DIY Rebuild Help: Testing the trans on the bench, it won't go into gears
11-17-2011, 07:03 AM
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DIY Rebuild Help: Testing the trans on the bench, it won't go into gears <Backstory>
I am putting a LS1 & T56 into my 71 Chevelle. To get the motor and trans, I purchased a donor 1998 Z28 (wrecked). The Z28 was still driveable, so I took it for about a 5 mile loop before the teardown began. During that drive, I noticed it didn't want to go into 3rd without double-clutching, and that the shifts felt sloppy. So, I decided while I had the trans out of the car, that I should do a rebuild.
Since the car had 100K on it and I really didn't want to have to do this twice, I ordered the normal rebuild kit, plus bearings, a 3/4 shift fork, and some stuff like that.
<Problem>
I took my time, worked through the rebuild manual step-by-step as methodically as I could. The first time I fully assembled the transmission, I decided to test it on the bench. It would not go into 5th/6th or reverse.
Knowing something was wrong, I pulled the trans back apart. Turns out when I slide the case on, I had knocked the 5th/6th shift rail lever off of the interlock plate.
Assembling for the second time, I was much more careful with this, and I believe I got it on correctly. Last night, fully assembled again, I tried to go through the gears while the trans sat on the workbench. Now, I the trans will go into 5th/6th, but not 3rd/4th!
Obviously, I am doing something wrong here, but I am frustrated and do not know what it is. Do you have any advice, recommendations, methods, things to check, etc?
Please help.
I am putting a LS1 & T56 into my 71 Chevelle. To get the motor and trans, I purchased a donor 1998 Z28 (wrecked). The Z28 was still driveable, so I took it for about a 5 mile loop before the teardown began. During that drive, I noticed it didn't want to go into 3rd without double-clutching, and that the shifts felt sloppy. So, I decided while I had the trans out of the car, that I should do a rebuild.
Since the car had 100K on it and I really didn't want to have to do this twice, I ordered the normal rebuild kit, plus bearings, a 3/4 shift fork, and some stuff like that.
<Problem>
I took my time, worked through the rebuild manual step-by-step as methodically as I could. The first time I fully assembled the transmission, I decided to test it on the bench. It would not go into 5th/6th or reverse.
Knowing something was wrong, I pulled the trans back apart. Turns out when I slide the case on, I had knocked the 5th/6th shift rail lever off of the interlock plate.
Assembling for the second time, I was much more careful with this, and I believe I got it on correctly. Last night, fully assembled again, I tried to go through the gears while the trans sat on the workbench. Now, I the trans will go into 5th/6th, but not 3rd/4th!
Obviously, I am doing something wrong here, but I am frustrated and do not know what it is. Do you have any advice, recommendations, methods, things to check, etc?
Please help.
11-17-2011, 07:56 AM
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3rd/4th (and previously 5th/6th) felt locked out. Shifter does not move towards the gears at all.
Initially, I was not spinning the input shaft. I then tried that to see if it would help. The input shaft was difficult to turn also. I could not turn it simply with my hand, a pair of pliers to get some grip and leverage was needed. Is that normal?
Initially, I was not spinning the input shaft. I then tried that to see if it would help. The input shaft was difficult to turn also. I could not turn it simply with my hand, a pair of pliers to get some grip and leverage was needed. Is that normal?
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11-17-2011, 12:05 PM
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merv,
I practiced many times with the guide pins. I think that was part of my initial problem when 5th/6th wouldn't go in. This second reassembly, the 5th/6th was not a problem, but the interlock plate was slightly too low for the second pin to go in. I had to pry up on it slightly (holding the shift rail from the top) to get the guide pin in.
I'm my uneducated opinion, this seems to be where I am screwing up. I can't seem to get both pins in correctly without knocking a rail lever off.
I practiced many times with the guide pins. I think that was part of my initial problem when 5th/6th wouldn't go in. This second reassembly, the 5th/6th was not a problem, but the interlock plate was slightly too low for the second pin to go in. I had to pry up on it slightly (holding the shift rail from the top) to get the guide pin in.
I'm my uneducated opinion, this seems to be where I am screwing up. I can't seem to get both pins in correctly without knocking a rail lever off.
11-17-2011, 01:23 PM
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That sounds similar to what I did, but I will give it another shot.
At this point, I guess there is nothing else to do except give it another try.
At this point, I guess there is nothing else to do except give it another try.
11-17-2011, 02:14 PM
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I decided to take a 1/2 day from work. This thing is really annoying me.
Since I have had this thing apart many times, I was getting bored with taking it apart the same way each time. So, I decided to start with the adaptor plate end this time. Hoping it would give me some interesting perspective.
Well, as it turns out, it looks like I got the shift rail guide pins in there correctly (see the pics).
After I took the adaptor plate off, the transmission shifted fine, and I was able to spin it by hand. Does this mean it is literally too "tight" and I am compressing things slightly when assembling? If the guide pins and shift levers are in there correctly (which they appear to be), this seems logical.
Thoughts?
Thanks again for all of your help!
Since I have had this thing apart many times, I was getting bored with taking it apart the same way each time. So, I decided to start with the adaptor plate end this time. Hoping it would give me some interesting perspective.
Well, as it turns out, it looks like I got the shift rail guide pins in there correctly (see the pics).
After I took the adaptor plate off, the transmission shifted fine, and I was able to spin it by hand. Does this mean it is literally too "tight" and I am compressing things slightly when assembling? If the guide pins and shift levers are in there correctly (which they appear to be), this seems logical.
Thoughts?
Thanks again for all of your help!
11-18-2011, 10:14 AM
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Success!
I assembled it again yesterday afternoon. At that time it would go into 1-4 & R with no problem, but was blocked from 5&6. Also, the input shaft was difficult to turn again.
Based on some of your comments, and what I had seen, I was confident I have the shift levers correct. The only remaining item was the blocker rings. I pulled the tail housing off and sure enough, the 5th gear blocker ring had turned on me during assembly. This must cause enough bind in the system to make the trans hard to spin.
After correcting this, the trans turns freely and slides into all gears without a problem!
Thanks again for all of your help!
I assembled it again yesterday afternoon. At that time it would go into 1-4 & R with no problem, but was blocked from 5&6. Also, the input shaft was difficult to turn again.
Based on some of your comments, and what I had seen, I was confident I have the shift levers correct. The only remaining item was the blocker rings. I pulled the tail housing off and sure enough, the 5th gear blocker ring had turned on me during assembly. This must cause enough bind in the system to make the trans hard to spin.
After correcting this, the trans turns freely and slides into all gears without a problem!
Thanks again for all of your help!
