How can I tell if a synchro is worn out? where would the damage show and what should be measured or inspected?

Would scoring on the top cause issue?

I want to swap a gsx 5th set on to a gst. The synchros are obviously different right? I have a whole set anyway . I'll check the inside. Thanks.

I just removed the end cover of a fwd km210 trans and there is no place for a synchronize to ride on the cover. Is this missing or just not a part of this transmission? This is revers or 5th gears syncro? I'm assuming it's just missing. I was about to do a 5th gear swap from an awd trans. Is this going to be a problem? I only stopped because it has red lock-tight on the end nuts. I will have to heat them tomorrow.

Thanks for the picture. As I expected the metal piece that screws to the case and holds the wave spring is missing and the last brass syncro that rides on it isn't present. I'm going to try to assemble a complete awd trans from all the parts I have and remove the input shaft and install a welded center differential. Supposedly these km210s shift very poorly anyway. Other option is remove the locktight and swap an awd 5th and reverse gear on there.

I don't think any Mitsu trans from this era has a reverse syncro; at least not from the factory. I could be wrong, but it's like every Honda of the era and all others before that.

I have some pictures for you taken from the Mitsubishi service manuals.

Link provided to the manual for you to have at'er, and or for reference sake.

http://www.lilevo.com/mirage/Manuals/FWD%20Manual%20Transmission%20F4M21-F5M2X-F5M3X-W5M3X%20Series%20PWEE8902-ABCD%2022A.pdf

Nearly all the manual transmissions repair manuals are located there. I uploaded all I could find from around the globe. This will help more than just our OP.

Spring update on that one.




I did post a pic of the F5M33 FWD trans end case, so you could see what that one looks like. The F5M31 is listed in the manual whenever you get to pics like above, it just doesn't list it in the titling of the manual and chapters, as such.
If you don't find what you are looking for there, it likely doesn't exist. I doubt that your FWD transmission will be any different than the ones printed in this 1989 copy of the factory repair manual.

Pictures inbound. It turns out I have an early and late model transmission pair. It will illustrate the end cases per the picture above. There is not an extra assembly bolted/screwed to the case end cover however, so be prepared for that.

I think the FWD's had interchangeable end covers to a certain degree, within certain frames.

My two transmissions shown were (the one with the end guts missing) the 1989 Plymouth Colt (C53A turbo KM210) as original to the car as far as I know, with nearly 183,000kms and very worn fibrous syncros in second and third, and secondly the other KM210 came from Virginia and was reported to be a turbo Mirage trans) but had the different end cover plate thing. Neither had the wave spring I was looking for, so it must have been the F5M33 FWD DSM trans that I have now installed that was coming back from my memory.

The 89 Colt/Mirage trans should have fibrous syncro liners which are great for holding/slowing engagement of the syncronizer and gear, so easier on the shifting persons arm but they do wear out faster given a high abuse over long term type scenario. 90 DSM transmissions were like this too. When I had the fifth gear syncro for my original trans out (the one with guts missing) I noticed it had the grooved style syncro and no fibre ... so it is leaving me kinda perplexed!

Keep in mind that a 1993 FWD DSM transmission if turbo, will have switched to a 27 spline count open differential. You can swap in any differential FWD or AWD to the transmission, so that part is good, but the AWD uses ball and cage and requires a substantial amount of shimming, so food for thought before you go that route. I run the AWD front diff setup in my FWD trans, and it works great and as I suspected it would after I had a local trans shop set the preloads and shim the center differential. AWD Galant and CSM's share the 25 spline count axles for front axles. DSM turbo axles switched at 92.5 MY or production date.