6speed moan/growl low rpms

[TWestcott]

2003 nvg 5600 moan/growl at low rpms. what is this noise? How can it be eliminated? 2002 down did not have this problem.

 

[KBennett]

I asked the same thing when I got my truck.



Here is the thread:

Growl

 

[DLeno]

2 possibilities. one, you have the dreaded clutch chattering spring problem. there's a TSB on that.



or, you have a normal NV 5600 transmission -- these guys have a burst rattle that occurs as the engine expresses power through the drive train. occurs due to mechanical resonances at certain crank resonances and power levels. there's just no way to eliminate this. I've spent quite a bit of time analyzing mine, talking to the dealer, talking with others on the net, talking to NV themselves on this. bottom line is that they rattle a bit due to gear lash and this is a normal part of this transmission and a consequence of the large gears. remember this transmission weighs 200 lbs MORE than the 48RE. its a beast, and it growls. the 02's did it too, but you just couldn't hear it over the engine noise.



thats my understanding to date. -Doug

 

[yogibear]

They are about 200lbs. heavier than the NV4500 also.

 

[RobbieH]

Originally posted by DLeno

the 02's did it too, but you just couldn't hear it over the engine noise.

That's exactly right, and that is probably all there is to it. You should hear one of these truck trans in an open vehicle like a Jeep. The NV4500 is a semi-popular swap and they are LOUD.

 

[Blakers]

Originally posted by RobbieH

You should hear one of these truck trans in an open vehicle like a Jeep. The NV4500 is a semi-popular swap and they are LOUD.

And I bet they are much quieter than another popular swap transmission, the New Process 435.

 

[bmoeller]

Originally posted by DLeno

you have a normal NV 5600 transmission -- these guys have a burst rattle that occurs as the engine expresses power through the drive train. occurs due to mechanical resonances at certain crank resonances and power levels. there's just no way to eliminate this. I've spent quite a bit of time analyzing mine, talking to the dealer, talking with others on the net, talking to NV themselves on this. bottom line is that they rattle a bit due to gear lash and this is a normal part of this transmission and a consequence of the large gears.

I read in the PSR that the ZF 6spd transmission has it also. For the same reason.

 

[RWILL]

Hi, I have an 03 HO w/6sp and it has a very pronounced gear rattle when starting off in 1st or 2d and also when driving at very low speeds in 1st, 2d or 3d. I had it in to a dealer and was told they all do it. I have driven several other of these 6sp's and have never heard this noise before. It rattles or chatters under load as you take off and then continues to rattle, chatter, growl until I shift into 3d gear. I also have a minor whine in 6th gear at approximately 65 or 70 mph or at about 2000 rpm. It doesn't whine in 5th at those speed or rpm's. The noise on take off is so bothersome that I will not keep the truck if I cannot get it fixed by the dealer.



Has anyone experienced or heard of this??

 

[Joseph Donnelly]

Rwill you probably have the old style clutch disk and the dealer will give you the updated one under warranty. However, you have to expect some noise from a diesel truck with a heavy duty truck trans--it ain't no Chrysler Imperial.

 

[DLeno]

To my knowledge there are two issues, each with considerable variability between trucks. the transmission gear lash thing is normal and I'm afraid that some trucks are worse than others on that. The clutch is another story, and there's a TSB out that describes the diagnosis procedure.

 

[RWILL]

Thanks for the reply. I talked to a Chrysler tech rep and he said some had a few thousand'ths too much play in the intermediate shaft which caused the rattle, but he did not indicate that they would fix it. My other question is this: if I do have the old style clutch disk would it make noise after the clutch is engaged or only while engaging as in taking off. This truck is noisy when taking off (launch noise as he called it) and just idling around in 1st or 2d gear. If I accellerate just a little the noise will go away above about 1700 rpm. Thanks, Ron.

 

[DLeno]

what you describe is called "burst rattle" by NV and to me sounds like transmission gear lash. I find that in my truck and can somewhat control the noise by playing with different launch behaviors. Sounds like you have something else to chase down (intermediate shaft) as well. The challenge you face is to get the dealer to understand and detect the differnece between gear lash singularly caused by the transmission, and any ancillary mechanical factors (like intermediate shafts, dampers, etc) that might make a known grear lash issue worse. In other words, I suspect that the variability amoung different trucks might not all be due to transmission differences (production variances).



I'm not experienced with the clutch problem. only read about that fact that it makes noise when you put the clutch pedal in (disengage). see category 6 (Clutch) Here

 

[RWILL]

thanks, my truck doesn't make any noise when I depress the clutch, so I am probably dealing with a transmission noise, as everything else seemed to be OK based on the dealer's diagnosis.

 

[ddutil]

Try to amsoil your transmission with series 3000 5W30. Mine is silent now, and i save 10% on fuel. It's a bit harder to shift at very low temp (-5 F and below) but a lot smoother otherwise.



I'm so happy I can now hear the turbo whistle Dan

 

[DLeno]

Dan, you mean you silenced your transmission (at least for the most part) by switching to Amsoil? thats pretty cool! does the Amsoil meet all the correct weight and other specs, so there's no warranty issue?

 

[Mr.Goat]

Have been reading all the responses on the groaning and moaning coming from the 6 speed.



Mine makes all these noises as well, always has. I personally think it's all normal drive line transmission noises. Mine has 30 thousand K's on it and the truck has worked flawlessly. Have never had it back to the dealer. Change my own oil etc.



My partner is always complaining the big " F"... ... truck is nice but noisy, not nice and guiet like her Subaru. Well I should hope not. After all it is a truck, and a heavy duty beast so it's bound to make truck like noises. My humble opinion for what it's worth.



Pete

 

[DLeno]

hmm. was hoping for some new info out of this thread. looking into this a bit further, I note that Amsoil series 3000 is not a fluid intended for manual transmissions with syncros. did someone say that Amsoil would take on the liability for using their series 3000 Diesel engine oil in the NV5600? DC certainly won't. From my reading to date, Mopar 4874464 is a 30 wt manual transmission fluid. There's a bunch of old threads discussing the issue. Does anyone know if anything has changed, or if an suitable fluid might exist other than the Mopar stuff? I'm aware of Penzoil synchromesh, but thats all.

 

[EMD-Run8]

Mine only has 400 miles on it and will be Amsoilized asap. I'll say this-----the NV5600 doesn't much different than a transmission in a class 8 tractor. NO FOO FOO HERE BUBBA!!

 

[DLeno]

me, I dont' ever stray from stock unless I understand the consequences, good or bad. For example, junking the stock filter box for a proguard-7 is wise. putting anti-slip friction modifier in the rear diff is not. so without fully understading why one would put a CI-4 Diesel engine oil in a manual transmission with a fair amount of yellow metal components, I'll wait for more information before *I* would do this.



In other words, I haven't yet seen enough evidence that straying from the Mopar or the equivalent Penzoil lubricant is a good idea. Those lubes are specific for manuals with syncros, and meet a very specific set of specifications that crankcase oil doesn't. So no, I won't put crankcase oil in my transmission just because someone says it quiets the gear lash. For all I know it will eat brass or other yellow metals not found in a crankcase. So let me ask you guys: on what basis, other than quieting the gear lash, are you changing to the Amsoil crankcase formulation?



I note the following, comparing Penzoil synchromesh to Amsoil 3000:



Penzoil is formulated for synchromesh manual transmissions for GM and chrysler. Amsoil 5w30 is a CI-4 engine crankcase oil.



Penzoil meets Chrysler spec #MS 9925 for manual transmissions. Amsoil 5w-30 does not indicate conformance to this spec



Penzoil viscosity index is 208 versus 176 for Amsoil. That means Penzoil maintains a more consistent viscocity over the temperature range of interest. In particular, the high temperature absolute viscosities are within about 20%, but the amsoil 5w30 is about 50% thicker at 40 degrees C. No wonder it shifts harder when cold



Penzoil indicates excelent compatibility with yellow metals (bronze, brass, copper). Amsoil does not.



I realize that there are manual transmissions out there using Engine oil. My Honda does in fact, though it does not expect a CI-4 diesel engine oil, and I do not know the yellow metal content of my Honda transmission.



I dunno, guys, the evidence doesn't look good to me...

 

[yogibear]

Well, the only evidence I have, is I used Amsoil Series 3000 5W30 oil in my 00 NV5600, for 200K, and have it in my 03 now for, lets see, 105K, -15K when installed, =90K, and no problems at all. Thats enough evidence for me. TJMOT,



Larry