Please explain Cad Jet-away/hydramatic kickdown operation...

I have a '58 365 with the cad jet-away auto trans. My trans has two cooler lines coming out of the four ports with the other two ports capped off.

What kind of kickdown does this use? Is the kickdown necessary? If so, how do it work? And what do I need to make it work?

As always, thanks a ton for everything!



Eye candy to show my gratitude in advance for all the help and perfect solutions you guys will surely give me very shortly.

 

Photo of shift linkage on trans.

 

the hydros need the throttle pressure lever at full stop with wide open throttle. then you fine tune the rod length to get decent shifting and so it downshifts properly upon slowing for turns in town.

 

What is on the trans linkage in my pic is what I have. What am I missing? Is the tv rod on the inside (closest to the trans body)? Where does the tv rod connect on the other end? And how does it work?

And thanks!

 

If the linkage clicks when u move it that's not the throttle pressure. The
throttle orig was hooked in with throttle linkage.. We used to use a cable in
hot rods to adjust the pressure. Any multi carbs etc orig stuff won't work. Ask Evil
how he did his. I had some input on that awhile back.

 

Throttle pressure = tv?

The inside linkage (closest to t he trans body) is clicky. The outside linkage is springy and does not click.

I have some kind of wierd vacuum diaphragm with linkage from the firewall of a '58 cad (different car than my engine). It was connected to the throttle linkage on the firewall. But I have no idea how this will work on my pickup or how it worked originally.

I'll give evel a shout and see if he can help out. Thanks for jogging my memory! I seem to remember reading about trans adjustment heartaches on livewire a long time ago.

 

The outside lever is a "kick down" or passing gear. These trannys had no TV.
You can use a cable to activate the lever when the throttle lever goes to wide open.

These transmissions were invented before the wide spread use of color tv's, and work much better with a CHROME pan.

 

Haha! So what exactly is this tv rod I keep hearing about?

 

TV- throttle valve- on later trans these controll internal line pressure which in turn controlls shift firmness while limiting excess line pressure to help with fuel economy. The linkage on your trans controlls the passing gear. People who bought new '58 Caddy's were way more concerned with passing than gas milage. The throttle valve controll cable is what most mechanics call any external transmission controll that's not actual shift linkage these days. Most of these guys have never even seen a 58 Caddy. TV controll came along with the 700r4, but that was what? 20 years ago? Internal line pressure on your box is controlled by balls and springs. If you ain't worried about the kick down feature just leave it unhooked, but it's real nice to have.
The "tv rod" is the original type linkage used on the passing gear- it was a rod.

 

Thanks Chub!

 

your tv rod will hook up to the outer clevis there, the one with spring tension. the other end will hook up to your carb linkage. be sure to use the stock carb linkage plate, because you want to be sure that the throw is perfect on this adjustment, if not it will f it up real quick.

 

Ummm, I don't have a stock carb linkage plate. When I got the engine, it had the stock four barrel manifold with an aftermarket Edelbrock. Now I have a Weiand 3x2 with Rochesters and a vintage linkage.

What now?

 

Befriend an old grey haired transmission man. Combine his knowledge with your ingenuity. In this application rod or cable, as long as full throttle and full pull at the lever come together at or about the same time you have a good starting point.

some times it just don't come in a kit.

 

I'm dealing with the exact same trans and issue: no original parts, a completely custom application, etc.

I've gotten few concrete answers, even from reading the manual, but what I have surmised is that the outer lever (under pressure, not the one that clicks), is not just a kick down: it's acts similarly to a TV setup and will control shift points across the range, as well as contribute to premature death of said trans if not correct.

I can also say that from experience, mine was simply bolted to an open hole on an edelbrock 1406 (which didn't give anywhere near the correct travel), and it wouldn't shift out of second. I've since dismantled the car and haven't gotten to build a new linkage and plate and test it out.

for what it's worth (b/c of lack of solid info), I'm simply going to start with a linkage that is all the way back (rear of car) at idle, and all the way forward when carb is actually at WOT. I'll figure it out from there, unless someone miraculously gives me some better answers.

The inner (the one that clicks) is your shifter: Park all the way forward, N, D, 2, 1, R (if I remember correctly). Regardless, Park is at one end w/ neutral below, and Reverse is at the other end; I just can remember how man clicks in between.

 

Hydros suck unless it's a b&m hydrostick I'm waving the surrender flag and I'm gonna
Put a la salle or and early ford top loader..It's never worked right even with all the tricks
And linkage I made.. I highly suggest not using The hydro.. I have suffered for all believe me...

 

Ditto on the find an old transmission guy. These operate similar to the old Ford AOD transmissions and first gen Powerglides. No vacuum modulator I'm guessing? A good old timey trans shop can even fab up a custom TV linkage for your application or help you pinpoint what cars you need to scrounge for parts to make yours work. Good luck, trans linkage stuff can be a headache.

 

Worlds biggest pain in the ass tranny... dump it

 

Thanks for the pm evel. I'm going to have to try to make this work for now. I have the good cad trans. I don't have a good 350 or 400. And I spent a grip on chrome so getting hold of one soon isn't exactly an option.

There's an old timer and a shop in town I can reach out to. Hopefully I can get some info from them.

Thanks everybody.

 

That vacuum diaphragm that came off the firewall of the 58 sounds like a part of a cruise control setup.

 

When set right these are a fun transmission to drive with. They're four speeds, so you have P-N-D-3-2-1-R, some column indicators are marked a little different but it's the same thing. My old Pontiac could be doing 70 at the top of the highway ramp without taxing the engine hardly at all. And it got decent fuel milage for a 4000+ lb car with an automatic in it.

I would say worst case find one that nobody's touched and photograph the linkage, and see if you can copy it on yours. With a 3x2bbl maybe you can use parts for a Pontiac or Olds with a 2bbl carb to set it up. Pontiac, Olds and Caddy all shared this trans.

 

..................................Hmmmm, no...................It needs it , to operate properly, to help control the functions of the valve body, it ain't just a "passing gear" linkage.......................And I believe, that a Torqueflite transmission, uses a type of "TV control".............................Best I remember, those early GM transmissions, had "rig pin" holes in all the linkages and bellcranks and gizmo's, to get you in the "ballpark" when setting up the linkage from scratch, and then do your fine tuning adjustments, with the threaded linkages.

 

So does anyone have any pics of the stock linkages so I can wrap my head around some design ideas?

And thanks again!!

 

Terd - Meister..................
I got a box of "stuff" the other day, and it had some manuals in it, one of which I THINK, is a Hydramatic manual................I'll look in the A.M........................PM me your address, and I just might send it to ya', after I "eye fuck" it, and see iffn' it's applicable, to what you need...............Hell, I'll prolly' send it anyway, cause you're such a swell guy!

What year Hydramatic we talking about, in case I missed it earlier?

 

Patterson's Hydramatic Shop is just a 5 min. drive from the Clubhouse on Cabarrus Ave. just south of 136. They have the knowledge to help you out. vic

 

I totally disagree. Dual coupling hydros work just fine I had one in my 389 powered 55 Belair. A little slow shifting especially between 2nd and 3nd but there tough. As far as the shift control rod ,from what I remember, set it so it is closed position at idle and fully rotated at full throttle. I'm sure some old hydro guys will chime in on here and set you straight.

 

My 4 speed manual car has 4 "passing gears". It just depends on how fast I am going which one I use to pass with.

 

There were many automatics that used throttle linkage to control the TV (throttle valve) in the transmission. In the early 60's Ford started using the vacuum modulator to control TV pressure. Turbo 400, ST300, Th350 followed suit with vacuum modulators. Chrysler Powerflite and Torqueflites were linkage controlled setups. Down the road GM went back to linkage controlled TV's in the 700r4 transmissions.

In any event, the TV linkage controls internal pressure to be used for shifting. It, along with the governor pressure determine when the transmission shift valves will allow the shifts to occur. It also controls kickdown type downshifts.

It is very important to get these adjustments correct, or transmission damage might occur if ignored.

The Jetaway transmission had it's own issues, but was durable enough in most cases. I prefer the older dual range (single coupling) hydro, as they shift much more distinct and firm. They also don't have sprag clutches as they Jetaway has. Those sprags are the weakest link in the Jetaway.

Both the dual range hydro and Jetaway used a fluid coupling, the reason why there is that really low first gear. But a fact that might not be known by most is that the flywheel drives the torus cover, then the front planetary, then the fluid coupling members. When the front clutch ( dual range)is engaged or the small coupling is filled (Jetaway), the transmission is mechanically locked up, meaning the main fluid coupling is NOT supplying torque to the output shaft. This is why there is a lurching effect at the 1-2 shifts. In 4th gear, the transmission is essentially mechanically locked to the output shaft.

 

Thanks a ton!!! PM inbound. And you're a swell-er guy!

1958 engine and trans, by the way.

Thanks Uncle Vic! I'll reach out to them and see what I can find out. I'll be sure to post whatever info I get.

 

My apoligies to any one one I may have misdirected. Some times in our later years we remember all but certain details. The info I gave was correct-for a different transmission- again my apologies.