Help.....Tranny shifts hard from 2-3 ?
10-02-2007, 05:45 AM
#1
TECH Regular
Thread Starter
iTrader: (1)
Join Date: Mar 2004
Location: Downey, California
Posts: 484
Likes: 0
Received 0 Likes
on
0 Posts
Help.....Tranny shifts hard from 2-3 ? Hi all, I have a 4l60e and I rebuilt it about a year ago and put all the good stuff in I also put in a trans go shift kit after that it shifted hard at low speed in to 2-3 I even tuned the pressur down on the 2-3 shift tables
well it was OK but I took almost all of the shift kit out expect for a few things I left in..
Well it shift even harder no 2-3 but only at 5%-10% throtle I already lowered the 2-3 line pressure -51% @0%-20% tps
its ok but dosen't feel right I did notice for awhile that my idle is iratic when I come to a stop and takes a sec to lower to idle I Cleaned my MAF almost a year ago also my IAC...
I'm thinking of putting my shift kit back in but wanted to check before I drop my Valve body again..
ThankS guys ...
well it was OK but I took almost all of the shift kit out expect for a few things I left in..
Well it shift even harder no 2-3 but only at 5%-10% throtle I already lowered the 2-3 line pressure -51% @0%-20% tps
its ok but dosen't feel right I did notice for awhile that my idle is iratic when I come to a stop and takes a sec to lower to idle I Cleaned my MAF almost a year ago also my IAC...
I'm thinking of putting my shift kit back in but wanted to check before I drop my Valve body again..
ThankS guys ...
10-02-2007, 06:31 AM
#2
Are you running an EPC or a vac-mod? If you are running an EPC try to return the pressure table back to the stock settings. With a shift kit the transmissions line pressure has already been increased. Its one or the other not both. If you are running a vac-mod I would check to make sure that you do not have a vac leak. Also are you running a second gear solid billet servo? If so that piston removes all accumulation for 3rd and will produce a hard 3rd gear shift as well as second. How large of a feed hole are you running for 3rd? I think that .093-.110 is all that I would recommend. I guess what my question is what have you done with the trans? Are you getting any codes that you effect the transmissions line pressure? Did you inturnally adjust the EPC solenoid? Need some more info. Vince
10-02-2007, 12:49 PM
#4
TECH Regular
Thread Starter
iTrader: (1)
Join Date: Mar 2004
Location: Downey, California
Posts: 484
Likes: 0
Received 0 Likes
on
0 Posts
Thanks for the quick responce,
I have : 13 vain pump, red alto 3/4 clutch pack, .490 boost valve w/ longer center spring, transgo valve body plate 2-3 feed hole is .093, corvette servo, kevlar band, high rev pump spring, heavy duty sun shell,new sprags, it shifted great when I first rebuilt it around 20,000 miles then I busted my plantary gear november so I put all new gears, 5-pinion plantary gears, new seal kit, but I notice my over run clutches were alittle dark brown so and I notice my little square filter was collapased and my parts guy recomend the shift kit.
that was about 6000 miles ago,
after I took out most of the shift kit I liked it better with it in my second gear was firmer and when i'm cruising around 55 or so and give it alot of gas without down shifting it feels like it slipping.. and when I had it in my line pressure off set was -40% and it felt better then now at -50% I also had to remove some pressure when i'm coming to a stop and it down shifts from 3-2 some time I get a bump...
so when I say alost all of the shift kit is out I still have the valve body plate that was drilled out according to trans go,
when you say EPC that is my "main line pressure" if so its at stock settings now
I use the C. A. T. S. tunner,
with the shift kit in :191238 miles 4-10-07
idel 70 psi
idel in reverse 95 psi
1500-2000 rpm 235 - 240 psi in R
1500-2000 rpm in D 160 psi
in N 1500 rpm 75 psi
in N 2000 rpm 120 psi
I called trans go and he said its norm to have alittle bump but I didn't have it before I put it in.
thank you.
I have : 13 vain pump, red alto 3/4 clutch pack, .490 boost valve w/ longer center spring, transgo valve body plate 2-3 feed hole is .093, corvette servo, kevlar band, high rev pump spring, heavy duty sun shell,new sprags, it shifted great when I first rebuilt it around 20,000 miles then I busted my plantary gear november so I put all new gears, 5-pinion plantary gears, new seal kit, but I notice my over run clutches were alittle dark brown so and I notice my little square filter was collapased and my parts guy recomend the shift kit.
that was about 6000 miles ago,
after I took out most of the shift kit I liked it better with it in my second gear was firmer and when i'm cruising around 55 or so and give it alot of gas without down shifting it feels like it slipping.. and when I had it in my line pressure off set was -40% and it felt better then now at -50% I also had to remove some pressure when i'm coming to a stop and it down shifts from 3-2 some time I get a bump...
so when I say alost all of the shift kit is out I still have the valve body plate that was drilled out according to trans go,
when you say EPC that is my "main line pressure" if so its at stock settings now
I use the C. A. T. S. tunner,
with the shift kit in :191238 miles 4-10-07
idel 70 psi
idel in reverse 95 psi
1500-2000 rpm 235 - 240 psi in R
1500-2000 rpm in D 160 psi
in N 1500 rpm 75 psi
in N 2000 rpm 120 psi
I called trans go and he said its norm to have alittle bump but I didn't have it before I put it in.
thank you.
Last edited by slagger; 10-02-2007 at 12:58 PM.
10-02-2007, 01:05 PM
#5
Well transgo is correct in that smoothe and performance dont go hand in hand. Everythigs a compromise. If you ae looking to get a nearer stock feel to the 2-3 shift. Change the palte back to stock and use the smallest hole size suggested by transgo for the 3rd clutch that might get you a good compromise. Lowering the line in order to get the bump to go away is not the answer as your also lowering the holding ability of the clutch whichmay cause it to fail prematurley.
__________________
10-03-2007, 05:09 AM
#6
TECH Regular
Thread Starter
iTrader: (1)
Join Date: Mar 2004
Location: Downey, California
Posts: 484
Likes: 0
Received 0 Likes
on
0 Posts
so 2-3 feed hole is what causing the bump
if so can I just make the hole smaller?
plus would that also cause the 3-2 down shift bump?
it not all the time just when your going fast and come to a quick stop.
plus on the trans go shift kit it has my tranny with the .093 but there is a differant piston that takes a .073 hole size. tell me would just .020 make that much differants.
thank you.
if so can I just make the hole smaller?
plus would that also cause the 3-2 down shift bump?
it not all the time just when your going fast and come to a quick stop.
plus on the trans go shift kit it has my tranny with the .093 but there is a differant piston that takes a .073 hole size. tell me would just .020 make that much differants.
thank you.
Last edited by slagger; 10-03-2007 at 05:19 AM.
10-03-2007, 10:14 AM
#7
A littles alot when it comes to hole sizes. And on the quick slow down you may want to check that your converter is unlocking as it should when you hit the brakes, But with any performance build theres going to be some jerkyness in the downshift , You have to remember the same mods that affect the firmness of the upshift also do the downshift since the same componets are coming on through the same feed holes just at O throttle the presures lower. You really cant get a stock feeling performance transmission its like asking for a "wet hair dryer "
__________________
Trending Topics
10-03-2007, 12:37 PM
#8
TECH Regular
Thread Starter
iTrader: (1)
Join Date: Mar 2004
Location: Downey, California
Posts: 484
Likes: 0
Received 0 Likes
on
0 Posts
My converter is unlocking,
I have one more Q I plan on changing the plate would I be ok to leave the plate stock and don't drill any larger holes or, drill the holes as per trans go instrution but, leave the 2-3 feed holes stock?
thank you.
I have one more Q I plan on changing the plate would I be ok to leave the plate stock and don't drill any larger holes or, drill the holes as per trans go instrution but, leave the 2-3 feed holes stock?
thank you.
10-03-2007, 12:43 PM
#9
I wouldn't mess with it, this is the first post I've ever seen were the 2-3 was too firm. There are hundreds saying their 2-3 is slow, delayed or slipping.
It took me a lot of screwing around to get mine right (then I swapped to an M6).
But obviously it's up to you, if you plan on upping the power soon I'd wait on the trans. A lot of people also get 2-3 problems after adding more power.
It took me a lot of screwing around to get mine right (then I swapped to an M6).
But obviously it's up to you, if you plan on upping the power soon I'd wait on the trans. A lot of people also get 2-3 problems after adding more power.
10-03-2007, 12:49 PM
#10
TECH Regular
Thread Starter
iTrader: (1)
Join Date: Mar 2004
Location: Downey, California
Posts: 484
Likes: 0
Received 0 Likes
on
0 Posts
firm I don't mind but its the bump at low speed that drives me crazy.
i'm thinking of put back the shift kit but just not drill the 2-3 feed holw bigger leaving it stock size. after I first rebuilt it with the 3/4 clutch pack it shifted great,
i'm thinking of put back the shift kit but just not drill the 2-3 feed holw bigger leaving it stock size. after I first rebuilt it with the 3/4 clutch pack it shifted great,
10-03-2007, 01:19 PM
#11
I'll let Performabuilt help you with that. With my trans it was a matter of timing. My band release hole size didn't match the third apply.
I ended up starting over with a new transgo plate.
I don't think Performabuilt was here back then.
I ended up starting over with a new transgo plate.
I don't think Performabuilt was here back then.
10-03-2007, 01:36 PM
#12
TECH Regular
Thread Starter
iTrader: (1)
Join Date: Mar 2004
Location: Downey, California
Posts: 484
Likes: 0
Received 0 Likes
on
0 Posts
I just got off the phone with transgo he was telling me its not going to hurt anything with the bump he was also telling me that if I was to make the hole smaller it would make it tighter but we think some of my shift firmness might be that i'm runing a .490 boost valve from sonex and they provided me with the bump spring that it is about 1/4" longer then stock and I used transgo springs that is slightly shorter then stock lenght.
he told me how to check and i'm prob going back to the stock boost valve and use transgo boost valve springs..
he told me how to check and i'm prob going back to the stock boost valve and use transgo boost valve springs..
10-03-2007, 02:13 PM
#13
TransGo is correct in that its not going to hurt anything with the bump . And yes you can leave the holes stock but honestly that defeats the whole purpose of the shift kit on the weakest clutch set in the trans
As I said before theres a compromise to everything, Sometime to get durability its nessesaryto give up some drivability. You also mentioned hat when you first installed it with the shift kit after the build it felt good. But What I imagine has happened is the clutch/band clearance has since opened up which is normal this to can add to the bump as with additional travel you get a greater apply speed and I dont mean it shifts fast what I mean is that the velocity reached by the apply piston is greater which will contribute to the sudden bump. I have seen clutch sets particulay the 3-4 set built at .025 clearance and I know this because I built the unit and then the unit be in service for several months when we were experimenting with various 3-4 sets at one time an when the unit was torn down for inspection the clearance on and unburned perfect clutch set be .035 to .045 so this to may be coming into play. I also noted you have the poly bushings there is a very good reason GM does not use these and its not cost. The muh stock bushings also help to dampen this feeling, I have heard I dont know how many people complain about bumps and vibrations etc after installing these. They just do not have the motion absorbing properties of the stock type bushings and mounts.
As I said before theres a compromise to everything, Sometime to get durability its nessesaryto give up some drivability. You also mentioned hat when you first installed it with the shift kit after the build it felt good. But What I imagine has happened is the clutch/band clearance has since opened up which is normal this to can add to the bump as with additional travel you get a greater apply speed and I dont mean it shifts fast what I mean is that the velocity reached by the apply piston is greater which will contribute to the sudden bump. I have seen clutch sets particulay the 3-4 set built at .025 clearance and I know this because I built the unit and then the unit be in service for several months when we were experimenting with various 3-4 sets at one time an when the unit was torn down for inspection the clearance on and unburned perfect clutch set be .035 to .045 so this to may be coming into play. I also noted you have the poly bushings there is a very good reason GM does not use these and its not cost. The muh stock bushings also help to dampen this feeling, I have heard I dont know how many people complain about bumps and vibrations etc after installing these. They just do not have the motion absorbing properties of the stock type bushings and mounts.
__________________
