1987 4-speed trouble

[MrMike]

Looking for some ideas. My 87 Extra Cab 4x4 just started popping out of 3rd gear (hard). I removed the shifter to make sure the bushing was ok and it appears normal. I've got about 165,000 miles on it and have replaced the fluid with 2 parts lube and 1 part Marvel Mystery. Counting on an adjustment and not a replacement.
Thanks for any input.

[obex26]

Very common problem. No lube is going to stop it from coming out of 3rd gear. Sounds like the syncros are on their last leg. I suggest looking for a used replacement even a 5 speed at that. The cost for a used tranny will be alot less then trying to rebuild your 4 speed. You could easily swap it out yourself in a weekend. Another suggestion if you dont want to buy the toyota repair manual from the autoparts store you can go to your public library and usually find it there.