I have done a bunch of reading on the type r servo for my c6. Every since I put my new higher hp 390 in my once crisp shifting c6 is now slow shifting from 2nd too 3rd. I have read the type r servo can cure that. I want real world reviews from you guys. I really wanna order one but want to wait for more input. Thanks in advance
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You don't have a racer, you have a pickup truck with a 390.
No need for the R servo.

Try adjusting the modulator. Chances are your higher hp 390 makes less intake vacuum and the transmission is seeing your engine at a different throttle position than it really is. That is why these parts are adjustable. If your modulator is not adjustable, get one that is.

Should take a little fiddling around with, but you'll get it.

 

Okay makes sense. I just put a new black stripe modulator on. I turned the screw on the old modulator in all the way counting turns and set the new to the same. But the soft shifts were present before I replaced the modulator.so now the big question turn it in or out to adjust? I have never played with those. By the way thank you for the response

 

A servo runs the band in a c6. The band in a c6 runs 2nd gear. If your second gear is grabbing on the 1-2 shift, the band is working. If the 2-3 shift is soft a clutch pack is probably to blame more so that a servo. You can simulate a better servo by running the band tighter, for a short duration only of course to troubleshoot, run the band at 3/4-1 turn instead of the 1 1/2 turns from seated. If problem gets better/worse, you can imagine band performance is initiated into the problem solving at that point, as either not releasing or not grabbing.
I would blame modulator, kickdown linkage, or governor. Might be just plain worn out, or just dirty. My 11.25:1 545 stroker WILL step through second on a 1-2 shift, but not 2-3 and not 3-2, but mine has a "n" or "O" or something, basically the worst servo. Keep in mind if the servo is swapped to an r code servo, the strut needs to match, or the servo pressure CAN damage the case. Don't just bolt in an R code, thinking "Well, my problem is probably fixed now" I have put some pretty stout 390 and 460 motors to these, and the 545 is all that ever slipped one. I bet the servo will handle it if the modulator, valve body, linkage, and all are right.

 

If you are not running it swap over to type F trans fluid this will firm it up.

 

Yeah, N servo isn't the best.

You would screw the modulator IN to get firmer/harder shifts.

If that doesn't work, (it should) if the servo is really old, it *may* be rock hard and thus acting sluggish. Simply replacing the servo piston would help fix the problem. Typically when this happen tho, you have 2nd gear apply issues. Also remember the servo releases mostly via spring pressure. I try to use the strongest spring I can find.... but I have the advantage of having a dozen c6's laying around.

Either way, I still think adjusting the modulator is your best bet.

Drew

 

Thanks guys I really appreciate the info. I'm going too adjust the modulator. Pull my Haynes manual out and see how to adjust the shift linkage just to make sure. And switch to type f. I'm running dex 3. If that doesn't work then pull it and rebuild with a shift kit. I'll repost this weekend with results.