dctoner

The more I read the more I'm confused.

Can someone explain to me "lockup"

I know that is when the TC is locked up.

I guess what I'm asking is for some one to walk me through the
different stages the tranny goes through when accelorating. And how O/D plays into all of this.

I thought I knew how it worked but the more I read on this site the more I question my knowledge. I think them majority of my confusion is the different ways people describe "lockup" "lockout" etc.


thanks

bluebull

Lockup means the transmission is transmitting 100% of the power through the transmission. A manual trans has 100% power going through the transmission all the time as long as the clutch is ingaged.

On our trucks the normal sequence is 1st gear, then 2nd gear, then 3rd gear, then 4th gear (or OD), then the clutch inside the torque converter locks against the housing (simular to a manual) which then gives us 100% power transfer. Called a 4 speed with lockup. You could almost consider it a five speed if you take the converter locking into acount, but really only has four forward gears.

I think it was model year 2000 DC started using programs in the pcm to lock the coverter clutch in 3rd gear and 4th gear with a momentary unlock at shift between the gears. DC also used a program called torque management in OD on the 2000 to help the transmission live longer.

On a modified auto transmission you can get lockup all the down to 1st gear if you so desire.

dctoner

So with my 98 when I shut the OD off, I'm no longer in Lockup. Correct? Being in 4th Gear.

I have not owned a dodge before this one and the Tranny seems really odd to me. It seam to shift normal from first to second (except being really soft, drawn out shifts), but 3rd seems like it shouldn't even be there because it doesn't stay there long enough to use it. Most of the time it slushes right into 4th. And then is slushes into OD, which is a painfull lugging, even though my rpm's are up.

Is this normal for a stock slush box, and I mean heavy on the slush.

I have owned 3 other chevy Autos and none were this bad.

bluebull

IF you shut the O.D. off manually (button on end of shifter) then the transmission will lockup in 3rd. So it should go 1st, 2nd, 3rd, lockup.

Gear selector in D with O.D. on it should go 1st, 2nd, 3rd, 4th, lockup.

I see you have 118,000 miles on the transmission. Have you ever had the fluid changed? It should be serviced every 24,000 miles none towing and 12,000 miles towing. Serviced means fluid change and band adjustment.

How about the fluid color and smell? It should be a deep pink color and smell like lite plastic or that injection molding stuff we use to have when we were kids. If the color is dark or brown and smells burnt it is waaayyyy past a fluid change, get it out and some new fluid in there right away.

How about fluid level? check it a after you have driven the truck 8 or more miles and then check on level ground with the truck in neutral and the parking brake set. It has to be in neutral to check for correct fluid level.

bluebull

Wanted to clairify a little more.

I think where most people get confused is the lockup and OD part. Lockup and OD are not the same thing. Then they look down at the gear selector and see only three simbles for forward gear.

OD and 4th gear are the same even though the selector only has three engagements. The button on the shifter controls if it goes into OD (4th gear). If you do not push the button to turn OD off (which is the mode the transmission is in when started by default) then the transmission will run 1st, 2nd, 3rd, OD (or 4th), and then lockup.

If you push the button in on the gear shifter after start up then the transmission will not go into OD (or 4th), it will run 1st, 2nd, 3rd, and then lockup

dctoner

Bluebull,

Thank you for your time and explanations.

I just bought the truck, the guy I bought it from had just changed the fluid and filter 10k ago, and I know it has been done at least once before that because of a sticker under the hood. Fuid level is good, color and oder is good. I don't know if it has ever had a band adjustment, probably not, he did not know much about the truck.

So am I correct in assuming that with OD off and when it sound like it shifts out of 4th this is what is called lockup.

I don't think I have ever had it lockup in 3rd!

Is there a way to hook up an LED of some sort to know when it is locked up?

I usually pay attention, but during city driving it would be nice to have a reminder.

Smokee

The tranny will not likely lock up in city driving unless you are going over 55 mph, or you have the OD button locked out(orange light).

bluebull

City driving it is a good idea to leave it out of OD so it can lockup once in a while in third. The transmission will cool alot better in lockup, no matter if it is OD or 3rd, as long as it can lockup the transmission will live longer from better cooling.

Transmission should lockup in 3rd gear (button pushed out of OD and light on dash light up) at approxiamately 30-35 MPH under lite throttle.

Transmission should lockup in OD (no light on dash saying OD off) at approximately 48-50 MPH under lite throttle.

The heavier you push on the throttle the later the shifts.

bluebull

dctoner,

Some thing is puzzling me. You say you have never felt it lockup in 3rd before. The next time you drive your truck try this. Start your truck, shift into drive, push button on shift selector to take it out of OD sequence, light on dash should come on saying "OD off"
now drive down the street at lite throttle watching your tachometer and counting the shifts, you start in 1st so the next shift you feel and see on the tach should be second gear, then you should feel and see on the tach another shift which would be 3rd, then you should feel and see on the tach another engagement of the transmission this is lockup in third. If you increase your speed to go over 50-55 MPH and then push the button on the shifter this will take it out of 3rd lockup and shift into OD, after the shift into OD you should feel another engagement and that would be lockup in OD. At every shift or lockup engagement the tach should drop rpm's.

There is a way to hook up an LED but I forget how. The lockup command is a grounding to complete the circuit. I beleave it is the orange wire with black strip coming out of the PCM. Please do not take my word for this, maybe someone can chim in and explain that part better.

dctoner

I may have been wrong about the 3rd gear, but I will make sure on my way home tonight.

I think the big difference between this truck and my last chevy is the lockup. I'm used to possitive shifts to each gear and no lockup. either that or I have been sleeping for the past 15 years while driving

dctoner

OK, what is wrong with this thing.

Bluebull, I tried what you told me, OD off(with light on dash saying off) light throttle, I get one shift at 30 to 40 mph nothing more, even if I get up to 60mph

Here is what is interesting, after the shift at 30 to 40 I ran it up to 50 mph and then manually shifted it down to second, it geared down with no problems, then around 25 I manually geared down again to first with success. Then I started out in first and manually worked my way through the gears. Everything seemed fine.

But when I start out in "D" Drive it almost seems like I'm starting out in second. Would this be cause by the bands being out of adjustment?

With OD on (no light in dash) it still shifts around 30 to 40 then again around 50 and then it seems like it sort of slides into another gear right after that, which I'm thinking that is lockup.

Does any of this make sense?