Can someone tell me what part numbers the 3rd gear synchros match up with?
Is the JDM Y1 cable tranny common with other trannies?

 

Well, it's "done" ready to fit in tomorow.
First thing, I definitely got conned on the warranty repair. When I opened up the box, the magnet was still covered with metallic grit, so I doubt the mechanic even opened up the box, sure didn't clean it.
Next he claimed there was still "1.5mm" space between the synchro cone and the 3rd gear. Well he needs a new set of feeler gauges as I only got 0.7mm. New clearance is 1mm and wear limit is 0.4mm.
So I see the 3,4 and 5 bronze synchros are all the same size ... thinking .... well the clearance on the 5th gear was about 0.8mm, more than on 3rd gear. So I did a swap, the thicker 5th is now on 3rd .
So that must be why 3rd is the first one to go bad...synchro ring on 1st is the largest, then on 2nd is next largest, and then 3rd, 4th, and 5th all get the same size synchro ring. So probably 1st, 2nd, and 5th are adequate design by comparable sizes, but poor old 3rd (and to a lesser extent 4th) is marginal and underdesigned by comparison.
OK, now I have a bit thicker (and less used) synchro ring on that troublesome 3rd, plus I have cleaned out the grit off magnet, plus now I'm going to use Honda MTF 75W85 instead of 15W50 motor oil/ .
And maybe if I just change a little slower and double clutch..I'm OK again.
Anyhow, if the thing still crunches, I'll just go and order the set of three newies and get around to doing it all over again.
Watch this space.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by JohnCRX &raquo;</TD></TR><TR><TD CLASS="quote">Well, it's "done" ready to fit in tomorow.
First thing, I definitely got conned on the warranty repair. When I opened up the box, the magnet was still covered with metallic grit, so I doubt the mechanic even opened up the box, sure didn't clean it.
Next he claimed there was still "1.5mm" space between the synchro cone and the 3rd gear. Well he needs a new set of feeler gauges as I only got 0.7mm. New clearance is 1mm and wear limit is 0.4mm.
So I see the 3,4 and 5 bronze synchros are all the same size ... thinking .... well the clearance on the 5th gear was about 0.8mm, more than on 3rd gear. So I did a swap, the thicker 5th is now on 3rd .
So that must be why 3rd is the first one to go bad...synchro ring on 1st is the largest, then on 2nd is next largest, and then 3rd, 4th, and 5th all get the same size synchro ring. So probably 1st, 2nd, and 5th are adequate design by comparable sizes, but poor old 3rd (and to a lesser extent 4th) is marginal and underdesigned by comparison.
OK, now I have a bit thicker (and less used) synchro ring on that troublesome 3rd, plus I have cleaned out the grit off magnet, plus now I'm going to use Honda MTF 75W85 instead of 15W50 motor oil/ .
And maybe if I just change a little slower and double clutch..I'm OK again.
Anyhow, if the thing still crunches, I'll just go and order the set of three newies and get around to doing it all over again.
Watch this space.</TD></TR></TABLE>

Nice, keep us posted on how this works out for you. Personally I would NOT use a thick *** 75w80 oil in there. The thinner the fluid, the BETTER, not worse. Look at how many guys are using GM synchromesh with great results (it's thin as water).

 

Yea dont use the heavy *** weights! Go with the GM synchromesh ( the really light weight stuff), although honda MTF (similar to 10W-30, not 75W-85) will be sufficient.

 

Well it turned out great...the tranny is as good as new again!
Living in Australia, we don't seem to have the GM or Pennzoil Synchromesh anywhere, so I have used Honda MTF 78W80, and really it is VERY thin, like the engine oil I was using before.
Not sure if the oil cured the crunch, or maybe the warranty "repair" actually did work. The mechanical said the synchro ramp on 3rd gear had bronze build up and was subsequently "glazed". I was a sceptic when he reckoned he "deglazed" the ramp, but maybe he did it and it has worked OK.
Whatever, the tranny is feeling like new, without any new parts.
If you guys got a crunch that can't be cured with good MTF, it's a lotta work but maybe you could look at deglazing the bronze deposit and swap in the 5th synchro ring as well......works for me......lotta work though.

 

are you from sydney?
and if so who carried the work out for you..
I am wanting to rebuild my gbox..