MK2 Golf transmission problems

So I have an 85 Golf that is having some transmission problems. When I bought the car the entire shift linkage was wore out so I replaced it. Well I drove it for awhile with no problems till now. The other day I put it in reverse and then when I went to shift to first the gear selector arm on the transmission was locked up well it unlocked and drove fine then a couple of days later it wouldn't let me into reverse but after getting it to work it did go into reverse. Sometimes its also like its hard to get it into gear when shifting but other times its perfect. Anyone got any ideas of what it could be?

Probably the slip joint is loose, if it isn't tight and in the exact right place it makes shift changes difficult and reverse impossible.

Do you mean the piece on the end of the rod that connects to the shifter? Because that parts is tight. When it locked up the other day the actual part on the transmission that selects the gears was locked up. Sorry I dont know the exact names of the parts.

I don't see internal failures on those trannies too often.

When you replaced the parts, did you use an alignment tool to set it up? If not, that's the first place to start. Also check the reverse block out plate under the shift boot. If it's broken the linkage will bind between 1st and reverse because it helps guide the shifter.

Unfortunately a worn clutch will also screw with 1st and reverse engagement.

Yeah I used the alignment tool and replaced the reverse lock out plate when I redone all the bushings in the linkage. The clutch seems to be okay and the previous owner said it had been replaced but seeing how some of the other repairs had been done its possible. It doesn't do this all the time and when it locked up I disconnected the linkage from the transmission and I still couldn't shift it even at the transmission.

Have you checked the gear oil? I only aske because of the half dozen or so 020 transmissions (some in cars some already removed) I have picked up in the last 8 years, ALL of them had sludge for gear oil.

Motor mounts okay? Can cause alignment issues with the linkages.

When I bought it the gear oil in it was horrible. It actually got changed twice because the first time I changed it I found out the drive flange seals were leaking bad. I used redline MTL and its full now. I will check the motor mounts out but it doesn't seem like I am getting much engine vibration.

In reply to cabbagecop:

I am going by the advice of a local VW "legend", Dick Shine, when I write this: The 020 does not work well with Red Line. He recommended I use only OEM or Amsoil GL4 compatible (75W90). I have run the Amsoil in my racing 020 trannies since 2003 and not had a single issue. I ran the first one I built with Amsoil from 2003 until 2008 without opening it up and then i only took it apart to swap out the 4.64 ring and pinion for a 3.94.

Okay I will try to find a local amsoil distributor and see if that helps. It has been shifting perfectly the past couple of days. Also I want to thank everyone that has helped I am really impressed to have so many replies quickly.