hard to shift into 4th??

[TWhetten]

I drove my truck around town all day just fine. On my way home I was slowing down for a stoplight and shifting from 5th to 4th was hard. It was also difficult to shift from 4th to 3rd, but all the other gears were fine. It also seems worse when downshifting, but when upshifting it doesn't just fall into 4th like normal. Any ideas what the probelm could be?

It is an '03 with the NV5600 and 110,000 miles.

 

[MMeier]

Possible synchro problem perhaps? My "spare" 5600 is on the garage floor with no 3rd or 4th.

 

[rbattelle]

When was the last time you changed the transmission fluid?

Ryan

 

[TWhetten]

The fluid has never been changed. Guess I should have done that huh? I was afraid it was a syncro problem. Probably to late to chage the fluid now.

 

[RHestand]

The fluid has never been changed. Guess I should have done that huh? I was afraid it was a syncro problem. Probably to late to chage the fluid now.

Drain it and see what comes out, then if not too much debris, put in fresh and try again.

Also is your clutch acting normal?

Good luck,Ray

 

[betterthanstock]

Even though it's synchronized, you should double clutching when downshifting, especially if the rpm will be high in the lower gear. Otherwise, the synchro has to accelerate the gear shaft and clutch disc to the higher rpm. It's a lot easier on the synchro when upshifting, since the gears will slow down on their own due to friction.

 

[RHestand]

Even though it's synchronized, you should double clutching when downshifting, especially if the rpm will be high in the lower gear. Otherwise, the synchro has to accelerate the gear shaft and clutch disc to the higher rpm. It's a lot easier on the synchro when upshifting, since the gears will slow down on their own due to friction.

Thanks for the double clutching idea.

When you DC to a lower gear, do you also rev the eng. between clutch strokes?

Thanks, Ray

 

[TWhetten]

Even though it's synchronized, you should double clutching when downshifting, especially if the rpm will be high in the lower gear. Otherwise, the synchro has to accelerate the gear shaft and clutch disc to the higher rpm. It's a lot easier on the synchro when upshifting, since the gears will slow down on their own due to friction.

Thanks for the tip, I have the same question as RHestand.



Now it gets wierd. Sunday morning I had to drive my wife to work because the roads were so icy, I didnt want to drive it but it is the only 4x4 I got. The first two times I shifted into 4th it was hard, then the third time I could barely get it to go in, then after that it loosened up and has been fine. It feels like nothing was wrong. I changed the fluid today and it didn't look or smell bad and there were no shavings in it. Maybe I have a self fixing NV5600:-laf (knock on wood) I hope I didnt just jinx myself. It was probably just warning me and will go out during Christmas.



Also the parts dept told me the trans took 4. 75 quarts of fluid, so I put in a full six quarts for the overfill TSB. But it still wasn't coming out the top hole of the PTO cover as alot of people on here say they fill it up to, did I put in enough?

 

[betterthanstock]

Thanks for the double clutching idea.

When you DC to a lower gear, do you also rev the eng. between clutch strokes?

Thanks, Ray

Of course you rev the engine. Let's say you're going downhill, in 5th, at 1600-1800 rpm. You want to downshift to 4th (for more engine braking).

So, you put it in neutral, take your foot OFF the clutch pedal, gun the engine to about 2800, just a quick blip, don't hold the RPM there (that spins the clutch and internal gears to 2800), then quickly step on the clutch and put it in 4th, and let go of the clutch. Should go in like butter after a little practice. In fact, with a load, down hill, it can get scary, and you may need to rev the engine to as much as 3500 when double clutching, while holding the brakes with the toe and mashing the gas pedal with your heel (heel and toe) or by holding the electric trailer brake button by hand. You need to know how much faster the engine will be revving in the lower gear, so you don't exceed 3500 when it shifts in the lower gear, or you may do valve damage at about 4000 rpm. That's why you anticipate downhills, and downshift before you get going dangerously fast.



Now, if you're going slowly in traffic, and your rpm drops to 1200 or 1100, then you don't need to double clutch. The speed difference in the next lower gear is low enough that the synchros will handle it just fine. Just don't wait too long in neutral when downshifting, or it will get harder for the synchros, as the shafts slow down, and the synchros need to speed up the shafts when downshifting. So you quickly take it out of gear, then hold a gentle steady pressure on the lever until it goes in gear, then let go of the clutch. But if you coasted out of gear, and it refuses to go in gear, you can either put it first in a higher gear to spin it up, then into a lower gear, or just rev it up in neutral (just a quick blip to around let's say 2000 rpm) with your foot off the clutch, then step on the clutch and put it in gear, after a long coasting in neutral.

 

[nickleinonen]

many times i skip the double clutch and float the trans out of gear into neutral, blip the throttle then clutch for the next gear. . same end effect with one less clutch movement

the only gear i have trouble with is 3rd and only when going up the gears. . with my 99% city driving, 3rd gets used all the time going up and down the gears [heck, i downshift to 1st to avoid using service brakes]. . i really hope i don't start having greater troubles with it. . i don't want to start redoing the synchros in my transmission [and new ones are not available, and many rebuilds seem to be crap too ]

 

[betterthanstock]

many times i skip the double clutch and float the trans out of gear into neutral, blip the throttle then clutch for the next gear. . same end effect with one less clutch movement

]

Key word here is "float". It means balance the throttle until you feel no effort at pulling it out of gear. At low revs, our engines have little braking, and it works just fine, you can take it out of gear before a stoplight without the clutch, at about 1200 rpm, before the engine shifts to "fast idle" and starts to put a load on the gears. You don't want a clunk when you pull it out of gear. I 've tried to shift gears completely without the clutch, and it requires your hand to act like a rubber band (if you want no grinding). Pull steady out of gear and into the next gear, as you let go of the throttle. If you imagine the force that a rubber band would apply to the lever, that's about right. If you get grinding, you pulled too hard, or slowed down too much in neutral. That should come in handy if you lose the clutch, but for everyday driving, it is still harder on the synchroes and slower than to use the clutch. (It takes the engine more time to wind down to the correct rpm to slide into the next higher gear, than it takes just the gears when you use the clutch)

 

[KWilkinson]

If any of you are still under warranty, there is an updated countershaft that supposedly fixes the 3rd/4th problems with the NV5600. I believe the only differences is the synchros, but you need a hefty press to break it all down so the dealers I used to work for just put complete countershafts in. Ive done 3 under warranty a year or two ago, and a bunch of out of pocket customer pay. Im not sure when they started putting in these countershafts from the factory, but the last one I did the truck was late 04, which was barely covered under warranty. Give a call to your local DC parts house and see if they have dealt with it before. I know the trucks I have put the shaft in seemed to fix it, but I am not sure on how well it holds up.

Good luck!

 

[rbattelle]

many times i skip the double clutch and float the trans out of gear into neutral, blip the throttle then clutch for the next gear. . same end effect with one less clutch movement

This is how I always do it. I never knew BTS's method of double-clutching was appropriate for downshifting, but it makes perfect sense.



The way I've been doing it (rev engine with clutch depressed while shifting down) probably does little or nothing for the transmission (since it's disconnected from the engine at that point), but obviously it's good for the clutch and engine to have engine speed close to drive speed before letting out the clutch.



I really like the way BTS describes doing the double clutch on the downshift. But sounds like it would take quite a bit of practice to get good at it. That's a whole lot of clutchin' and working the throttle, and the shift lever. Not sure my brain can handle it all without plowing into the guy in front of me!



Nick - if you're having trouble with 3rd gear I'd be sure to change the transmission fluid more frequently than you would otherwise. Might help the transmission survive.



The only gear that gives me trouble is 2nd during the 1-2 shift when the temperature is below 40°F. But I've found a work-around for it.



Ryan

 

[betterthanstock]

This is how I always do it. I never knew BTS's method of double-clutching was appropriate for downshifting, but it makes perfect sense.



The way I've been doing it (rev engine with clutch depressed while shifting down) probably does little or nothing for the transmission (since it's disconnected from the engine at that point),

Even letting the clutch pedal come up half way while you rev it up, then press all the way down again before putting it in the lower gear, would be enough to rev up the gears and the clutch disk to the proper rpm before downshifting. I think you can handle that!



I said take your foot OFF the pedal , to have everyone understand, as opposed to the ambiguous "clutch in" or "clutch out" that some people use.



I think all OEM handbooks ought to give heel-and-toe double clutching instructions.



here's a video



He does a perfect one at 43 seconds, and at 53, and 101... .



YouTube - Double Clutch Downshifts

 

[rbattelle]

Even letting the clutch pedal come up half way while you rev it up, then press all the way down again before putting it in the lower gear, would be enough to rev up the gears and the clutch disk to the proper rpm before downshifting. I think you can handle that!

Good idea.



Great. Now I feel "guilty", like I've done my transmission a disservice by not doing this for the last 75k miles.



Ryan

 

[SShafranko]

I do 80% highway driving. I also shift into every gear 80% of the time without the clutch. (only when transmission is warm). Slides in like butter. Used to be hard the first 15,000 miles but after that it has been great. I 'm probably saving clutch but wearing synchros. I'm just so addicted i can't stop now. Its so much easier. Just lazy i guess.

 

[nickleinonen]

if you're having trouble with 3rd gear I'd be sure to change the transmission fluid more frequently than you would otherwise. Might help the transmission survive.

i've changed the fluid 2 times so far, and i have less than 60,000 kilometers on it [less than 40k miles - also why i service based on time, not mileage]. . it isn't bad if i hammer through the gears at higher engine speeds, but if i am puttering around, it catches and feels very notchy. . 4th sometimes does it too, but very rarely compared to 3rd which will do it daily especially when cold. i am quite tempted to make up something to allow me to run a coolant loop through the transmission to warm up the oil [like a copper coil inside a fast cooler]

 

[rbattelle]

I tried the double clutch action while downshifting tonight. Going to take awhile to get the movements synchronized, but it did seem to improve the downshift feel at the stick.

Ryan