Manual Transmission T56 | T5 | MN12 | Clutches | Hydraulics | Shifters

3rd Gear Grind?

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Old 07-18-2006 | 12:28 AM
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Default 3rd Gear Grind?

Ok I got about 300 miles on my new CenterForce DF twin disc clutch and I just started to notice that when shifting into 3rd gear quickly at high rpm's it catches for a second and grinds the gear. When I first installed the clutch it never had this problem. However if I shift at lower rpm's and more slowly it shifts fine. What could the problem be? I got new tranny fluid, dot-3 brake fluid etc in the car after install.

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Old 07-18-2006 | 01:04 AM
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Bent shift fork possibly. You ever slam gears?
Old 07-18-2006 | 10:52 AM
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Default Maybe

I have done some gear slamming but not a terrible much. The gear isn't slipping or anything but just grinds. Is it ok to keep driving the car as it is with the grind? Also, like I said, it won't grind if at a stop and in neutral grabbing gears. Only when actually the car is in motion. If so how do I see if it's bent shift fork? Is it an easy fix?

Last edited by Halloran; 07-18-2006 at 11:16 AM.
Old 07-18-2006 | 02:45 PM
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Not really an easy fix. It is a cheap part but semi-expensive labor. If you do it I would go ahead and have the tranny gone through and replace the blockers/sliders/synchros.
Old 07-18-2006 | 02:46 PM
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It has the "bent shift-fork syndrome". You probably have a 3-4 fork that is broken or bent just from the sounds of it. It is probably just slightly tweaked. I broke mine in half.
Old 07-18-2006 | 03:27 PM
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When I had that problem, it was my synchronizers going out. 3rd gear too. Delaership said it was a known problem with ls1's.
Old 07-18-2006 | 04:05 PM
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Originally Posted by Jayh
When I had that problem, it was my synchronizers going out. 3rd gear too. Delaership said it was a known problem with ls1's.
And that is the other part. Yeah, very common.

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Old 07-18-2006 | 07:55 PM
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Default Dealer repair?

Is it worth to have a dealer repair the T56 or just buy the repair kit from Kragen or Pontiac dealer and do it myself? How much knowledge is involved in replacing the syncros and the tweaked fork?
Old 07-18-2006 | 09:35 PM
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Do not take it to the dealer, they will probably charge you 2-3 thousand dollars.

Order the parts you need from http://www.t56rebuilds.com/ and they have a 3-4 day turn around time. Or you can get the parts and take it to a local fbody shop.
Old 07-18-2006 | 09:46 PM
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What parts should I look into getting? I'm sure I'll need the 3-4 syncro and the steel fork upgrade but anything else? I'm not exploding with money so the more I can save the better. I just want the car to last and replace any serious things while the tranny is out.
Old 07-18-2006 | 10:12 PM
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Well, you'll want to replace as much as you can while you are in there.

- steel 3-4 shift fork
- synchro rebuild kit
- sliders 1-2 3-4
- bronze fork pads 1-2 3-4
- billet slider keys 3-4
Old 07-20-2006 | 06:21 PM
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Default Sliders

On T56rebuilds.com I'm assuming the 1,2,3,4 gear M/S is referring to the sliders? Are the sliders absolutely necessary? I mean at $129.00 a pop that gets a little pricey. I started to notice today that the 4th gear is starting to grind to. I'm not sure if it's syncros or just maybe the fork. I'm assuming it's just the fork since the car has over 100k miles on it...
Old 07-20-2006 | 08:27 PM
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Lets get ORANGEAPEEL, post ***** ,in here again, one more time , also , after all have spoken , to agree that this is a known and a well documented concern and there are many posted replies.




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