Help ! Sudden No Auto Gear Shift
10-16-2012, 08:50 AM
#106
Nordschleife Master
Thread Starter
With helper, I attempted to rotate both wheel forward while in Park. This was not possible. Felt like we were playing 'tug o war'. When switched over to Neutral, both freely rotated forward with helper rotating my opposite side.
10-16-2012, 08:56 AM
#107
Looks like most are trying to have you test if the drive from the box to the diff is broken, hence turning both wheels in the same direction or one off the ground. You need to do that before going onto anything else. Edit, my post crossed yours, I see you just did that so -
If the selector is unobstructed through the movement and the selection switch on the gearbox is working properly you may have no modulating pressure at all from the governor.
Hard shifts are usually a bad vacuum connection (no vacuum at all is very hard shift) and you adjusted the pressure, which shouldn't really need doing unless there is another problem. Have you checked vacuum at the tranny end?
You can swap out the modulator without dropping the tranny if that is suspect.
If the selector is unobstructed through the movement and the selection switch on the gearbox is working properly you may have no modulating pressure at all from the governor.
Hard shifts are usually a bad vacuum connection (no vacuum at all is very hard shift) and you adjusted the pressure, which shouldn't really need doing unless there is another problem. Have you checked vacuum at the tranny end?
You can swap out the modulator without dropping the tranny if that is suspect.
10-16-2012, 09:08 AM
#108
Nordschleife Master
Thread Starter
Looks like most are trying to have you test if the drive from the box to the diff is broken, hence turning both wheels in the same direction or one off the ground. You need to do that before going onto anything else. Edit, my post crossed yours, I see you just did that so -
If the selector is unobstructed through the movement and the selection switch on the gearbox is working properly you may have no modulating pressure at all from the governor.
Hard shifts are usually a bad vacuum connection (no vacuum at all is very hard shift) and you adjusted the pressure, which shouldn't really need doing unless there is another problem. Have you checked vacuum at the tranny end?
You can swap out the modulator without dropping the tranny if that is suspect.
If the selector is unobstructed through the movement and the selection switch on the gearbox is working properly you may have no modulating pressure at all from the governor.
Hard shifts are usually a bad vacuum connection (no vacuum at all is very hard shift) and you adjusted the pressure, which shouldn't really need doing unless there is another problem. Have you checked vacuum at the tranny end?
You can swap out the modulator without dropping the tranny if that is suspect.
10-16-2012, 09:12 AM
#109
Correct, no vaccum, you will still get shifts, but shifts like you are at maximum throttle all the time. But if you have no vacuum and a bad modulator, I don't know what symptoms would show. I know the former from experience.
10-16-2012, 09:18 AM
#111
Does the car start if you select anything other than P or N? (it shouldn't) but make sure the brake is on in case.
Your most likely culprit after the other tests you have done and has been pointed out before is the modulating pressure is insufficient, this should be your first point of diagnosis now.
Your most likely culprit after the other tests you have done and has been pointed out before is the modulating pressure is insufficient, this should be your first point of diagnosis now.
10-16-2012, 09:27 AM
#112
Rennlist Member
I had something like that happen to me while driving my 86.5 with a 89 A/T. I was poking along in traffic and lost all forward gears, coasted to the break down lane put it in park. Moved the selector through all the gears and when I put it in drive I was able to drive away. Never repeated itself. I assumed it was dirt in the valve body.
10-16-2012, 09:29 AM
#113
Nordschleife Master
Thread Starter
Does the car start if you select anything other than P or N? (it shouldn't) but make sure the brake is on in case.
Your most likely culprit after the other tests you have done and has been pointed out before is the modulating pressure is insufficient, this should be your first point of diagnosis now.
Your most likely culprit after the other tests you have done and has been pointed out before is the modulating pressure is insufficient, this should be your first point of diagnosis now.
Will address the pressure scenario today.
Thanks again.
10-16-2012, 12:52 PM
#114
Rennlist Member
Obviously the root cause of the issue hasn't been determined, but the conditions now seen to have changed.
10-16-2012, 12:58 PM
#115
Nordschleife Master
Thread Starter
Simon,
Put it in Drive and (I could only get to see the L rear) she was trying to move. It would move several inches, then stop, then a few less further. I gave it gas and it would do the same. That's a first since it's been on stands.
Put it in Drive and (I could only get to see the L rear) she was trying to move. It would move several inches, then stop, then a few less further. I gave it gas and it would do the same. That's a first since it's been on stands.
10-16-2012, 01:21 PM
#116
Rennlist Member
Try idling it in drive and getting out and looking at the right rear and see ir it's spinning. Ir set up a mirror so you cann see the right fron the drivers seat.
Edit that should have been "right" I corrected it.
Edit that should have been "right" I corrected it.
Last edited by 76FJ55; 10-16-2012 at 01:45 PM.
10-16-2012, 01:52 PM
#117
Nordschleife Master
Thread Starter
Sorry, had to step away for a bit.
In Drive again and the L would only move a few, then stop, move a few, then move no more. The R never moved. Funny in Reverse no movement, but if I helped it, it would spring back forward to its original position.
In Drive again and the L would only move a few, then stop, move a few, then move no more. The R never moved. Funny in Reverse no movement, but if I helped it, it would spring back forward to its original position.
10-16-2012, 02:01 PM
#118
I'm not saying ignore everyone, but you are not really gaining anything right now by seeing if wheels spin.
You said the ATF level is good (so TC is not drained). I'm not sure why the car rolled when you put it in park, but the previous wheel turning test seems to indicate the park lock is good. If something in the drive broke you would have heard it.
You have major slip in all stick positions, the WSM manual is clear on this - modulation pressure.
Let us know what you find.
You said the ATF level is good (so TC is not drained). I'm not sure why the car rolled when you put it in park, but the previous wheel turning test seems to indicate the park lock is good. If something in the drive broke you would have heard it.
You have major slip in all stick positions, the WSM manual is clear on this - modulation pressure.
Let us know what you find.
10-16-2012, 02:24 PM
#120
Former Sponsor
If you read his post #106, the fact that it rolls downhill, in park, is apparently not correct.