Sonny

My 5-speed seems to shift a hair notchy to thrid gear sometimes but not bad. One thing I have noticed recently is that on my dirt road (2 miles) I drive it in second gear but have a couple minutes in second the tranny start to "hum" and I notice some vibration in the gear shift along with the hum. Now this is also recently started happening in 3rd and 5th gear too on the highway. It did have the 5th gear nut fix. This hum and vibration only happens after a minute or so of continue running in that one gear not as soon as I shift. What could be happening? Do I need a rebuid? How much cost on a 4500 to rebuid? Thanks, Sonny

farmer dave

SOnny, you need to fill in your sig to let us know what year truck you have and so on. Someone should be able to help you.
dave

Sonny

I think I have the sig filled hopefully but originally my truck was an auto and the fellow I bought it from converted to a 1998?? NV 4500 5-speed a few years before I had bought it. I wonder if i should just drive it until ??? then rebuild. It definately does'nt sound right with that hum and vibration. It won't do it in 4th gear though.

Lil Mule

I am having exactly the same problems you are. NV4500 5 speed manual trans, mine has progressed to a rattle in 2nd and 3rd, and a hum in 5th.

When i first heard the noise I did a complete flud change in both the trans and transfer case. While it helped it did not cure the problem. Now 20,000 miles later it is definitely noticible.

From looking at the exploded view of the transmission, 1st and reverse sit on one side of the mainshaft, while 2nd and 3rd sit on the other, looks like 4th is a permanant part of the mainshaft.

It looks like 2nd and 3rd gear both spin on the mainshaft via a bearings. It is my belief that it is tese bearings that may be failing in mine. Unfortunately the exploded views I got were from my local dealer's parts dept and are mildly confusing.

At 165,000 miles I am almost due for a clutch and have parked the truck until I have the funds to open the trans and find the problem(3 weeks).

As I have not opened the trans yet, this is what I would call a SWAG (scientific wild a$$ guess) so please don't base much on it at the moment.

Sonny

Lil Mule, That probably explains it why it does'nt do it in 4th gear then. I'll try changing the fluid first also..... but I have a bad feeling about my tranny. Is there shops that can rebuild it so it actually STRONGER than original?? Like they do on the autos for example. Thanks, Sonny

Lil Mule

In all honesty the NV4500 is quite the stout unit. The only real problem I have ever heard of is 5th gear falling off.

I'm doing mine myself, one of the advantages to being an equipment mechanic. If I don't have the tools or equipment, the shop does.

yrusoslow2

I have a bad vibration in mine as well. I have not been able to figure it out. I am not sure if it the clutch going bad or the tranny. I hope to have both of them done soon. If you guys find anything out would you please post. Thanks

Lil Mule

I'm pulling both PTO plates off tomorrow hoping I can see inside. If so I should be able to pinpoint a bad bearing. If this is the case I will take pictures and share my findings.

Wish me luck

infidel

These guys are the CTD manual transmission specialists
http://www.standardtransmission.com/dodge.html

Sonny

Thanks for all info. I was thinking of changing out the fluid in the tranny and switching to synthetic to quiet it down maybe, until I can afford to have it looked at. What would be a good syn fluid for the NV 4500? Thanks, Sonny

infidel

I personally believe the synthetic Castrol Syntorq that DC and NV says is the only fluid you should use is the best. But that's just me.
The link I gave above is the best price you will find.

Lil Mule

I believe it came originally with synthetic in it, at least thats why my owners manual says.

I've pulled bith PTO plates off to see what's inside and everything looks good.

Fom the noise it was making, I was expecting to see a mess or at least a lot of metal in the bottom of the trans.

There are three shafts in the trans. The mainshaft, which carries all the removable gears and synchros. $th gear looks to be permanant on this shaft.

Then there is the countershaft, this is a 1 piece shaft with 4 gears covering 1,2,3, and 4.

Last is the reverse idler shaft.

The gears on the mainshaft are stationary and in constant mesh with the countershaft. Somehow when you shift through the gears the gear selected is locked into the mainshaft. From the picture and what I've seen so far, it is hard to tell how, but I beleve the sychro packs have something to do with this.

The link infidel gave is an excellent resource for parts prices and if you are a reasonably competent mechanic, this would be doable with enough time.

Sonny

I ordered the Castrol Syntorq from Napa yesterday. I'll bandaid the tranny with that for now. Its not that bad its jsut has the annoying hum sometimes. Thanks, Sonny

infidel

Make sure to check it out good, Napa has never been able to get Castrol Syntorq for me. What they may have ordered for you is Castrol Syntec which won't work. Syntec is motor oil.

Things may have changed but in the past Castrol had a deal worked out where only Chrysler and Ford could sell Syntorq in small containers. It could only be sold in bulk to other customers like Stardard Transmission who rebottle it for end consumer sales.

I've heard folks rave about getting Syntorq for $5/qt when in fact they bought Syntec.
Syntorq is a minimum of $14/qt, dealer charges $22

DeereDiesel

Mine used to hum in 4th gear but I could drive though it and itd go away, almost like a vibration i guess. Well about 2k miles later while I was pullin a load it started tickin real bad even at a stop in nuetral. It wouldnt tick when the clutch was pushed in. I pulled the NV out and found that the constant mesh on the countershaft to the input had broke off about half the teeth. From what I could tell it was caused by improper end play in the shaft, so I r&r every thing in the tranny except gears and main shaft. Put in the big input shaft and dual disk clutch while I was in there. I ordered my parts thourgh Blumenthal Mfg. NV had 150000 on it. Might be from sled pullin too. ?
carty