i have a ITR tranny on my engine.... and im having a problem with my 4th gear... when i shift 3rd to 4th at around 3k RPM it shifts fine but when its at high RPM about... 4K and up it will grind right before it goes into 4th gear.... grrrr! but it does not happen when i down shift.... and now about 20 mins ago it stopped doing that.... what is going on...? something broke inside... is that why there nomore grinding...? thanks for the help and you guys have a greay day.

 

its very likely the fluid.

flush the tranny and use just tad bit heavier fluid and see the result.

I had the same problem with my GTI, it grinds 2nd gear no matter what rpm, then I changed the fluid to GM's specifically for ZR1's, and it worked wonder, shift better and no grinds even at redline.

 

synchro might not be doing too good.

I also agree change the oil with some redline synthetic, thats good stuff, it should help.
Also ispect your oil for small brass shavings and other debris. Brass shavings = shitty synchros.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by anthonylee29 &raquo;</TD></TR><TR><TD CLASS="quote">i have a ITR tranny on my engine.... and im having a problem with my 4th gear... when i shift 3rd to 4th at around 3k RPM it shifts fine but when its at high RPM about... 4K and up it will grind right before it goes into 4th gear.... grrrr! but it does not happen when i down shift.... and now about 20 mins ago it stopped doing that.... what is going on...? something broke inside... is that why there nomore grinding...? thanks for the help and you guys have a greay day.</TD></TR></TABLE>

having the EXACT same problem....does it once and while and then it'll stop....i'm gonna change my fluid and start with that....being it's the cheapest.