6 spd transmission gear grinding when shifted

[Theodore K.]

I normally ask about my 57 vette. I also have a 1998 Camaro and I suspect the 6 spd manual transmission is the same or like the 1998 corvette transmission.
My problem is that when I first start up the car and begin driving, shifting form 1 thru 4 is okay. However, when I try going to 5th and then from 5th to 6th, I hear some gear grinding. I can double clutch it and it shifts okay. Also, after the car warms up good then I can go through all 6 speeds without problems. I have changed the transmission oil (Dextron II or III) but it still does it. the lower gears never grind. I am wondering if anyone else has this problem and if so how do you fix (or can you fix it?). I am suspecting that there is a slight synchro issue when cold. Is there any additive that can help this situation or has there been a service bulletin that covers this. The car has the 5.7 liter LS-1 engine.
Any help or comments appreciated.
Ted

[Edward J.]

Re: 6 spd transmission gear grinding when shifted

Ted, I rebuilt a 6 spd trans in a 2002 Z28, for a frenid of mine with same problem, The driver a young man drove it for quite a while this way with the first 4 speeds. When we finally took out and dissay the transmisson it needed much more than a syncro for 5 and 6th, When taken apart we found that one of the syncro retainers had broken and the keys feel out and did a little more damage to some gears and one of the shafts.

Any way my advice is to fix it before the problem get worst, this is a weak link in the Borg warner 6 spd. trans. The parts are expensive even in the after market. These transmisson don;t like speed shifting into 5th or 6th which will give you a problem if done to may times.

[Theodore K.]

Re: 6 spd transmission gear grinding when shifted

Ed,
Thanks for your comments. I don't know if you know the answers, but your friend might. Before he decided to have you fix it, did the 5 & 6 grinding occur at any temp or just before the transmission warmed up? Mine is okay after it warms up and doesn't do it the rest of the day. Also, did he have grinding in the other 4 gears after awhile? When I changed the fluid a short time ago, the ATF was a little dark but certainly not too bad and I did not have any metal chunks come out with the oil. I even probed the case with a magnet and did not retreive any pieces. Although Brass is not magnetic and would not be grabbed anyway. What ballpark was the rebuild parts? I have done the4 speed Muncie on my 57 Vette successfully so I could probably handle this. Was the transmission very heavy to handle getting out or on the bench? Anyway, I would appreciate your further response.
Ted

[Edward J.]

Re: 6 spd transmission gear grinding when shifted

Ted, I am not sure how the problem started, but when it started it was poping out of 5th gear then its was both 5th and 6th only ,It had no other gear issues. he spent about 1200 on trans. The clutch and pressure plate w/flywheel he found a kit on line also which was another 400-500. to do the transmisson. the transmissons are not that heavy, but you will need a couple of hands putting it back in the car, as the Camaro does not give you much clearance at the top of the bell housing. and having a trans. jack will make things easier. and a screw jack to jack the front of the engine up by the harmonic balancer, you'll need this for sure to help with the clearance at the top of bell housing. you can go on line and down the disassy. and re-assy. instructions they are on the web. which you will need also.

[Theodore K.]

Re: 6 spd transmission gear grinding when shifted

Ed,
Thanks again. Do you know the link to download the instructions on how to do (as you mentioned). Mine is not jumping out of gear, just grinding when cold. ButI think I must be prepared for this as I may have to re-build it.
Thanks and Merry Christmas.
Ted