300zxls1

iTrader: (12)

Just picked up up a 2005 RST RCSB 4.8 with a t56 swap. It has a stock ls1 clutch and slave cyl. and the stock 5spd master cyl. Looked through old posts and it seemed pretty beat to death probably needs a good vacuum bleed and possibly to shim the slave cyl. Right now with the clutch all the way to the floor the clutch still does not fully disengage the truck still pulls forward when starting in first and wants to stall out when stopping. So of course sense the clutch dosnt fully disengage the truck dosnt want to go into any gear.

I am putting together a vacuum bleeder setup to fit over the hex on the slave cyl. But I was just wondering if I was still going to need to shim the slave to get the clutch to disengage before the pedal gets to the floor. If I do need to shim it I am just wondering why I would need to. Sense it is a stock LS1 clutch and slave. Seems the adjustable mc's are to pricey or not even made for the trucks. But is this problem really related to the volume of the stock 5spd mc. I know with the LS1 RX7's everyone switches to a Willwood 7/8" bore diam. master cyl.

Thanks for the help.

1Bear

iTrader: (1)

Tick Performance makes a remote bleeder line that would probably come in real handy for you and while they also make adjustable clutch master cylinders for F-Body’s, Y-Body’s and GTO’s, I don’t believe they offer anything for the trucks. It may not hurt to contact them though.

Daryn

iTrader: (19)

how old is the ls1 clutch?... you probably need to keep bleeding. thats about it

300zxls1

iTrader: (12)

Ya I checked out that bleeder line, cool setup. I am hoping the vacuum bleeder solved the problem.

Im not sure just bought the truck yesterday, the previous owner said it has about 5k miles on it.

TurboGibbs

iTrader: (6)

I've been running a T56 swap for 3+ years. I have stock master cyl and stock T56 slave. You need no shim. You either have a bad part or you need to bleed it. Bleeding is a slow process that requires more patience than pumping. You get the fluid aerated from over pumping and you might as well quit. Hand vacuum pump bleeding is good and other methods.

300zxls1

iTrader: (12)

Ya I agree I bled it for about 30 minutes today and I will do it again tomorrow. I have a hand vacuum bleeder setup. I just need to adapt to the right size hose to fit over the hex bleeder on the slave cyl.

Glad I dont need to shim it, didnt make why it would be need to.

300zxls1

iTrader: (12)

Previous owner said he had just change the slave cyl so hpefully it just has air in it still.

PathfinderJr

iTrader: (6)

One guy somehow measured his stock 4.8 flywheel that came with a 5-spd and saw that it was offset something like 10mm away from the block. He claimed that if you swapped and used a "regular" LS1-type clutch set-up you'd need to shim the slave. I got a couple cheap shims when I swap so I can measure the before and aft just to be sure.

cheyenne383

iTrader: (25)

Make sure it's a T56 slave cylinder instead of the stock 5 speed unit.

300zxls1

iTrader: (12)

Is the end of the 4.8 crank different than the LS1 5.7 crank? I dont see why when using a LS1 clutch assembly and a LS1 T-56 you would need to shim it. The mating surface on the 4.8L iron block and ls1 aluminum block are the same. So unless the 4.8 crank is different I dont see any reason to need to shim it.

I bled the clutch again today a bunch more times and its better but still not close to right.