4 speed 727

[Hammerx]

i just cant get past that feeling. you know the one. the next SHIFT. 4th gear, where is it? why is this thing not shifting? i keep waiting, and waiting....

somtimes ( every few miles) i look to make sure that i put the indicater squarely over the little "D" and not any further to the right!

so, my question is: is there a 4 spd 727 that will bolt up to my 1989 gw 360/229tc?

i know that the 700r4 is a great swap with the required adapters, but i am looking to keep it as simple (amc/cry)as posiable. ;)

besides, i am about to rebuild the 360 and if i swaped in the 700r4 - why not get the 350 to go with it?

so.....know of any good bolt on prospects?

[joe]

The 727 is a 3 speed(standard 1:1 high gear ratio). A 4 speed AT will have 4th as an OD gear(0.74 or such ratio).
Unless you're running non-stock alxe ratios in your 89 Wag(stock 2.72 or 3.31's) OD will be useless. If you're running 3.54's or lower(numerically higher) go for it but 3.54's would borderline though. With your stock gears the OD will constantly be kicking out and going back to 3rd anyway so you've gained zip for your money.

[Hammerx]

joe,
thanks for the reply. swaping the r/p to say 3.73
or even a 4.10 ratio wouldnt be a deterrent.

what came w/4spd 727 that would swap in?

[joe]

I'm not aware of any 727's w/OD but I don't know much about AT's either. My little XJ has the AW-4 AT with 4th being OD but I don't know how it'd hold up behind a V8 or how compatable it is. It's hooked up to a AMC 4.0 dragging an NP231.
You're prolly on the right track with the 700 series GM AT plus adapters etc but I bail out here for others more knowledgable to fill in the blanks. ;)

[Bob Barry]

The A518 is a TF727 with a weak overdrive extension housing. It's fundamentally a 727, but it's different enough in the internal oil-flow that it's not just a bolt-on. I also think that the output shaft is different from a TF727, so a whole unit won't just bolt into place.

[derf]

Originally posted by Bob Barry:
The A518 is a TF727 with a weak overdrive extension housing. It's fundamentally a 727, but it's different enough in the internal oil-flow that it's not just a bolt-on. I also think that the output shaft is different from a TF727, so a whole unit won't just bolt into place.Not only that but the A518 doesn't have the AMC bolt pattern in it's bellhousing. The TF727's for ChryCo engines have a different bolt pattern. It won't bolt up without an adapter.

If you're going to all the trouble, you may as well put a 700R4 in. It's a better tranny.

Oh, and go with 3.73's or 4.10's to take advantage of the overdrive if you do.

[J10Truken]

I have noticed when pulling my tent trailer up hills that the tranny (tf727) in my j10 sort of does a half step shift down before going into second gear. It will hold this half step for quite awhile making the tranny feel like a 4 speed. What's up with that?

[derf]

Originally posted by J10TruKen:
I have noticed when pulling my tent trailer up hills that the tranny (tf727) in my j10 sort of does a half step shift down before going into second gear. It will hold this half step for quite awhile making the tranny feel like a 4 speed. What's up with that?It might be a lockup torque converter opening up under load. Some 727's have a lockup converter. When it's locked, it acts like a manual tranny clutch. No drivetrain loss from the converter. When it's open, you get 10-20% drop in RPMs from the engine to the input shaft of the tranny. That's why it feels almost like it's downshifting just a little.

[Peter Matusov]

Derf,

when the TC is open, you have 10-20% increase in engine RPM, not drop. When it locks, you have a drop - typically of an order of 200rpm - and it does feel like half-upshift.

peter

[Andrew]

What has the locking TC?

[derf]

Originally posted by Peter Matusov:
Derf,

when the TC is open, you have 10-20% increase in engine RPM, not drop. When it locks, you have a drop - typically of an order of 200rpm - and it does feel like half-upshift.

peterYeah, that's what I meant. Remind me to proof read a little more next time... tongue.gif

[Rande]

Derf, proofread a little more next time.... ;) tongue.gif

[J10Truken]

That is what it is guys. I know my unit has the lock-up converter from when I opened it up to do a kit. Thanks for the info.