The Oldsmobile Connection

88delta88 · Joined: 09 Jun 2003 Posts: 2407 Location: Canada

Surprise, surprise! another late 80's 3.8 litre with tranny troubles.

I just dont know how serious this problem is, or how to fix (if it's user serviceable), I was hoping someone here might be able to give me a bit of info.

When I'm cruising (55-65km/h or about 32-38mph) the car rolls along very smoothly until (im pretty sure its the locking torque converter) it feels like another shift after 3rd gear, and the car starts shaking (shuddering back and forth as if it were totally missing on one cylinder, but I know the engine is not missing). the harder I press on the gas, the worse it gets until it shifts back to 2nd. It only does this at the one speed range.

The reason I know this is not an engine related problem is on the highway it doesnt do this, at the same engine RPM, nor does it do this in any other gear.

I dont have a problem with the torque converter sticking when slowing down from the highway.

What could be the problem, and more importantly, how much does this usually cost to repair? Yes - I have checked my tranny fluid :-) its a nice clean dark red color, and does not smell burnt.

Thanks guys!

86Delta · Joined: 06 Nov 2003 Posts: 281 Location: NJ, USA

i know that feeling you describe pretty well, except my car did it in first gear but i also had a hard time diagnosing it because it felt like a miss. if it doesn't turn out to be a miss, i hate to say it but it looks like you are going to have to spring for a rebuilt trans. it was a worn band that caused mine to chatter.

strokercutlass · Joined: 09 Jun 2003 Posts: 379 Location: Wis

I can't remember right off if you can do it on your car (I can check tomorrow at work if I remember), but, as you probably know already, these trannys had a tendency to have problems with the torque converter lockup solenoid. Not all of them stuck when decellerating. On some of these transmissions, you could unplug the connector at the front of the trans on the drivers side, which would disable the lockup for the torque converter, yet still allow 1st thru 3rd shifting, with the exception of locking up the T.C, for slightly better gas mileage. In later years, when they went to electronic shift control and such, you could no longer unplug the trans, but I "THINK" it can still be done on yours. I'd begin by unplugging the lockup and seeing what happens. If it doesn't help, then I'd have to agree with 86 delta in saying that a band is most likely worn, and the tranny will need to be pulled and rebuilt, which will be a pretty involved process, unfortunetly :?

88delta88 · Joined: 09 Jun 2003 Posts: 2407 Location: Canada

:beer: I think I'll need one or two or three of these... this is not good news, but I shall try unplugging the locking converter. If its just a problem with the lockup staying locked, then why does it buck like that?

I am almost certain it is not the engine missing, so, given the transmission history on these cars, I'd better start saving. Is there something more reliable that I could throw on there instead, even if I have to spend a could extra bucks?

I do remember there is a vacuum line that runs to the tranny on the front, with a diaphram coming off the front. What is this for? Also electrical connectors aswell. I'll also start calling the tranny shops. Can bands not be tightened on automatic transmissions?

Thanks for the help guys...

86Delta · Joined: 06 Nov 2003 Posts: 281 Location: NJ, USA

:shock:

86Delta · Joined: 06 Nov 2003 Posts: 281 Location: NJ, USA

DO NOT UNPLUG THE LOCKUP!!!! that trans is not like a 3 speed. a 440T4 needs the lockup to survive. on a 3 speed you can just unplug it if its messed up because the trans was first designed without the lockup and it was added later. the symptom of a converter staying locked is the car stalling when coming to a stop, restarting in park or nuetral and dying again when put into gear.

the vacuum line going to the front of the trans is for the modulator. the 4 wire connector on the front is for the lockup function, and the harness by the shift linkage is for the nuetral safety switch and backup lights.

i'm pretty sure it is only on older chysler transmissions that bands can be tightened, i doubt that would do any good because if it chatters the band is probably shot anyway.

as far as a more reliable trans goes your options are kinda limited, you could check with trans shops about updates that came in later years (like 83-86 700R4's were upgraded to 87 and up internals when rebuilt) i think as the years went on GM made slight improvements on the 440T4 (4T60).

strokercutlass · Joined: 09 Jun 2003 Posts: 379 Location: Wis

hmmm..thats odd. I've owned a couple 87-88 LeSabres, as well as our shop cars, that have had the low speed shudder 88delta described, and have bypassed the converter lockup and ran them for an extended period of time without issue. Not to say this is the "right" way, simply that it worked in my case. Once again, I can only go off your description "feels like another gear after 3rd", which would indicate that its dropping into lockup, and may be a matter of the lockup being "overcome" due to low speed, weight, and RPM range dropping extremely low for the speed the vehicle is moving at, since you said it doesn't do it at higher speeds. As always, a verbal diagnosis such as this can only tell a person so much, and theres no replacement for "hands on" diagnosis by a reputable person or shop. As you said, 88..it might be a good time to start sticking some money away. In regards to the band adjustment, certain Chrysler 3 speed RWD transmissions (904 and 727), Ford C-4 and C-6 RWD transmissions, and GM Powerglide 2 speed RWD transmissions are the only ones I'm aware of that have band adjustments, and very few people have the knowledge to do it properly anymore.

88delta88 · Joined: 09 Jun 2003 Posts: 2407 Location: Canada

update:

I didn't see 86delta's post about not unplugging the connector until AFTER I went and did it.

Nonetheless;

It drove like a new car!!! So many differences, absolutely no bucking, and it shifts VERY smoothly through the 4 gears, without the lockup kicking in. I havent driven it much since I did this, but I tested the thing out thouroghly.

When I used to slow down, the trans used to clunk sometimes when downshifting, it does not anymore. It responds faster when you want it to downshift and even my idle is smoother (Im not kidding about that). I realise the torque converter is required for everyday use, and I dont want to run without it, but I believe I have narrowed down my possibilities from the bands to the TCC.

What do you guys make of this? Does the torque converter have to be changed totally, or is there something only wrong with the lock-up mechanism?

I must say though, my car drove like it hasnt driven before with that connector unplugged, it was a night and day difference!

86Delta · Joined: 06 Nov 2003 Posts: 281 Location: NJ, USA

well the problem you have here is that you might have to spring for a rebuild anyway. to fix something with the lockup solenoid in those trans' the side cover has to come off, so that means the drivers side half of the engine cradle will have to come out. so if you are going through all that trouble you might as well pull it all the way out and rebuild it. gotta take it out to change the converter anyway. according to the book it is an 8 hour job, to R&R the trans in those cars. nothing is too much of a hassle, just a lot of work. the last one i did i did in around 6 1/2 hours.

all i'm saying is that it wouldn't be cost effective to just patch up the trans, considering you have to pull it out anyway, might as well do a total rebuild with a new converter. just my $.02.

88 Coupe · Posted: Thu Mar 18, 2004 4:54 am Post subject: Transmission problems - again

Hi 88delta88, 86Delta, strokercutlass, everyone
Glad to see you made progress. Now plug it back in and see how it works. If it does you had a loose or dirty connection. If it doesn't, then it still might be something loose in the wiring. Next, the computer, since the TC was locking up on the highway. Trans guy would be one to check computer. At that time he will verify converter switch and lockup. I'll bet on the wiring to the switch.
If you need to use the car while you save up some bucks, You can buy some time by leaving the converter unplugged. Just leave it in third, and only go to fourth on the freeway/highway. Just to be safe you might want to pull it down to third when climbing hills etc. The primary reason for converter lockup is to prevent heat buildup due to slippage, which is instant trans killer.

89Delta88 · Joined: 07 Jun 2003 Posts: 19 Location: Brush, Co

Looks like im not the only one having trans troubles.....thats why i had my car parked for almost a year, the torque converter was locked up.. would not budge at all..but i was screwing around with it one day and it started workin again.. but i unplugged the TC solenoid and its been that way since last year since it 'died'..the only drawback it seems is that it makes my service engine light come on and off..

speedy266 · Joined: 25 Jun 2003 Posts: 347 Location: Ontario, Canada

my tranny is giving me problems as well, seems sluggish, also it likes to hold gears it. when i have the gas down pretty far it'll just keep holding until i ease off the gas a bit then it will shift. Also under WOT (wide open throttle) it gets up to 3500rpm then it seems like it goes in to neutral because the rpm just jets to 5000rpm then i let off and it switches....

73Delta88 · Posted: Thu Mar 18, 2004 2:00 pm Post subject:

speedy266 wrote: it seems like it goes in to neutral because the rpm just jets to 5000rpm then i let off and it switches....

yep, my ol' Lincoln started doing that right before I sold it. VERY bad sign.

I'm spoiled with my TH 400, everyone I talk to says they're bulletproof. All I do is keep the fluid clean and it shifts as good as new! It's 31 years old and has never been taken apart, aside from dropping the pan to change the fluid / filter which I do at least once a year even though the car only sees the road for 6 months

85cieraholiday · Posted: Thu Mar 18, 2004 4:53 pm Post subject:

Ive been told that the Cutlass Ciera trannys ( I would GUESS that is applies to the other GM cars with 3-speed automatics) that you should never open the tranny up (when it gets old)if it hasn't been oped before. This is what the guy at autozone told me, and what I read on a site some time ago (may have been epinions.com).

88delta88 · Joined: 09 Jun 2003 Posts: 2407 Location: Canada

Ok, i will check my connections, and I even beleive that my ALDL program has a section in there about the torque converter lockup. I can watch when the computer sends the command to the converter and then I should feel it kick in, should I not?

Well... with just over 150,000km's on her (less than 90,000 miles) I officially hate the transmission general motors designed for an otherwise great car.

Thanks for all your help guys! Much appreciated!