02 426 5th gear slip

1 reply to this topic
  • 426tahoe

Posted October 14, 2008 - 09:16 PM


so all the gears work fine untill i get to fifth, then it feels like im pulling the clutch in and out over and over(power no power, power no power) no grinding i can hear. i have the case split now and theres a little bit of metal shavings total of a small mound smaller around than a dime, about half. all the gears look fine, no teeth missing no chunks. i can cycle thru the gears and they all work fine. fifth does not slip as hard as my fingers can try. the clutch looks brand new. could it be a bent fork not pushing all the way when its all together? possible to spin a gear on the shaft? not exactly sure how it all works yet. i dont see any worn spots on anything that could explain the metal shavings. any help or advice is greatly appreciated.

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  • grayracer513

Posted October 15, 2008 - 05:07 AM


The individual ratio pairs in the trans each have one gear splined to one shaft, and the second gear of the pair freewheeling on the other shaft. The gear is engaged by having a splined gear next to the free gear slide over on the shaft and lock into it with 3 to 4 locking lugs, or "dogs", thereby fixing that pair to the shaft. The lugs have a slight undercut so that applied load helps hold them together, but over time, they wear and become rounded over. When the undercut reverses, the load forces them apart. Shift the shift fork cannot be pushed back to a neutral position as with most car transmissions, the fork flexes as the lugs push out of mesh. Once they disengage, the load is gone, and the fork slams them back together, starting the cyclic "skipping" that you feel under a load. The fork becomes bent by this.

The problem with 5th gear will require a 5th gear pinion, a 3rd gear pinion (the gear that locks in 5th), and the #2 shift fork (the one that moves the 3rd pinion). Be sure to look the others over for wear conditions that might indicate the need to replace them.

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