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Ferraripete Ferraripete is offline
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Join Date: Jun 2006
Location: Charlotte NC/San Diego CA
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Quote:
Originally Posted by JFairman View Post
"when i went from second gear to third, i did not get the shifter fully into third and there was a small grind and the gear shifter was then kicked back into nuetral."

This action wouldn't move the shift fork because he never pushed it all the way into 3rd, instead he let the clutch out while the slider was pushed over the Porsche steel split synchro ring and compressing it so it was trying to match the rpms of the 3rd gear set to the shaft they are located on when he let out the clutch.
He never got it into third but the sliders selector teeth were touching and bouncing over the selector teeth on the gear set. This could destroy or round off the fine teeth on the slider and the gearset and also cause alot of wear to the synchro ring possibly burning it and the brake band up and other associated synchro parts.
Not being able get it into 3rd gear at all now sounds a little like an anchor block or stop block or brake band in the synhcro assembly is knocked out of place and blocking the slider from sliding over the synchro ring. something is keeping the synchro ring from compressing so the slider can slide over it and engage the selector teeth.
Ususally when the selector teeth are used up or rounded off they will still engage the gearset but then pop out when you let out the clutch.
Also as the slider goes all the way over the synchro ring and engages the selector teeth on the gearset locking it to the shaft, the part of the slider now over the synchro ring has a larger inside diameter and the porsche steel synchro ring which is split then expands into that area which then helps hold the slider in place keeping the selector teeth engaged and the gearset locked to the shaft.

If the shift fork had slipped on the shift fork rod than when the gear shift lever is in the nuetral position than the 4th gear synchro would be partially engaged or fully engaged depending on how far the brass fork slipped because the same shift fork and slider that selects 3rd gear selects 4th gear on the opposite side when moved in the opposite direction.
The shift lever would feel quite diufferent when going for 4th gear and he said the rest of the gears feel the same and if thats so it's unlikely that the shift fork changed position on it's shaft.

Drain the oil and look for fine metal particals on the drain plug magnet and in the oil while in sunlight.
You can also take the inspection cover off the bottom of the transmission after draining the oil and look up in there. 4 - 13mm nuts hold it on.
If it's not the external shift coupler you'll be doing this anyway.

The bottom shaft thats right above the inspection/guide fork plate plate has the first and second gearset synchros, and the top shaft has the third and fourth gearset synchros but if you look up there with a flashlight real carefully and know what to look for you may be able to see if the third and fourth gear slider with it's shift fork are exactly halfway between third and fourth gears and their synchros while the shifter is in nuetral.

good luck with it... The slider and synchros for one gearset will be around 500 in parts but the labor is what adds up, and thats not including the replaceable selector teeth on 3rd gear if they are no good.
Of course while it's apart you may as well replace the first and second synchros while in there if they are getting tired and any worn bearings.
You never downshift into 4th so that synchro usually has an easy time of it and probably doesn't need replacing unless it's been abused.
we went through the inspection process you discussed and there were fine metal filings as you suggested there would be. the shops assessment (black forest racing) was exactly what you describe.

your parts pricong seems in line. what would you estimate the labor to be?

thank you for the thoughtful response!!!

pcb
Old 02-16-2010, 03:19 PM
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