SM465 synchro alignment question, putting top cover back on

[mattfranklin]

I'm putting my SM465 back together after a cleaning, inspection, and fresh set of gaskets.

The top cover is ready and from what I've read, I might need to have the shifter halfway into reverse. I've tested it. All of the forks move in the right directions. All good.

But I also know the 1-2 and 3-4 synchros need to be in neutral. The 1-2 was easy to slide around and get into neutral. But I can't seem to move the 3-4 synchro out of 4th. It moves a little, but not enough. I don't want to wreck anything. It doesn't move around by hand pressure. I've tried a little prying and tapping, but those don't move it enough.

QUESTION: Is there some sort of spring or clip I need to move out of the way before i can slide the 3-4 synchro manually into neutral?

Once I get these into neutral the cover can go back on.

[mattfranklin]

It looks like it may have been pushed too far into 4th when the cover was off. I probably did that myself when I put it into 4th and 2nd at the same time so I could torque the output yoke.

Anyway, the synchro got pushed a little past the keys (all 4 of them) and I can't get it back into neutral.

Has anyone had this problem? How do I get them simultaneously pushed in while trying to slide the synchro back into place?

[kwmech]

With the lid off you'll have to get a couple of strong flat blade screwdrivers and go down the side of the syncro hub and pry it into neutral. Reverse gear has to be 1/2 way in and out of gear to get the lid on

[mattfranklin]

Originally Posted by kwmech

With the lid off you'll have to get a couple of strong flat blade screwdrivers and go down the side of the syncro hub and pry it into neutral. Reverse gear has to be 1/2 way in and out of gear to get the lid on

Cool. Thanks, I'll try that. I didn't want to risk breaking or bending anything.

[mattfranklin]

Good news.

SHORT STORY: It popped into correct position with only light hand pressure, some assembly lube, and a small screwdriver poking in the right places.

LONG STORY: I was getting all psyched up to force it with the two screwdrivers. (I was not super hopeful because over the weekend I did a lot of straining and grunting doing almost the same thing, but prying with only one screwdriver or lightly taping with a brass hammer.) Tonight, as I prepared to make it happen I wanted to give it the best possible chance of happening. So I got out a little tub of Red Line assembly lube and put a dab on the leading edges of all three keys, then I manually put a little preload on the synchro with my right hand while pushing down on the leading edge of each key with a small straight blade screwdriver. The plan was to work my way all the way around before putting the big screwdrivers to it. When I was lubing and poking at the second key, the whole synchro snicked right into place with very little hand force. It surprised me how little force it took.

Anyway, thanks, KW, for the encouragement to use more force, and I wanted to let you all know how it turned out.

[mattfranklin]

Originally Posted by kwmech

With the lid off you'll have to get a couple of strong flat blade screwdrivers and go down the side of the syncro hub and pry it into neutral. Reverse gear has to be 1/2 way in and out of gear to get the lid on

I'm at the stage where I'm trying to get the cover back on. The transmission is in the truck. I have tried a few times. It's hard to keep the reverse gear where it's supposed to be. It wants to slide out of gear and not stay halfway in. I'm using a big blob of axle grease, but it still wants to slide just a little. But I think I'm ok. (just a crazy thought, but it would be interesting to make a spacer out of wax -- that would melt out of the way when the tranny warmed up -- but that just might end up being a huge mess -- maybe an ice cube would be smarter. )

I have tried it a couple of times with the shifter handle still in it but it's pretty cumbersome. Now I'm trying it without the shifter handle. I'm eyeballing it to get the shift fork about halfway into reverse.

Then I slip the cover into the zone slightly rotated to the right to clear the truck floor/firewall area. Once it clears the floor I rotate it to the left until it's properly level and lower it onto the tranny box. I made better progress, but it still binds up about an inch or inch and a half above the box.

QUESTIONS: Do you think this will work if I keep fiddling? Where should I poke and fiddle and pry and look to get this in? Or it is a lost cause and should I take the tranny out of the truck? I hate going backwards because it was not easy to wrestle the tranny into place.

[mattfranklin]

Anyone? Bueller?

Any tricks in getting the back cover on?
Does it have to be out of the truck?
How do you know the shifter forks are positioned correctly.
Any special magic?

Thanks!

[wildwilly4x4]

I did mine while it was in the truck. I put the reverse gear halfway between engagement, and slid the reverse fork to half way engaged, put the top cover on, stabbed a couple of bolts, then stabbed the shifter. Once I had a couple of bolts in and the stick in, I started it to make sure it all lined up and worked. Perfect the first time.

[mattfranklin]

Originally Posted by wildwilly4x4

I did mine while it was in the truck. I put the reverse gear halfway between engagement, and slid the reverse fork to half way engaged, put the top cover on, stabbed a couple of bolts, then stabbed the shifter. Once I had a couple of bolts in and the stick in, I started it to make sure it all lined up and worked. Perfect the first time.

Thanks! I'll keep trying then. Maybe I'll also adjust the jack stands to get the tranny closer to level to minimize the chances that the reverse gear slides on its own.

[mattfranklin]

Got it in! After about 20 tries. Had to do it with the shifter out so it wouldn't get blocked by collisions with the dash. Got the reverse fork position set up beforehand: halfway into reverse. Even with the front rims (no tires) on the garage floor there was still a slight tilt to the tranny that made the reverse gear want to slide into neutral. A big blob of grease slowed it down a lot and held it in the right place, halfway into reverse. I'm talking BIG BLOB. Maybe half to three quarters of a cup in volume.

The biggest problem I had was that, as I wrestled the cover in around the floor and firewall, it wanted to push the reverse fork fully toward the "in reverse" position.

My two main tricks were lowering the cover in pointing at 1:30 or 2:00 and dropping the reverse fork inside the box until the front edge of the cover cleared the firewall and then rotating it to high noon before the final drop. Then, tipping the front slightly down to engage with the 3-4 slider and then lowering the rear until it engaged the 1-2 slider. At that point it hung up about an inch above the case. Then I reached in through the top receiver hole (where the shifter normally fits) with a long screwdriver and slowly moved the reverse rail into neutral. At that point the cover dropped perfectly into the case.

I actually think I may have gotten it right on the 2nd try, but I was doubting myself that it could be so easy and even with the clutch pushed in I could not turn the yoke, so I thought I was locked in two gears at the same time. (My problem was the clutch was not yet adjusted to completely disengage; so it fooled me.) It took my another 18 tries to get it right *and* convince myself that it was right.