1986 Honda Accord LX manual transmission issues.. Please help.

[cncking2000]

Hello all, I have the vehicle mentioned in the title. When I first got this car, I did not have fifth gear at all. A pull of the fifth gear cover on the trans showed 5 completely shot. No teeth at all. I replaced all of the parts that are accessible from that cover, (syncros, gears etc) I flushed and filled the trans with Honda MTF. No large pieces of metal came out, and probing the drain plug area with a magnet pulled nothing out as well. 5th gear is working fine at this time.

My issue is this. I have had issues with being able to use 4th, and today, on a road trip, I was left without a reliable 4th gear. It would never stay engaged.. It just kept popping out of gear or not engaging at all. Forcing the shifter all the way occasionally got it to hold. After a particular deal of difficulty trying to use 4th, I went to 3rd. After using third, at 60 MPH, I shifted back, 4th engaged without issue. I did not have to force it in.

The weather here is of issue as well. It has been -10 to -15 the last few nights. I am wondering if this is an issue with a linkage being frozen, or out of adjustment. I would think syncros, but after that 3rd to 4th shift, 4th has had no issue holding, or engaging, accelerating or decelerating.

What could be the problem? Any advice is appreciated, I am parked in the middle of nowhere, camping at a Motel. Please advise oh greats of 3Geez

[2oodoor]

Does sound like synchros or thrust washers misplaced or too tight but since youre holding the shifter I would double check shift rod adjustment and check for ice chunks. I would say a good limited slip additive would help the synchros but you used Honda MTF which should have those friction "nanos" in it already.
Try double clutching in neutral between 3-4 shift.

[cncking2000]

The trans has not been looked into short of oil and 5th gear. I do not see how the thrust washers and syncros for 4th would be affected. It doesn't matter double clutched, or not. It just wouldn't hold the gear. When I could get it into gear, it would pop out shortly after/ Now, it doesn't. I don't understand it.

[lostforawhile]

which honda manual fluid did you use? it changed,you need the original one, if you cant find it use syncromesh

[cncking2000]

I used the MTF that is the equivalent of 10w30 just with a Honda label. I am going to check the levels and make sure I don't have a leak or anything else like that as well.

[Dr_Snooz]

My guess is that one of the teeth from 5th floated down and wedged itself into the shift linkages inside the trans. After a few miles, it repositioned itself and you were able to shift again. If you never got the remnants of 5th gear out of the trans, then they will float around causing all kinds of interesting things to happen. Not sure how you fix that easily though. Just hope you have one float up and into some rotating gears.