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Timken Clutch Release bearing, NV5600

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Throttle Position Sensor Quandary or FUBAR?

I don’t know. I tried to offer diagnostics a while back that focused on external issues.

Diagnostics beats any swags.
 
I know you’ve suffered a lot on this project.

If I was trying a diagnosis that focused on leaving the clutch alone I’d test the hydros. A very common under diagnosed source of shifting problems.

Remove the SC and it’s pushrod. Attach a simple steering wheel puller across the face of the SC. Block the piston from moving.
Two fingers jab at the clutch pedal. Not a hard push a crisp jab and hold.

The observation is how far does the MC pushrod move from pedal up position to jab and I feel pressure. MEASURE the distance accurately.
 
There's an Oriley's down the street, I'll stop by after checking out and see if they have anything that would work for this test. The tool that a friend fabbed up; that I used to test and bleed the same master/slave cylinder assembly is 1100mi away.

I asked for South Bend to send a new hydro unit with the single disk. I'll call STG tomorrow and see if they have the same hydro unit in stock new and if I can use it on a test drive.

If I'm able to get a new hydro from STG and it doesn't work I'll swap the shifter for laughs, I brought the OEM one for testing just incase. I'm waiting on parts till the end of the week anyways.


I know you’ve suffered a lot on this project.
I'm going on my 5th removal and replacement of the trans for a clutch. I just don't understand why I'm running into these issues back after back and at every step of the way. I don't beat the piss out of it, I keep meticulous logs, source only the best parts and supplies, I've done extensive research, I've put it in the hands of the experts 1100 miles away from home but I don't have any better results to show for it. Maybe I'm just living in a bad joke, like the Twilight Zone and Ground Hog day rolled up into one.

Regardless; Thanks for the suggestion, I'll try it to the best of my ability.
 
As I’ve recommended before, I’d listen to Gary. I don’t think the new clutch is going to fix your problem.
 
DBM,

Testing the hydro's is about the only external system you can work with. Might as well pull the clutch pedal while investigating this and look at the I bet plastic pivot pin that anchors the pedal. Insert screwdriver between the head of the pin and pedal, twist and pin pops out. Look for wear that reduces the stroke due to slop. Same for push rod pin.

Gary
 
DBM,

Testing the hydro's is about the only external system you can work with. Might as well pull the clutch pedal while investigating this and look at the I bet plastic pivot pin that anchors the pedal. Insert screwdriver between the head of the pin and pedal, twist and pin pops out. Look for wear that reduces the stroke due to slop. Same for push rod pin.

Gary

I'll give both a look over today when I get the chance and ask if STG has any spares.
 
You're referring to point 3 and the hinge point of the pedal itself correct?

upload_2021-11-9_8-11-13.png
 
FWIW, I put two clutches (single disk SBC with flywheels) in two trucks and the drove exactly the same after install.... My truck is, was and always will be tough to shift... (just like a truck trans) where as my buddies 05 with less miles on it shifts like a passenger car... smooth with little feedback.. As Gary said confirm your hydraulics are A OK, otherwise it just may be the way that trans is gonna be and you'll have to learn to play with her, Thats how my 04 was and once I figured out the rhythm, it was smooth sailing... She didn't like high RPM upshifts so I so I just shifted early unless I needed to like pulling grades.
 
I wasn't able to check the clutch pedal hinge bushings, but I was able to check the rod pin and test the throw of the clutch pedal.

The rod pin for the master cylinder eyelet looks and feels worn, its not even and its grooved. I don't have a new one to compare it with. Oriley's didn't have one, Didn't get a chance to ask STG with my running around today for supplies, but I'll get ahold of them tomorrow about it since im settled now.

I'll have to link too a google drive folder for the pictures, the zooming in ate up alot of storage space and its too big of a file to drop here. The pin is near the bottom. I know its missing a tab but the other three catch just fine.

Here is a video link of @GCroyle suggested test for the slave cylinder. Thoughts?

I'm going to swap a new hydro assembly first before I pull the trans again, if all goes well Dual disk stays in and I send the single disk back to SBC and eat the shipping costs unless STG wants to buy it for their inventory.
 
Sounds like not a clutch problem, so I would continue to diagnose the Hyd system, personally I liked the SBC singe disk and it had plenty of TQ capacity; I never drove a dual or ordered one because it seemed like overkill, but it all sounds like dragging or engagement issues,.. my problem when I had the symptoms you seem to have was a frozen pilot bearing that eventually wore out, but mine was 1 or 2 gears from a stop, getting it in gear I'd use 3rd or 4th and then put into 1 or 2.... just wearing out the other syncros..:confused:
 
DBM,

As soon as I saw the TyWraps being used to hold the puller, I shut it off. BOGUS SETUP!

I don't want to promote or whatever but pretty sure you have a 2nd gen hydro if I remember like I'm bleeding on my old 2nd gen in this video. Bolts to attach the puller firmly to the SC flange. The biggest takeaway is not does the system create pressure, it's quickly it STARTS to create pressure.

If you could see the transfer port that allows fluid into the front pressure chamber of the 2nd gen MC its small, maybe a MM or less. The piston starts behind that port, goes forward closing off that hole and BINGO that exactly when the system starts to create pressure. Your pushrod travel I bet if fully burped is 1/16" or so. Anything more deserves the R&R burping that I show in this video. The hydro's start at about 23 min mark.

IIRC that pin can be tested with a same dia bolt just as a trial. Don't remember the size but worth a look.

I'm hooking up the Airstream in a bit, no service where I'll be so good luck.

Gary

 
As soon as I saw the TyWraps being used to hold the puller, I shut it off. BOGUS SETUP!

It's the best I could do on the road

Anything more deserves the R&R burping that I show in this video. The hydro's start at about 23 min mark.

I'll start wit the hydro replacement then before I give the green light for the single disk. I'll ask about the pin.

Hopefully its the hydro, and I'm back on the road by Friday evening or Saturday Morning. Thanks for your help and suggestions.
 
One thing came to mind, I remember on my buddies old SBC setup that we recently replaced, there was a washer that had to be installed behind the clutch fork pivot point to bring the fork out closer to the flywheel on the far side.. but this was on a older SBC single disk setup.. not sure if the DD needs such an adjustment.
 
One thing came to mind, I remember on my buddies old SBC setup that we recently replaced, there was a washer that had to be installed behind the clutch fork pivot point to bring the fork out closer to the flywheel on the far side.. but this was on a older SBC single disk setup.. not sure if the DD needs such an adjustment.

That washer has to be removed for clearance and fork travel reasons on the Dual Disk. I removed it according to SBC's assembly instructions for the Dual Disk. Stock single disk it has to be there.
 
New clutch hydraulics were installed with a new Mopar master cylinder rod pin first thing this morning when STG opened up. Took it for a test drive around Fort Worth, got on the highway, hit traffic, tried to down shift into 4th from 5th and I'm still hitting a wall, not able to put it into gear. This is on top of the notchy shifting that comes with a dual disk. 3rd is even more notchy when I can down shift into it.

At my wits end I went back to STG to ask why a dual disk clutch isn't able down shift from a higher traveling speed given everything is 100% accounted for in the drive train, both the transmission and transfer case as well as the Clutch, Hydraulics, Shifter, fluid volume, fluid temperature, etc.

Juaquin and Cory both said "weight", the weight and centrifugal force of the clutch assembly as its rotating is unable to slow down fast enough for a downshift when slowing down from highway speeds.

They mentioned this isn't this first time they've removed a SBC dual disk to put a single disk back in because of shifting issues. They showed me a dual disk out of another NV5600 truck that was in the shop; this one wasn't fully organic, it was organic and ceramic. Customer had it in for a month before deciding to take it out.

I have a few questions for South Bend Clutch come Monday.

Where is the disclaimer about this product if this is by design how it shifts out the box?

It's not a secret that South Bend Dual Disk clutches of any material shift hard, I thought I could get past this to an extent with a short shifter. The short shifter helped, but its a band-aid.

Is there are lighter weight dual disk clutch assembly in R&D?
This is not a one off issue of shifting, many people have run into this problem and will continue to run into this problem with SBC's dual disk design. The issue is weight. The assembly is too heavy. Period.

I'm not privy to the trade licensing or patent holding of SBC's products but maybe their design for their dual disk is a result of that. Multi disc clutches aren't a new, but the SDD3250-6-ORG is a pretty primitive design. Here is a quick glance at an Eaton Class 8 offering. Vlair uses a similar drive strap on their quiet clutch line for dual disks. Going back to weight another dual disk offering comes to mind from Clutch Masters FX1200: 05CM2-TD12S-S. A different design also featuring drive straps, but without a floater plate, the unit is advertised as 10% lighter than an OEM single disk clutch assembly. I forget the shipping weight for the South Bend Dual disk; I have the packing slip in a receipt binder at home 1100 miles away. I have the packing slip for the 1947 OK HD though and it was 114lbs. Clutch Masters also has special request available for a billet aluminum flywheel instead of a billet steel one.

Lets recap my endeavor
  • My second clutch installation in my drive way with the dual disk was correct,100%, Text book installation, no error.
  • My Hydraulics were fine, 100%, swapped out for a new set today and I still have the same shifting issues.
  • My Transmission didn't need a rebuild, 100%, I'm still having the same shifting issues on the same clutch even after it was rebuilt.
  • My shifter isn't an issue, 100%, it was used on the OEM single disk without issue.
  • There's nothing wrong with the fluid im using or the amount, 100%
  • Its not my driving style, 100%, you have to down shift or double clutch back into a gear unless you're going to come to a complete stop and start from 1st or 2nd again every time you take it out of gear.
The dual disk is the problem by design. SDD3250-6-ORG is being removed and credited back. The 1947-OK-HD is being installed Monday morning at STG.

I've been in Fort Worth, TX going on two and a half weeks now and counting, for a 1400.00 dual disk that doesn't shift worth a damn.

1400.00s could've bought me a nice cowboy hat and some decent boots.

Admit what you don't know, and share what you do. I'm getting a drink.
 
Single disk installed yesterday. Test drove over 108+ miles this morning.

I'm not going to lie to you, its not 100% but it's a hell of alot better. The single disk overall is night and day in shifting and engagement, near effortless compared to the dual disk. I can consistently down shift into forth and third around town. This issue still remains in downshifting from 5th at highway speeds into traffic or for off ramps. Point of note my idle speed at operating temp in neutral is back down to 750, the dual disks weight bumped the idle up to around 8-850.

Speed is a variable, I managed to pull it into 4th on the highway as I was slowing down from around 50mph and my engine speed was over run by the wheel speed. I hit 3800rpms as I let out the clutch; no engine damage, no valve contact.

I drove back over to Standard Transmission and Gear with 2 dozen Doughnuts from Dunkin as a small thank you for their time and assistance in the past week and half. Took one last test drive with Juaquin around Fort Worth to verify all the engagement noises I was hearing were normal and let them know I'll be heading back east tomorrow morning sometime.

I don't have any more time or money to spend in Texas for this issue. The single disk is much more manageable and consistent. Street and city speeds are perfectly fine down shifting into 4th and 3rd. Highway off ramps or getting into 4th from 5th while slowing down is going to have to be a feature. STG doesn't have an answer, but we both agree that speed is a variable. For what its worth I'm much more happy with the 1947-OK-HD. Everything from top to bottom has been gone through and the issue persists.

For clarity's sake with the single disk. I have no issue on the street 50mph and lower down shifting into 4th or 3rd. My downshifts are well timed and smooth, you can almost slap it in. This changes as I'm slowing down from highway speeds, I could be in 5th gear decelerating from 50mph to 40mph and attempt a down shift to 4th and It will not go in. The dual disk gave me issues on the street downshifting into 4th and 3rd, consistently to a point where I had to focus my shifts. I can let my hands and feet do the thinking with the single disk now.

I'll write up a final conclusion after I get back home and finish the 500mi break in period of the clutch in stop and go traffic around town. I'll give South Bend a call after I get back home and see what they think. Unless the clutch, transmission, or transfer case grenades' its staying in. All my warranties still stand.

There is one variable unaccounted for that preludes my shifting issues with both the South Bend Clutch dual disk and single disk. My Spyntech locking hubs. I was thinking about this earlier as I found myself laying frame (like all the pretty Chevys I see down here) stuck in mud in a highway shoulder. I was on my test drive this morning and an important call came in from a relative out of the country. I pulled over quickly and thought to go onto the grass as the two lane highway was moving pretty fast. The grass was a trough of deep mud. Nothing I did was moving me as my right side wheels were churning batter. A class 8 truck driver pulled over and yanked me up and out God bless him. I wish I had the cash to give him for his time, but I'll just have to pay it forward to someone else when the circumstance allows me.

Too the point, the Dodge AAM 9.25 front axle is live and puts resistance on the transfer case and transmission as it rotates. That's all done away with when locking hubs are installed. My thought process is the weight and rotating resistance of the front axle rotating assemblies would not only bring my drive train speed(gear rotating assembly) down quicker but maybe in a more shift-able range. I'll try locking my hubs in on the highway after the clutch break in back home and see if it makes any difference. Thoughts?

Otherwise this thread will just be an unsolved riddle once its filed away in the archives.

Here are a few pictures of my truck with "Texas" mud for your viewing pleasure. Tire( Toyo Open Country AT 2s) pressure was 55/50 as per recommendation in a different thread. Enough mud packed my right front wheel to cause an imbalance.
Mud 1.jpg
Mud 2.jpg
Mud 3.jpg
Mud 4.jpg
Mud 5.jpg
Mud 6.jpg
 
The hubs not being locked will not have any effect on transmission speed slowdown. Nothing is transferred thru the transfer case in 2wd.

Also, 50 in 4th won’t produce 3800 rpms. Sounds like you meant 3rd. 50in 4th is ~2800 rpms. Which brings up another point, if you’re trying to grab 4th at 50 it’s going to be a difficult downshift unless you blip the throttle up.

Glad to hear the shifting is better and you’re hopefully onto the next chapter.
 
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