EJ gearbox overhaul

[EJVince]

Love this mainshaft replacer tool, makes the job real easy, of course I swivveled it round off the edge of the bench to make turning the wrench easier, this was just for the photo

[In the Shed]

Good job Vince,
Sanding block come in handy

Stephen

[EJVince]

Yes mate, the sanding block did come in handy

[Harv]

Good news.

From memory, the new synchro springs need to be expanded out by hand prior to using. There should be some info on that in the Guide - it came from a GMH Service Bulletin.

Cheers,
Harv

[EJVince]

Yes, spot on Harv, I would have been left scratching my head if it wasn't for that guide. It was the only way I knew what to do

[EJVince]

Pressed the speedometer drive gear back on today, Harv's 7A5 tool worked a dream together with my old front bearing retainer to press it on. Put new roller bearings in the cluster gear, and reinstalled with new shaft, clearance with feeler gauge within limits, new roller bearings in clutch gear and reinstalled. Put cover on loosely and goes nicely through the gears. Not totally satisfied with how the front synchro turns in hub, so will come back to this later.
Next spare time will work on pulling appart thr clutch parts in bellhousing, clean it all up, and replace springs and bearing.

[EJVince]

Tried figuring out why the front sychro doesn't spin freely, really feel a bit of an idiot I didn't figure that out before putting the mainshaft back in, I thought I had tried that, I know the rear one spins alright. At least it is still accessible, and I took some photos then stretched them out and took screenshots. I think this damage to one section of the bronze insert may whats making it catch. There does look like a bit of damage at the bottom but not sure that would stop it spinning freely.
I know you aren't supposed to polish the inserts, but wondering if the damage is only a couple of places, I might be able to do spot repairs gently with a file perhaps.
The alternative is to wait until I can find another second hand hub in good condition at a reasonable price, nowadays that might take some time.

What do the brains trust think, aside from this I am happy with the rest of the box. But pretty sure at the moment this would clash shifting into third gear.

[ardiesse]

Vince,

The ding in the bronze insert won't cause you any trouble. But you'll need to clean the groove for the synchro cone retaining circlip: run the point of a knife around the groove to get rid of metal particles.

Leave the synchro hub in neutral, or better yet, shift it into "top" (i.e. forwards). Then drop the top gear synchro cone into place. Push down on it gently and see if it rocks at all (it's not supposed to). With no weight on the cone, see if it turns in place.

Pull the synchro cone out and install the circlip. It should seat firmly in the bottom of the groove. You could even rotate the circlip in its groove to make certain.

Now re-install the synchro cone and follow it in with the circlip. The synchro cone should have a little axial movement: if you turn the gearbox on its nose it should be possible to turn the synchro cone freely with a small screwdriver on one of the engaging dogs.

Rob

[EJVince]

Thanks Rob, I will clean the circlip groove out, the issue is it won't turn freely, it seems to fit nice and doesn't rock which is great, but it wont turn freely with a screwdriver, turns a bit then seem to jam on something, this is what I need to solve or pretty sure it will clash going into 3rd gear. I was wondering whether the rough bit on the insert ding was jamming it.

[ardiesse]

Vince,

If you try to turn the synchro cone with the gearbox facing input upwards, it'll behave as you describe.

The other thing to try, with the cone and circlip installed, is to grab onto the engaging dogs with pointy pliers, and see whether the cone has free play when you try to move it in and out (axially).

Rob

[EJVince]

Thanks Rob, joining this forum was such a good move, what you guys don't know ain't worth knowing.

So I cleaned the circlip groove out once, put circlip in, thought it was right bit still wouldn't turn when i tried turning it like you said. Cleaned it out again, sat beautifully and turned. Installed synchro cone and circlip, pointed box downwards a bit, turned easily with screwdriver, still turned okay horizontal, happy days

Really appreciate your advice throughout Rob

Still got to work on clutch housing, but might not get a chance for a couple of weeks as off to Ulladulla for a break this coming weekend for a few days to meet up with friends, but will eventually get there.

Harv, should be good to post your tools back now that I know I don't have to pull mainshaft out again, really appreciate the lend mate, you're a legend

[EJVince]

Put the side cover on, and tried going through the gears several times. Still think there is a tendency to slip out of top gear at times. Was trying to see how this was happening, kept taking cover on and off, examined the cover pretty closely, and I do feel that to keep the hub in the right spot you need to push the lever a bit further than it naturely wants to go, fair bit of slop in the lever and you can see wear marks on the inner parts. I do have a fair few new old stock parts including a side cover, shaft, and I have new springs and ballbearings. Thinking I should try and build a new cover, or will still have grief with this box.

[ardiesse]

Vince,

The shift shaft in the photo is not worn at all. GM-H used a superior grade of steel. But I'd be inclined to inspect the detent spring and ball in the second-top shifter yoke, given that you're concerned about top gear jump-out. The shifter mechanism should have a really firm, notchy "clunk-clunk" action when you shift from second, through neutral, into top. Check that the spring's neither collapsed, broken, nor worn. Also check that the detent ball runs freely inside its bore. You'll see the polished track on the shift shaft where the ball runs. If the track's missing anywhere, except for the bottom of the "V", that's cause for concern. The shafts that the shifter yokes run on should be held firmly in position by the lock pins. If they have any fore-and-aft movement, that would need to be corrected. Even to the point of getting oversize lock pins made up.

It's been a good while since I last overhauled the shifter mechanism in a "red" crashbox, so I can't remember if you can "overshift" the shifter mechanism. By "overshift" I mean that you can move the shifter past the natural detent position when selecting a gear. I'd have thought that the shifter yokes would bang into the stops in the side cover at the exact "detent" positions. But one weakness of the "red" crashbox is the tendency of the bores in the side cover to wear out. It's only aluminium, after all. Still, the family HR had badly flogged-out bores in the side cover, yet stayed in gear perfectly.

It would be interesting to see if there was a thin-walled bronze insert to suit the gearbox side cover - like a K-liner for valve guides, but in the right diameter for the shifter shafts.

Rob

[EJVince]

Thanks for the detailed response Rob, that's given me plenty of ideas for the weekend when I pull it appart. Surely with all the new parts I have, together with what I can salvage from the old side cover, I can make up a decent assembly. The yoke that came with the nos side cover is slightly different to the one on my box, so possibly from later model. Will be interesting to see if the detent balls and springs I had custom made match the ones in the box when I disassemble, I gave them specs from workshop manual.

[EJVince]

Well that's dissapointing, thought I was going well, had made up specual tools to go in yokes which worked a treat to get detent springs and balls out, but the replacements I got about 4 years ago are a bigger diameter. Now really not sure what to do about that as really thought they would make a difference, seems to be 5/16 diameter rather than the old whuch were 1/4 inch, about 1/16 inch difference. Should have done this when I first got the springs.