Simon Williams Posted January 12 Share Posted January 12 (edited) Good morning all, and hopefully it's not too late to wish everyone a Happy New Year. It's cold in my garage, but nevertheless I'm shuffling overdrive innards in the hope I can find a combination that doesn't scream at me. This is the standard overdrive for the original (contemporary) Series 2a gearbox. I've just taken the syncro hub, which was jammed, to bits. Two of the springs are damaged, but I've got a rebuild kit from GLF so all's well so far. I slid the hub from the collar inside a large ziplock bag, so I caught all the bits OK. This overdrive has not been used in years, and there is a small amount of condensation damage in some of the bearings, so I think it's serviceable with a good clean to get the sludge out and a few replacement bearings. The gears look OK. What's the magic trick to re-assembling it - the syncro hub that is? Is it helpful to make a sleeve into which the hub slides and which you can enter the springs, ball and the little square piece one by one, maybe with a slot to load the bits and twist to hold them. Then slide the hub out of the sleeve directly into the splined collar, carrying the springy bits rather like entering piston rings into their bores out of a spring compressor. I get the impression that putting it back together inside my trusty plastic bag would be prudent. Any thoughts, recommendations etc. gratefully received. Thanks in anticipation Simon Edit for typo (there's always a typo)! Edited January 12 by Simon Williams Typo Quote Link to comment Share on other sites More sharing options...
Snagger Posted January 12 Share Posted January 12 Make sure you align the hub and outer sleeve correctly on their splines. Ideally, you’ll have marked their alignment before taking it apart, as they can bind if you alter the alignment. I strip it all apart, refit the hub to the sleeve and then fit all of the springs and square pads. With the sleeve just sitting against the springs, pads already slipped inside the sleeve, I fit one ball at a time, teasing the sleeve to a position that lets the ball in and then pressing the ball in with a screw driver and as soon as it is below the sleeve, pressing the square pad to slide the ball inside the sleeve. Once it is there, move onto the next one but try not to let the sleeve move relative to the hub as the ball is likely to pop out. It’s fiddly and frustrating, but hopefully won’t take long. I recommend doing it in a well lit, clean and uncluttered area where any dropped or shot balls will be easy to find. Towels laid on the bench and floor will stop them bouncing or rolling away. Quote Link to comment Share on other sites More sharing options...
Gazzar Posted January 19 Share Posted January 19 Grease is useful as glue mid assembly. Quote Link to comment Share on other sites More sharing options...
Simon Williams Posted January 21 Author Share Posted January 21 Good afternoon all, and thanks for your advice. I tried the "one at a time" approach, shot a ball bearing across the kitchen (which I did subsequently find) and decided I was on a hiding to nothing. So I made this, which is a collar of inside dia to accept the syncro hub, OD doesn't matter, with three 5/16 UNF tapped holes and screws around the periphery. The depth of the recess is enough to leave a little bit of the splined OD of the hub showing to line up the outer splined ring (selector ring). Pop the hub into the recess,, and remove one of the radial screws. Balance one of the little square blocks in position, drop a spring and a ball down the radial hole. Now replace the radial screw pushing against the spring until the ball is level with the inside surface of the collar. The ball is now securely captured in its hole, so rinse and repeat for the other two positions. Having previously re-discovered a position of the splines where the two parts slid convincingly, and marked the alignment accordingly, I brought the outer selector sleeve over the splines of the hub, and (working inside a clear plastic bag) wiggled the hub assembly complete with springs and balls into its correct position central to the outer sleeve. I found this bit rather fiddly and resorted to using a dental pick to get all three blocks into their proper positions but as long as the outer sleeve is held over the hub and tight against the collar the balls have got nowhere to go. You can use the dental pick through the skin of the plastic bag within reason. Hey presto! Hope this helps someone else trying the same exercise, and if it helps anyone to borrow the tool let me know. x 1 1 Quote Link to comment Share on other sites More sharing options...
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