Sunday, April 15, 2012

Gearbox update

So my third and fourth gear synchros were not great.  The fourth gear was probably reusable, but the third was pretty worn.  I ordered new ones from Moss for this weekend (today is Sunday) but they were out of stock, so I had to order a set from NOS Locaters on eBay (same guys as Scarborough Faire in RI).  They were to be delivered on Sat, but didn't make it, so I am now very behind.

To make some headway I cleaned up the shift tower extension and installed the first motion shaft.  Oops - the laygear won't go in with the first motion shaft installed, so now that has to be done over.  The shifter mechanism was missing the anti-rattle ball bearing that goes in the curved link arm underneath the shifter itself.  At Barney's suggestion, I instead used a 3/8" long piece of 1/4" brass stock (which I cut from the shaft of a large woodscrew - a #12 is 1/4") and it is all back together now.

Getting the bearings circlips into the inside of the laygear is a real PITA...if there's a trick I don't know it.  I finally cut about 1/4" off the end of each clip to allow them to squeeze together enough to drop into the grooves.  Now though, the inner set of bearings (captive in a race) on the forward end of the laygear seem to be bound up - too tight somehow and don't roll freely.  If I have to take the whole thing apart again (meaning new circlips and another Moss order) I am going to be very frustrated.  Maybe if I have to do it over, I will go back to trying to add the fourth bearing and have a local machine shop drill the shaft, etc.  Seems I have some time before I'll be able to get it done anyway.  If I dropped off the parts at the local machine shop tomorrow they could probably have them done before I get back from my trip.

UPDATE 4/27/12

I reassembled the gear box last night.  I got the layshaft done by completely stripping it again, then installing the caged needle bearings in the front (from VB - better quality than the Moss parts, IMHO) and the longer bearings in the rear for more bearing contact area.  The longer bearings are the same as the ones that normally go between the first and third motion shafts - you need to order 20 of them, VB sells them loose.  I cut the spacer tube down 1/2" using my lathe and a hacksaw then filed it smooth.  I used a pair of the old needle bearing "caps" flipped around so the stepped side was away from the new needle bearings, and used a bit of bearing grease to glue them in place for reassembly.  A 5/8" dowel cut to the length of the layshaft plus the two spacers allows you to put the layshaft in the bottom of the case (let it float) while inserting the first and third motion shafts - then you replace the dowel with the layshaft by sliding it through.  Everything seems fine, though I had a hell of a time getting the rear tail extension back on and the shifting forks to line up.  I'll be sure to put the shift tower on and test it before putting it back in the car, though!

Update - 4/29/12

DONE.  Back in the car.  Seems to get all the gears fine - but very stiff.  Have to fill with oil and actually test it by starting the car still, however...probably on Monday or Tuesday night as now it is time for bed!

Carb update

I reassembled the other two sets of carbs I had to play with and decided to go through my own before putting them back on the car (though I am still waiting on some transmission synchro rings and it will be another week or so before any reassembly happens!).

Mine needed new shafts - not bad but not great, and now is the time.  I finally got the hang of quickly and accurately rebushing the carb bodies.  Using the reamer with the 5/16" shaft and the 3/8" cutters, I reground the flutes at the shaft end to make them angled such that they will bite the material when fed from the shaft end.

I found a socket that fit the cutter end perfectly and used my variable speed drill to rotate while applying downward pressure with the carb body held in my large vise.  Takes two seconds to line drill the carb, and it comes out perfect.  Don't drill all the way through - leave a small shoulder at the bottom.

The best carb bushings aren't the bronze ones from McMaster Carr - they are the ones from Moss.  They fit better, and the 5/16" ID oiled-bronze bearings have an ID which is just slightly too large for my liking.  I used red thread locker to seat the bushings. 

I also ordered a braided carb to carb fuel line from Moss just to dress it up a little.  Looks very nice.