th350 trans and kick down cable

what is the side effects to not hook up the passing gear cable on a th350?

 

None that I know of except the lack of a passing gear when you need it.

 

You will have to manually drop down a gear to pass.

 

Ran mine for a while without one with no problems.

 

I don't use it.

 

It will stack shift,1,2,3 by 30 mph. It uses a govener(to let the trans know what the rear wheels are doing) and throttle press (the kick down cable) to let the trans know what the engine is doing. Between the two the valves and springs in the valve body it figures through pressure where to be.
As speed increases pump press does proportionally blowing the shift valves off at set pressure intervals.
Throttle pressure blows off line pressure holding the gear a little longer on light pressure and a lot longer on hard throttle pressure.
When the throttle pressure is fully engaged it puts it in the previous gear.
So hook it up and keep the trans alive longer and a lot nicer to drive.
Hope this helps,Gary

 

If it's a light weight car, you won't need it. I was going to hook mine up and after quite a few members ran through what happens in a light car, I didn't do it. A light weight car could get a little squirrelly, doing the passing gear thing.

Do some internet research and you'll see the results. I've never had mine hooked up and my trans shifts great. Never heard of stack shifting and I'm not sure what that has to do with a passing gear, but ya read something new everyday.

 

I have to disagree, this a TH350, not a 200r4 or a 700R4. Cable is for kickdown 3-2 for passing, not line pressure control like the TV cable on the later overdrive transmissions. I normally run a B/M transpak on stage II and manually downshift when needed, never used the kickdown cable.

 

I ran mine unhooked with the 4.11's but when I switched gears to 3.25's I hooked it up. Honestly I had heard about the slight tension needed for the line pressure but really couldn't tell the difference being hooked up vs unhooked.

 

My 48 International gets real squirly on damp pavment with the kickdown hooked up. My bias ply's just don't have the grip. I have to realy watch foot pressure when its raining.

 

i was wondering because i do have a street/strip BM shift kit in it, i expect to be down shifting manualy, was wondering if it would damage the trans because of (line pressure) could be effected(not sure), i have ran cars without before, some were ok and one off them did not, needed to hook up for trans to work properly. if i have to i will but alredy lots of linkage with the 8 carbs

 

Is it the car in your avatar?

 

yes it is, i would try it but up here there is snow for a couple of months yet, it was not hooked before and i only drove the car about 40 miles gently. but i have made i few changes over the winter, gears,shift kit, motor, sthall torque ect, the linkage is pretty busy and not much place to hook-up

 

g.m. could have saved alot of money if they knew they didnt need them

 

I've known people who have blown up TH350's doing this and insist they don't need that cable. It does effect the shift points under normal driving, not to the extent of a 200r4, but enough to where it will shift at an improper point (too low RPM etc).

 

Sounds like you already know you're answer. I'd leave it unhooked.

 

Why? It only comes into play, when you stomp on it. I've never had it effect my shifting. Ever.

 

i agree tfeverfred,only works when you hog on it,no other efect

 

Trans will shift earlier than it should without it hooked up. Not a problem if you manually shift it, or have a shift kit which will hold the gear longer than usual. A stock trans will puke if you leave it unhooked for a prolonged period of time.

 

No chance. If you look at the connector for the kickdown cable at the carb it is slotted, the cable does not even get pulled until WOT. Sits idle any other time. Governor on the side controlls shift points in automatic mode, I spent enough time with them changing springs and weights back in my street racing days. Adjustable vacuum modulator was good for only minor changes.

 

Mine shifts at the right time, all the time. No bad experiences yet. A while ago, I ran a junk yard 350TH without a rebuild, for 3 years. Worked great. Even my trans shop said I didn't need it.

You're saying, if someone drove a car and never tried to pass someone, the trans would die? That doesn't sound right.

 

Just so nobody goes off with the wrong information: the TH350 is the ONLY automatic of that I am aware, that can be used with the cable unhooked, and not suffer damage. EVERY other automatic (of that I am aware) will suffer damage if operated in this fashion.

Lastly, and in my opinion ONLY: why not show off your fabrication skills and hook up the damn thing?!?!!?

Cosmo

 

It's not a matter of hooking it up. It's a matter of controling a light weight car, when it goes into high speed passing mode. That's the opinion of some people who have tried it.

 

Well....I do run the kickdown cable, every car I've built, lots of misinformation here. From T buckets up to my gonna be totally overpowered plymouth coupe, I run the cable hooked up.
1, No, it won't damage the tranny unhooked
2, it does more than wot operation, properly adjusted it controls part throttle kickdown
3, part throttle kickdown makes the car a pleasure to drive, as the car will downshift in traffic for a little more rpm to change lanes or impress yourself with what a nice car you've built.
4, Adjust the cable so that the cable is pulled fully at wot, then it'll shift all the time like its supposed to, even at part throttle.
5, No...the shift down at wot won't help you lose control of your car, you can do that just as easily yourself moving the shifter , which at some point you're gonna do if you indeed think of yourself as a true hot rodder.

 

A Turbo 400 also works fine without the electrical kickdown hooked up. Same as the T350, it just will not kick down instantly when you floor it. The vacuum modulator will sense the throttle and it has a delayed kickdown, if the speed is slow enough. The governor and vac modulator are what control the shift points in T350 and T400.

 

Exactly

 

thanks guy's, also do you kno what is the outlet pipe for the trany cooler, the top or the bottom fitting on the trans. want to add a cooler after it comes out of the rad. if i could start the engine i could check the direction of the flow but for now i can't it is in the basement for the winter, if i am not mistaken the top is out and the bottom is return.

 

Been running a TH350 for over 7 years without having the passing gear. No issues at all. It has a B&M shift kit installed and shifts great. The car is light enough where I haven't needed the passing gear anyways.

 

bottom is out , top is return

 

Mine was broke for a while. Made the car feel lazy and seemed to affect the shift points more than just eliminating "passing gear"