NV5600 Reverse synchro?

[Lumpy]

Every now and then, I'll shift into reverse, and she'll just grind away, and I really have to force it into gear. Other times, it slips right into gear. Doesn't matter if it's when I just started the truck, From a dead stop, or going to reverse straight from a forward gear. I've never been into one of these transmissions before, so just seeing what you guys think? I'm thinking the synchro is going out. I wouldn't imagine the NV5600's have a clutch brake, that's more heavy duty. Truck is in my sig, 63k miles. Any input is appreciated!



Kevin

 

[Prairie Dog]

No clutch brake but mine is sometimes hard to get into reverse too. I find putting it into 3rd and then R allows it to slide right in.

 

[RustyJC]

Every now and then, I'll shift into reverse, and she'll just grind away, and I really have to force it into gear.

No reason to force it. Just nudge it into a forward gear, THEN into reverse.



Rusty

 

[MARK JAQUITH]

Have a 2001. 5 HO 3500 4x4 bought new in 2001--has done the same thing you described--even when new--sometimes it would grind--95% of the time it would not grind. Now have 223500 miles on it and it still does the same thing--the one thing that reduced the grinding to almost no more -was I put on the adjustable clutch cylinder from South Bend Clutch LOL



Mark Jaquith

 

[04blackcherry]

Mine has always done that. Rock it in fwd then try again.

 

[GCroyle]

Lumpy,



I didn't see a mileage on your truck and any clutch replacement history, that would be helpful.



Pilot bearings at advanced wear, the needles might pile up causing (assuming seperator cage is destroyed) the input shaft to continue to rotate, next time might be more spread out, no problem shifting.



I am also a promoter of testing the release system to assure yourself that it is giving you a full stroke. And IMHO nothing tests it like blocking the S/C from extending and checking the M/C pushrod travel from static to dynamic with hand pressure on the pedal, 1/8" M/C pushrod travel = good, more = bad.



Lots of discussion on regular fluid changes for the NV5600.

 

[Lumpy]

GCroyle, my truck just rolled 63K miles. I just bought it a month ago, but according to all of the service records I received with it, it has never had a clutch changed. I just drove it from Missouri to Alaska a couple weeks ago, still figuring out it's little querks. I did an engine oil and fuel filter change as soon as I got home, but didn't have time to do anything else before I had to go back to the mine. I plan on doing a good, transmission/transfer case oil change, diff oils, and a good once over the brakes, wheel bearings and front end when I go home Monday. What kind of oil to these transmissions require? I'd prefer to run synthetic if possible.

 

[TboneMan]

Do the service records indicate whether or not the transmission fluid has been changed? Mine has more difficulty as the fluid becomes older. I usually drain and replace the fluid every 30-40K miles (223K on the truck). A I had a lot of trouble as the clutch slave and master cylinders became week.



I add extra (put an extra 1/2 to 2 quart in via the top PTO plate bolt hole). and that helps shifting too.

 

[Lumpy]

Well it might have just been me. I started going from 4th to reverse and it slips right in every time. TboneMan, service records indicate that the trans. oil has been changed 4 times since the truck was new. I'm going to do it when i get home just for kicks.

 

[JBallou]

There is no syncro for reversing. Assuming you push the working correctly clutching pedal in and then within 2 seconds try and cram it into reverse. It is normal, the gears are still spinning and with no syncro to match gear sped from the coasting momentum of gear mass they grind. Do the checks like perfection clutch suggested, if ok, modify your shifting behavior. Put in another gear to stop the gear spinning, then R.

Every truck or car I have had has done this to some extent. And putting the trans in first then reversing has solved then.

Assuming no pilot bearing problems.

 

[rscurtis]

A look at the 5600 parts list shows a reverse gear synchronizer. The 4500 also had a synchronized reverse unless it was used in a Chevy, the reverse synchro was eliminated.

 

[HBarlow]

My memory tells me the NV-5600 used in the '01 Ram dually I had did in fact use synchronizers in all six forward gears and reverse.

The problem the OP mentioned is common in all true truck transmissions. The gears are relatively wide and are often not lined up correctly when you attempt to shift into first or reverse.

The technique I learned long ago when you encounter resistance when trying to shift into first or reverse is to move the shifter back into neutral and briefly engage then disengage the clutch then try again. Engaging the clutch for a moment rotates the driving (driving vs. driven) gears in the transmission.

If that doesn't work, it occasionally does not, shift into second or some other gear first or even move the truck forward an inch or two and try to shift into reverse again.

The NV-5600 is a good and very tough transmission. Mine gave me 302,000 miles of service before the main bearing set got noisy. Standard Transmission in Ft. Worth rebuilt it and it still works great today at around 360k owned by my long time mechanic.

 

[Grizzly]

Well it might have just been me. I started going from 4th to reverse and it slips right in every time. TboneMan, service records indicate that the trans. oil has been changed 4 times since the truck was new. I'm going to do it when i get home just for kicks.

I believe the transmission fluid has been changed too often, which is about every 15K miles. No telling what fluid was used or how much.



I'd change it again with the OEM fluid and use the amount stated in the service manuel. Then I'd only change the fluid according to the maintenance schedule stated in the service manual.



george

 

[Lumpy]

I believe the transmission fluid has been changed too often, which is about every 15K miles. No telling what fluid was used or how much.



I'd change it again with the OEM fluid and use the amount stated in the service manuel. Then I'd only change the fluid according to the maintenance schedule stated in the service manual.

Thats my plan. I'm going to do that tomorrow along with checking the diffs and a good grease job.