6 spd clutch adjustment

[LEPage]

Does anyone know if there is any adjustment on the clutches on these trucks? I'm on my second NV5600, and not liking it much. It's a real bear to row thru the gears driving, just doesn't seem to disengage properly, and sitting still and trying to catch a gear to leave a stoplight is nearly impossible sometimes. Same with reverse. Only have about 12K on the new gear box. Have not changed oil in it yet. I am running a Luk Ceramataulic clutch.

 

[JEpling]

Does anyone know if there is any adjustment on the clutches on these trucks? I'm on my second NV5600, and not liking it much. It's a real bear to row thru the gears driving, just doesn't seem to disengage properly, and sitting still and trying to catch a gear to leave a stoplight is nearly impossible sometimes. Same with reverse. Only have about 12K on the new gear box. Have not changed oil in it yet. I am running a Luk Ceramataulic clutch.

I have this same problem with my truck, also on my second transmission 1st one locked up solid while driving down the road at 19000 miles on the speedo, second one shifted good for about 11000 miles and has started shifting the same way as yours,same way my 1st one did before it broke!! I was a bone stock truck on the 1st transmission when it broke. now i am running a sbdd #3600 clutch with lots of up grades and 42000 miles on the truck but have to fight to get it in a gear to pull out or back up! now i know i am not the only one.

 

[Cattletrkr]

Yeah, it's a bear every now and then. I've got over 220K total on two different trucks and never a NV5600 problem. Don't know what else to say other than now you know why they went to the G56. Driveability.

 

[betterthanstock]

Sounds like a sticky clutch, which is ruining your synchro's. Don't blame the transmission, blame the clutch not disengaging properly.

It could also be the pressure plate being overly depressed. Try putting it into gear while you don't press all the way on the clutch, then press deeper and see where you get the lightest effort. If it shifts better a little ways off the floor, your linkage is pushing too hard. If it feels like it gets worse, then it's not pushing all the way to release the plate. Aftermarket clutches are not always matched properly to the length of pedal travel.



It could be a warped disc also, or air in the hydraulic circuit, which they say cannot be bled off, needing new hydraulics.

 

[jelag]

The clutch is not adjustable,,,,,, """betterthanstock"" has some good advice..... let me add this little bit of advice and tip... .



Stop on a slight grade..... with the truck in gear and the clutch pedal down... . and let your foot off the brake..... like when your at a stop light and there is a slight grade... . if the truck starts to roll... . the clutch is releasing..... (mind you... if the grade is down hill your transmission is in reverse) and look at the transmission... . on the other hand... if your lift your foot on the clutch pedal... and the truck starts to move with the pedal just off the floor. . here are a couple of tips... .



1 - when you put the new clutch in you most likely ground the flywheel... this moves the clutch assembly towards the engine leaving a larger space between the release bearing and cover...



2 - usually the tip of the slave has a plastic button that can wear... . or gets lost...



both these conditions make the hyd. master and slave work outside the design limits and leaves the clutch pedal closer to the floor... . either lengthen the rod in the slave... or get an adjustable rod... . I take care of this on my trucks by making the rod longer..... I cut the thing and lengthen it..... and if its too long will grind the end to get the release of the clutch where I want it.....



Also understand that the plate load and wear of diaphram clutch is a bell curve... as the pressure plate wears... . and the disc wears... the fingers of the diaphram move towards the transmission and the pedal gets closer to the top... . or its rest position... so all this needs to be paid attention to.....



Jim / Pacific Clutch

 

[SpicyJam]

Sounds like a sticky clutch, which is ruining your synchro's. Don't blame the transmission, blame the clutch not disengaging properly.

It could also be the pressure plate being overly depressed. Try putting it into gear while you don't press all the way on the clutch, then press deeper and see where you get the lightest effort.

Mine from the first day I bought did not want to go into forward or reverse gears, and take off was eratic. Since then I know that while trying to go into reverse, I have to take my foot off of the clutch pedal slighty, and then it will go right in. As far as taking off from a light, I just ease off the clutch, get rolling and then add fuel from the go pedal. The 6 speed acted the same with the stock clutch as it does with the Southbend.

 

[South Bend Clutch]

1 - when you put the new clutch in you most likely ground the flywheel... this moves the clutch assembly towards the engine leaving a larger space between the release bearing and cover...



both these conditions make the hyd. master and slave work outside the design limits and leaves the clutch pedal closer to the floor... . either lengthen the rod in the slave... or get an adjustable rod... . I take care of this on my trucks by making the rod longer..... I cut the thing and lengthen it..... and if its too long will grind the end to get the release of the clutch where I want it.....



Jim / Pacific Clutch

1. Yes, when grinding a flywheel you are moving the clutch surface of the flywheel towards the engine. But, if the flywheel is properly done, usually, no more then . 010" is removed. Properly working hydraulics moves the throwout brg. 7/8". So grinding the flywheel really should not have an effect. Our max tolerance of metal removed is . 040". A brand new flywheel is 1. 500" thick so all you have to do is measure the over all thickness of the flywheel once surfaced and if it is thinner then 1. 460" then get a new flywheel.



2. Folks, listen to the words of the two components in a hydraulic assembly... (Master cylinder), (Slave cylinder). The master cylinder tells the slave cylinder what to do, the slave cylinder does what it is told. By lengthening the slave rod only relocates the rod itself in the cylinder. The master still tells it to move 7/8" (No additional throw). Now, if you lengthen the master cylinder rod that connects to the clutch pedal, you will achieve the desired end result. By doing this you will be forcing more fluid through the hydraulic system and telling the slave to travel farther.



We offer the heavier duty 94-97 hydraulic assembly with the master cylinder rod cut and threaded so they are adjustable with different length couplers to match the desired years of the trucks.



Hope this helps.



Peter

 

[betterthanstock]

Since then I know that while trying to go into reverse, I have to take my foot off of the clutch pedal slighty, and then it will go right in.

I think you'll get way more life out of the synchro's if you add some slack to the pedal, or put a stop behind it so it won't go in all the way to the floor.

 

[SpicyJam]

I think you'll get way more life out of the synchro's if you add some slack to the pedal, or put a stop behind it so it won't go in all the way to the floor.

Being that I am a dealer for Peter at Southbend, I have the Double disc still sitting beside my desk at home. When I put it in and change the master and slave with his, I will take care of the throw then. I have been living with the hard to go into reverse since new, so a few more months won't bother me. Thanks though for the thought.

Funny that was old trick I use to use on my drag car, putting a block under the pedal so I didn't overthrow the pedal when power shifting... ... ... ... ... ... . but diesels are so much more fun... ... ... ... . lol.