In reply to Hungary Bill (Forum Supporter) :
It can be pretty hard to see from outside, normally when they crack around the pivot ball everything looks pretty normal externally in terms of function.
Here's a picture of a fairly catastrophic failure to show what I'm talking about in case it didn't explain very well.
I've seen them not blown through like that though, so the damaged section is flexing over the pivot ball robbing you of some of your throw out bearing travel.
Synchro's for the most part are dumb parts, what I mean by that is they don't know if they've been sitting for a day or a decade, either their worn or they aren't. I'd say multiple rapid synchro failure would be fairly evident by a lovely bronzy metallic oil when you drained out your gearbox.
Some gearboxes hate some oils, a number of mazda gearboxes I've seen/had will refuse second gear shifts when cold depending on what oil is put in them. But given yours was playing up before and after the change, I'm less ready to point the finger at oil choice.
Second and fourth both being the same side of the shift pattern could be a clue, and may point to a failed bushing as has been mentioned.
In reply to daeman :
aw crap. See? I thought you were talking about the easy side to look at! 
In reply to Hungary Bill (Forum Supporter) :
No worries mate, I wasn't sure I'd explained it well so thought a picture might help.
You might be able to get your finger in there far enough to do a feel inspection if you can't get line of sight through the hole the fork passes through.
Hopefully it's not the issue, but then again, other than being labour intensive, it's a pretty cheap fix
daeman said:
In reply to Hungary Bill (Forum Supporter) :
No worries mate, I wasn't sure I'd explained it well so thought a picture might help.
You might be able to get your finger in there far enough to do a feel inspection if you can't get line of sight through the hole the fork passes through.
Hopefully it's not the issue, but then again, other than being labour intensive, it's a pretty cheap fix
Apologies for the picture taken with a potatoe, but here's what mine looks like:
(i couldnt get to the other side. Too tight)
hard to tell, but when looking with the flashlight i dont see any obvious signs of protrusion.
Edit! Chinesium borescope to the rescue! Here's the opposite side:
Easy money.
Okie dokie, I've decided I've had enough with crawling under the car (having sufficiently beat that horse to death) and decided to attack from the top. Marlin Crawler parts have not arrived yet but I dove in to that shifter bushing just to see what I could see. First a little background:
When I got my truck back from the shop, something had impacted the center console. Not sure if whatever hit that wacked my shifter but could be cause for concern here.
Furthermore, my truck was the victim of a body lift. Just say no folks. It looks like the cutout in the tunnel had been wacked sufficiently in the first and fifth gear areas. It probably explains why I've always had to hold the shifter in first when taking off (it kicks itself out about 50% of the time).
Underneath that rubber boot panel, I found two chunks of dark plastic that very nearly had me concerned I was seeing metal. Both chop up easily with a box knife so no metal concerns there. I'm assuming this is the shifter bushing issue you guys mentioned earlier, but it doesnt look anything like the bushings I was expecting to see based off the marlin crawler website (edit: this is because i need to pull the rubber boot up. Looking back at MC's website it all makes sense now.)
For now, we wait. Here's what the top half looks like:
Good times.
Ninja Edit! Visual NDI complied with on clutch pedal bracket. No defects noted.
A holiday season, 2 quarantines, and several months later, i got the bushings installed. Definite improvement in terms of feel, but the problem is getting worse.
In addition to the random loss of synchros, now when i let off the gas it sounds like my second gear is trying to imitate a Jake brake (completely quiet when accelerating)
Video below
https://youtu.be/EN8Bq0fcW48
Good times
