Shifting Issue

[Ace17]

Just a little background...

I have a TBI truck with a new vortec 350 motor, and rebuilt nv3500 swapped in place of the original 700r4. All is going well for the most part, except I'm having a shifting issue. The clutch for whatever reason doesn't seem to want to disengage quick enough. Keep in mind these are all new parts(clutch, flywheel, pre-bled slave/master cylinder kit, etc).

When I'm driving(this usually happens with gears 1, 2, and 3) I'll press the clutch in, and there's always a delay before I can fully put it into gear, kind of like lockout, but if I wait long enough, I can eventually shift. So if I'm in first gear, I'll press the clutch, and then it seems like it doesn't want to come out of gear when I want it to. It will eventually come out of first, but then I have to delay a couple of seconds before it will go into second.

I actually removed the transmission at one point and had a mechanic look at the internals to see if it was rebuilt poorly, but he said it all looked good, new synchros and all.

I'm thinking it might be the slave/master cylinder system, but it doesn't leak, it's new, and it was already pre-bled from the factory. I'm at a loss considering everything is new. If you guys have any ideas they would be greatly appreciated.

[RobertISaar]

what kind of fluid are you running?

[Ace17]

I'm running Penzoil Synchromesh at the moment, apparently it's the factory equivalent to the fluid GM used to make. I've tried Royal Purple Synchromax as well, but it's even thinner than the Penzoil and the transmission didn't feel as good shifting.

[RobertISaar]

well, there goes my guess.... it's amazing how many wonky shifter issues I've fixed by dropping cheap 80-90 that a lot of people pin in their transmissions and getting the specified fluid into a transmission/transaxle.

does the tach respond like the clutch isn't releasing? and you mention 1-2-3, does it happen for the 3-4 or 4-5 shifts?

[Ace17]

For whatever reason, 3-4, and 4-5 seem to be okay...my guess is because the rpms are usually lower by the time I'm going into 4th gear.

When I press in the clutch, the rpms and tach immediately go down as they should, but there's a short period of time where the rpms are going down and it doesn't want to let go of the previous gear in a timely manner(keep in mind I'm a pretty steady driver). And after I pull it out of 1st gear, there's a slight delay before I can put it into 2nd gear. None of the gears grind or anything, but it's like I'm getting temporarily locked out until it decides it's ready to go in gear.

It's great because I have a good point of reference, considering I have an chevy s-10 5speed as well. It shifts smooth as butter.

[RobertISaar]

perhaps try holding 3rd longer before shifting into 4th, see if elevated RPM there also causes it to happen in higher gears?

I would think if the hydraulic system were acting up, all gears would be effected equally.

what happens if you double clutch?