_kirk_

iTrader: (1)

Hi guys, I need your help.

For the entire build with tons of pictures, you can look here:
http://silviav8forums.com/forum/viewtopic.php?t=1282


Vehicle:
1992 240sx


Engine/Trans:
2004 GTO LS1 with T56
Unknown mileage, engine was pulled in 2008
Stock engine and trans from what I know


Parts breakdown:
Filled with new ATF fluid
New one piece driveshaft
Stock clutch that came with the engine
Stock pressure plate
Stock flywheel
Stock pilot bearing
New slave cylinder GM Performance 15046288
New Wilwood 3/4" master cylinder 260-1304
New SS braided clutch line
New Tick bleeder line
New Pro 5.0 Shifter with stops removed
New F-body shift linkage 12523298 (had to use this to get away from the elongated shifter extension on the GTO's)

Here are some pictures of the clutch and stuff when I had the engine out:




















So I got the swap done, and got it running a couple of weeks ago.
The main problem I have with the car is the transmission will grind in all of the forward gears I've driven in so far (first through fourth).
The grinding occurs when you push in the pedal and try to put it in a gear.

-From a stop, push in the pedal, move the lever to first and it will grind. I can feel and hear the speed of the grinding slow down and eventually it will go in gear. If you wait long enough with the pedal down, you can put it in first without grinding.

-From a stop, push in the pedal and move it to second, it almost goes in instantly. Very little grinding.

-Moving down the road in first, pedal in, shift to second and it grinds until the speeds match and then it will go in. From second to third is the same thing, grinds until the trans speeds down (I'm guessing). From third to fourth is the same thing.

-I can skip shift from first to third and it doesn't grind hardly at all.

The system has been bled, and bled, and bled, and bled again using new DOT3/4 fluid.

The pedal has been adjusted 4 times. First it was practically on the floor. Second moved it up about 1/2" from the floor. Third it sat about halfway. Fourth time I adjusted it back down just a hair. All produce the same grinding.

Pedal pressure is good/great. Feels firm and pedal returns all the way on it's own.

I have driven down the road in 4th gear at a fairly slow speed, pedal in, rev the engine, dump the clutch and it pulls HARD. No odd noises from the clutch. Clutch seems to move the car fine with no problems.

Drive down the road at a higher RPM in 2nd gear, let off of the throttle and let it engine brake and then push in the clutch pedal and it seems like it releases fine.

With the engine off, I can move it through all of the gears no problem.

I had the car on jack stands and was able to drive through all of the 6 gears with very little grinding (probably because there was not much rolling speed on the trans between shifts).


I really just need to see what you guys think the problem is. I don't want to pull the engine/trans and replace everything and still have the same issue.
What are some simple things I can check / replace / look for?

Sorry for the long post, and I appreciate your input!
I will try and get a video of what it's doing and post it up this weekend.

therealcreeper

iTrader: (37)

I just skimmed so maybe you answered it, but from a stop in neutral how easily will it go into first and reverse? Also, have you tried putting it in 1st with the clutch pushed in and revving to 6k?

A LOT of grinding issues are caused because the clutch is not fully disengaging, and that's usually the first thing to try to rule out before you go tearing the trans apart. Since you bought it used maybe it's just bad. Try the revving to 6k thing and maybe try a different shifter before you pull it though.

SWEET98SS

iTrader: (8)

From reading on here a bazillion times, I believe it would be a clutch releasing problem, if it goes into gear great with the car off and not with it on, that would be your problem. I used to have the same problem until I got my tick master.

_kirk_

iTrader: (1)

Creeper, with the engine stopped it goes into all of the gears and reverse fine.
I will try putting it in gear, pushing in the clutch and revving it to see if the wheels turn.

Sweet, thanks! I'll check and see if it's releasing or not.

If it ends up being the clutch not fully releasing, what is the fix for that? Sweet, you mentioned a new Tick master cylinder (I assume the adjustable one), but I already have a new master that has an adjustable pedal...
Would I need a new clutch disc? New PP?

Thanks again for your help! I'm new to these T56's...

SWEET98SS

iTrader: (8)

I would trying adjusting it more. Maybe its not adjusted enough.

_kirk_

iTrader: (1)

I've adjusted the engagement point 4 times already.
First it was on the floor (this was the first time I had the car running).
Second it was about 1/2" off of the floor board.
Third it was maybe 3/4 of the way up the pedal travel.
Fourth I moved it down to about where I like it (about 1" from the floor board).
All of those made no difference to the grinding.

I've also bled the Wilwood master cylinder about 20 times with a Mighty-Vac.

Thanks!

therealcreeper

iTrader: (37)

Tick recommends not using the mightyvac with their master, maybe the Wilwood shouldn't be bled that way either. How much vacuum did you create? I think it can screw up the seals in the master

Secondly, you don't just guess with the adjustment haha. You should really start low, then with the engine running try to put it into 1st with the engine running. If it doesn't go in easily, bring it up slowly until it does. Then once it'll go into gear easily try the 6k rev to make sure it's fully disengaging. If it's not, then bring it up a tad more at a time until it does.

and when I asked if the trans went into gear easily I meant while it was running. If it's hard to get into 1st and reverse that's usually an early sign that the clutch isn't disengaging. Going through the gears fine with the engine off doesn't really tell you anything. I bought a trans that shifted super smooth through all gears, no input shaft play, everything looked great, but when I tore it open it needed a mainshaft, 1-2 synchro, 2nd gear, blocker rings, bearings (2 exloded), fork pads, slider keys, etc.

_kirk_

iTrader: (1)

Cool, cool.
I was careful with the vacuum. Didn't go over 10 (inches of mercury?). I wasn't using the PSI side of the gauge anyway. Most of the time I would just take it to around 5.

What's happening is with the engine running and clutch pedal down, once the trans "matches speeds" (after it grinds some or slows down enough) it goes into all the gears fine. It's just that initial "slow down" and then you can put it in any gear easy as you please. It's like it takes it a while to disengage/release or something.

When I adjust the master cylinder, really all it is doing is changing the position of the pedal in relation to the MC rod. I've heard stories of people stroking the rod too far and blowing the seals in the slave. Is that a problem I should worry about? I don't want to adjust the pedal "up" too far and get too much stroke on the rod.

You've been a great help! Thanks again!

therealcreeper

iTrader: (37)

Well you can drive a manual car with no clutch pedal at all once you're moving, as long as you can match rpm's well enough, so it could still easily be the clutch just not disengaging properly. I would go out and do the test and go from there.

and the only time you need to worry about damaging the slave or pressure plate by overextending them is when you just eyeball the pedal and use too much travel. you want to do it how tick recommends and checking disengagement between each minor adjustment.

_kirk_

iTrader: (1)

Can you link to this or tell me what Tick recommends please?

OK
Over the weekend I got the rear of the car in the air. Started it up, emergency brake off, put it in 4th gear, left the clutch pedal down/in and revved the car. The rear wheels did move ever so slightly.
Put it in first with the clutch pedal in, revved it again real high and the wheels moved.

I put the car back on the ground, and put it in 6th and let the clutch out a couple of times thinking that it might have had something on the surface of it that needed to burn off. That didn't help.

With the car stationary in the garage, clutch in it will grind going into first and second. It won't grind going into reverse, but it does take it a while before it will slip into reverse. I can let the pedal sit for a while on the floor and it won't grind going into the gears.

So I guess it's a clutch release problem.
The only thing I have changed on the engine/trans is the brand new slave. I guess the slave does not push out far enough to completely disengage the pressure plate?
Do you think it I will need a shim, or could it be something else?

I have a friend with a spare master cylinder that is the same as mine. I might swap it and see if that helps.

Thanks again for any help or ideas.

_kirk_

iTrader: (1)

Well, I swapped a new 3/4" Wilwood master cylinder into it and it's still doing the same thing. Like the exact problem, so I don't think it's the master. I also don't think I can bleed it any better.

There's really not much else I can do except pull the trans and see what's up.

:/

I'll let you guys know what I find.

_kirk_

iTrader: (1)

Welp...

Still having problems...


Got a new Monster Stage 2 with lightweight flywheel








Drained the trans.
Here is a sample of the fluid that came out. Only had maybe one mile on the fluid? I expected it to be gross due to the trans grinding like it was, but not this bad...?


(the stuff on the bottom of the bottle is what has settled out of the fluid)






Got the transmission out




Got the old clutch out







Got the old pilot bearing out




New flywheel and pilot on





Clutch disc on





Pressure plate on




-------------------


So got the car back together.
Filled with just almost 4 quarts of DexIII ATF.
Wilwood 3/4" master cylinder topped off with new DOT3 fluid and bled the system.
Get good pedal pressure.

Start the car.
Clutch in to the floor. Trans won't go in any gear. Just grinds away.

I checked my clutch master and adjusted my pedal stroke so I got a full 1" of travel. It helped just a tiny bit.
Now with the engine running, I can clutch in and wait about 10 seconds for the grinding to slow down enough for it to go in gear.
When it goes into gear the clutch engages (turns the wheels) about halfway up the pedal and feels good.


So someone please tell me what to do, or what to check?
I have no clue what is wrong, but am suspecting the trans at this point.

New pilot bearing (input shaft on transmission looked super nice)
New clutch (that says it requires no shim)
New slave with new throwout bearing
New master cylinder

Could it be that every single synchro is bad in this transmission?
I just really want to go drive my hotrod... And this is pretty frustrating.

Any and all help will be greatly appreciated...

SWEET98SS

iTrader: (8)

Does it go into gear with the car off?

lynx853

iTrader: (8)

you have to manually bleed it. no mighty vac. its prob going to take at least 20 times of pumping and MANUALLY bleeding it for it to work right. get a buddy, a few beers, and start pumping away at that clutch pedal. helps to have the car level when doing it too.

_kirk_

iTrader: (1)

Sweet98, Yes, it goes through the gears fine with the engine off.

Lynx, with the new clutch I bleed it some with the mighty vac on the bleeder line. And then bled it manually about 20 pumps with the end of the line submerged. No change.


Maybe I need to spend a day and just bleed a whole jug of fluid through it... :/

Thanks for the replies!

SWEET98SS

iTrader: (8)

If it goes into gear with the engine off then and not when its running then the clutch is not fully releasing, thus the grinding. Can you adjust your master more? I a problem with mine that it would grind sometimes from the clutch not releasing all the way, new master solved my problem, I have the tick unit.

_kirk_

iTrader: (1)

Thanks.
I have adjusted the master quite a bit. I am a little concerned about over-stroking the slave, but at this point I'm willing to risk it.

I have the master set up right now where it's stroking right at 1" of travel. The Wilwood has a maximum stroke of about 1-3/8". So I guess I'll try pushing more fluid at it.

It's just odd because no other 240sx swapped LS1 that I have read about has had the problem of the master not stroking enough...

Thanks again!

SWEET98SS

iTrader: (8)

It just seems like its not releasing all the way. Is that the same master everyone else uses?

TA_BUD

iTrader: (4)

did you put a new slave cylinder in, most guys use one from vettes, or 2001,2002 f body

Wesmanw02

iTrader: (4)

Here's a definitive test to see what going on:

1. Hold the clutch to the floor, engine off, transmission in neutral.

2. Start the car.

3. With the clutch still held to the floor, engage 1st gear.

If it grinds, your clutch is dragging.

If it goes in easily, its the synchros in the transmission that are causing your problem.