Gearbox Rebuild

[smo17003]

I've stripped down my gearbox (4 speed) for a rebuild, i.e. renew all bearings, seals and gaskets and I would like to know what to look for or what to measure when it comes to wear on the syncho hubs, selector forks etc. I have no idea if the 'box was OK before the strip down as my car was purchased as a "basket case". Any advise much appreciated.

Mike

[rgh0]

Mike

Things I would check on the parts that normally are being reused in a rebuild as follows


1. Check all gears for chips or visible cracks or major signs of wear.
2. Check fit of gears onto the output shaft they should be free to spin with no signficant "slop".
3. Check layshaft for wear where the needle rollers run and that it is a tight push fit into the casing.
4. Check synchrohub and syncro ring and gear engagement teeth for smoothness of engagement and remove any burrs with a stone.
5. Check the syncro blocker bars for wear and replace if badly worn. The syncrohub should smoothly lock into engagement when pushed into place if not the blocker bars are worn or there retaining spring weak,
6. Check the wear on the syncro ring hub. There is a defined minimum clearance spec between the syncro ring and gear hub it sits on when pressed together. I dont know it off the top off my head and have lost the reference, someone else may know it or just replace the syncro rings. First and 4th are normally the least worn so if 2nd and 3rd clearances signficantly less you know you may have a problem.
7. Check wear in the rear bush that supports the output shaft
8. Check wear in the input shaft surround that the clutch throwout bearing rides on
9. Check clutch throwout arm for cracks around the pivot hole
10. Wear is not normally a problem with the selector rods or forks or detent balls and interlock pins but generally inspect for damage
11. Check reverse gear slides smoothly on shaft and shafts is a tight fit in casing.

cheers
Rohan

[dlbarnes1]

One thing I would add to Rohan's list:
Check the selector (detent) springs per the manual. If necessary, add shims or replace.
I added shims to mine. Really made a difference in operation of the gearbox.

Dave 72 Sprint DHC