727 2-3 upshift bind

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360duster

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Hi Guys, just put my trans back in the car after complete overhaulin. Put in a kit with alto red clutches, red lined bands, a 4.2 Kickdown lever, billet rear servo piston and retainer. I put the TF2 Kit in, too. Converter is a Turbo Action 3500 stall unit (new).

It seems to work fine, nice quick shift from 1-2, from 2-3 under part throttle it feels that there is some bind, two gears engaged at the same time, not extremely but i can feel it. I found out that it´s due to the front band is not released completely but the front clutch is fully engaged. Possible solution is to slow down the clutch action due to a smaller orifice (i already put the plug in that was supplied with the TF2 Kit) or quicken the band release.

I have to check my notes regarding the band adjustment, but would loosen the front band 1/4 to 1/2 turns help in this case without making sth. worse?

I did not check it under full throttle, this weekend i wanna go dragracing - can there be any damage to the trans using it like it is?

Thanks for info!

Michael
 
Your driveshaft U-joints sure won't like this jerking action in the driveline.
Sometimes you can 'tune-out' the overlap in the 2-3 shift by altering the band adjustment. Trial and error in this case.

My previous transmission had the same issue and I managed to lessen the overlap slightly with a band adjustment. I didn't put too much effort in it to try to completely get rid of the overlap, as the transmission was about to be swapped for another one with a TransGo-kit in it.
 
2-3 shift overlap (bind up) is a fairly common problem. What front servo did you use (old or new style) and how many springs did you put in it? I've found the old style servo along with 2 springs usually works well. Backing off the front band adjustment helps slightly but if it's a very bad bind up don't expect it to cure it. You can also drop the front band apply lever down to a 3.8 which releases faster. One thing's for sure, you need to get it fixed fast cause it'll trash things real fast if you don't.
 
ok guys, thanks @all for the support and the tips.

Tracy: it´s the newer servo, trans is from 73 and it was all original. I put all the OE springs back in. If i remember right, the transgo instructions supplied with the kit said back of 2 turns, so i did like this. Later i read in munroe´s book that the adjustment is specific to the kd-lever.....since i´m running a 4.2 lever it should be backed off 2 1/4 turns. It´s not a very bad bind up, i just can feel that there´s sth. slightly wrong. I will try backing off the front band another quarter turn and see if this works.

Thanks Michael
 
it is a 3 friction retainer, the clearance is on the high side but in spec...must take a look at my notes when i´m at home this evening.

Michael
 
ok guys, thanks @all for the support and the tips.

Tracy: it´s the newer servo, trans is from 73 and it was all original. I put all the OE springs back in. If i remember right, the transgo instructions supplied with the kit said back of 2 turns, so i did like this. Later i read in munroe´s book that the adjustment is specific to the kd-lever.....since i´m running a 4.2 lever it should be backed off 2 1/4 turns. It´s not a very bad bind up, i just can feel that there´s sth. slightly wrong. I will try backing off the front band another quarter turn and see if this works.

Thanks Michael

That's a little tight but I haven't found 1/4 turn to make a big difference. If backing it off 1/4 turn helps but it still needs a little more you can try backing it off 1/4 turn more but I wouldn't go more than that. If that still doesn't do the trick locate an old style servo and put it in. The new style load control servo's seem slower releasing which causes the overlap. A few yrs. ago I did a trans for a buddy and it had the load control servo along with a 5.0 servo lever in it. It bound up real bad on the 2-3 shift. OldKimmer sent me a old style servo with 2 springs and I put that in and changed the lever to a 4.2 and adjusted the band to 2-1/4 turns and it shifted fantastic then.
 
Trans worked fine under full load, got my first 11 sec timeslip with the valiant (11.98)!

It shifts quick and crisp, just what i expected.

Regarding the bind up: i´ll try the mod Mr. Munroe describes in his book, closing the little hole in the rear portion of the servo. According to him it will perform like the older one with this mod......if not i´ll get the old style servo.

Thanks at all for the always great support! this was my first auto trans ever, i learned a lot at this board here!

Michael
 

Trans worked fine under full load, got my first 11 sec timeslip with the valiant (11.98)!

It shifts quick and crisp, just what i expected.

Regarding the bind up: i´ll try the mod Mr. Munroe describes in his book, closing the little hole in the rear portion of the servo. According to him it will perform like the older one with this mod......if not i´ll get the old style servo.

Thanks at all for the always great support! this was my first auto trans ever, i learned a lot at this board here!

Michael

=D>=D>=D>=D> Well Done and A nice Time slip too . Hope I will be as Succ
essful
 
.....................good job, but the thing is that u may have thought it shifted great under full power but in fact u didn't notice the bind up cause the car had the power to pull through it.........u still need to get the bind up out of it or it will kill the trans........kim..........how many springs in the front drum........
 
There are only 9 springs in the front drum.....still forgot about your question regarding the clutch clearance....will check this evening.

Michael
 
More springs = later clutch engagement. Your coming on too fast, recommended by the big dogs to either install them all and tune with a plug, or install a percentage based on what lever you use, 5.0 being all 15, 4.2 being 15% of that so 12-13, and 3.8 25% being 10-11.

All isn't lost.


Did you install the orafice plug? the stock hole is .140. Since your running low on spring, I'd advise installing that sucker, and if you have, close the hole up to the in the .110 area with either a 1/8 27 NPT plug, or a small freeze plug. That should get it done.
 
Nice time Duster. Oldkimmer has a good point about it may be binding up at WOT also and you just don't feel it. There are a few ways to go about remedying it and the smaller orifice PoisonDart recommended is one

BTW: I have Munroe's book and I think I remember him telling how to mod the newer servo but can't for the life of me find it again. What page is that on?
 
ok guys, i will get into it later this year, no time to work on the car until September. Then i will install my lift in the garage before.....will make working at the trans much easier. Removing the pan and the VB is no problem, but is it possible to remove the KD-Lever and the front servo without removing the trans? Do you reach the set screw that secures the pivot shaft trough the trans bell?

Anyone knows a good way to remove the plug that came in the TF2 kit? I could bite my *** that i did not tap the bore when the trans was apart....now i don´t like to get metal chips inside due to drilling and tapping.....

I think about blocking the accumulator with a blocker rod. At the moment there is one spring installed between the VB and the piston, just like it was before. Do you think it´s a good idea?

Michael
 
..........The blocker rod would help with ur bind up.............the acc spring should be removed that goes between the acc and vb...........hp trannys had a long thin spring between the piston and case...........I always put a spring there if I don't use a blocker rod.........I would use the factory line pressure spring, but now I don't think they send a replacement for it anymore....................and yes modify that cl servo...........kim......
 
Hi GAZ!!! nice to have you here!

Great to be here Michel. To remove the orifice I've used a Spax screw & a pair of pliers in the past. It works well. Do you have 2 springs on the front servo piston or just the small diameter one over the guide pin?

When you tap the case for the screw-in plug for the front clutch, liberally coat the tap with petroleum grease. (Vaseline) This will catch the swarf & it wont end up in the trans.
 
regarding the front servo: i do have the big spring installed over the piston rod, then put it all together with the piston rod guide

Michael
 
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