holidaysedan

So my recent '69 Cutlass has Rocket 350 2 bbl and Jetaway. I've had lots of 4 spd HydraMatics, THM350s and 400s, even a 2 spd PowerGlide in a 250 6 cyl Nova, but this one is new to me. I realize that it's basically a Buick Super Turbine 300. What is the reputation of Jetaway, durability-wise? Easy or difficult to rebuild and maintain? Can modern tranny shops deal with them? Just like to hear others experiences. Being in my 70s I no longer have that "need for speed" that I once had, so this car will just be a laid back cruiser. ...share your knowledge & experiences anyone??

oldcutlass

Your 69 Jetaway can still be serviced by any transmission shop, although with a failure I would go to T350 because its almost a drop in swap. Its a pretty reliable transmission that will last a pretty long time if not whipped like a rented mule.

Lonnies Performance

They are not a terribly complicated transmission, but they were only used a few years.
For a "modern shop" to be experienced with them, likely means someone with 40-50yrs. of transmission experience is still employed there.

With experience & a manual, most could rebuild one.
Also, available rebuild kits are typically old stock that may suffer from aged, shrunk or hardened seals, so I would not be anxious to rebuild unless necessary.

holidaysedan

The Jetaway will be treated gently, but nothing lasts forever,

So regarding "almost drop-in"... if it came to failure and the cost was close I'd certainly go with a THM350, again, if cost competitive. Lots of them around.

So "almost" - what would need to be changed or modified to use the 350 3 spd tranny?

oldcutlass

You would need a kick down cable (there are many ways to accomplish it) and if you want although not necessary a 3 speed indicator for what gear your in.

holidaysedan

Good to know, thanks... any vacuum modulator line ?

oldcutlass

Yes, the Jetaway also has a modulator.

matt69olds

If the Jetaway needs rebuilt, swap in a TH350. It’s a almost direct bolt in, and the added 1st gear will make you swear the engine has an extra 50 hp. An even better swap would be a 2004R, but that can get a little more expensive

JohnnyBs68S

My Jetaway took about as much abuse a 350-2bbl could give it and it never failed me for 112,000 miles. It combined w/ a 2.78 open rear returned an easy 20 MPG on the highway (only ~13 in town). My friends were impressed that 1st gear would hold until 70 MPH. Unfortunately, mine started leaking and after a few years I got tired of topping off the fluid. I had already changed my rear to a 3.90 posi, which complemented my swap to a 200-4R nicely. If you are just cruising wiith no plans to hot-rod your 350, I'd stick with the Jetaway until it NEEDED to be rebuilt, then swap it w/ a TH350. If it ain't broke, don't fix it.

69CSHC

Unfortunately it has somewhat of a negative reputation. Its nickname is "junkaway"... However my only experience with one was positive, many years back I owned a 1966 442. The car was numbers matching all original switch pitch Jetaway. Trans worked beautifully, WOT shifts were around 5000 RPM and consistent, normal shifts were smooth as silk. Car was 3.23 posi and had good giddy-up even though it was getting long in the tooth. In my case the trans outlasted the engine... car was well over 100,000 miles.

If that's definitely the case, your set. Properly maintain it and it will take care of you.

Absolutely ! Original A2 (automatic 2 speed) 442 road test was 15.5 @ 90 MPH virtually identical to what my 69 can run on its best day. Meanwhile the 66s big block 400 was 350 HP vs my 69s 310 HP. The 442 was 3.23 anti spin while my 69 is 2.78 open. So, a much better performance rear end and 40 additional horsepower literally erased by a 3rd gear.

holidaysedan

Ya I'll leave it alone as long as it's OK, can't afford to just up and swap it if not needed, other things need attending first!!

65Delta

My '69 was factory equipped with a TH350 but, somewhere in her past, a ST300 was swapped in. I went back to the TH350. The kick down cable is hooked to the accelerator pedal, shift cable bracket for the TH350 is available as a repop, and you'd need the correct shift quadrant/detents. The overall length is the same as is the spline count on the output shaft so you can reuse the driveshaft.
As for experience & parts no one really knew the Jetaway and it took a few tries to get the correct filter kit. Pretty much any shop can rebuild a TH350 so a much better knowledge base.

holidaysedan

Good to know - do you happen to know the filter kit # for the Jetaway?
thnx

JohnnyBs68S

RockAuto shows this PN available:

PIONEER 745039 Kit Info
Trans. code Super Turbine 300

There's also a WIX PN that looks the same:

WIX 58880 {Click Info Button for Alternate/OEM Part Numbers} Kit Info
300; Base Model

Note that I looked this up for a '68 since all 350s w/ AT used the ST300/Jetaway, not just the 2bbls like in '69.

holidaysedan

Great info - thanks Johnny!
Roger in NY

Noel Anderson

Hi Roger,
My 69 Cutlass Supreme Holiday Sedan came from the factory with the Turbo Hydromatic 350, so it would be an easy swap for you. As noted earlier the kickdown is on the gas pedal and not the carburetor. There is a manifold vacuum line going tho the modulator valve. The shift indicator is in your speedometer pod. If you decide to change to a 350, I can provide you with my spare. I personally have been thinking about swapping to a 200-4R if mine goes bad. From what I have read that swap would be just as easy, and allow a better rear end gearing.
Noel

holidaysedan

Thanks for the kind offer, but for now will keep it original, I've got plenty of other stuff to deal with first!

yeahbuddy

I used a Jetaway for 10 years in my 68. I just got a TH350 and cannot wait until I get rid of the Jetaway. Let me know if you want another.