Kickdown/Passing Gear

[69f100ranger]

I just had both my engine and transmission rebuilt and will be shortly putting them back on the truck. My question to you all is how necessary is it to put the passing/kickdown gear rod back on the trany and linkage to the carb?

Pros & Cons if any.

Al

[FORDification]

Well, I suppose it's not absolutely madatory to reinstall it, but why wouldn't you want to? I would think it's going to make driving the truck less enjoyable, since you'll have to manually upshift the tranny whenever you give it gas to pass a car or accelerate up an on-ramp.

[morganater]

My truck's downshift set-up sucks. It may just be the C6's gearing or something but its really wierd. MY truck will literally shift into 3rd gear IDLING if my idle is set to about 800 which it is in the winter. The only way i can get my truck to auto downkick (the rod IS hooked up) is if i stomp it going about 30. any speed higher than that and it will wind out 3rd and be really slow. I can always use my nice b&m ratchet action shifter to bring it through the gears, but even when i kick it down into 2 manually it seems slower than winding out two from a dead stop. Also, ever since I have had my truck the c6 will rec up a little inbetween gears before it shifts automatically. It has been doing this forever and I have learned to control it, and my tranny has lived through it. I wonder what is causing it? Anyone have any insight, or similar experiences with a c6 in all those regards?

[69f100ranger]

The reason why I'm even considering not attaching the kickdown is because I too have had similar problems with the truck shifting too early near idle. The transmission also would delay alot before the first gear would even kick in after start up. I have tried playing around with the idle and the hook up of the kickdown but nothing seemed to work. Hopefully now that its been rebuilt I won't experience this. So maybe I will try re-attaching it and see how it works out.

[68F250]

It's normal for the transmissions to short-shift in our trucks when you don't have your foot into it, that's the way they are set up from the factory.

As an example, here are the shift speeds for a 3.54 ratio with a 31" tall tire (from the '68 Shop Manual):

Part throttle
1-2 shift @ 6-8 mph
2-3 shift @ 6-17 mph

To kickdown detent (this is the best the vacuum modulator can do)
1-2 shift @ 25-37 mph
2-3 shift @ 46-62 mph

Through detent (W.O.T. this is where the kickdown comes in)
1-2 shift @ 33-41 mph
2-3 shift @ 61-70 mph

Personally I would hook up the downshift rod because it serves two purposes. One is it allows you to force the tranny to downshift at higher rpms and hold that downshift longer before it upshifts. Second, and probably more important, it boosts the line pressure to keep the band and clutches from slipping under load.

[MudinMan4x4]

I dont have mine hooked up and mine works just fine it usually down shifts when i get on her and shifts when i'd like..but after reading that I'm gona give my kick down a chance and who know's maybe I'll enjoy it

[69f100ranger]

It's normal for the transmissions to short-shift in our trucks when you don't have your foot into it, that's the way they are set up from the factory.

As an example, here are the shift speeds for a 3.54 ratio with a 31" tall tire (from the '68 Shop Manual):

Part throttle
1-2 shift @ 6-8 mph
2-3 shift @ 6-17 mph

To kickdown detent (this is the best the vacuum modulator can do)
1-2 shift @ 25-37 mph
2-3 shift @ 46-62 mph

Through detent (W.O.T. this is where the kickdown comes in)
1-2 shift @ 33-41 mph
2-3 shift @ 61-70 mph

Personally I would hook up the downshift rod because it serves two purposes. One is it allows you to force the tranny to downshift at higher rpms and hold that downshift longer before it upshifts. Second, and probably more important, it boosts the line pressure to keep the band and clutches from slipping under load.

I just put my tranny and engine back in after rebuild and I freaked out when the tranny would only shift into 2nd gear at about 45 MPH. The transmission shop told me to disconnect the kickdown and I did so yesterday and it is now shifting just as you stated it should above. I believe the problem is with my kickdown lever and I just recalled that the rod came off of a 302. Does anyone have a pic of one from an FE and where I might be able to buy one. Or should this not make a difference?

Al

[shrektruck]

I have had problems with this before. My tranny shop did a rebuild but put the kickdown back with the old bushings which, at 25 years old were shot. I brought it back (3 times) before the owner looked at it and told the shop monkey to replace all the bushings.
Bam! started shifting like a dream.

[DuckRyder]

There are two adjustments. One is the Modulator (most of them anyway) have a screw inside the vacumme nipple.





The other is at the carb. (needless to say turn off the engine)

Hold the atomatic tranmission kickdown lever in the WOT throttle position.

Hold the Throttle in the WOT position.

Adjust the screw in the carbs kickdown linkage to obtain 0.060 clearance.

HTH

[FORDification]

...I believe the problem is with my kickdown lever and I just recalled that the rod came off of a 302. Does anyone have a pic of one from an FE and where I might be able to buy one. Or should this not make a difference?

Yes, the kickdown rod for an FE/C6 is going to be a little bit longer than the one for a 302/C4, mainly due to the difference in sizes of the engine/tranny combo. I thought I had a pic of a 390 kickdown, but I can't find it. I do have two pics of other kickdown rods. Both of these are from trucks:

This one is from a 302/C4 setup:

[img]http://www.fordification.com/board/tran ... 302-C4.JPG[/img]

...and this one is from a 351/C6 setup:

[img]http://www.fordification.com/board/tran ... 51M-C6.JPG[/img]

The next time I'm at the shop I'll be sure to get one of my 390/C6 setup and post it to this thread.

[willowbilly3]

RWIW we drove an 85 Bronco with a 300 and C^ for years without it hooked up and I never had any complaints about the way it worked. It was still working fine at 193,000 miles (may have been rebuilt sometime before it rolled 100,000)

[DuckRyder]

Lets see if this works:

Here is a C6 FE rod.



I found out quite by accident they are pretty easy to bend. If you don't need much bending the one you have or adding one of Holley's extensions might help you out.

[69f100ranger]

Thanks guys I will be comparing these pics with mine to determine which one I have. If all else fails I'll just drive it w/o, as some have stated they have done for years with no problem.

Al

[68F250]

You can drive without it and for the most part never notice a difference.

It's that last bit of WOT that finally actuates the kickdown, that's where you'll miss it.