davidhouston23

Well this started two days after I put the lucas fix into the car, it was shifting hard so I figured why not. Anyways yesterday I noticed the transmission start slipping on the interstate doing 70. So I exited off and turned around to go home.

Now the issue here is once I hit about 40-45 MPH it acts like it's in Neutral and I have to gas it to keep it accelerating, to me it's like it's riding around in 2nd gear or something. The weird thing is if I floor it, it shifts like it normally would until I let off the gas, then it just cruises in the high RPMs like it's in 2nd gear.

I drained the fluid today because it said it was too full on the stick, and put 5 quarts back in, and it's sitting right on the full line now. But it's still doing the same thing. Gonna have to make a few calls tomorrow and have someone look at it I guess, but does anyone know what the problem might be? Someone said something about a valve may be sticking or something since the lucas is so thick.

BTW, it's a 1998 Trans AM.

jimmyblue

iTrader: (11)

Sounds similar to what heppened when I put
B&M Trick Shift in mine. Messed up the
converter clutch big time. In 4th gear at 40
it's the TCC that keeps RPM down. There's
0% commanded line pressure at light load,
low cruise etc. - not true zero pressure but
very little. So you need a clutch to keep
its friction. My clutch never did recover
despite several fluid changes. The clutch
packs in the trans itself were unharmed,
fortunately.

Look at it this way, now you have a really
good reason to buy a performance
converter. One that even the stingiest
wife can't dispute.

As a rule, hard shifting is not a sign of a
trans problem but something else that
is pestering the PCM into upping line
pressure on shifts - a sensor fault perhaps.

Old-timey miracle goos are a bad idea on
newfangled motors and transmissions,
built with seal & friction materials that
didn't exist (or weren't used) back when
(if) said goo was compatibility-tested.
Just because they say it's OK, doesn't
mean a thing.

davidhouston23

Thanks for the response. I've had a few friends tell me that my transmission filter may have been dirty before I Put the lucas in and that the lucas could have clogged it up pretty bad. I guess pulling the pan off and putting a new filter and some more new fluid wouldn't hurt.

How much does it normally cost to have a new converter put in if this happens to be the problem? And how does one test this, could a shop tell pretty quick?

1quickirocz

You need to have it code scanned to check for any tranny DTCs. Sounds like a possible seal problem. When you get on the throttle the PCM turns up the line pressure which may overcome your seal problem at full throttle but as the pressure drops it leaks down past the seal. Been inside of multiple trannys with you same issue. most always ended up being a seal problem. get a good rebuild and a new converter and be done with it..

davidhouston23

Okay another question, will it hurt the engine to drive it to a shop to have it looked at / code scanned? And also will it hurt the tranny anymore than it's already hurt?

johnLs1camaro

iTrader: (28)

i think your one of your clutch sets went bad... if you can cruise there it wont hurt anything any worse... just take it easy and besure you dont have to rem the **** out of your car to make it there...

CamaroRick

iTrader: (24)

sounds like he 3/4 clutches are burnt up.

GT Griller

iTrader: (8)

SOunds like u lost lock up to me.....and if u grenaded that lock up clutch i would NOT continue to drive it because if there are chucks of the cltuch floating around i wouldnt want them to make it thru my pump or else ur tranny will starve of fluid and go bye bye completely...beleive me it happen to me.

davidhouston23

Holy hell, so many different things it could be. I don't know anything about transmissions.

Im gonna call a shop in the morning if this filter change doesn't work. I'll update later.

Thanks.

lt170chevelle

iTrader: (2)

very simple procedure to this. check your fluid for any shavings ,metalic particles,or clutch material.Also smell it . if you havent driven it much since you changed the fluid, just drain it and drop the pan. look in the bottom of the pan for the same...material and sludge. if it isnt totally sludged up then you possibly have a clog,damaged seal. if its full of crud then you have fudged up something already and going to need a rebuild and a new convertor wouldnt hurt. the way you explain it ..its hard to pinpoint exactly which is a possible problem. could be the 3/4 clutches going out...but will rev pretty high on the highway..or convertor clutch which is just your lockup which would be noticable higher rpms but nothing too drastic....just my 2 pennies

built408

iTrader: (10)

Sounds like the 3-4 clutches are burnt up. The input shaft is probably loose in the input housing, causing a pressure loss. Common problem in f-body's. Does it do it worse when hot?

jimmyblue

iTrader: (11)

If it still pulls well in 1, 2, 3 at higher throttle (you
may not have the road, for WOT 4th) and doesn't
flare then you can deduce that the clutch packs
and band are not ruined. I expect that they all
(OE build) use the same friction material and a
fluid surface contamination would bother them
all (or not) similary (driving-dependent glazing
aside).

If it's only low RPM, high gears, light pedal that
is messed up then it points to lockup clutch.

If by "acts like it's in neutral" you mean it free-
revs with more gas and doesn't pull any harder,
then it may be a much sadder story. More gas
with holding clutch-packs and an unlocked
converter will at least result in more pull as the
slip increases.

davidhouston23

By acting like it's in neutral I mean after it starts slipping I can push the gas in and it rev the engine like it's in neutral. If I floor it while it's doing this it will accelerate again, but I spin all over the road like it's going to 1st. I'm sorry for the vauge explanation i'm giving but im gonna have it checked out on Monday. If it turns out I need a rebuild, I may just buy a new tranny and be done with it.

I've been searching prices around here and everyone is quoting me 1800+ for a rebuild, though i've found a nicely priced transmission on everdrive.com. I'll update once I figure out the problem, but I appreciate all input so far.

Oh and to the guy that asked if it got worse once the car warmed up yes it seems like it does.

02 BLK WS6

iTrader: (11)

You get what you pay for especially when it comes to transmissions. Don't take a cheap route, you will be in the same seat in a year. I grenaded my tranny pretty good. I spent about $800 in parts and $400 on a used vig converter when I rebuilt mine.

GT Griller

iTrader: (8)

WERD

If u have kept drivin ur more than likely gonna need a new tranny......Chuncks of that destroyed lock up clutch can pass thru ur pump and ruin ur transmission.....It happen to me with my old fuddle...it just stop locking up but shifted thru the gears fine..if i nailed it, it took off like a bat out of hell but once i was in fourth it woulndt lock up like normal cruising it would take more rpms to keep it going......i kept driving cause i had no choice and ended having some peices of the clutch block the passage way for fluid thru my pump...starved the tranny of fluid and burned up my tranny.