NV4500 Problem

[leathermaneod]

Hi all,

I'm having a slight(hopefully) issue with my 01 2500. 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

[Justin Spring]

Do you have a twin or single disc clutch?

I got the same issues. But I got a twin disc. Have had the same problem ever since the tranny was rebuilt/twin disc was put in.  I find going 4th then to reverse and 2nd then to 1st while stopped it slips right in. My third while driving can sometimes be weird to shift into though. 

I've just lived with it and was told it's just the nature of the twin disc. 

[leathermaneod]

I honestly don't know for sure but I believe it's only a single and stock from a parts store. The PO told me the owner before him replaced it and that's what he thought it was. Weird thing is that it seems to have got worse just lately and suddenly, which makes me wonder if it's partly due to cold weather. I was concerned that it was syncronizers but from what I've been reading it sounds like it would grind if they were bad. Maybe it's just a throughout bearing. I would like to replace the clutch with a south bend or valair anyway lol. I was mainly concerned about hurting it more in the mean time. No money or time to put a clutch in right now, plus I wanna do rear main and carrier bearing while it's all apart.  If they told you that it's just way it is with yours I guess it's not a urgent thing for mine haha

thanks for the reply and tips on getting it to shift!

[TFaoro]

Sounds to me like the pilot bearing is sticking. 

I wouldn't drive it too long the way it is either. You don't want it to tear up the input shaft.

Edited January 9, 2016 by TFaoro

[leathermaneod]

Thanks TFaoro, if going to fourth and then second works, is it still hurting the input shaft? Also, if that doesn't work is it still the pilot bearing? How long is too long? If it does hurt the input shaft what happens? Replace it? How hard/expensive is that? Don't really have money or time for this right now haha. One more thing, what exactly does the pilot bearing do? I mean I know the input shaft goes through it, but how does it cause this problem? Is there any chance this could be caused by cold weather?

thanks again!

One other thing, while dropping the trans what all should I do? So far I'm planning on clutch and hydraulics, pilot bearing, throw out bearing, rear main, drive shaft center support. Am I missing anything? Anything I should do to the trans itself?

Sorry for all the questions. I don't know much about transmissions. 

 

[eddielee]

Front seal on trans should be done with bearing.

[dripley]

When my truck,6 speed, was new it did the same thing. Not that it refused to go into gear but was much easier to get into gear by catching a high gear then putting it into 1st or reverse. That went away with time and miles. i just installed a new South Bend single disk clutch and it is back to doing it again. It does seem to be getting better not sure yet. Another issue I have is that I shortened my slave cylinder rod about 1/4" when my old throw bearing was failing. This might be stopping my clutch from disengaging 100%. This could cause the gear train to rotate making it difficult to get it into gear. The pilot bearing could be doing the same thing by spinning the input shaft while the clutch is depressed. 

Edited January 9, 2016 by dripley

[leathermaneod]

how does the pilot bearing spin the input shaft? is it normally supposed to stop it from spinning? 

[dripley]

If it is binding on the input shaft while the engine is running it will turn the input shaft while the clutch is disengaged. That will make it harder to put into gear, especially a low gear. It is easier to get it into a higher gear and that will stop the gear train from rotating allowing you to get a lower gear.

Another thing that can cause the issue is weak hydraulics. If it is the OE hydros the seals could be getting weak and leaking by a little. I lost my master cylinder several years back and had similar issues as you have. My leak was internal and no fluid loss was evident. Next time you try and put it into gear, pump the clutch an extra time or two and see if that helps. If it does that would point to the hydros going out. They are a lot easier on the wallet and you to change out. 

I installed a SB 1947 OFE clutch. I was told be the vendor and also read on SB's site that this clutch could make the gears a little harder to use so I expected this of my clutch. Still might change out the slave and see if the shortened rod is contributing to it.

[leathermaneod]

Thanks dripley! I will definitely give that a try. My next question was going to be if there is anyway to isolate the problem a little more but you already answered that :-) I do have another question though. As I pull up to a light/stop sign and put the clutch in and take trans out of gear, it is normally easy to get right into second gear if I keep the clutch in. For example, stop sign I pull up and down shift without letting the clutch out, easy to get into second. Stop light I pull up, shift to neutral, and let the clutch out while waiting. Put the clutch in and second is hard to get into. Does that indicate anything specific? 

[dripley]

When you pull up and stop with the clutch in and shift straight to second the gear the gear train is not rotating. In essence you are doing the same thing as putting it into a higher gear before the lower gear. When you let out the clutch the gear train is rotating. Next time you are sitting stopped let the clutch out quickly and you should hear the engine load up momentarily as spins the gears. It is very noticeable with my 6 speed. Then when you push the clutch in the gear train is still rotating. It should spin down to a stop but if something is try to spin the the input shaft it might not, hence the difficulty of getting it into a lower gear. Hope that makes sense, I have it in my mind better than I am trying to say it.

Edited January 9, 2016 by dripley

[leathermaneod]

Yes I know exactly what you mean about hearing the load on the engine when you let the clutch out quickly in neutral. I think you explained it all very well. So I guess if double or triple clutching at a stop before trying to shift into second doesn't help the problem that would point to the pilot bearing then? 

[CSM]

It points to an older truck that needs the trans pulled and checked out.  There are likely a few items that need fixing that aren't causing problems yet, but you might as well pull it and check it out.  

[leathermaneod]

Do you mean pull the trans apart too? Or just do the stuff that was already mentioned? And will it hurt anything if I drive it gently and shift to fourth before second? My problem is I don't have the time, money or a place to do this properly right now. I can pay someone if it's urgent but I really hate to do that...

Edited January 9, 2016 by leathermaneod

[dripley]

Maybe. I am not sure. My clutch is doing it out of the box and mine has a true bearing and not a bushing like some clutches have. It would be nice to know what clutch is in there. If it was mine I think I would just ride for a little while see if it gets worse and then maybe the culprit will show itself. I have never lost a pilot bearing to know its symptoms beyond it spinning the input shaft. If it is the hydros they will get worse and fail. That will leave you stuck somewhere. Mine failed and I had to drive it without the clutch back to the job and change it out there. Not much fun and it is hard on everything.

All that being said I am not talking about my truck. It is yours and you are going to have to make the call on what to do. I am just expressing my opinion.

[Royal Squire]

Your probably already doing this, but make sure you push clutch pedal all the way to the floor. 

[leathermaneod]

2 hours ago, dripley said:

Maybe. I am not sure. My clutch is doing it out of the box and mine has a true bearing and not a bushing like some clutches have. It would be nice to know what clutch is in there. If it was mine I think I would just ride for a little while see if it gets worse and then maybe the culprit will show itself. I have never lost a pilot bearing to know its symptoms beyond it spinning the input shaft. If it is the hydros they will get worse and fail. That will leave you stuck somewhere. Mine failed and I had to drive it without the clutch back to the job and change it out there. Not much fun and it is hard on everything.

All that being said I am not talking about my truck. It is yours and you are going to have to make the call on what to do. I am just expressing my opinion.

 

I really appreciate your opinion and everyone else's! I don't have enough knowledge or experience to make the call on my own. 

2 hours ago, Royal Squire said:

Your probably already doing this, but make sure you push clutch pedal all the way to the floor. 

Yes I normally do make a point of pushing the pedal all the way it, but I will try to think about it more just to be sure. I do have a nice pedal imprint in the carpet under the dash though lol

Heres another thing I tried that may indicate something to you guys. I sat in the parking lot at work and let the clutch in and out and each time I tried to put the trans in 2nd, all while not moving. It was pretty tricky every time. Sometimes a little harder, sometimes a little easier, once or twice it made a weird squeakish noise as it went in.  Idk if that means anything or not but I figured id mention it to you all.

Thanks again for all the help!

[dripley]

I have always had a lazy clutch foot. With the new clutch I am really having to think about pushing it all the way to the floor.

Check your hydraulic fluid and be sure it is not low.

[leathermaneod]

fluid level is good. Now i need to drive it and test out some of this stuff you guys told me about. 

[leathermaneod]

Alright so I just got back from a 30 mile test drive and getting fuel. I did some shifting without the clutch...I was told by someone on another forum to try it. He said that if it worked without grinding that the syncs are good. Anyway about the time i got back, another member told me thats its very hard on the syncs and will eventually damage them. Hopefully the damage is very "eventual". In the future I will take his advice and not do so. Over all it went fairly well. I can shift up and down from 2-5. It went well except for a few good shudders/bangs from the front end when shifting out of third, and a good clunk when going into 4th. The one time shifting out of 3rd was really bad and I was really scared I broke something for real. I think a bump in the road may have contributed and it seemed that I let off the throttle at the wrong time. Thankfully, nothing seems broke at this point though. Like I said I definitely won't be doing that anymore. It is kinda fun though especially when the gears "float" in so effortlessly. I can certainly see how it would be really hard on the syncros and the trans in general. I wish I had waited before trying, oh well can't change it now so hopefully nothing is broken or hurt too badly. 

It seems like the cold temps may just be the majority of the issue. Or possibly, aggravating a future issue that is only very slight at this point. It was 40*F when I went for the drive today and I drove 30 miles total. I did have a little trouble with second a few times throughout, but pushing the shifter back to neutral and then back to second fixed it. I think part of my problem is that I try to shift too quickly, more like a car. Double clutching didn't seem to make any difference as far as making it easier to get in gear, possibly made it slightly worse lol. Hitting 4th and then 2nd also worked very well when I did have issues. 

Another interesting thing to point out is that when I first started the truck, I had no problem shifting into second. I did however have a little trouble shifting all the way into first after I shut the truck off when I got home, I had to press the clutch in. I also forgot to mention that lately the truck has been shaking/shuddering a little while letting the clutch out. Not sure if thats significant or not. 

Thanks once again for the help everyone. Let me know what you think when you read this.