T56 Install - Moves with clutch in

[analyte]

I finished up my T56 install yesterday and was going to take her on a trial run today. I'm using a LS1 T56 with a Mcleod 8710-10 SFI bell, clutch, and PP along with ATS OEM modified hydraulics.

The problems (probably related):

- I can't get it in gear with the car started
- If I kill the engine the tranny slides in gear easily, but when started the car creeps in first or reverse with the clutch pushed in

I can hear the throwout bearing pushing the PP fingers with the engine off and pushing the clutch so I know their is movement. I was in contact with Tyler throughout the ordeal so I know everything went in correctly and smoothly. I was told no adjustment shims were needed for anything, just slide the tranny in through the clutch/pp and hook up the hydraulics.

This is my first clutch install, but not first manual. I'm not sure what could be wrong. I'm going to grind the welds off my clutch stop and remove it in case I have it stopping it just before 15/16 inch.

Any other ideas if it's not the clutch stop?

Thanks,
Kerry

[analyte]

okay, I pulled the clutch stop out of the equation and it still wants to creep in gear with the clutch all the way in. It also will not go into gear with the engine running.

It seems I may be pulling the T56 to fix this. Any ideas on whay I'm looking for? I spent 3 days putting it in slowing checking everything twice so I'm not sure what I will be looking for that could be the problem.

Kerry

[Van B]

I'll be watching this thread, because I am having the same problem plus a few more. I didn't feel like I was getting all of the air out of the system, so I ordered a new master from Tyler.

At one point, after I bled it, it would do exactly the same thing you describe.

[analyte]

There doesn't appear to be many lurking here tonight so I will call Tyler tomorrow and report back.

I put a post on LS1tech.com and it appears this is a common symptom of a clutch with air in it. I think Tyler bench bleeds everything before he sends it out, so I don't understand how air got in it.

Most likely, I will be going to get a Mityvac to bleed the system since I am by myself and don't have a second person around to work the clutch for me.

Kerry

[camcojb]

Does Tyler know which clutch you're using? Different clutches need different volumes from the master/slave/hydraulic TO to get the clutch disengaged. If there's not air in the system it sounds like the volume of the master is too small or there isn't enough plunger movement.

Jody

[analyte]

Jody,

I've talked to Tyler 2-4 times a week for the past few weeks. I am using the full recommended setup. The 12 in Mcleod clutch with Mcleod P/P using the Mcleod SFI bell. I got all of this info from ATS so that is why I went with this setup. I am new to the whole clutch thing, so I was looking for a recomendation.

I called again to verify that nothing needed to be checked with a dial, shimmed, etc. and was told it all slides in with no fuss, as it did. He never said it and I didn't ask, but I'm sure he's used this setup or he wouldn't have never recommended it.

Now if its not air in the lines, I am back to square one with no idea what's up. The T/O doesn't touch the fingers until right before it touches the floor, about 1/16-2/16 before clutch stops.

Kerry

[3kidsnotime]

Another thing to check is make sure there is no load pressure on the input shaft to the crankshaft, Did the trans slide into the bell housing and seat or did you have to pull it up with the bolts? DO NOT drive the car this way but back the bolts off a little bit on the trans put the car in gear and depress the clutch, try to start it and see if the car wants move, If you have a load problem from the trans to crankshaft DO NOT run the engine at all I have seen it most times take the thrust out of the thrust bearing and or crankshaft, I hope the problem is simple and not this but some thing to look at.

[youthpastor]

maybe i'm being too simplistic here, but if the parts are the ones reccomended and it creeps- it really sounds like an air in the system problem. we see this all the time, sometimes they are a pain to bleed- did you mention how much throw you have on the slave? how does the pedal feel with the car off- it's amazing how much a couple of air bubbles can change things-Chris

[analyte]

With the bell, aluminum spacer ring, and the tranny I was able to slide it in to about 3/8 in from seating itself. I asked on LS1tech.com and was told I could use longer bolts to gently pull it the rest of the way, as others had done, since the slave pressure has to be overcome. So I used 4 bolts to pull it in a couple of turns at a time until seated, but none of the bolts ever felt tough or in a bind.

If I need to back off the bolts to verify the input is not in a bind, how much should I back the bolts off? 1/4 in, a few turns, just broke loose?

The slave is stock LS1 OEM from ATS, so I think it uses the same movement as the master in a 1:1 ratio, which is 15/16 in. The only other car with a hydraulic clutch I am able to compare to was my 540i6 and the T56 clutch feels about the same, medium but not firm, and the T56 grabs at the end of the clutch travel instead of right off the top like the BMW did.

Kerry

[3kidsnotime]

If you have pressure on the input to crankshaft, it is easy to tell when you back the bolts off do them evenly and you will be able to tell it will actually push itself out do it till it relaxes, then try the cranking steps good luck, and dont be worried you will figure it out and be shifting soon.

[3kidsnotime]

Depending on what type of pressure plate will also have a bearing a three finger or a diaphragm use diffrent release bearing one long and one short.

[ron w]

I would check the adjustment on the clutch arm may not be long enough or try opening the bleeder valve and submerging it in fluid and pump pedal just had the same problem with my freinds 32 ford with same set up arm was not traveling far enough 1/2 inch off on the adjustment loose over 2inches of clutch travel

[analyte]

3kidsnotime,

I just came in from doing what you asked. I backed the bolts out so that there was no pressure. The tranny came back only enought for me to just slip my fingernail in between the trans case and the alum. ring.

I then dropped it done off jacks and in 1st with the clutch depressed I hit the starter and it surged forward and continued to when the engine hit. I killed the engine and tightend all bolts back up. Does this confirm the problem is not a input bind issue? Do you have any other ideas for me to look at? I appreciate the ideas.


I looked in the bell "window" and the slave/TOB is right against the fingers of the pressure plate as it sits with the clutch depressed. Is this correct, or should it be backed off to some degree?

"Edit"

I just got a link on a Mcleod clutch install in an LS1/T56. The install shows shims used to allow for the correct TOB travel to disengage the clutch. Neither my clutch nor my pressure plate came with any shims so I don't know if they were left out or must be bought separate. In any case, I may have to pull everthing out and change the shim thickness. :(

Here is the link to the install showing the shims:

http://www.installuniversity.com/install_university/installu_pages/donations/mcleod_clutch_install.htm

Kerry

[3kidsnotime]

You dont have a bind issue so next make sure you have all the air from the system if that is no cure you will need to shim it, Good Luck and keep us posted :thumbsup:

[analyte]

First off,

I called Mcleod and they wanted to sell me their master, but said I could also shim it when I asked. I then called Tyler after ATS opened and he stated the same thing since I wasn't getting enough travel to disengage the clutch. So....to recap....

After installing a rebuilt T56, new master, new slave, and new clutch my 66 Chevelle with an external 454 it would creep in gear with the clutch in and I couldn't get it in any gear while running. The hydraulics were bench bled by ATS and then I spent a couple hours tonight bleeding the system on the car with my mityvac. I'm confident no air is in the system as I got none even with all my effort. None of the bleeding helped my problem. I didn't expect any air and got none so ATS did a heck of a job getting it right the first time!

Therefore, I pulled the T56 tonight based on Tylers direction and measured the bell to P/P fingers distance and the bell to slave distance. These are the results:

bell to P/P fingers: 2 2/16 inches

bell to top of slave extended: 2 6/16 inches

When installed the slave is compressed 4/16 (if I understand correctly) and from the previous install, 4/16 is not enough travel to disengage the clutch. I will be calling Tyler back tomorrow to give him the data so we may determine the shim size required. Anyone want to guess what size shim I will need to get the correct travel? How much travel does the p/p fingers need?

Thanks for all the help so far. I will keep all updated for future reference!


Kerry

[ron w]

did you have this clutch set up in the car originaly if not did you readjust your clucth pedal to clutch master rod it is either 6-1or 7-1 ratio if that rod is to short by only an half inch you loose six to seven times that in pedal travel I realy think this is your problem like I said before I just had the same problem that fixed it Ron

[analyte]

I converted over from a TH400 to the T56 so I am new to all the hydraulics and clutches.

I adjusted the rod for all it was worth, which took out the clutch stop, and it didn't make a difference. The travel is still limited my the end of the master cylinder. So the entire 15/16 of travel within the master cylinder is being consumed, I am sure of that.


Kerry

[ron w]

your telling me that the clucth master only hase 15/16 of travel that doesn't make sence I'm going to check mine i'll get back to you Ron

[Teetoe_Jones]

Factory hydraulics only have a max pushrod travel of 15/16" before it bottoms out, and cracks the master.
We also do not bleed the hydraulics here, they come pre-bled from GM, all we do is mod the pushrod length, so I know there is zero air in the hydraulics.
I'm sure you just need a small shim to take up that last bit of travel to fully release the clutch.

Tyler

[analyte]

Tyler is right! I checked as mentioned in this thread before and there was no air in the hydraulics.

After talking to ATS today, I spoke with the metal fab guy at work and he is making me a shim to install behind the slave. I measured out the dimensions of the slave so it will fit nice and clean behind it. After he is done with it, I will send it through the PO4/ecoat system to protect it from rust and in it will go.

Tyler and Shane at ATS has been great throughout this whole ordeal. I couldn't have pulled it off without their products and support. I'm glad it's almost finished, but I couldn't even imagine doing this type of install without their help!


Kerry

[Bowtieracing]

Yeah! Teetoe has come a long way since first met him at camaros.net :cool:

I cant wait to see more parts from ATS :thumbsup:

[analyte]

I got it all back together and it is now running very well, tranny-clutch wise. I will list the details and pitfalls that I encountered along the way.

To recap, I'm using the LS1 T56 with a Mcleod 8710-10 SFI bell for a 2 piece block (454 in my case) along with modified OEM hydraulics from ATS. I coupled this with a 168 neutral balance Mcleod flywheel, 12 in clutch, and pressure plate. The setup was nice, but it has a couple of issues.

The 12in clutch/PP from Mcleod requires a total of 1/2in travel in order to fully disengage the clutch. The stock hydraulics, in my case, only traveled a total of 1/4in by itself. In order to increase the travel I had to fab a shim or buy one from a clutch vendor such as SPEC.

I ended up having my metal guy at work make me 2 shims, 1 - 1/8in and 1 - 1/4in. I then installed the 1/8in shim behind the slave using longer bolts, that wouldn't bottom out early but increased the thread count in the faceplate. I reinstalled the T56 and using 4 bolts to hold it I started the car and tried to put it in gear. It would go into first gear, but it required a significant amount of force to get it there. Getting it into reverse was almost twice as hard. At this point I knew the 1/8in shim wasn't enough giving only 3/8 total travel.

I then pulled the T56 again and installed the 1/4in shim in place of 1/8 shim. This would give me a total of 1/2in travel when the clutch is pushed. I reinstalled the T56 and bolted everything back together again. Once started the tranny would go into any gear easily, including reverse. The rear tires would not spin anymore with the clutch depressed and in gear. The clutch pedal also has about 1.25-1.50in of play before the clutch disengages so it is in a sweet spot for me at least.

If I would have known how much travel this clutch needs to disengage, I probably would have went with a 11in clutch that needs less travel. So far I have been happy with the clutch and the break-in period seems to be going well. This is my first clutch install so I'm unsure if I will feel anything different after 500 miles, but so far so good.

The T56 is a sweet setup and the guys at ATS and T56rebuilds.com were great and always helpful with my questions and tips. The only recommendation I would give is to call the clutch maker first and ask how much travel is needed from the slave before you install everything. Then you can just measure you distances from bell to pp and bell to slave to determine your travel as is and how much shim you will need the first time.

Thanks to all for the help everyone!!

Kerry

[4mm]

This is my first clutch install so I'm unsure if I will feel anything different after 500 miles, but so far so good.
Kerry, by the way you dug into it and found the solution, I would have never guessed it was your first time. Congratulations on getting it done and thanks for letting us know the outcome. :thumbsup: