NV5600 Problem?

[mberry]

I'm having trouble with my transmission not wanting to go into 1st or 2nd gear when the truck is stopped. It also grinds a little and is notchy while moving at slow speed like when I'm slowing down. Feels a little like the clutch is not disengaging completely but I can't be sure. It's been so long since I've had a manual transmission I'm not sure what I am feeling.



I have under 17K miles on the truck. It just started last week on my trip back from MD. Temperature is not a factor. Does it warm or cold. I also changed the oil in it to Red Line MTL at 8K miles. No oil is leaking anywhere that I can see.



Does it just need an oil change or am I having a larger issue? I need your opinions please. Thanks.



Mark.

 

[Fuzzy Bear]

Hard Shifting

I've had problems with it shifting for quite some time. Had the clutch upgraded to a South Bed FE to support mods. After a few weeks, could not get it to go into 2nd. Talked to the shop that did the clutch, said try pumping your clutch pedal a bunch of times. If it gets better it indicates the hydraulic master/slave cylinder is the problem. Yeah, pumping a lot did help, so I called Peter at South Bend. He said they have seen a number of 2003 trucks that had bad master/slave cylinders. Rather than replacing with a possibly weak stock one I ordered the heavier duty (94-97 modified) they recommend for dual disk clutches. Put it in the other day and it definitely does disengage a lot sooner. I think the rod is a bit longer. Still having times when it won't go into 2nd. If I move the shifter back and forth in the neutral area, it goes easier, but still that's not right. I put Redline MTL in a couple months back, but when the clutch was replaced, there was fluid on the transmission. I bought some new, and will be changing it out this weekend. If this doesn't help, I guess its back to have the clutch checked.



Doug

 

[GRudy]

Something else to check. My '99 NV4500 with a South Bend Con-OFE did the same thing to me with about 40,000 on the clutch. What I found was the slave cylinder bolts had come loose which didn't allow full throw of the fork. There was only about an 1/8" gap between the slave cylinder and the bell housing but it was enough to cause the problem.

 

[mberry]

Thanks guys. I have a stock clutch. Is there an inspection plate or anything that I can get to the slave cylinder/TOB to see if it's loose or leaking?

 

[Fuzzy Bear]

Sealed System

There is no way to check it. On my 2003 there is a fluid resevoir on the firewall. I did add some DOT-3 brake fluid, but it didn't help. The replacement does not even let you open it.



Doug

 

[JCleary]

Mine has the same problem, but it comes and goes. Mine also won't go into reverse sometimes.



My fix is to shift into 3rd first, then the gear you want. Somehow the gears line up properly and it slips in. Kind of sucks when you're sitting at a green light, though.



Another thing I do is pull the shifter towards second 'til it stops, then forward into neutral, and it slips into second on the second pull (awkward wording, I know)

 

[jwilliams3]

You guys might try upgrading to a 12 Valve master and slave unit.

Worked for me.

 

[Vaughn MacKenzie]

Guys, one thing I noticed on my '01 and my '03 trucks is when they seemed to get a little sluggish and difficult to get into gear, I would put it in neutral and pump the clutch pedal hard to the floor about 6-8 times. Shifting greatly improved after that. I'd do it every 2-3 weeks, kept things shifting good.



Vaughn

 

[Gary - K7GLD]

Check THIS out for obvious similarities:



https://www.turbodieselregister.com/forums/showthread.php?t=127088

 

[Tim]

Why don't you guys just take off in 2nd gear? Wouldn't that solve the problem, or does this occur when stopped as well? I suppose if the clutch isn't releasing it doesn't matter if you're stopped or not.

 

[mberry]

I do start off in 2nd when I'm empty. Last week I was towing a decent load so I used 1st most of the time to start out. Thanks for the post Gary. I think I'm going to switch back to the OEM lube and see what happens.

 

[jelag]

I might suggest that you remove the slave cylinder from the truck and slowly push the rod in..... as you do this check for bubbles in the master cylinder. . bubbles indicate some air in the system...



Brake fluid will draw moisture to it... . and that can lead to moisture that can boil off during times when the engine is hot and cause problems...

 

[Patriot_RAM]

I upgraded to a SBC DD 3600 6CB clutch. After a couple months, it was a little harder to get it in AND out of 1st and 2nd, but it is intermittant. Any suggestions? I have about 48k on the truck and about 17k on the clutch.

 

[jwilliams3]

12 valve master and slave unit.

 

[Gary - K7GLD]

I do start off in 2nd when I'm empty. Last week I was towing a decent load so I used 1st most of the time to start out. Thanks for the post Gary. I think I'm going to switch back to the OEM lube and see what happens.

If you do, and it helps you as it did me, I'd appreciate some feedback...

 

[Fuzzy Bear]

Have the 2nd Gen Master/Slave

I did order the modified 94-97 master/slave unit from South Bend and now have it installed. Most of the problem has gone away. I still have a couple issues and have contacted the installer and will work with them to resolve. What is happening now is that when I come to a stop and put it in neutral for a bit, then try to shift into second to take off, it will not go. I can pump the clutch once or twice and it frees things up. This I don't think is indicative of a hydraulic problem anymore. Second problem is with the new master/slave the clutch doesn't seem to engage until its almost all the way out. Its not a good angle with my leg and makes for a rough takeoff. I think the clutch should be engaging sooner. Maybe its the length of the shaft or something, but it will get changed.

 

[mberry]

I might suggest that you remove the slave cylinder from the truck and slowly push the rod in..... as you do this check for bubbles in the master cylinder. . bubbles indicate some air in the system...



Brake fluid will draw moisture to it... . and that can lead to moisture that can boil off during times when the engine is hot and cause problems...

I don't have the facilities for that kind of tear-down Jim, but thanks. It's very dry here so moisture absorption into the fluid is not an issue. I've only got 16K+ miles on it. I'm going to take it to the dealer and have it checked out if the fluid change doesn't help. I also can't upgrade anything at this point since I have no funds for that.



Thanks everyone for replying.