black79transam

Question for everyone I did a search and was unable to find anything. My 98 WS6 with 109K on it is stock with the exception of a SLP lid. I have noticed that when I first start up the car and begin driving the first shift is hard, like it kicks pretty good but every shift after that even if from a stop is very smooth. It's seems like it does this every time I first drive the car. Any ideas what this could be?

KQuinn

worn 2-4 band or sticking 1-2 accumulator valve. the valve is small.

black79transam

I was told to start with the 1-2 solenoid, is that the same as the accumulator valve?

Jake's Performance

iTrader: (2)

It may just be air in the 2nd servo area causing the first shift to be different.

Z28_LS-WON(1)

I have a 98 Z28 and mine does that too. It is all stock besides LT's/ORY and LS6 intake. But it shifts hard all the time from 1st to 2nd but not in a bad way. 2nd shifts pretty smooth but it has a small kick to it as as well. Drive and over drive feel normal.

mrvedit

No, the 1-2 accumulator is under this cover:



Therefore you only need to drop the pan and remove 3 bolts to open the Accumulator. Inside will be a piston, a pin and two springs. The piston will often wear a hole around the pin, or if the piston is plastic, crack. Either will cause various 1-2 shift problems. Either replace the piston with an aluminum one (about $2) or install a Sonnax Pinless piston ($11):

http://www.transmissionpartsusa.com/...-07799803k.htm

The Pinless one also takes solves problems with bore wear and is recommended.

You could replace the solenoids ($15 each) but that is probably not your problem. Instead I would next remove the servo from the side of the trans and replace all the seals in it. ($10)

If this doesn't solve it, then you probably have a more serious problem like a worn band which will require a removal and rebuild.

black79transam

Wow thanks for all the info

I think I will replace everything you mentioned as I don't really want to crawl under there more than once. Would you happen to have a picture of the servo? I have little to no experience with transmissions.

mrvedit

Sure:



The two gold rings are part of the Transgo Shiftkit and will not be part of yours.

That picture shows three seals on the servo and an o-ring for the cover. The middle portion (the 2nd gear servo) will pull out by hand to expose another seal.

The servo is on the side and this can be difficult to reach in some cars. Here are pictures on how to open it up.

First wack it with a mallet to loosen the cover:



Then compress the cover any way you can to remove the snap ring:



Start to pull out the cover; you first have to cut the blue o-ring:





It can now all be pulled out by hand:





Like I said, accessing the servo can be a pain. You might consider having a trans shop do that for you. Might cost $100 to R&R the servo and re-seal it.

mrvedit

The solenoids are easier to replace as you only have to drop the pan. There are on the right side of this picture above the 1-2 accumulator.



First remove the electrical connector with your fingers. The solenoids are held it with a simple clip which can be removed with a screwdriver or needlenose pliers. One solenoid is spring loaded (about 1 lb force) and will pop right out; the other only needs an easy pull.

black79transam

Wow guys thanks so much for all of this info. I can tackle most mechanical projects with directions and easy to see and understand pictures like this. Looks like I will be collecting parts and head from there. I will update this thread once I have everything replaced.

mrvedit

Since it is tough to get the servo out in most F-body cars, I would start by dropping the pan and replacing the 1-2 accumulator parts and, while you are there, the solenoids. If your pan does not have a drain hole, I suggest first pumping out about 1 gallon of fluid through the dipstick with a simple pump available for $8-$12 at Harbor Freight or most auto stores:

justin hover

You have an agressive first gear ratio comparably to the other gears. Mine was very noticable after I was tuned, increased line pressure...kinda like a shift kit. Makes first gear shifting much more aggressive, like it shoots it right into 2nd=churping

01ssreda4

iTrader: (96)

Engine load determines the commanded shift pressure. Do not rule out a bad/failing sensor like MAP or MAF. Ive also had TPS's not reading right and would cause an extremely aggressive "put-in-gear" feel. There are lots of things going on that determine a transmission's behavior.

mrvedit

All good points too!
A sensor problem would likely make all shifts much firmer.
The MAF can often be tested by just unplugging it - you will get a "check engine light" but the car should run very close to normal.
(Just to be absolutely safe, don't WOT with the MAF disconnected.)
A scanner can show you the TPS, MAP and MAF values too,; you just have to know to use one. Generally free rental at most auto stores.

joecar

It this happens only when cold, there are temperature pressure modifier tables that can be edited in the PCM calibration to lessen the kick.

Jake.Z

What happens if u have a built tranny? Still same cause?

pricesgarage

try the basics check for dtc if it has a 1870 code set the ecm will increase line psi if no codes change the fluid and filter and a lubegard additive and good atf like amsoil or mobile if if u have any dtc u need to address them first