2010 clutch help, will not disengage

[sag2]

Another tech contacted me pretty frustrated. Has a 2010 truck that came in with clutch burned up. They pull it out and it is aftermarket twin disc. The transmission case was also cracked so they changed the case. The customer says install stock dual mass back in the truck. They install it and the front bearing retainer contacts the clutch disc when they start it and turns the end of the tin retainer blue. I told them to cut 1/4 off the retainer since they said the throw out bearing has plenty to ride on. They did and now no contact or noise, but the clutch will not release enough to shift it.
The transmission case is the same dimension as the old one, all factory parts, and the poor guy had it apart 5 or six times already. I directed him to the pressure plate reset procedure in the service info, but that should only be for installing new disc's in a used pressure plate.
I'm not sure what he is missing, so I was looking at Starparts tonight. Using his VIN it lists a dual mass flywheel under the engine section. In the clutch section it shows what appears to be a pressure plate and clutch setup similar to an aftermarket flywheel, clutch and pressure plate. So now i'm really confused. Was there more than one clutch setup in 4th gen trucks? Anyone have a guess as to what this guy is missing?
I do not see many manual transmission trucks, and the ones I have use a flex plate and a DMF assembly that comes as one piece out of the box. I do not know if the master and slave was changed when the aftermarket clutch was installed, but he says it looks OEM.

 

[GCroyle]

sag2,

All G56 came with DMF and self adjusting cover. Resetting the SAC should be possible but after install the SAC spring "situation" can tell it the SAC has adjusted normally or over stroked and went into FUBARVILLE. Also, are they using the original hydro's which have a 16MM MC bore, or an aftermarket larger bore that strokes the SAC father than designed POSSIBLY allowing over stroke and a round trip ticket to FUBARVILLE. Tech got a bore scope? MIGHT be able to see SAC spring thru slv cyl hole, but view might be limited.

Edit, 16mm MC can be ID by the line being retained with a wire clip, not a 1/8" roll pin.

Gary

 

[kcpolk]

May have bent the disc when the T.O. Collar contacted the disc hub Sag. If the disc is bent, even slightly, it would require more of an air gap from the pressure plate to release. Also, many aftermarket clutch suppliers use different bore (slave and master cyl) hydraulics. This is okay for their particular clutch set-up. Probably best to get the stock hydraulics with the OE DMF clutch.... the hydraulics come as an all inclusive, pre-bled assembly from the Dodge dealer. Also, check the pilot bearing and input shaft. A worn or damaged pilot bearing can cause "non-release" symptoms. Just a few possible points. Keep us posted. This is how we all learn! Best wishes!

 

[sag2]

OK, thanks for the input. I asked him about the hydraulic's and he said it looked to be OEM, certainly not adjustable like the South Bend. He had it out so many times already he could have purchased a new master/slave himself!
And am I following correctly that if the cover is over stroked it will not work as designed any longer? Does it deform the fingers or bent something internally?

 

[GCroyle]

sag2,

Yes, I'd advise against over stroking the SAC in general. It's a unique system. Over stroking might lead to unwanted forward adjusting. And I think the teeth that it advances on are not setup for reset and reuse multiple times. Install, use, wear, SAC advances, repeat. Not really reset and reset and reset.

Hydraulics, can someone check if the line attaches with a clip or a roll pin to the MC?

What about that quill to disc interference issue? With all correct parts, that don't happen on its own?

As this one got restored to drive plate and DMF how about someone describing parts used from crank out to bearing. Any anomalies? Changes to system installation?

Gary

 

[sag2]

He said the owner purchased it used and the original owner is the one who changed to 13 clutch setup. According to him they ordered everything out of StarParts from the flex plate to the transmission case. The adapter plate was not changed as far as he knows.

 

[GCroyle]

Back to external basics.

Hyd system, pedal feels crisp by finger tip touch right off the the top, or NOTICEABLE sponge zone at initial pedal push. Pedal feel?

Any chance to try to eyeball the SAC spring through the slv cyl access hole? Tough but can ID if SAC is way over adjusted possibly.

 

[sag2]

OK, the trans was out when I stopped by. It looked to be assembled correctly from what I could see. The only thing I'm not sure of is the flex plate, not even sure if it will install backwards. The slave cylinder line is held with a roll pin. The fingers are not exactly all the same height, maybe 1/16 difference. The photos show the part numbers they installed. After looking at it I suggested they pull the clutch off and verify the flex plate, and if that is OK to try a new master/slave. Bearing and fork is also new and judging from the witness marks on the splines where the clutch plate is riding it should have plenty of throw. The old and new transmission case measure the same length.

 

[GCroyle]

Sag2,

I doubt you can put the drive plate on backwards. The 16mm MC, every one I've ever seen attached the line with a horseshoe type clip. Roll pin was the 18mm NV5600. Slave cylinders same diameter. Side by side the body is noticeably necked down too.

Look at your pic, see the faint witness mark that the arrow is pointing too? I bet that is a mark that will match the bearing OD. This mark is indicating for some reason that the system has over stroked. Draw a pic of the bearing in profile, add a G56 spring tip profile under it, release stroke, the bearing always rides on the crowned curve of the spring tips. Now, continue stroking further, the bearing OD will contact the spring tips like your pic.

Suggestion, look for witness marks on the underside of the spring tips and matching witness marks on the disc. If you see these matching witness marks, that's a smoking gun for a release problem. Rotating clutch tried to drive the disc but with steel to steel. But I don't remember if it will contact the disc or not. If the truck was still intact, if you DON'T push the pedal all the way to the floor, would it work? Maybe stop about 1 1/2-2" before floorboard contact.

Pic's a bit blurry, any contact on the splined hub area to quill, again, witness marks?

The position of the SAC spring looks reasonable, but no known dimensions as guidelines exist. If it was any further, I'd more concerned, but no guarantee on that observation.

Gary

 

[South Bend Clutch]

Another tech contacted me pretty frustrated. Has a 2010 truck that came in with clutch burned up. They pull it out and it is aftermarket twin disc. The transmission case was also cracked so they changed the case. The customer says install stock dual mass back in the truck. They install it and the front bearing retainer contacts the clutch disc when they start it and turns the end of the tin retainer blue. I told them to cut 1/4 off the retainer since they said the throw out bearing has plenty to ride on. They did and now no contact or noise, but the clutch will not release enough to shift it.
The transmission case is the same dimension as the old one, all factory parts, and the poor guy had it apart 5 or six times already. I directed him to the pressure plate reset procedure in the service info, but that should only be for installing new disc's in a used pressure plate.
I'm not sure what he is missing, so I was looking at Starparts tonight. Using his VIN it lists a dual mass flywheel under the engine section. In the clutch section it shows what appears to be a pressure plate and clutch setup similar to an aftermarket flywheel, clutch and pressure plate. So now i'm really confused. Was there more than one clutch setup in 4th gen trucks? Anyone have a guess as to what this guy is missing?
I do not see many manual transmission trucks, and the ones I have use a flex plate and a DMF assembly that comes as one piece out of the box. I do not know if the master and slave was changed when the aftermarket clutch was installed, but he says it looks OEM.

The after market dual disc probably used a crank spacer. Have the installer make sure there was nothing left on the crank which would move the OEM assembly to close to the transmission.

Peter

 

[sag2]

The after market dual disc probably used a crank spacer. Have the installer make sure there was nothing left on the crank which would move the OEM assembly to close to the transmission.

Peter

Thanks Peter, I was not able to ID the aftermarket clutch so I don't know what may have been changed with the install. I will have them double check and make sure there is no spacer.

 

[sag2]

Sag2,

I doubt you can put the drive plate on backwards. The 16mm MC, every one I've ever seen attached the line with a horseshoe type clip. Roll pin was the 18mm NV5600. Slave cylinders same diameter. Side by side the body is noticeably necked down too.

Look at your pic, see the faint witness mark that the arrow is pointing too? I bet that is a mark that will match the bearing OD. This mark is indicating for some reason that the system has over stroked. Draw a pic of the bearing in profile, add a G56 spring tip profile under it, release stroke, the bearing always rides on the crowned curve of the spring tips. Now, continue stroking further, the bearing OD will contact the spring tips like your pic.
OK, good point, I never noticed that but can have them place the TO bearing on the fingers and see if it is contacting where the marks are.

Suggestion, look for witness marks on the underside of the spring tips and matching witness marks on the disc. If you see these matching witness marks, that's a smoking gun for a release problem. Rotating clutch tried to drive the disc but with steel to steel. But I don't remember if it will contact the disc or not. If the truck was still intact, if you DON'T push the pedal all the way to the floor, would it work? Maybe stop about 1 1/2-2" before floorboard contact.
So if I understand you correctly, the clutch is actually fully released before the pedal hits the floor, but if you continue to press to the floor the fingers may actually contact and carry the disc with it feeling like it never released. Great observations to very subtle clues.

Pic's a bit blurry, any contact on the splined hub area to quill, again, witness marks?
No more contact with the bearing retainer to disc, but as Peter said below, it may have a spacer still on the crank and that would explain both points above.

The position of the SAC spring looks reasonable, but no known dimensions as guidelines exist. If it was any further, I'd more concerned, but no guarantee on that observation.

Gary

See notes embedded above. Thanks again for all your help.

 

[GCroyle]

Sag2,

The bearing will not make contact there if you just put a bearing on the fingers, must be stroked beyond normal range to make that witness mark. Just use a caliper to get bearing OD and compare to witness mark OD.

G56 stock system only needs about .4" or so for full release. 18mm NV5600 hydraulic system will stroke to about .55" so stroking beyond required (.4") MAY trigger SAC over stroke and the bearing OD to spring contact marks in your pic and disc to damper spring contact is a clear proof of over stroking. Not positive if this system will create the disc to spring witness marks or not.

The DMF to crank drive plate has a pilot stamping for centering, see pic. Not sure how creative someone would need to be to shim here, remember this does move the whole system closer to trans but it would be a WTF moment to see a shim or spacer between crank and drive plate.

"Fully released before pedal hits the floor"

Short answer is YES. All stock config "as issued" hydraulic release systems have pedal reserve travel. Reserve travel is upward pedal travel from the floorboard prior to initial clutch engagement. Actual amount varies from vehicle to vehicle. Think over 1 1/2-2" for a system like these. Any system in stock config that starts to creep as soon as you lift the pedal is a pretty clear sign that first, the system has an air bubble. Other possibles are investigated AFTER you can prove that the system is fully bled. A commonly over looked and not fully understood concept. Just blame the clutch, I know its fully bled, I used 3 qts of DOT 3. Right.

Gary

 

[sag2]

He called me today and confirmed the flex plate can only go on the way it is installed, and no shim between it and the crank as Peter suggested there could be. I advised to just order up a new master/slave and see what happens. Will keep you advised of the progress. I can't believe this customer has not just hauled it out of there.

 

[GCroyle]

Sag2,

G56 system hydro's right? Any confirmation about witness marks on the disc or bearing OD to D-spring?

 

[sag2]

The new master/slave was different from the one he pulled off, old had metal flex line, the OEM had plastic, but it still will not disengage. I'm totally confused now. He put it in the press before he bolted it back on and he said the fingers did not have to move that far before he could move the clutch plate, so that proves the clutch cover is still good. He bolts in in, bolts up the trans, installs the MC and it still will not release. So he pulls the slave out and sticks an extension in the bell housing, pry's it in and no release. Not being there I was getting frustrated on the phone as he explained what he did and it still didn't work. So thinking about the fork, i'm guessing pushing the slave cylinder rod 1" should move the TO bearing about 1/2". If in the press the clutch released by pressing the fingers down 1/2", then you should be able to duplicate that in the truck using the extension and pry bar, and moving it 1-1 1/2". I left him with add a 1/4" or so shim to the slave rod and see if that releases it. The frustrating part is he can't see whats going on inside the bell housing. I suppose more to follow. How could something so simple be this difficult?

 

[NIsaacs]

The fact that the front bearing retainer made contact with the clutch disc is an indicator of a depth issue. Is it possible the engine adapter was changed with the twin disk clutch? Is there a possible difference in the transmission case between years somewhere? Has a depth measurement ever been checked?

Nick

 

[GCroyle]

Sag2,

A fantastic question, how could something this simple be so difficult. Care to sit in our Tech Support calls today?

G56 SAC DMF based system should release in less than 1/2" bearing travel, more like .4" really.

Here is where this is still a bit weird, the continuing observations about the previous contact of quill to hub, more to the story?

What if the pressure plate was lifting off AND creating the proper air gap for the disc to spin down and shift easily, BUT (remember the unknown contact) something else is interfering and rubbing that we haven't been enlightened on? Pilot bearing rubbing on nose of input shaft?

CAUTION about adding more salt to the stew in regards to required release stroke vs. lets add some more release stroke it can't hurt right? No modifications required for correct stock system which is what you're reporting.

CAUTION CAUTION Do Not extend the slave cylinder push rod. Doesn't change anything. The volume of fluid moved by the Master Cylinder dictates the slave cylinder stroke.

This hydraulic system is the easiest to test of any I've worked with, but interpreting the results can get tricky.

To test independent of the clutch. Remove SLV CYL mechanically, remove dust boot and push rod, install steering wheel type puller on SLV CYL flange, finger tight on bolts. Use screw of puller to block piston. Push on clutch pedal with your FINGER TIPS ONLY. Observation: Pass = (on G56 stock hydro's) just over 1/8" and pedal goes hard, Remember, this is not a pressure test, it's an efficiency test of the circuit. Greater than 1/4" you better be thinking air bubble time. Air bubbles compress, wasting travel.

I feel like we almost at a Paul Harvey moment coming up here about "The rest of the Story" soon.

GAry

 

[EDankievitch]

Years back I did a clutch on a Chevy pick up and had it not release when we were done. It ended up being the Piolit bushing being too tight on the shaft. the fact that some thing had to be ground down to make it all fit bothers me. I'll bet the clutch is releasing and something else is jammed up or forcing the clutch disk into the pressure plate. Any one know why the twin disk clutch caused the bellhousing to crack? At this point you need to get everything back to stock. go with the vin number and make sure.

 

[TFucili]

Can the input shaft be wrong?