Manual Shifting Trouble

[KingJames224]

Hi,

I bought an '89 non-turbo Supra in May with 133k miles. I just had the upper end rebuilt, and wouldn't ya know it, a week after I got it from my mechanic, this new problem surfaces.

almost since I got it, the shifting has been rough. It is often difficult to move the stick into a gear because there is resistance, and there seems to be slippage also. Also when changing gears, there is sometimes a "knocking" noise unless I shift very carefully.

The real problem is that a week ago it just stopped shifting into 4th. All the gears work but 4th....I can put the stick into the 4th postition, but it's as if it's in neutral. I don't know if it is the clutch or the transmission, but I'm sure it's one, the other or both; they are both original.

I'm just beginning to become car-savvy, but if I had to guess I'd say the clutch definitely needs replacing, and may even be the root of the 4th gear problem. But with my limited knowledge I can't rule out the tranny. Could anyone help me deduce what the problem is...? Or lend me some tips as to how I could test the clutch and tranny to get a better idea if one or both is bad?

My mechanic told me the transmission just wouldn't suddenly stop shifting into a certain gear without any grinding of gears to warn me. However, I wonder if it is wise to just swap out the tranny since I read in the manual that it has to come out anyway to get to the clutch. I mean, it is original, and maybe bad. I'm thinking that I should try to find a used or rebuilt one to swap if and when I replace the clutch....especially if I pay someone else to do the labor.

I'd love to do the labor myself, but I've never done something like this before. I've replaced alternators, starters, belts, and other bolt on stuff, but there's something about the tranny that just knocks my confidence. Is there anything tricky I should know about removing/replacing transmissions? Special tools? Tips?

I just realized how long this post was....Please, any comment, information, or opinion is greatly appreciated.

Thanks in Advance,

James