Transmission issue 1993 80s

[Formulaonehd]

Hi all

This has been discussed before but my 93 4spd cruiser has been behaving odd with gear changes after a lengthy stint in the garage (not being used) prior to me buying it .

I suspect the solenoids are stuck and ordered some direct from bargwarner. What I wanted to ask is what rpm should my truck be when travelling at 60mph (100kmph) ? Mine is currently showing about 2600rpm at that speed and to me that says it's stuck in 3rd gear ?

Other symptoms include :
1) When cold it thumps into reverse
2) changes up a gear from take off too quickly and I suspect it is going into 3rd from 1st
3) very harsh kick down back to 1st gear when you plant your foot .
4) won't kick down gears at higher speeds say over 80kmph

My dash lights are working fine as we re-plugged the old barrel connector near the starter motor

Again I suspect the solenoids but I'm not sure what gears I am in to confirm this

Cheers

 

[LINUS]

Weird - #3 & #4 seem like opposites.

What happens when you kick in & out the manual O/D override switch at 50KPH & light foot pressure? (Trying to see if you can even catch the OD gear).

Does the cluster in a AU 80 have the "O/D off" light & does yours work when you kick it out?

 

[cc93cruiser]

Have you tried adjusting the kick down cable?

 

[baldilocks]

Disconnect the harness from the side of the tranny and drive it shifting manually. If this works then the problem is electrical and most likely the solenoids. Is the O/D off light flashing? There may be codes stored in the transmission ecu.

You might do a couple drain and refills too.

 

[Formulaonehd]

sorry for slow reply guys
yes have adjusted tge kick down cable to no avail

overdrive button doesnt do anything nor shows up on the daah ,
i can adjust gears manually but it feels like second gear is never engaging . what rpm should i be seeing at 60mph/100kmph in 4th?
cheers

 

[Formulaonehd]

also forgot to ask , disconnecting the tranny is that tge cable down near the starter ??

 

[Formulaonehd]

the OD does nothing and no dash light fof it that i can see
if the car is doing 100kmph or 60mph at 2500rpm in 4th gear is that about right??

just tested things again today an

Disconnect the harness from the side of the tranny and drive it shifting manually. If this works then the problem is electrical and most likely the solenoids. Is the O/D off light flashing? There may be codes stored in the transmission ecu.

You might do a couple drain and refills too.

took it for another drive to pay particular attention to the gear changes. Her s what I noticed :

O/D not working , no dash lights. Feels like it is jumping to 4th gear from 1st and stays there . I think it's 4th because at 60mph/100kmph its revving at 2500rpm, is that normal rpm at that speed ??

When I take over manually it will shift into 3rd gear from "L" when "2" is selected , so looks like second gear is being skipped. Then when you shift into "D" it will shift into 4th gear. It could be changing in this fashion but hard to tell what gear you are in with a 4 Spd = 1st, 2nd , 4th . But either way gears are being skipped
I'm
I haven't disconnected the tranny harness yet, will try that tomorrow if I disconnect the tranny what will happen in "D"? Does it skip 3rd?
Cheers

 

[sk8salomon]

Other symptoms include :
1) When cold it thumps into reverse YES
2) changes up a gear from take off too quickly and I suspect it is going into 3rd from 1st YES
3) very harsh kick down back to 1st gear when you plant your foot . Sometimes
4) won't kick down gears at higher speeds say over 80kmph Don't know, I'm afraid to take it up that fast (max 30mph so far)

My dash lights are working fine as we re-plugged the old barrel connector near the starter motor Mine are not

Cheers

Just saw your thread and thought I'd chime it for what it's worth.

 

[SmokingRocks]

No OD light = now power at TCM or TCM failure. Start at the TCM and verify that it is receiving power.

 

[baldilocks]

If it's skipping second gear the trans has defaulted into a "limp" mode.
Have you disconnected the harness from the trans and then shifted through gears manually? If this works fine then your problem is purely electrical.
There is another thread going on with similar symptoms. You may investigate the round coonnector that is below the PHH and has wire leading to the park/neutral safety switch. If the PHH spent some time leaking on it the pins and jacks could be corroded or broken.

 

[Formulaonehd]

If it's skipping second gear the trans has defaulted into a "limp" mode.
Have you disconnected the harness from the trans and then shifted through gears manually? If this works fine then your problem is purely electrical.
There is another thread going on with similar symptoms. You may investigate the round coonnector that is below the PHH and has wire leading to the park/neutral safety switch. If the PHH spent some time leaking on it the pins and jacks could be corroded or broken.

Thanks Baldilocks i havent yet disconnected the harness i'm hoping to do that today.
We rewired the barrel connector and dash lights are working again now. I'm not sure if that plug also has wires for the O/D in it?

Limp mode? Interesting like the others said above trying to diagnose bits and pieces as where i live is remote and the labour to do jobs is hugely expensive!!

 

[Formulaonehd]

Ok s following the FSM today i disconnected the tranny harness and vehicle is behaving the same.
Takes off in 1st skips 2nd and goes into 3rd, then when you click up to 'D' it goes into 4th.

Since the tranny was disconnected, Can that be a solenoid or should second gear have worked when I shifted into '2' ?

 

[baldilocks]

Ok s following the FSM today i disconnected the tranny harness and vehicle is behaving the same.
Takes off in 1st skips 2nd and goes into 3rd, then when you click up to 'D' it goes into 4th.

Since the tranny was disconnected, Can that be a solenoid or should second gear have worked when I shifted into '2' ?

What it is doing is normal when the harness is disconnected. This proves that the trans is fine mechanically and that the trans is recieving no inputs from the tcu which, I believe, was suggested earlier.

 

[Formulaonehd]

What it is doing is normal when the harness is disconnected. This proves that the trans is fine mechanically and that the trans is recieving no inputs from the tcu which, I believe, was suggested earlier.

I wouldn't say it's normal as in both 'D' and manually shifting it will skip gears. In D it goes from 1st to 4th. When manually changing it skips second gear and goes into 3rd then into 4th . Exactly the same sequence when manually shifting with the harness disconnected

I couldn't see how to diagnose the TCM failure in the FSM , my thinking though is what would the TCM have to do with the tranny when it's disconnected ?? I would have thought it was purely mechanical if second gear can never be achieved ? Or as someone pointed out in another thread they replaced the solenoid and all fixed, but I thought the solenoid was an electrical component to engage the gears which shouldn't affect the gears when the tranny has been disconnected ?

 

[Formulaonehd]

Please resident 80s experts don't leave me high and dry just yet I think we are making progress
And honestly I have learnt heaps thanks to you all over the time I have owned my 80s

So we know 2nd gear can't be selected with tranny harness connected or disconnected but what we haven't worked out yet is why the OD light and button aren't working and yet 4th gear can be achieved. ?? I will do a replacement of solenoids and new fluid regardless but the OD thing has me puzzled , all the threads here are about blinking OD lights for codes

As Baldilocks pointed out above the gear sequence with the harness disconnected is correct ?? 1st -->3rd--> 4th. ??

 

[SmokingRocks]

What did you find out? I am experiencing this exact issue and I'm pretty sure I've walked it back to the throttle position sensor being faulty. But I'm not convinced that the TCM isn't failing too.