Down shift from 4th to 3rd crunch (Page 1/1) pontiacfierokid1985 JUL 15, 11:11 PM Ok so I’m getting a weird crunch noise from the shifter everytime I down shift from 4th to 3rd around 55-60 mph when slowing down. I have a early 86 gt 2.8 4 speed Muncie what should I be looking into here? It never did this when I first got the car. I run 5w30 in the transmission should I thicken it up to 10w30 and see if it goes away or is the damage already done pmbrunelle JUL 15, 11:45 PM Probably a worn blocking ring in the transmission. Just need to replace it... Redline MTL has a reputation for fixing the kind of ailment you describe; it's worth a try. Have you been double-clutching your downshifts?