Re: 95 zf5 problems
Not an expert on transmissions, but, experiance says this is a shift fork issue. 2 of them in your case. 1-2 fork and 3-4 fork. Not that it matters. Either way it has to come out for repair. Up side... both going out at same time is a blessing. Change them all while your at it. Probable Cause, (I hope) previous owner was a gorilla and damaged it by forcing it to find the right gear. Otherwise its a weakness in that model.
Converting my MD5 to the zf due too similar issue and light/heavy duty concerns. 5-Reverse fork. no 5th and kickout on reverse.