727 issue for thermodynamicists

[Gerald Morris]

Since Summer is here and the time is right for stalling in the streets, I too need to post some 727 blues in hope a righteous Torqueflite Master can inspire me with Right Knowledge.

For some months, I've been experiencing 2-3 flare-up at around 33-35 mph, which has now degenerated to major slipping, BUT:

In HOT weather, after a mile or 3, 3rd starts to catch. After noting this was somewhat better when using Type F in my sieve/transmission, which I re-snugged the pan bolts to 12.5 ft-lbs on to reduce the leak, I poured 24 oz of Lucas transmission fluid additive in, and happily report that once warmed up, Mathilda grips 3rd gear well enough to permit me to putt around in "D" without manually dropping down to 2nd gear.

Having read the FSM, and a couple Torqueflite eBooks online, I'm weighing the hypotheses that

1.) the clutches are gone, and only fricative additives in Type F and more in Lucas are permitting the steels to work with the clutch remnants

versus

2.) The forward band is loose as a goose and tightening this and adjusting pressure to the forward servo will pop 3rd in a bit more forcefully and suffice for the summer

versus

3.1 and 2 BOTH are correct.

I can drop the pan, change the filter and diddle the front band (external adjustment, right?) and pressure to the servo easily enough, but if I need to pull it for a rebuild/replace, then I need to go tool shopping. I also have a 1977 727 w a 400, but for that I need a 0 balance torque converter for my excellent old 383 especially since the old converter is doubtless 19 spline.

My major question is: WHY DO I JUST GET 3RD GEAR WHEN THE TRANNY HAS WARMED UP TO ABOUT 200 Fahrenheit?

 

[traintech55]

I think you have answered your own question, but you are looking on where to start.
I would start by dropping the pan and changing the filter, if you have a lot on clutch material in the pan you will have your answer. Do the band adjustments and use the best fluid you can find.
Thank god the 727 trans is easy to rebuild, when I had the one in my 300 done it only cost me $500.00.

 

[detmatt]

You are headed for a complete rebuild but I think you already know that. It's a good time to start collecting parts and info though.

Here are a few of the improvements made to my trans. I found a used late '90s 46RE on Craigslist as a doner for some of the mods. The valve body got a shift improver kit and the oem steel check balls were replaced with the composite ones from the 46RE as they don't beat up the separator plate like the steel ones.
New TCI HP intermediate sprags.
New style dimpled input bushing in pump housing for improved oiling.
Replaced main output shaft bearing.
Back planetary set was replaced from the oem 3 gear set to the 4 gear from the 46RE.
Front clutch pack springs went from the 9 originals + 3 reds from the 46RE to = 12.
Front clutch pack bushing replaced with new updated grooved style for improved oiling.
Front clutch pack discs changed from 4 oem to 5 Alto-red .062 discs.
Back clutch pack discs changed from 3 oem to 4 alto-red .062 discs.
Kick down apply lever changed from 3.2 oem to 3.8.
New front and rear bands, good ones.
6 1/2" washers used as blocker in the low/reverse apply piston assembly.
Removed casting flashings from case(one was dangerously close to falling off which would have been disasterous)
This was all done by a close friend of mine whose a guru imo and I'm really looking forward to experiencing the performance of this trans.

 

[BeatersRus]

and by complete rebuild you should Deffo flush the valvebody too <<<<

as far as the weight balance thingy.
you can cut a vertor weight off carefully.
so its easy to turn a weighted vertor into a 0 weight vertor.

the fine splines tho,thats a toughie.
im actually getting ready to swap my working fine spline cable op trans to a reg 727.

 

[twostick]

I would have the kickdown linkage checked and properly adjusted before I did anything.

Not enough throttle pressure is what usually causes that 2-3 flair and if you are extremely lucky the adjustment might make it behave again.

If the KD wasn't out of adjustment or correcting it doesn't fix it, the damage is done and it's time to pull the trans.

Kevin

 

[Gerald Morris]

You are headed for a complete rebuild but I think you already know that. It's a good time to start collecting parts and info though.

Here are a few of the improvements made to my trans. I found a used late '90s 46RE on Craigslist as a doner for some of the mods. The valve body got a shift improver kit and the oem steel check balls were replaced with the composite ones from the 46RE as they don't beat up the separator plate like the steel ones.
New TCI HP intermediate sprags.
New style dimpled input bushing in pump housing for improved oiling.
Replaced main output shaft bearing.
Back planetary set was replaced from the oem 3 gear set to the 4 gear from the 46RE.
Front clutch pack springs went from the 9 originals + 3 reds from the 46RE to = 12.
Front clutch pack bushing replaced with new updated grooved style for improved oiling.
Front clutch pack discs changed from 4 oem to 5 Alto-red .062 discs.
Back clutch pack discs changed from 3 oem to 4 alto-red .062 discs.
Kick down apply lever changed from 3.2 oem to 3.8.
New front and rear bands, good ones.
6 1/2" washers used as blocker in the low/reverse apply piston assembly.
Removed casting flashings from case(one was dangerously close to falling off which would have been disasterous)
This was all done by a close friend of mine whose a guru imo and I'm really looking forward to experiencing the performance of this trans.

I actually recall your reference to finding that 46RE, which has me thinking about prospects for later model Torqueflite descendant donors/parts already. I appreciate you itemizing the improvements. Yes, I'll be collecting parts and data for this job, God-willing I can keep Tilly going w her original until autumn. Much obliged!

 

[Gerald Morris]

I would have the kickdown linkage checked and properly adjusted before I did anything.

Not enough throttle pressure is what usually causes that 2-3 flair and if you are extremely lucky the adjustment might make it behave again.

If the KD wasn't out of adjustment or correcting it doesn't fix it, the damage is done and it's time to pull the trans.

Kevin

The KD hasn't been done since I got the car, but it shouldn't hurt at this point for me to try adjusting it. The nitwit boy who sold it to me had it hooked up utterly WRONG topside, which I remedied. I don't have proper kickdown on it, never did, so some adjustment there likely is warranted. I'll check my filter next weekend. The fluid is clean though that doesn't matter, as it gets cycled FAR too frequently. Seals are also shot.

 

[Gerald Morris]

I think you have answered your own question, but you are looking on where to start.
I would start by dropping the pan and changing the filter, if you have a lot on clutch material in the pan you will have your answer. Do the band adjustments and use the best fluid you can find.
Thank god the 727 trans is easy to rebuild, when I had the one in my 300 done it only cost me $500.00.

Think I'll hunt up some good grade Type F on EvilBay. No question it shifts better all the way when using Type F. That's what got me to buy the Lucas stuff, when Wallyworld was totally OUT of Type F. Yeah, filter to be changed next weekend. The cheapest rebuild quote I found to date down here was $625. Most of these shops want $1200-$1400. I MIGHT attempt it myself, but only if I've got something reliable to use in the interim.

 

[70bigblockdodge]

Kick down/throttle valve adjustment, easiest way is WOT kickdown linkage needs to be all the way rearward period no gap for reducing shift harsness as stated in FSM. With rear wheels up in nuetral tighten kickdown band adjustment till driveshaft stops turning then back off till it starts to turn then 3/4 to 1 turn backed off after that. If you are going to drop pan anyway the low/reverse band can be done like this also but I would try external adjustments first, fluid is not free and if external adjust do not cure problem or reduce it your looking at last legs anyway so leave the fluid till it dies and concentrate on rebuild replacement trans.
Adjustment procedure thanks to Rick Ehrenberg from the pages of Mopar Action.

 

[detmatt]

By the way now that I've got more seat time in the car with this trans I'm very pleased with its performance.

 

[Gerald Morris]

Kick down/throttle valve adjustment, easiest way is WOT kickdown linkage needs to be all the way rearward period no gap for reducing shift harsness as stated in FSM. With rear wheels up in nuetral tighten kickdown band adjustment till driveshaft stops turning then back off till it starts to turn then 3/4 to 1 turn backed off after that. If you are going to drop pan anyway the low/reverse band can be done like this also but I would try external adjustments first, fluid is not free and if external adjust do not cure problem or reduce it your looking at last legs anyway so leave the fluid till it dies and concentrate on rebuild replacement trans.
Adjustment procedure thanks to Rick Ehrenberg from the pages of Mopar Action.

Big thanks for succinct, useful reply! This tranny still leaks about 1/2 pint daily, sitting, which I catch in a pan and re-use after pouring through crude filter. I have a drainplugged pan to ease pan dropping, good re-usable Mopar gasket. Will implement swuggested adjustment on KD and forward band next weekend AND check the filter. If I can stave off the Inevitable a couple more months, such effort will be WELL worth it.

 

[Gerald Morris]

By the way now that I've got more seat time in the car with this trans I'm very pleased with its performance.

Glad to see it. Happy Moparing!

 

[70bigblockdodge]

Big thanks for succinct, useful reply! This tranny still leaks about 1/2 pint daily, sitting, which I catch in a pan and re-use after pouring through crude filter. I have a drainplugged pan to ease pan dropping, good re-usable Mopar gasket. Will implement swuggested adjustment on KD and forward band next weekend AND check the filter. If I can stave off the Inevitable a couple more months, such effort will be WELL worth it.

Adjust the low/reverse band in the same way when pan is off. The low reverse band will not fix flare up on 2-3 but it is the opportune time to adjust low/reverse band when pan is down.

 

[traintech55]

Big thanks for succinct, useful reply! This tranny still leaks about 1/2 pint daily, sitting, which I catch in a pan and re-use after pouring through crude filter. I have a drainplugged pan to ease pan dropping, good re-usable Mopar gasket. Will implement swuggested adjustment on KD and forward band next weekend AND check the filter. If I can stave off the Inevitable a couple more months, such effort will be WELL worth it.

If you have the pan down for ANY reason, replace the filter.

 

[Gerald Morris]

If you have the pan down for ANY reason, replace the filter.

Agreed. I plan to.

 

[330dTA]

By the way now that I've got more seat time in the car with this trans I'm very pleased with its performance.

Did I understand you correctly... did you have the A727 modified to a 4 speed automatic? No?

 

[detmatt]

No, I just used some of the parts that have been improved out of the 46RE to improve performance and longevity to the 727.