last year i had a problem with my 5th gear hub and slider and also the 3rd and 4th gears were to short. so i replaced the hub and slider to fix that problem which it did and the tranny shifts into 5th and reverse perfect now. also we changed the ATS 3rd and 4th gears out for a b16 3rd and 4th. all went back together fine put it in the car and went for a drive and now im getting a whining noise from third gear but only at low rpms under low strain or wen down shifting. the more u accelerate the more the noise goes away and also all the other gears are perfect and dont make a noise. i used a liter penzoil symcromesh and a liter of 5w30 oil to top it up with. i no ill have to take the tranny out to fix it but im just wondering what to look for before hand. iv googled it but havent found anything of use. any help would be appreciated, thanks in advance

 

When you replaced the 3rd and 4th gears, did you change them as a b16 match set with both the countershaft and mainshaft gears from the same transmission? You may have a mis matched set of gears or some wear on the tooth face causing the whine.

 

ya the gears are a matching set i took out of a tranny. i replaced the third and fourth gear sets and the fourth gear doesnt make a noise jus the third. i was also told by another person that the gear could be warn and to try some lucas in it. the only thing that makes me wonder is that last year i put an LS fifth in it and was tachin 3000 at 100 km. now this year im tachin 4000 at 100 km and 4500 at 110kmh and i used the LS fifth over again. wonder if i got a third and fifth gear mismatched. but wen u shift the pattern is perfect, drops to 7000 everytime and third doesnt seem to be any longer or shorter then the others. its got an ATS 4.9 final drive so the gears r quite close. im gonna hunt around today and see if i can find the tooth count for the gears to be sure