C5 has many issues. December 27, 2007, 04:30:15 AM I had to replace the C5 in my 86. Suck's, but at least I already had an extra that has been in the garage for about 3yrs. The good news is the new one works,BUT not too well. When I start the car(in P) it jumps foward about 2". After it warms up, it doesn't do it. Also, If I don't come to a complete stop at a stop sign, it wont down shift to low until I step on the gas. Seems like it get's stuck in D, then a sluggish down shift when I accelerate. Last but not least, it will go to low gear if I stop at a red light,but when I take off it has a super sluggish 1-2 shift. The only thing I've done to this tranny is a fluid & filter change. Would a band adjustment maybe take care of this, or am I going tranny shopping? Quote Selected
C5 has many issues. Reply #1 – December 27, 2007, 08:30:54 AM what trans fluid did you use?did you check the level after the trans warmed up and in park? Quote Selected
C5 has many issues. Reply #2 – December 27, 2007, 09:01:05 AM The C5 still has a vacuum modulator on the side. Check your vacuum line for cracks and integrity; if it checks out, replace the modulator. It's around $20 or so, very inexpensive, then go from there. There's a good chance that's all that's wrong with how it's behaving now. Quote Selected
C5 has many issues. Reply #3 – December 27, 2007, 03:32:25 PM 10-4 what Eric said,make sure you hooked the vac back up. Quote Selected
C5 has many issues. Reply #4 – December 28, 2007, 08:10:20 AM Fluid level is O.K. I used DexIII/Mercon. I forgot to mention in my first post that I did replace the vacuum modulator. I checked the vac. hose yesterday & everything seems to be fine. I've been told that type F will make it shift harder, but it may shorten the life of the tranny. Is this true? I really don't want to change the tranny again unless I'm bolting it up to a V8 & that's not in my budget at the moment. Quote Selected