904 Downshift

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Hey Fabo!

I went the route of the Bouchillon cable set up on my 904. At WOT on the carb , I still have perhaps 1/4-5/16" of travel left before assembly bottoms out on transmission. I'm not getting a down shift when I tromp it and just poking along mildly accelerating it goes to 2nd at 10-12 and into 3rd maybe 18 mph..

Get the slack out?

Thanks!!!

 

[Bad Sport]

Hey Fabo!

I went the route of the Bouchillon cable set up on my 904. At WOT on the carb , I still have perhaps 1/4-5/16" of travel left before assembly bottoms out on transmission. I'm not getting a down shift when I tromp it and just poking along mildly accelerating it goes to 2nd at 10-12 and into 3rd maybe 18 mph..

Get the slack out?

Thanks!!!

I think so. Your shift points seem a bit shallow.

 

[Woods74]

The slack should be around 1/16 measured full pull at WOT. Be safe about it, your ride depends on it!

 

[TrailBeast]

That's the next step, and just so you know I really like the part throttle kickdown kit I got from Torqueflite Patty and his website.
It cost about 50 bucks and the valve body has to be pulled to install it, but it's real easy to install.
I wanted my downshifts to happen with less throttle because I didn't like having to get into the secondaries on the carb to get it to kick down at lower speeds in hilly neighborhoods. (my car is a daily workhorse for service calls)

I usually opt for a lower gear with higher RPM's than more throttle and the PTKD kit makes the trans do it on it's own instead of me having to drop down a gear manually.

 

[eestatic]

Awesome response!!

I wasn't aware of the part throttle availability but that sounds like exactly what I'm looking for.

I had to modify the kit but points of entry to the carb look very true and same for transmission to alleviate binding concerns..I'll see if I can squeeze the slack a bit more.

The folks at the edge of town do say the car sounds good in the interest of transmission tuning

 

[eestatic]

OK, I went to T'Flite Patty's Shop Mart and saw a kit but (for my 904 console shift) will I need other various valve bodies to make something work?

<Cut-n-paste>

This bolt-on valve body sub-assembly enables “part-throttle kickdown” (passing gear, DRIVE back to SECOND) without having to depress the gas pedal all the way to the floor; 3-2 kickdown will occur at aprox. ¾ throttle (instead of full-throttle). There is no effect on 2-1 kickdown. Chrysler used 2 types of part-throttle valve bodies; this is the more universal type and will mate to any 1967 or later valve body which has the fluid feed passage for this accessory (most 1967 with upper casting number 2538956, 1968 upper casting number 2801856 and 1969-1970 upper casting number 2892348). If you are unsure whether your 1967 valve body has the necessary fluid passage, e-mail us for a picture to I.D. the presence of the passage. A special button-head screw is supplied to address clearance issues when installing on the 1960-1970 valve bodies or later model “simple” style of valve body; also included is installation information. This can also be installed on 1960-1965 valve bodies by mating a late 1966-1968 valve body upper half to a cable-shift 1960-1965 transfer plate (lower half) to effect the part-throttle kickdown on a 1960-1965 cable-shift unit.

 

[fishy68]

Awesome response!!

I wasn't aware of the part throttle availability but that sounds like exactly what I'm looking for.

I had to modify the kit but points of entry to the carb look very true and same for transmission to alleviate binding concerns..I'll see if I can squeeze the slack a bit more.

The folks at the edge of town do say the car sounds good in the interest of transmission tuning

If your trans valve body is newer than 1970 the valve body should already have a part throttle kickdown module. That last 1/4" of throttle valve movement does 80+ % of the kickdown function so if your VB does have part throttle kickdown it's just getting into it when your at wide open throttle

 

[Bakerlite]

Fishy68, have you ever thought of extending the end of the kickdown valve that makes contact with the throttle valve? This would change when kickdown occurs (earlier) without effecting regular cruise throttle pressure functions.

 

[eestatic]

If your trans valve body is newer than 1970 the valve body should already have a part throttle kickdown module. That last 1/4" of throttle valve movement does 80+ % of the kickdown function so if your VB does have part throttle kickdown it's just getting into it when your at wide open throttle

My VB is a 1965 w/console shift


Well..just to gather data, I tried once more (with out any adjustments) and transmission ignores the request to downshift! Plus, just eeking along it shifts into 3rd at about ~20 ish & there is a minor "flare" as it shifts into 3rd...

 

[fishy68]

Fishy68, have you ever thought of extending the end of the kickdown valve that makes contact with the throttle valve? This would change when kickdown occurs (earlier) without effecting regular cruise throttle pressure functions.

No I haven't tried that but it's a good idea to keep in mind. I have ran into a couple cases where they kicked down ok but the cruise shift was real early and I found drilling a hole in the throttle lever just inboard of the stock hole changes the ratio to delay the cruise shifts later without the linkage bottoming out at full throttle.

 

[RustyRatRod]

Adjust the kickdown cable so it has the transmission lever all the way back when the throttle is opened fully.

 

[fishy68]

My VB is a 1965 w/console shift


Well..just to gather data, I tried once more (with out any adjustments) and transmission ignores the request to downshift! Plus, just eeking along it shifts into 3rd at about ~20 ish & there is a minor "flare" as it shifts into 3rd...

Ok. A part throttle kit will work for yours

The flare could be because you don't have enough throttle pressure. I always start with the adjustment at max and back it off if the shift speeds are too high

 

[AJ/FormS]

No I haven't tried that but it's a good idea to keep in mind. I have ran into a couple cases where they kicked down ok but the cruise shift was real early and I found drilling a hole in the throttle lever just inboard of the stock hole changes the ratio to delay the cruise shifts later without the linkage bottoming out at full throttle.

Fishy beat me to it. Can you do that on his tranny. It's been so long since I had an early tranny on the bench, I can't remember.
By any chance, you don't have a non-Mopar carb on there without the correct KD pin locating adapter on it;Do you? If your pin is in the wrong place, this is what happens; no KD synchronization.

 

[eestatic]

Fishy beat me to it. Can you do that on his tranny. It's been so long since I had an early tranny on the bench, I can't remember.
By any chance, you don't have a non-Mopar carb on there without the correct KD pin locating adapter on it;Do you? If your pin is in the wrong place, this is what happens; no KD synchronization.

This what I have: A holley 650 &Edelbrock Performer 318/360. Looking at the carb pivot shaft (fulcrum), the throttle cable & transmission kick down are sorta opposite of each other..

The 3rd. pic shown...throttle is connected to the "raised" hole at about 10:00 o'clock and the transmission is located in the bottom "right" hole at about 4 o'clock.

They seem to have similar travel.

 

[AJ/FormS]

Yeah, you bin chebbyized. The KD pin is in the wrong place. However in your case it should be a non-issue, cuz the pin no longer activates the KD linkage.
So you will need to either change the KD ratios, or change the line pressure, or change the governor pressures, or some combination of those.Do not make the tranny accept too much torque until this is figured out as the flare is the tranny's way of telling you it's in trouble. If the tranny has to work too hard like this, the clutches will be destroyed.
So next question, is the differential ratio the same as what the tranny was originally factory-tuned for? And has the tranny received any mods yet?

 

[eestatic]

Yeah, you bin chebbyized. The KD pin is in the wrong place. However in your case it should be a non-issue, cuz the pin no longer activates the KD linkage.
So you will need to either change the KD ratios, or change the line pressure, or change the governor pressures, or some combination of those.Do not make the tranny accept too much torque until this is figured out as the flare is the tranny's way of telling you it's in trouble. If the tranny has to work too hard like this, the clutches will be destroyed.
So next question, is the differential ratio the same as what the tranny was originally factory-tuned for? And has the tranny received any mods yet?

lol, the Bouchillon set up wasn't even close to mount on carb and if I could have, extrapolating, the transmission cable KD pin would hook up in the same "spot" just further to the outside!




Transmission has new clutches/bands/seals....no modifications.. and it has Factory 2:93 gears.

When I initially purchased the car, it would not down shift either but car died soon and I never had a chance to play with factory linkage

 

[oldkimmer]

................I have never used the cable set up on my own stuff but have installed a few .....will it reach the front hole on the lever.............kim...........

 

[eestatic]

................I have never used the cable set up on my own stuff but have installed a few .....will it reach the front hole on the lever.............kim...........

You're talking on carb.? Yes, I was going to put it there at first but hole was a tad too small so I went to the rear. I can slide the bracket forward.

 

[Bad Sport]

You might consider one of these:

http://www.summitracing.com/parts/EDL-1481/

 

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I tried that one and one other...:banghead: holes didn't line up and angular offset of bracket surface wasn't close...

 

[Bad Sport]

Is there a way to laterally move the cable bracket out toward the valve cover more?

If so, then I think the adapter would work.

 

[AJ/FormS]

If the current set-up has full opening throttle butterflys, and the gas pedal rests on the floor(or nearly so), and the car is not noticeably jumpy at small throttle openings, then, personally, I see no reason to use the MOPAR adapter. Since you have actually speeded up the butterfly opening rate, a manual trans equipped car will sometimes get jumpy. And if the pedal sits up too high when cruising, a nervous foot can also make it jumpy.
So if it ain't jumpy that part should be ok.
The problem is at the other end. The pulling action from the throttle has been reduced. This slows down TV pressure, and may not pull the KD lever far enough back( I'm assuming the Bouchillon cable correctly pulls the tranny lever to the rear of the car.) If you mock up the adapter, and measure the distance(eyeballing is ok), between the center of the butterfly shaft and the center of the factory installed KD pin, then compare that measurement to what you are currently getting, you will see what mean. About the easiest way around this, is to do what a previous poster mentioned, and that is to change the ratio at the tranny TV lever. That was fishy68 in post #10.
When you are finished the mod, refer back to post #11, for Rusty's comment.

 

[eestatic]

I'll post some pics of adapter when I get a chance

The car is actually quite tolerable and smooth accerating.

With assistant in car the throttle was straight up/down_open with pedal mashed to floor. I could see about 1/4" to 5/16" of cable slack left before bottoming out. I will address that one first to see if I can initiate a response before further analysis &#55357;&#56397;&#55357;&#56384;