oldsmobile 2 speed powerglide rebuild

[amrcnmscle]

i have a 1969 oldsmobile cutlass 'S' with a 350 v8 and a 2 speed powerglide, the time has come where it needs rebuilt or replaced. my question is do i rebuild it or put in a 3 or 4 speed transmission. money is somewhat an issue and also this is my daily driver/cruise car so i am looking for gas mileage as well as low price? please help with any advice...

[joe_padavano]

Originally Posted by amrcnmscle

i have a 1969 oldsmobile cutlass 'S' with a 350 v8 and a 2 speed powerglide, the time has come where it needs rebuilt or replaced. my question is do i rebuild it or put in a 3 or 4 speed transmission. money is somewhat an issue and also this is my daily driver/cruise car so i am looking for gas mileage as well as low price? please help with any advice...

Contrary to popular belief, your trans is not a Powerglide (which was never used by Olds). It is a Super Turbine 300 (ST300, also called the Jetaway by Olds). A TH350 is almost a bolt-in (the cable kickdown is the only difference) but won't help gas mileage since it also has a 1:1 top gear. The overdrive four speed 200-4R can be installed with not much more work than the TH350, but to get one that's been sufficiently beefed to survive behind your 350, you'll spend somewhat more than you will for the TH350.

[markowyo]

I have a '64 Jetaway in a Cutlass which has never given me a lick of trouble, and odd as it seems, 2 speeds work great behind that 330. I've considered it, and I don't care to trade it for a turbohydramatic.

Also, at 65 miles per hour I get about 21mpg.

[wmachine]

The Jetaway is definitely a weak transmission, especially compared to a TH350 even. I wouldn't even consider replacing it with another Jetaway, expecially considering the availability and ease of a swap to a TH350.

[amrcnmscle]

thanks guys for the advice and information about my transmission, much appreciated

[f-85]

I dont know about you guys, but i have had real good luck with the jetaway. About a year and a half ago i put in a 455 in my 64 F-85 at the same time i pulled the 2 speed and put in the th350. I loved the th350. The gear ratio was much better. 2.56 1st, i was loving it. It lasted me about 3 weeks before i blew it. Back to the 2 speed until i found another th350 . After a month or so i got another th350. Man i was loving it. It lasted 5 weeks. Back to the 2 speed again. Then over the winter i bought a built th350, and a stronger motor (1970 455) Now i was really flying! The trans really shifted firm! That one only lasted about 6 weeks. And this time it really blew. Man it was loud! Bang-klunk- crunch. Had to drive home almost a mile in reverse. LOL back to the 2 speed for a couple months. Now i finally have a good trans. I bought a built th700r4. Now im really happy! 3.06 1st gear and 4th in O.D. plus the lockup so its like a 5 speed. I couldnt be more pleased. But i still have that old 2 speed in the shed just in case. I had the 2 speed behind a BB for at least 4 months total. And i dont baby it. It has been the most dependable trans ive had with this car. I wouldnt say its weak. Yes the 1.70something 1st does suck. But i just couldnt brake that son of a gun! Just my experience.

Josh

[markowyo]

I did forget to say about the Jetaway ... smoo-ooth ... an Oldsmobile hallmark!

[nonhog]

Thinking about leaving in the 2spd when I go to the 455 swap . Its lived behind the 425 for who knows how long. My reason is Ilike the column shifter. I know I could replace my column with a 3 speed column but it scares me to think of the down time finding parts and pieces .
And putting the floor shifter (Hurst) wont look right (to me)
Are the Jetaways equal to powerglides in terms of strength ?
I toasted a powerglide behind a stock 427 390hp maybe it was the 460 ft. lbs. Yikes the 455 will have more than that . Hmmmm better rethink my plan.

[Jamesbo]

Originally Posted by nonhog

Hmmmm better rethink my plan.

Good idea