TH350 kick down

[tfeverfred]

Okay, I recently installed a new th350 tranny in my T. I didn't connect the kick down, just plugged it. I've never hooked it up (never hooked it up in my old one) and the reason was that somewhere (don't know where) I heard that in a light car like a T, when it shifts down to 2nd and back up to 3rd (like passing someone), things can get squirrely. While this does sound cool, it doesn't sound safe. So, is it true that having it hooked up in a T is unsafe?

Will I have great fun or go to the garage in the sky?

 

[sstock]

Fred. I have a th350 on mine and did not use the kick down. Really no need IMHO. I imagine a high rpm shift down under the wrong circumstances could yield an interesting result, and yeah stay out of the garage in the sky that way.
SS

 

[Screaming Metal]

hahaha...hope you won't go to the Golden Garage just yet, my friend!
The passing gear on your trans is just what it says, a passing gear. Its for the car that the trans used to be in when it was all stock, that big heavy 3200# piece of Detroit's finest.
The purpose was to downshift, bring the revs up to move that big heavy Camaro, Impala, Chevelle, Expedition, whatever it was, get all that momentum moving so you could pass.

In a light T, you don't need it. I don't even think about hooking one up, which I have enough horsepressure to swap ends while passing someone down the road on a dry day.

Imagine yourself going on a cruise, dew on the ground, jump out there on the road, and you have to pass someone and you have a fairly healthy motor, 3.55's out back, your car doesn't weigh 1500#.
Suppose some car had a wreck there a week before and wet the road down with oil. Just got thru raining, has just dried, and you swinging out, applying a good healthy strong 355 horses + to the ground.....things can get wild and wooly, and its not even under your control!

I have a manual valvebody in mine, I like std's, so I can shift without the clutch.....
To each their own.
Do you need a passing gear? NO.
If you want one, hook it up, but you don't need it performance wise.
If your T doesn't have the beans to go around a car, after you press on that accelerator, you'll be safer staying behind that car until you have enough room to safely do so.
If you can't get your passing gear to work and you really want it, you can always get a budget NOS system, and have a few hundred horses at a press of a button.
Its best to use sparingly if you've never been around the stuff....

You can get a budget 'cheater system' for about $250-300 for 125 to 200 horses. But they do have 400+ horse systems out there that will blow the oilpan slap off your shortblock.....

 

[tfeverfred]

Thanks, guys. These are the things that had crossed my mind before I ordered a hook up. Like I said....... I always just wondered if it was an exaggeration or a real concern.

So, I'll let her alone and just stomp on the gas like I usually do.

 

[Screaming Metal]

I have even messed around with injecting compressed oxygen into the intake. Works really well if you regulate it down, hooking up a microswitch and a couple of psi, gotta be careful though, you could melt down a perfectly good mill!
Doesn't add any hp, but it sure peps things up when you need that little extra push....I run propane injection on my diesel pickup, Dodge Cummins Turbo Diesel, twin turbo setup. I get close to 28 mpg with a crewcab dually....

 

[tfeverfred]

Hahah I don't need to pass enough to get nitrous.... but it sounds like fun. Seriously, not in the budget. The Lokar kick down is only $40.

On another note, when conditions are right, she'll slide a little in the 2nd to 3rd shift. By right I mean when I'm stomping the gas. Man, I love that sound. Hahha

 

[GT63]

I was told by TCI and the local tranny shop,I had to hook it up because not only did it control the "passing gear" but it also controls the fluid pressure under normal driving speeds, otherwise it could fail prematurely.

 

[Screaming Metal]

I was told by TCI and the local tranny shop,I had to hook it up because not only did it control the "passing gear" but it also controls the fluid pressure under normal driving speeds, otherwise it could fail prematurely.

Yes, it controls fluid pressure.
On any trans that I use for performance, and the Kickdown is not hooked up....I pull it till its just below kickdown, (that way the pump is putting out max pressure), then I crimp the cable housing to the cable with my big bolt cutter looking crimpers, then trim off the extra cable.

You can do the same thing by bending the cable back upon itself and put a cable clamp on it from any hardware store. Just be sure to pull it out while going down the road, till it kicks down, then back off a hair. I made a tool out of a universal choke cable for about 7 bucks, go for a ride, then I start playing. When I find out where that point is at, I use a roll of tape to tape it in place, once back to the shop, I crimp it.

 

[Telman2]

I've had 2 TH350 transmissions in my bucket over the last 45 years and never had the kick down hooked up in either one of them. Never needed it, never missed it.

 

[WMG]

Had the kick down on mine and just about lost it a couple of times when there was a bit of trash on the highway, gravel etc. Just got a new tranny from Jegs that does n ot have a kick down. When I get it back together I think I will have all the power I ever need to get around the slow pokes and I do not have an over abundance of HP's just a stock Camaro 305

 

[PotvinGuy]

I think there is a little mixup here. I can't speak to every tranny, but on the TH350 and TH400 the vacuum modulator controls tranny pressure. The kickdown, which is on or off, nothing in between, has no effect until it is engaged on WOT or otherwise. I have a TH400 in my bucket. I picked it 20 years ago because it has an electric kickdown and I was going to wire it to the ECU for my EFI. Well, I soon realized that a kickdown was insane in a car with so much power and so little weight. So I never hooked it up.

 

[PotvinGuy]

Little more info: on the 700R4, 2004R and 4L60 trannys, the Throttle Valve (TV) cable replaces the vacuum modulator and the kickdown cable of the 350/400. The TV cable controls kickdown and tranny pressure and shiftpoints, etc. The TV cable is essential and adjustment of it is critical.

 

[roadmonster]

It depends on your car, but I built mine with tall gears and wide powerband and the kickdown is a real thrill. At 60, it will go from 2000 to 3000 instantly with a smart little chirp and no squirreliness. I would not want to go from 3000 to 4000 though! If you have a low-revving car it is a blast and not unsafe at all. If you have a high-powered or high-revving car, I would be very careful.

 

[Screaming Metal]

The best thing to do, honestly, with a stock trans, is have a shift kit put in to firm up the shifts and raise your fluid pressure, independent of the cable or vacuum mod. Diff. trans use diff. ways to control pressure, depending on make.
Gerry from UK could probably give us a hand in this since that man drinks Trans. fluid for breakfast since he works on them all the time.
Whenever you run a manual valvebody, your fluid pressure is over-ridden, because the use of a MV constitutes a preformance enhacement, therefore, needs more pressure.

All cars and trucks can benefit from smoother, firmer shifts, gets you better fuel mileage, thats my 2 cents. Because our cars are about usually 1/3rd the weight of their old selves, moving 1/3rd as much weight is easier on the trans. But, when you add a converter and a motor thats sometimes double the horses....its best to have some help inside that trans. Just do some searches, look around, and the truth shall set you free, and down the road to some performance as well!
http://www.high-impact.net/transmission_and_gear/1autotransmakinglive.htm

 

[Gerry]

T Bucket and 350..
I have done away with the KD cable its just not needed. If you go for a manual VB and a shift kit then just bear one thing in mind, Its your throttle... and the harder you press the sharper the change. It will bite you in the rear at some point.... With this set up you will have sharper changes, and yes they will 'chip' your tyres on a dry road but will just as easy turn you 18o on a damp or wet one.

You can dial in the way it drives using an adjustable modulator. very easy. Pull off the vac tube and stick a screwdriver or hex key up the end of the pipe. Turn it 360 degrees one way and go for a drive. If it too hard turn it back 540. keep playing till you got what you want.
Personally i want mine to change like a Mercedes till its a balls out dual with a kid in a rice rocket.

There are pics on plugging the KC cable hole and changing the 350 to a side fill to eliminate the dip stick and tube somewhere around.

250 HP plus, and a 350 in a T. Just press the pedal and watch them all looking at your butt end.
JMHO. And yes it will still change down if the vac says it needs to.

I have not even got 2 and 1 on the T just P R N and D. Dont need 2 and 1 with 450 HP and a T that weighs about the same as a well made gazeebo.

As for coverters, I had mine stalled at plus 500 and the vanes brazed, just to keep them in place. A good tran shop should have a reference book on vane angles for loads of different cars, weight etc. ask them and they should (if they are any good) advise you on the mods to the TC you need for your car, its weight etc and the way you want it to drive, alternative is to contact a company like JW racing and tell them all the specs including cam, launch revs, fuel type, diff ratio, rear tyre diameter, weight, height above sea level etc and let them build a TC for you and your requirements. It will work exactly like you want but its not cheap.
Bit like screaming metal but not as friendly and funny........

G

 

[ellis8500]

OK, any body got any thoughts about a Ford AOD and it's TV cable?

 

[Wild Mango]

The best thing to do, honestly, with a stock trans, is have a shift kit put in to firm up the shifts and raise your fluid pressure, independent of the cable or vacuum mod. Diff. trans use diff. ways to control pressure, depending on make.
Gerry from UK could probably give us a hand in this since that man drinks Trans. fluid for breakfast since he works on them all the time.
Whenever you run a manual valvebody, your fluid pressure is over-ridden, because the use of a MV constitutes a preformance enhacement, therefore, needs more pressure. quote]





What Screamin' said!!!. Little lite car like a bucket, full manual valve body with engine braking in 1st and 2nd, reverse pattern so you shift away from neutral and reverse gives you all the control you need. Wet roads, having that engine braking in the lower gears helps keep the back end behind the front. Lets face it, all buckets are prone to swap ends. My own one, I go down to the garage, it's pointed the other way sometimes, esp. if its raining