AMC Eagle Den Forum

1979 - 1983 AMC Spirits and 1978 - 1983 AMC Concords => Spirit/Concord Drive Trains => Topic started by: SleepsUnderCars on November 02, 2011, 11:19:48 AM

Title: torque converter or tranny?
Post by: SleepsUnderCars on November 02, 2011, 11:19:48 AM
my 80 Spirit has a problem. It seems to have lost 3rd gear. It runs around fine if I shift it into 2, but if it is in drive it has nothing after shifting up from second. Like it is in neutral. I know the 80 Spirits came with both lockup and non-lockup TC, could this just be a bad lockup converter?
is there any way to identify which converter without pulling the tranny?
Title: Re: torque converter or tranny?
Post by: BenM on November 02, 2011, 11:49:26 AM
You may be able to read printing on the torque converter if you take the inspection cover off, but I don't recall any external differences.

According to my 76 TSM, third gear is both the front and rear clutches engaged. The rear controls all gears, but the front is only ever applied in 3rd and Reverse.  I don't see any mentions of 3rd gear only not working. How's your reverse?
Title: Re: torque converter or tranny?
Post by: SleepsUnderCars on November 02, 2011, 11:53:57 AM
reverse is fine. I can back up all day long. That's why I am thinking a lockup TC that is failing to lock
Title: Re: torque converter or tranny?
Post by: eaglebeek on November 02, 2011, 05:39:42 PM
The lockup doesn't engage until after the transmission has shifted to 3rd gear and the car is moving forward at around 35 mph (depending on final drive ratio). I doubt the torque converter is the cause.

I'm thinking one of the clutches/bands has failed. The other consideration is a hydraulic fault. Have you noticed if the shift quality or speed at which shifts occur have changed since your malfunction showed up?

I can do some research and come up with a better answer tomorrow (Thursday). Meanwhile, if someone else has an answer please post up!
Title: Re: torque converter or tranny?
Post by: mudkicker715 on November 02, 2011, 08:17:28 PM
You may be able to read printing on the torque converter if you take the inspection cover off, but I don't recall any external differences.

According to my 76 TSM, third gear is both the front and rear clutches engaged. The rear controls all gears, but the front is only ever applied in 3rd and Reverse.  I don't see any mentions of 3rd gear only not working. How's your reverse?

There is numbers however they are stamped on the inside. I cannot tell if I ever had a lockup by driving them. I know by tearing them apart I I had some.

Here comes the stupid answer. My 82 concord is in neutral from park to drive till I go half go to second than back to drive at takeoff. I need to adjust it.

Whats my response to your problem. He[% if I know not even sure if I have a lockup yet. Just saying check linkage.

Anyone that knows my responses, knows I only typy say one sentence. So read carefully.
Title: Re: torque converter or tranny?
Post by: DaemonForce on November 03, 2011, 06:13:01 AM
It's time for an overhaul kit.
Title: Re: torque converter or tranny?
Post by: SleepsUnderCars on November 03, 2011, 07:50:31 AM
yeah, I am figuring it's time to learn how to rebuild one.
Title: Re: torque converter or tranny?
Post by: SleepsUnderCars on November 03, 2011, 08:03:15 AM
it's not the linkage. Works fine in 'D' until it's time to shift into 3rd. Then it's nothing until I slow down enough to hit the downshift into 2nd.
Title: Re: torque converter or tranny?
Post by: carnuck on November 03, 2011, 12:44:01 PM
Sounds like the passing gear linkage is jammed down. Or the high forward clutches are burnt out. Not the converter or it wouldn't go anywhere.

It's up to you if you want to try this, but I have a number of times in the past and it revived most of the transmissions I did it to. A can of STP engine oil treatment in the trans. Drive it around a bit with that in there before heading for highway speeds so it gets good and warmed up and mixes in. Then cruise up to 35ish and back off the gas, put it in drive and coast about 10 seconds before trying the gas.
Title: Re: torque converter or tranny?
Post by: SleepsUnderCars on November 03, 2011, 01:58:45 PM
I'll try anythin at this point. What have I got to lose? Worst case I will be rebuilding....
Title: Re: torque converter or tranny?
Post by: HappyPappy on November 04, 2011, 06:10:06 AM
Might try SEA FOAM to, I've used it in engines already with great luck. 904 aren't hard to rebuild, helps if you have the right tools. Good luck
Title: Re: torque converter or tranny?
Post by: SleepsUnderCars on November 04, 2011, 06:56:18 AM
I tried seafom for transmission last night. No help. Have done a lot of reading on the net about Torqueflites, gonna have to rebuild.
have to get something else on the road first as I need transportation to work.
Title: Re: torque converter or tranny?
Post by: shanebo on November 05, 2011, 02:58:30 AM
If you do rebuild I would love to see pictures...I got my transmission sitting on an oil drum in my garage with exactly the same issue.
Title: Re: torque converter or tranny?
Post by: AMCKen on November 05, 2011, 03:23:07 AM
Also check that the linkage between the transmission and the throttle is set up correctly. A mis-adjusted kick
down can cause weird problems.
Title: Re: torque converter or tranny?
Post by: DaemonForce on November 05, 2011, 04:13:22 AM
It's not the kickdown linkage. It's a fault within the transmission itself. What he's experiencing is a normal shift from 1st to 2nd and it shifts into 3rd making you believe that this would be the kickdown linkage at fault. If this were the case, it wouldn't shift out of 2nd. Problem is, instead of going into 3rd it behaves as if it went straight into neutral and keeps this behavior until the vehicle slows enough to where it kicks down to 2nd again. This is clearly a fault somewhere between the torque converter and tail housing. I suspect the front clutches to be burned out but it's also possible that there are other faults as well. An overhaul will tell.

I suggest very thorough examination. Deep cavity search. Assume nothing. 8)
Title: Re: torque converter or tranny?
Post by: carnuck on November 06, 2011, 12:09:56 AM
Either the high forward clutches burned out or if they are still good, the drum seal popped. I used to replace those seals for trans shops that didn't have the tool back in the day.
Title: Re: torque converter or tranny?
Post by: eaglebeek on November 11, 2011, 11:19:35 PM
Something that hasn't been asked yet...does SleepsUnderCar's Concord have a Chrysler transmission? Everything I have on TorqueFlites says if the transmission slips in 3rd it's likely it's going to slip in reverse also. The rear clutch is applied in all forward ranges, so I think it's OK. SleepsUnderCars says reverse is fine, but the front clutch is applied (with the rear band) in reverse and 3rd (with the rear clutch). So now I'm confused and left to wondering if we're even talking about a TorqueFlite. ??? :eagle:
Title: Re: torque converter or tranny?
Post by: carnuck on November 11, 2011, 11:35:55 PM
The high forward clutches are engaged in drive (3rd only) and reverse. First gear can still work with bad rear clutches because of the one way sprague which takes the load off them, but it doesn't work in reverse so reverse wouldn't work if they were bad.
Title: Re: torque converter or tranny?
Post by: SleepsUnderCars on November 12, 2011, 04:51:47 AM
yes, it is a Chrysler 904.
i have done some reading up on this, the best article i found seems to point to the front clutch pack. the one thats only applied in 3rd and reverse. yes, reverse works...for now. what i have read says i can expect that to go out soon. i am probably just going to park the car until spring, i found a cheap winter beater to use for my commute to work now.
Title: Re: torque converter or tranny?
Post by: carnuck on November 12, 2011, 10:23:03 AM
It is possible there is a clog in the valvebody keeping it from going into drive. . If the passing gear valve was jammed, it would rev fairly high before going into second from first.

PS: It's a 998 (related to 904, but with bigger rear band) and probably a lockup
Title: Re: torque converter or tranny?
Post by: AMCKen on November 14, 2011, 06:13:54 PM
If it's a Spirit, (as mentioned in the first post), it IS most likely a 904. : )
Title: Re: torque converter or tranny?
Post by: carnuck on November 15, 2011, 11:25:49 AM
Sorry, but no. 904 wasn't used after '79 on the 6 cyls. They were snapping rear bands before warranty was up.

<----PS: Ex-Mopar trans tech, back when Hemis were still available.
Title: Re: torque converter or tranny?
Post by: ammachine390 on November 15, 2011, 06:46:02 PM
Sorry, but no. 904 wasn't used after '79 on the 6 cyls. They were snapping rear bands before warranty was up.

<----PS: Ex-Mopar trans tech, back when Hemis were still available.

According to my service manual, 1981 6 cylinder Spirits/Concords came with 904s.
Title: Re: torque converter or tranny?
Post by: carnuck on November 16, 2011, 07:50:44 PM
Since they look the same to most casual observers, it's not a biggie. The case has a couple ribs where the wider rear band lives inside to tell them apart.
Title: Re: torque converter or tranny?
Post by: SleepsUnderCars on November 18, 2011, 11:06:59 AM
it's a 1980 spirit ith an Iron Duke. 904.
Title: Re: torque converter or tranny?
Post by: AMCKen on November 19, 2011, 05:54:05 PM
http://s143.photobucket.com/albums/r122/AMCKenA/?action=view&current=998A.jpg

Shows a 998 out of an Eagle. The 2 ribs on the side aren't on a 904.