Just overheard the story on the show, where some lady’s car (apparently, Honda with manual transmission) is unable to hold 5th gear. I completely agree with car guys conclusion, that synchro is bad. However, years ago I was able to contain the problem without ever taking the transmission out on my 1987 Accord, on which 5th gear was immediately popping out literally 9 times out of 10, and still not holding well on that 10th try. On that car, transaxle can use regular engine oil. What I did, was draining older conventional oil and filling it with the best quality synthetic engine oil of the same grade, and that completely reversed the situation - now, 9 times out of 10, 5th gear held for as long as it was in, for at least a year - until that car’s body finally rusted to the point when I had to get rid of it… if hers (or anybody else’s, for the matter) car uses specialty transmission fluid, she still can try using synthetic MTF from well-known aftermarket brands like RedLine (that’s what I use now) - easy fix, and if it still doesn’t work, it’s a relatively cheap try, compared to outright tranny replacement.
Good advice. I had a friend who even went so far as to use AFT, automatic transmission fluid to “smooth out” the shifting. I had my doubts but the car lasted as long as the time I new him many years later. He had a doctorate in chemistry and assured me it was OK. I never question him on matters like this.
A worn out transmission is a worn out transmission and it’s going to take more than a fluid change to fix it…If you can get it into a gear (any gear) and then it pops out, it’s not the syncro, it’s usually a worn mainshaft bearing allowing the shaft to run out of alignment…On some designs it can be a worn or broken detent on the shift mechanism or a bent shift fork…