Spl170s

iTrader: (8)

okay, don't know what is causing this...but here is a quick rundown of what is happening.

tranny was freshened up with a new 3-4 clutch set and everything was tore down and cleaned and reassembled. everything looked good.

The car is driving fine it seems until time for OD to kick in.

If i have the car in "D" and drive around.......the car will ge tto 3 and then you may feel a slight bump like 4th is engaged .......but the speeds and rpm's don't show that.....seems like still in 3rd. Now if i let off the gas at around 50 or so, the RPM's drop quickly and then the car jsut coasts down to lower speeds.

Now if i am in "3" and do the same thing...the rpms' will start to lower...but they seems to stay with the MPH happening...doens't just drop off so to speak.

Almost like car jsut lets go of gear when i let off the gas while in "D"....

Only think i know that i messed with before.....was when i had a vig3200 a year ago or so, i had removed a "torque converter clutch orifice" thingy from the end of the input shaft. I read about it in a build up from century transmission in a GMHP magazine. UNtil here this last time having this tranny back in, i was running a TH400 setup for a while...and then jsut now have gotten my original 4L60 back in with the stock converter..and now my OD doesn't seem to work right.

I have no clue..but need some suggestions quick!!

Thanks

CamaroCain

iTrader: (1)

have you talked to the person who installed it?

Spl170s

iTrader: (8)

i installed the tranny into the car. i also did the clutch swap. everything went smooth and jsut like it had been before my last 3-4 clutch failure when i had local tranny guy build it. i was going through 3-4's quickly. so, i was the one who did the clutch pack swap this last time. nothing out of the ordinary and i double checked myself on eveyrthing.

coudl that orifice check ball like thing be causing something like this?

Spl170s

iTrader: (8)

TTT

Again, the car doesn't seem to be shifting into 4th. When i was saying in "D" that would be 4th in my car.

Put it in "D" and start driving, every shift is felt until it is time for 4th...don't feel anything. Get up to higher speeds....like 55-60....rpm's are running high due to being in 3rd still...let off the gas and the rpms will drop to like 1200 or so....and the car jsut coasts down.

Have the car in "3" and do the same thing.....now if i let off at around 55-60...the rpm's will not drop so quickly...they creep down with the speed of the car slowing down.

It's like something isn't engaging and holding right...like pressure isn't being applied proplerly somewhere.

like i said, only think i know i messed with was that orifice thing on the end of the input shaft......it has something to do with torque converter clutch engagement.....

i plan on having it scanned tomorrow to see if something comes up...hopefully something does...i don't know what it oculd be.......

anyone???

Spl170s

iTrader: (8)

went and had it checked with scanner at parts store....no codes.

NO CATZZ

iTrader: (10)

I had the same thing happen to me when I installed my Transgo. After many phone calls and dropping the vavle body and seperator plate 4 times I figured out what the problem was. The servo on the passengers side of the tranny has a paper or fiber-like gasket that goes around it. Since it is not a complete circle (it is slash cut so you can install it) it is easy for it to come off before you get the entire servo assembly installed. I was so frustrated but again relieved that it was something this simple. Take the servo out and check this gasket because without it when it tries to engage 4th there is nothing holding the fluid behind the accuator (or what ever it is called) in the servo so 4th is never fully engaged.

Tip: Use some Vaseline to hold the gasket in place while you install the servo. And you can do this while the tranny is still in the car.

Good luck.

Brains

iTrader: (7)

No catzz is right on the money.. if you have 2nd gear, and you have 3rd gear, you should definitely have 4th gear (since the band and the high gear pack will be applied to get 4th gear). If you lose the band apply for 4th gear via the 4th gear servo stacked on top of the 2nd gear servo, you just stay in 3rd gear.

The other thing you noted, placing the selector in 3rd drags the motor down when you let off the gas. That's by design, as the transmission only applies the "overrun clutch" in selector postisions 1, 2, and 3. The overrun clutch applies to give engine braking, and it also helps prevent sprag breakage since with that clutch applied the sprag is effectively out of the picture (until you overpower the clutch, but you still have both the sprag AND the overrun clutch sharing the load).

Spl170s

iTrader: (8)

This is something i can do easily enough and make sure it is right. Thanks for the help guys...i will try to get to it tonight or tomorrow and post up what i find in there!

Thanks

Spl170s

iTrader: (8)

do i have to drain fluid to do this also?

thanks

Brains

iTrader: (7)

Nope, a little will drain out when you pull the cover, but not much.

Spl170s

iTrader: (8)

okay, thanks!

Spl170s

iTrader: (8)

i don't think this was the issue for mine. i got the cover off and pulled out the 4th piston....it had a black ring on it with the slash cut to it......was seated well on the piston and showed no signs of it being off or anything.

my next question is on the gold shims. i don't beleive the band was checked with the shims when they were installed. i remmber there being 2 before so i jsut reinstalled them and didn't think nothing of it. starting to wonder if having the 2 in there was my problem. what do these gold colored shims for the servo area do...the shims that come with the trans go kit?

my next move will be the valvebody to see if i have a stuck valve i guess.

just makes no sense....i got all gears but 4th. weird...

anyone?

Brains

iTrader: (7)

Those gold shims get you a more firm 2nd gear apply.

Do you have a scan tool handy? Check to make sure the PCM is commanding 4th gear, just to make sure If your scan tool supports it, the pressure switch pack in the transmission should report only switch D4 being active in 4th gear. If both D3 and D4 are active, that means the transmission is still in 3rd gear. That would let you know if the transmission is both being commanded into 4th, and that oil pressure is being developed at the proper feed locations in the transmission. If you still don't have 4th and everything to this point checks out, I'd still point to the 4th gear servo either being out of adjustment, or maybe missing the clip on the apply pin. There's a few other possibilities, like valve body gasket tears, sticking valve in the valve body, missing or goofed up orifice plug in the servo case, etc.

Spl170s

iTrader: (8)

wow, sounds like fun....

i am going to go to local tranny shop tomorrow to have them show me the servo area on a stock tranny...to make sure everyting looks right.

i am confused by the comment on the "4th gear servo being out of adjustment or maybe missing the clip on the apply pin"

What adjsutment?
And where woudl this pin be?

If i don't see anhting else here, i will take it to the dealer once i get it buttoned back up...let them scan it. i knew it wasn't throwing codes...but i guess that doesn't mean there isn't somethign wrong electrically

SOM WS9

Did you by chance install a Trans Go shift kit in the car?

I'm having the same problem with mine, and I think it came down to an error in the instructions in the shift kit. The problem lies in the 3-4 accumulator piston. The Trans Go instuctions say to install the accumulator spring into the case, then the piston onto the spring. The piston is supposed to go in the case first, then the spring sits in the piston.

I figured this out after calling the Trans Go tech line. The person I spoke with told me it sounded like the problem was in the 3-4 accumulator. As soon as he said it, I remembered seeing a difference between the shift kit insturctions and the factory manual when I installed the shift kit. I mistakenly assumed that these people knew what they were doing when writing the instructions for the shift kit. So today I'll be fixing that problem (hopefully). I'll post results in a day or so.

Keep us updated on your progress.

Spl170s

iTrader: (8)

Yes, the car does have a trans go shift kit in it.

Currently, i can drive the car anywhere, all day long and it drives fine. But once 4th (OD) shoudl come in...the car will jsut lurch with it a little, but not go in fully. You can tell it is trying, but just can't engage it.....like something is holding it back.

So yours is doing the exact same thing right now? As far as you can tell it is trying to go into OD....but jsut can't engage it right? Maybe this is my problem then too...because my kit was installed following the intructions as well.

SOM WS9

I'm going down to the garage in a few minutes to check it out. I'll let you know the results, but I'm willing to bet this is the problem.

I used the full manual kit in my car, which is the same as the standard kit, but it comes with a couple extra valves. When I shift into 4th gear on the throttle, I feel nothing, it's still in 3rd. But when I back off the throttle and shift into 4th, the RPMs drop but it doesn't feel like it grabs. So it's trying to apply the band, just very weak.

Spl170s

iTrader: (8)

Yep, mine feels the same way, you can tell it is trying...but jsut doesn't do it......

i will be doing mine today or tomorrow.....hopefully this gets it for both of us.

You woudl think the insructions could be right for a company their size?

skunk50

trans has 80k

when cold, it makes a noticeable metallic grinding noise (like a penny on a sheet of metal that's vibrating constantly).....in "D" and "R"everse.

usually goes away after it warms up. but now it does it after a long drive....i only hear it when i'm pulling up the driveway and completely stopped.