hey all, appreciate your help.

i have a '71 imperial with a new 493 that quickly smoked the original trans, so i just rebuilt that too with a kit from Cope, and installed a transgo tf-2 shift kit. the problem i'm having is at moderate throttle the 2-3 shift isn't very crisp, the motor flares more than i'd like then it grabs pretty well. at big throttle the shifts seem pretty tight. i have the kickdown link adjusted for full pressure at WOT, the kickdown band adjusted out 2.5 turns if i recall, it's a red flex band if that makes much difference... anyway i'm wondering what i can do. i was reading in Munroe's torqueflite book about opening up that orifice plug you pound into the case to make the front clutch apply faster and help tailor the shift, but i dunno. i was out beating on the car tonight and i'm afraid i'm going to burn something up again. thanks.

the flare is controlled by this orifice yes... I never experienced a flare with this orifice...
What type of kickdown lever ratio do you have? How many springs did you install in the front clutch retainer?
I usually use a 3.8 or 4.2 kickdown lever ratio and install 10 or all 15 springs plus the orifice or a self made 1/8" NPT orifice with the same hole. Till now it worked pretty well.
But the good thing: it shouldn't harm the transmission to much. The front band just releases to early before the front clutches can apply. Usually it's the contrary on the 727/904, that's also not good for the trans.

Since you probably don't wanna reopen the trans and change springs or kickdown levers the easiest thing would be to increase the orifice size. It's a trial and error to get the perfect size. But since you only have a small flare you probably will have to increase the hole 1 time and then you will have a perfect shifting trans!

thanks... i don't know the lever ratio (stock, whatever that is!) and there's 9 springs in the front clutch retainer (also stock).

so i guess i'll mess around making that hole bigger. can it be made "too big"?? i guess if 3rd comes in real hard that's too big eh?

Cheers

A 71 IMP ...with a 493 ?

Now THERES a sleeper for ya. How fast is it?

I asked on the lever ratio because of the turns! You should be able to see the ratio when you remove the pan. Depending on the ratio you have to adjust the front band. I don't think it will change the flare problem but it's always good to know the ratio and like that the band adjustments.

The biggest hole you can make is to remove the orifice as original! But then you will probably have to much overlap causing the 2-3 shift to feel hard and maybe noisy ("clonk" sound). Best to see this if you lift up the rear end in the air and start to accelerate and look at the wheels when the 2-3 shift comes. If they slow down a lot or even stop you got too much overlap.
I would guess you just need to increase the size of the orifice hole. Too much and it will start to have more overlap that makes you loose ET and also is hard on the transmission…

haha yeah it's pretty fast. tonight i stayed with a subaru sti to maybe 120? (the speedo sucks) then lined it up against my wife driving our '03 z06 vette... she was impressed how hard it was to outrun me.

i think i may be looking for an a518 trans eventually though. Even with 2.94 gears, it needs overdrive.

when i had the trans apart i looked at the lever and couldn't read a number on it?? i'll tap that hole and creep up on the orifice sizes until maybe i can make a difference.

it really seems to be a part-throttle thing. the first time i floored it and let it wind out in 2nd the shift to 3rd was pretty impressive... at 6000rpm! i haven't done that too many times yet, hell it's probably going to 3rd at 100mph. just like you're saying i don't want it binding up on full throttle shifts.

It shifts at a very high RPM, did you install a special governor weight?!

Did you install some type of aftermarket linkage like Lokar etc.? These make often wrong kickdown settings so this would explain why at WOT it is ok and then at part throttle it's maybe not enough kickdown signal from the carb.
It's not easy to adjust it the correct way except you got an original type of kickdown linkage or the one from Bouchillon Performance...

But opening up that hole (best would be to remove the orifice to drill that hole up a little bit) will surely reduce this flare. And I guess you are very close to optimun since the flare is small and only at part throttle... at WOT it doesn't flare and seems to be perfect...

John Kunkel surely got also another good idea how to improve this...

How many springs are installed in the front servo? On the <1971 front servos there where versions with 1 and others with 2 springs.. the one with 2 as used on Hemis and 440 make the front band release quicker thus helping flare up.
I guess this was done since the HP 440 also only had 6 springs in the front clutch retainer thus applying the front clutches quick.
Today mods are going more into the direction of installing all 15 springs in the front clutch retainer and leaving the front servo with both springs...
But anyway... removing the big spring in the front servo can also slow down the release of front band. But will make more 1-2 shift bindup, on the other hand you surely installed a heavy spring in that rear servo? (and HOPEFULLY and stronger spring retainer!)

it probably has a 2.8 lever in it , that should release pretty quickly so your problem is the clutches applying to slow under light throttle.

Use an allen wrench to check the clearance between the lever and the servo pin that actuates it , 5/16 should be a snug fit , I set to 1/4" with a 4.2 lever .

What orifice do you have in there now ? I'd start by leaving it out completely ???

it has the stock governor weight. i adjusted the line pressure screw about "2 turns in from just flush" per the transgo instructions. the kickdown setup is the original equipment 1-piece rod. a difference is I put a thermoquad on the motor (an AVS was original) and the TQ must have the throttle shafts or at least the linkage is further forward, so to be able to get the kickdown rod all the way back at WOT i stuck a bolt in this slot (see pic) to shorten it, otherwise i was out of travel on the regular adjustment. if yall have ideas on that i'd welcome them. when you do the tf-2 kit and grind the throttle valve shorter you have to readjust the rod back somehow correct?

i don't know about the servo springs, i'll check that and the pin clearance, thanks for the suggestions.

the motor seems to pull well to 6000. the cam is 231/237 @0.050, 112 lsa, 0.560" lift with 1.6 rockers. e-heads, headers etc. although 5500 would probably be adequate

tighten the kickdown band 1 turn and try it. that should solve it

All lever ratios should have the clearance set the same,I use a rear sprag roller to set all mine,thats why the factory had more turns for low ratios and less turns for fast ratios. As far as the flare up I bet you will have to remove the restriction all the way or increase the line pressure,not a good idea if it holds the power in high gear now.

Dang, thats a lot of iron to be pushing around like that.

Instead of slowly increasing the orifice size try it with the orifice plug removed.

so the latest is, i'm losing 2nd gear. when it kicks down to 2nd it sliiiiips then goes, i'm backing off cause i feel it slipping. it used to be brutal. and i barely feel the 1-2 upshift it's gotten so soft.

could i have wrecked a new red-lined front flex band already? maybe the flaring i was noticing on the upshift was the band starting to slip too soon? it chirped the tires the other day shifting to 3rd, so the front clutch must be applying ok.

are flex bands garbage? the original piece was a solid band. i'm thinking i should have gotten one of those. i may be making 600 lb/ft? and this imp weighs close to 5000# ? any other upgrades should i think about for this trans at this point... higher ratio lever, better servos, more clutch springs... etc. looks like i'm taking it apart again.



Cheers