Hi all,

I'm having a slight(hopefully) issue with my NV4500 in the truck in my sig. Since I bought the truck at 248,000 it's always been a little tricky to get into first and reverse. If you put it in first before going to reverse its easy but first can be a little tricky. Anyway I just hit 254,000 and second gear is getting a little hard to get into when I stop at a light/stop sign. However it's only hard if I let the clutch out then put it back in. For example I stop at a light, take out of gear and let clutch out. Then put clutch in and try to put it in second and sometimes it's really hard till I play with it a bit. Usually I can get it but it seems like it's getting worse quickly. If I keep the clutch in from the time I take it out of gear until the time i take off from the light it will go in fine. All other gears shift fine aside from fifth feeling a little weird sometimes. I replaced the fluid right after I bought it with OEM fluid and overfilled about half a qt. I didn't check the fluid yet but I will as soon as I get a chance. It also got colder recently, was down below zero for a day or so but the truck still does it even with weather a little warmer around 20's-30's. What does this indicate? Am I hurting it by continuing to drive it? Also as soon as I shut the truck off it will go into any gear fine

 

Sounds like your clutch is dragging. First thing I'd do is replace the master cylinder, or the clutch hydros as a unit (to avoid bleed hassle).

When the clutch drags, the force has to be overcome by the synchro cones in that prevent gear grinding. Essentially little clutches that are engaged by spring loaded tabs as you shift gears. When the clutch drags, it is hard on them.

In theory there are all kinds of bearing issues that could cause similar problems, but usually they are accompanied by other symptoms. If it persists after a new master cylinder I'd guess a tweaked clutch disc. I have a different clutch, but I think the construction of the OE style is similar between the 12.25 adn 13". I wrinkled the OE style outer friction sheetmetal at about 350hp causing it to drag.

 

Thanks for the reply and the info! Do you know if there is any way to test if the hydros are the problem? I'd hate to replace them and have it be something else....I know the south bend unit is pretty pricey....

 

Do you have any idea what type of clutch is in it? Could be a worn pivot ball too.

Fwiw I have no idea how many miles are on my NV (well used when I got it plus 90k), but I have always found it a lot easier to shift to 4th before 1st, 2nd or reverse from a stop. How does it shift from 1st to 2nd? May just have worn syncros, they don't last forever. Try waiting an extra few seconds after pushing the clutch in, if its still "sticky" the clutch is most likely dragging a bit, which strains 1st/2nd and reverse syncros.

 

Unfortunately, I have no idea what clutch it is. I tried going from fourth a few times today and it worked well. 1st to second shifts ok but have to do it very slowly. Gota very deliberately pull it out of first and push it into second. No grinding or anything though.

Thanks for the reply!

 

Does it shift better once it is warmed up?

My 5600 doesn't like colder temps and thick fluid....

 

I think it seems too. kinda hard to tell because I don't normally drive it enough to get the trans really good and warmed up. My drive is only just enough to get the engine up to temp.

What about putting the truck in gear with the transfer case in neutral to get it warmed up?

 

At standstill shifting should be unrelated to fluid for the most part since the input end is *supposed* to disconnect the power with the pedal down, and the output end is already stopped. It will shift better warmed up with a dragging clutch, too- mine did when it warped the disc.

With the truck off, gently push on the clutch pedal to see if you can get it to "settle". If it does, this means the u-cup seal on the master is bad.

If $ is an issue, perhaps just do the master? I did mine separately and IRRC it was not a problem. $40 give or take. Luk's complete kit is about $85 on rockauto.

 

If my clutch was dragging, wouldn't I notice it trying to move while sitting still in gear with the clutch in? That's what would happen if the master or slave cylinder was leaking internally isn't it? The clutch would gradually engage even though I was pressing the pedal...

I would like to try the test you mentioned but I'm not sure what you mean by "settle". Can you describe it more?

Money is kind of an issue in that I don't want to spend anymore on the truck right now. But if I do have to replace the hydros I would like to get the SB kit...thanks for the info though I didn't know you could get a kit for that cheap.

 

Diagnosis is very much like a bad brake master cylinder. But gentle pressure is what is needed since firmer pressure will puff the u-cup seal up and make it seal up. If you can put gentle pressure and the pedal settles toward the floor, it's a leaking master seal. But it's IME a difficult issue to catch.

Once you are in gear, a minor clutch drag won't really be noticeable. The forces needed to cause grief with the synchros are not much. Very little bit of drag will make it hard to shift- forces well below what would be required to move the truck.

Not sure what to say on the $ thing except if it were me I'd just cross fancy hydraulics right off the list. OE style stuff works fine, and a dragging clutch takes life off the synchros.

Course it might be a dragging pilot bearing, sticky (on IP splines) or damaged clutch disc. Whether it's worth $40 to cross hydraulics off the list before yanking the trans is a question I can't answer for you, but It's a question I would consider seriously.

PS: IME when similar "issues" turned out to be a bad clutch MC, I've not seen the clutch grab harder and harder to the point of engaging itself. I have no idea why not, it seems like it should.

 

I really appreciate you sharing your experience and advice on this! Especially the last part about the clutch not continuing to engage when the MC is bad. Based on that, I have pretty much decided to do something with the hydros, but I'm not sure what yet. I have a few more questions that need answered lol. First off, why do only the master cylinder and not the slave as well? isn't it a lot easier to just do both? plus then you don't have to worry about bleeding it...and what if its the slave thats leaking pressure? Second, I'm thinking about going with a cheaper one like you suggested, but so far I haven't been able to find one of these(from a parts store) that has the electrical connector for the safety switch(that won't let the truck start with the clutch out)...whats up with that? The one thats in my truck right now doesn't have one either and the plug is just shorted out with a jumper wire. So it works, but if I'm "fixing" it, I'd like to do it right...why do only the southbend/valair ones come with the connector/sensor? is there a better place to get an OE replacement other than auto zone?

 

I guess a foolproof way to see if its dragging is to jack the rear wheels up, push clutch in and shift to 2nd and see if the wheels move. Might be normal to see them rotate slightly then stop, shouldn't keep moving. If they do I'd run to Dodge and get a new master/slave assembly. About the same price as south bend etc. but the quality is there, IMO. Good luck!

 

I just discovered a new piece of info! I found a vid on YouTube by Mopar1973man about changing out the master and slave. He mentioned that his pedal was feeling odd and that there was some wetness under the master cylinder pushrod on the inside of the firewall. Seeing that caused me to remember that I had seen the same wetness in the same place on my truck! I had never worried about it because the reservoir was never low. That made me remeber that I had felt my pedal change very slightly once or twice but I had attributed it to the truck being new and me not being used to it or the shop being hard on it when the had the truck and wearing down the clutch. Now everything makes sense! I do need new hydros! Now the question is whether or not to go with Napa parts or Valair...which do you think? I also figured out why I don't have the clutch safety switch...one of the PO s just didn't transfer it over when they switched out the master before, or it just went bad and they removed and bypassed it instead of replacing it. So I guess I should get one of them too and put everything back the way it belongs...

Let me know what you think!

 

UPDATE:
So I went out to the truck and looked things over some more. Clutch master cylinder is definitely wet inside and outside of the firewall. Brake master cylinder is also definitely wet inside the firewall but does not seem to be on the outside at all. I also tested the brake pedal with the engine off and it got pretty darn hard. It may have crept down some but nowhere close to the floor and it was very hard, did not seem to be going any lower. It was and always has been pretty slow to return though. I believe I have the Hydro boost brakes. Does all this sound normal? could the wetness by the brake master cylinder just have worked its way over from the clutch?

I decided to order a new master/slave cylinder assembly from napa. It is half the cost of the SB unit. Its not adjustable and doesn't come with the safety switch, but I decided it was a lot more practical, if it fixes the problem. If not, I'll return it and get the SB.

 

Thanks for all the info everyone. I got the new clutch hydraulics installed today. I went with a sealed, pre filled unit from Napa. It was about $150. The removal and install really went pretty well. The hardest parts were getting the old unit out and the new one in(so much stuff to work around and fish through). My slave cylinder mounting studs came out rather than the nuts coming off. So I had to clean them up(they were rusty) and put the studs back in. I used blue lock tight on the studs to help them stay in next time. I didn't really drive it yet, but I'm hoping it will fix my issues. The pedal is definitely different. It used to have a ton of free play when all the way out, now it's fairly secure. Time will tell I guess. Oh btw, for anyone planning to do this in the future, be sure to watch Mike's (Mopar1973Man's) video on youtube. It was very helpful!