes. They increase line pressure so much that part throttle shifting is ruined. 700R4's are known for the 1-2 bang shift when cold as well. I've seen peg leg 305TBI's do it constantly with just mild throttle.

But a properly built 700r4 with a trans-go shift kit? They are smooth and firm during part throttle and get progressively harder as you approach WOT. And shouldn't be barking tires with light or mild throttle.

My GTA with the LT1 and full bolt-ons makes 1st useless. And a hard 2-1 downshift at WOT will break the tires loose and set the car sideways. However, a 1-2 WOT upshift after i've loaded the suspension and gotten out of the hole won't set the car sideways at all. The torque converter absorbs the driveline shock and keeps the rear planted.

jchaussee

So when I pop the pan off to change fluids and filter , is there evidence of a shift kit? I just want to make sure tranny isn't on its last leg. I have never had any good luck with 700r4s

Thirdgen89GTA

iTrader: (5)

No, no external evidence of a shift kit. Its all internal to the valve body.

I forgot one more thing.

Check the TV cable.

It will be attached to the throttle body be it TPI, TBI, or V6. There is no adjustment in this cable. It can't be adjusted for firmer, or softer shifts, there is only One Setting to Rule Them All.

Depress Slider button, pull cable sheath away from the throttle body attachment point, then manually open the throttle blades till it hits the mechanical stop (don't use the pedal, use the arm itself)

camaronewbie

When you remove that pan to change fluids/filter, get a drain bung put in to make the process easier next time.

UnderCover89TBI

iTrader: (25)

Sounds like a shift kit I wouldnt be too worried about it. you may be able to adjust the tv cable to make it a little less bad.

Thirdgen89GTA

iTrader: (5)

It has one setting only, and that setting is determined by the calibration method listed in several articles and threads on these boards. Its not like the old kick down cables. I've seen more than a few transmissions DIE due to a stretched TV cable, or an improperly calibrated cable. I've also seen people fry the trans in a day because they thought they could drive around with the cable disconnected because it was broken.

jchaussee

I know my tv cable is messed up. I do not drive car really, so I do need to replace it. But with it being consistant with its hard shift from first to second and it a%% end slide, I assumed it was more than just the cable. Because it does shift about where it is supposed too. But I am not expert by far with trannys and in my older chevy trucks I was known to blow a few 700r4s. Granted they were the early 80s trannies and had not been perfected yet, but if this in my car is the originall, then it is the same one I have come to love to hate

Thirdgen89GTA

iTrader: (5)

Tv cables do more than control just the shift point. They control shift firmness as well. A stretched or improperly adjusted tv cable is the cause of many trans issues on the 700r4 series.

The only place I know that sells a correct cable is the dealer. And that is one of the few parts I will only buy from the dealer. I tried an auto zone one and did not like it. The fit was poor And most importantly I could not get it to calibrate correctly.

jchaussee

Ya, I will have to go get one on Monday. Just so I am sure. TV cable is the bottom cable right? Also can you point me to a good thread on replacement. It looks like a pain in the rear to do

Thirdgen89GTA

iTrader: (5)

No threads that I know off off the top of my head. They are here though.

Best practice is to hook up the case portion at the top bit don't attach it to the throttlebody yet. The spring tension is too strong.

Then feed the cable down below. Once that is done jack the car up. Drop the cross member to let the trans tilt back and provide easier access. You'll be doing the actual tv cable install blind and there isn't alot of room.

There is a bolt the holds the tv cable to the trans. it's a 10mm bolt I think.

The tv cable Attaches inside the trans with a small hook. The fun part is getting the hook to stay connected while bolting down the tv cable case. A friend is useful here to put tension on the cable to keep the hook on the tv arm inside the trans.

I've substituted a rubber band for a friend befor though.

jchaussee

Ahh. Sounds like a lot of fun and curse words. LOL

UnderCover89TBI

iTrader: (25)

so your saying is if you adjust the cable the way you are supposed to and that is 100% right, if the shifting is too soon or too late or too harsh or too mushy. your stuck with it. what happens if you have a new cable and it does this. every way I ever read is that you do the preliminary setup and then slight adjusting forward or back on the cable to get it to be proper

Thirdgen89GTA

iTrader: (5)

If you adjust it correctly, and the cable is not stretched, or worn in any way, yet the shifts are STILL too soft, or wrong then you have a problem. Either with the gear and clutch assembly, or the valve body.

The purpose of the TV cables adjustment is to let the transmission know what exactly 100% throttle is. If you "adjust" it so that your shifts are firmer the transmission will think that what may be 80% throttle is 100% throttle. Which means shifts will occur higher in the RPM band, and be firmer. At part throttle this isn't bad. But at true WOT the line pressures will be TOO high causing excessive wear, heat, and possibly mechanical damage to the planetary gear sets and sunshells. 700R4's are already known for cracked, and damaged sunshells.

Conversly, adjusting the TV cable so that it believes 100% throttle is 80% throttle means that the line pressure will not be high enough during WOT shifts causing excessive slippage, wear, and yet again HEAT.

Why is heat so bad in a automatic trans? Think of the friction material in the transmission as a you would a brake system. The frictions have the same relationship as pads do to rotors. Excessive heat causes them to glaze, once they glaze they are useless and will NOT have any friction left, hence a slipping trans is the result.

Heat also causes transmission fluid to break down much faster. Transmission fluid is oil, but with many more detergents and additives that keep the valvebody free of contaminates so that valves operate freely.

Read this article. http://www.tvmadeez.com/article/index.php

As you can see in that article. You don't really adjust the TV cable so much as you calibrate it. This is also why having the proper TV cable for your car is so important. If the cable is stretched the transmission will not be calibrated properly.

91 zeee

That TV made ez article is really good...definately the place you want to start if you are not familiar w/ TV cables.