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T56 Hard to go into 1st 2nd or reverse

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Old 02-12-2017, 07:57 PM
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Default T56 Hard to go into 1st 2nd or reverse

It shifts fine when the engine is off but when the engine is running and the car stopped it is tough to get into 1st 2nd or reverse. Once it goes in it slides in and out no problem unless I put it in another gear.

It has a ls7 clutch and flywheel and Wilwood master and braided -3 clutch line.

I have replaced the shifter, pilot bearing, slave and master.

I put the rear end up on jack stands today and had a friend watch the wheels as I put it into gear.

Every time I pulled it into gear with the clutch fully depressed the wheels would spin about a revolution and stop. The wheels however would not spin after that with the clutch depressed at any rpm in any gear.

I believe the clutch to be disengaging, I have an adjustment rod and have adjusted it so much that it is engaging at the top of the pedal travel.

The best I can think, something rotating is slightly binding against the input shaft enough to get is spinning when it is in neutral.
Old 02-13-2017, 02:39 PM
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Originally Posted by ITSWILL
It shifts fine when the engine is off but when the engine is running and the car stopped it is tough to get into 1st 2nd or reverse. Once it goes in it slides in and out no problem unless I put it in another gear.

It has a ls7 clutch and flywheel and Wilwood master and braided -3 clutch line.

I have replaced the shifter, pilot bearing, slave and master.

I put the rear end up on jack stands today and had a friend watch the wheels as I put it into gear.

Every time I pulled it into gear with the clutch fully depressed the wheels would spin about a revolution and stop. The wheels however would not spin after that with the clutch depressed at any rpm in any gear.

I believe the clutch to be disengaging, I have an adjustment rod and have adjusted it so much that it is engaging at the top of the pedal travel.

The best I can think, something rotating is slightly binding against the input shaft enough to get is spinning when it is in neutral.
I think most times I've heard of this issue, it is the classic motor mounts case (when you have the 1-2 and R opposite sides of trans difficulty). Are they still the OEM ones?
Old 02-13-2017, 06:45 PM
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I have never heard of this "classic motor mounts case" before, could you elaborate? I have this in a RX-7.

I have polyurethane mounts at the engine and trans. It's possible there could be something wrong with one of the mounts.
Old 02-14-2017, 02:42 PM
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Originally Posted by ITSWILL
I have never heard of this "classic motor mounts case" before, could you elaborate? I have this in a RX-7.

I have polyurethane mounts at the engine and trans. It's possible there could be something wrong with one of the mounts.
If the mounts are bad usually I've heard of it being tough to shift into the sides of the shift pattern (in our case, 1/2 and R). If the mounts degrade enough, the trans could have a lot of trouble shifting but since you have poly... they don't degrade like rubber.

Is it tough to shift to 3/4/5?
Has your throwout bearing been replaced ever?

And your OP you said it can shift when the engine is off? I think that can be a symptom of a bad shifter fork too. This guy on the DSM forums had a similar issue to yours:
(http://www.dsmtuners.com/threads/sym...-shift.367983/)

Just tossing out ideas that might be worth looking into! Sorry if I'm all over the place.
Old 02-18-2017, 07:37 AM
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I pulled the trans last night. I measured the clutch to throw out gap and had about 60 thou clearance. I think that aught to be about perfect. The pilot bearing looks to be in good shape. I can't find anything rubbing. I did however find some slight damage to the input shaft where it goes in the pilot but nothing that seems like it would bind. Also there was a bit of input shaft play but not a lot. I will have to measure end play and see if it is in spec. Also noticed the tube that goes into the slave wiggled around a bit. Not sure if that is normal.

I also pulled the tailshaft housing off, there was some stuff on the magnets but no chunks. However the tailshaft bushing is worn and likely needs replaced.

Still not sure what the 1 2 R is.
Old 02-20-2017, 09:43 PM
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Input shaft shouldn't move at all, just had that problem in my C5, replaced it with a new unit, hopefully that should fix it.
Old 03-01-2017, 06:59 AM
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I tore the trans down fully and found the 1/2 and reverse synchro slider to be shot. I have a new 1/2 synchro on order and am going to flip reverse. I'm guessin this is not my root cause but rather the impact of an input shaft turning when the clutch is disengaged. At this point the issue could be a few things. Excessive input shaft lash, distorted input shaft pilot bearing surface, bell housing misalignment or air in the slave. The plan going forward will be to replace/optimize these things.
Old 03-01-2017, 07:19 PM
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Did you need a puller to get 5-6 gear off? I just did the tail shaft bushing with one of the direct fit ones AMP sells, worked perfect.
Old 03-04-2017, 06:47 AM
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I only needed the puller to get the reluctor off. I haven't done the bushing yet, but I just got the GM part.
Old 03-04-2017, 01:38 PM
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Check the splines on the main shaft and the 5-6 gear. the 5-6 gear is supposed to be a press fit on the main shaft.



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