Engine/Transmission (1998.5 - 2002) Any Ideas?????

[Fogie]

Had bearing noise coming up thru the shift boot. Pulled and rebuilt the NV4500 complete using the fully splined mainshaft, new bearings, new synchros... all the goods. Installed an SBC clutch with new pilot and release bearings. Still have the bearing noise. This bearing noise only occurs between 1400 and 1800 RPM. It is not speed related. Makes no difference if the truck is rolling or sitting still. Just get the RPMs in from 1400 to 1800 and we have the bearing noise. Can have the transmission and tcase in neutral or in any of the gears. I'm stumped with this one. Any suggestions or ideas as to where to go from here.



Thanks



Terry

 

[Fogie]

Bringing it back to the top... . Hopefully someone will chine in and give me a few suggestions as to where to look.



Thanks,



Terry

 

[moparguy]

Terry, a couple of suggestions that may or may not help. 1, pull the shifter and overfill the transmission with a extra quart of oil. 2. Have someone hold the rpm in the noisy range and crawl underneath to see if it's something else making the noise, exhaust pipe, that type thing.



For what it's worth, my SB Con-O has made noise since day one in neutral. I've learned to live withit.



Good luck



RJR

 

[B.G. Smith]

With clutch depressed, transfer case and transmission in gear, nothing in either is turning so they are eliminated as you already know. As suggested above, have someone hold the rpm's in the noise range and lift the hood and use a stethescope to probe around the components to see if you can locate the noise, doubt it's the alternator but could be the AC compressor or the vac/power steering pump, fan or water pump bearing. bg

 

[SMorneau]

Its the torsional vibration from the engine. That is why NV4500s fail so often and why they are using dual mass flywheels on diesels. Do yourself a favor and don't drive below 1,800 RPM. If you don't believe me, try and find a standard transmission truck with a 4500 or 5600 that doesn't do it at low RPMs. This is normal.

 

[DMcLeod]

My NV5600 developed a similar noise @ about 89,000 miles. Oil analysis ok. Changed oil anyhow (30k miles on oil), no affect. It's definitely noise from/through trans. You can feel the vibration in the lever and you can change the sound by putting pressure on the lever. I guess I'll live w/it.



I wasn't aware of a high failure rate of NV4500s. ???