Posted By: boscosis
727 - pulls motor down on 2-3 shift - 03/28/11 06:19 PM
On jack stands you can tell that the motor lugs a little on the 2-3 shift; you almost see the tires stop turning briefly also. On the track the shift is lazy and the mph/et are not what they should be. This is a race-only 727 with a billet drum, bolt-in sprag, and a non low band apply A&A manual valve body.
What should we look for? This valve body has worked fine in a different tranny.
THanks
Posted By: 68valiant68
Re: 727 - pulls motor down on 2-3 shift - 03/28/11 06:22 PM
what was the clearance in the high gear clutch pack? maybe to tight?
Posted By: dOc …
Re: 727 - pulls motor down on 2-3 shift - 03/28/11 06:24 PM
Shift timing is waaay off.
What are the critical specs?
Posted By: boscosis
Re: 727 - pulls motor down on 2-3 shift - 03/28/11 06:27 PM
I'm afraid that I didn't personally build the tranny so I don't know the clearances. Do you guys think it's a valvebody issue?
Posted By: dOc …
Re: 727 - pulls motor down on 2-3 shift - 03/28/11 06:30 PM
Can you at least check line pressure ?
Posted By: John_Kunkel
Re: 727 - pulls motor down on 2-3 shift - 03/28/11 07:43 PM
Easiest way to cure severe overlap is to place an orifice restrictor in the front clutch feed passage in the case. (circled in red below)
Remove the VB, tap the passage in the case to 1/8"-27 NPT and place a pipe plug with a drilled orifice in the case. I'd start with a .140" orifice.
Posted By: boscosis
Re: 727 - pulls motor down on 2-3 shift - 03/28/11 08:54 PM
Thanks for the help guys; I'm considering finally building my own 727 along with my brother this time around. I've pulled them apart before but only to salvage parts like drums or planetaries.
What manual/book do you guys recommend that I buy as a first-time "builder"?
Posted By: boscosis
Re: 727 - pulls motor down on 2-3 shift - 03/28/11 10:07 PM
Shifter alignment is perfect so I'm pretty confident that isn't the problem.
Posted By: 440Jim
Re: 727 - pulls motor down on 2-3 shift - 03/28/11 10:10 PM
Just to add to the good advice given,
if that trans has a 5.0 front band lever, take it out and put a 3.8 or 4.2 ratio lever in.
Posted By: theman440
Re: 727 - pulls motor down on 2-3 shift - 03/29/11 12:14 AM
How does it shift at WOT ?
Posted By: A727Tflite
Re: 727 - pulls motor down on 2-3 shift - 03/29/11 01:55 AM
You're not real clear with the problem at hand. You state that the trans almost locks up on the stands on the 2-3 shift, then you state it is lazy on the track. It's not uncommon to get overlap on the stands. What does it do on the track, run away on the 2-3 or overlap on the 2-3. What's lazy mean, it feels like it is slipping or not very quick to respond to the shifter movement? Watch the tach, if it jumps up on the 2-3 that's runaway, if the tach immediately drops and the car noses down on the shift that's overlap. Over lap means the front band hasn't come fully off before the front clutch has come on. Runaway means the band came off before the front clutch came on with sufficient capacity to pull the motor down. Any good valve body (A & A, Turbo Action, etc) out of the box installed in a properly built trans will not be off the mark, the rest is all timing. The number of front clutch springs vs. front band operating ratio and the front band release spring/s makes up the timing. Just the correct combination of parts. Believe it or not, go to the old Direct Connection manual, pick out the front clutch spring combination for your engine size, and match to the front servo release spring stack. You won't be disappointed. Remember, those packages were done by the engineers with only one motivation - make the Mopars as fast as possible.
Posted By: dOc …
Re: 727 - pulls motor down on 2-3 shift - 03/29/11 02:09 AM
Lucian Mancini
..... part of that Highland Park and CTC "family" ? ..
Posted By: boscosis
Re: 727 - pulls motor down on 2-3 shift - 03/29/11 12:32 PM
The 2-3 under WOT? Really nothing special - it seems to shift late (after the lever is pulled) and not quite as quick to change gears as it should be.
CAB - point taken and I appreciate the concern. We had just installed a new cable and my brother went to great lengths to check that its exactly where it should be. When we're ready to try again we'll check it very carefully for alignment.
Posted By: 65_gt_rag_402
Re: 727 - pulls motor down on 2-3 shift - 03/29/11 04:56 PM
You are correct about the 5.0 lever. My dart has it in there and it shifts like that . trans is now 7 years old and never had a issue with it. Still shifts hard! That is the symptom you will get with a 5.0 lever.
When you have it on the jack stands running , its more obvious .Nothing to worry about !
Darty
some time's you have to fudge the band adjustment a little to get it where it want's to be, is the band lever ratio the same as before? try backing off the band adjustment 1/4 to 1/2 turn and see if that help's,,if you tightened up the clutch running clearance then it engages before the band has released fully. 
Put the car up on jackstands and disconnect the shifter cable, start the car and shift the tranny manually from underneath the car at 1500 to 2500 RPM and see if it does the same as before, if not it is the linkage 
Think about how the bolt holes in the valve body are all (10)slotted so you can seat it with all the stock servo springs and such, move it 1/8 inch from one valve body to the next and your in trouble on the shifter adjustmenst on most aftermarket cable shifters 
It did that very thing where it bogged down going into 3rd gear, it just didnt shift right. I asked on here and was told to take that 5.0 lever back out and put in a 3.8. I did and it was perfect