Engine/Transmission (1994 - 1998) 5th gear nut quick question.

[QWaller]

Looks like I may be digging into the clutch here in the next couple of weeks. When doing this, is there anything that can should be done with the nut. I don't know much about them in these trucks but I hear that they loosen and you loose 5th. I thought I read sometime back that you could do something to the threads on the existing parts to prevent the loosening?

Thanks

 

[snappy]

The best thing would be not to loose it in the first place. Don't lug it in 5th and if you tow in 5th, keep the rev's up. The only fix that works is a fully splined mainshaft. Dodge released an updated 5th gear nut, it did not help me out. still lost 5th.

If you want to check it out, remove the 5th gear housing from the rear of the transmission. Then you will see it plain as day. You could back the nut off some and apply red loctite or install the updated nut. I'd leave it alone, except for applying some green wicking loctite. The nut takes a special wrench.

 

[SRath]

I would HIGHLY recommend having the upgraded nut kit installed before it ever goes out while you have that transmission so accessible. It doesn't just back off, it rocks on the shaft and gouges and carves lots of metal shavings into your oil.

 

[QWaller]

What is involved with changing out the nut. Is a special tool required and where does one get that part?

 

[Grizzly]

Do all 5 speed 2nd gen Dodge trucks eventually have the 5th gear problem? I had a 95, 5 speed for 10 years with 120K miles on the clock, which I ordered new, and never had a problem with the transmission or the clutch. In fact, I never had a problem with any part of the truck.

 

[hsmith]

The fifth gear problem is a NV4500 issue. Some fail, lots don't. Towing heavy in fifth definitely is hard on it.

 

[PDeverney]

I put a clutch in a guys 1997 dodge 3500 4x4 about 6 years ago. He also had no 5th gear caused by the nut backing off. I locktited the nut back in place and it has been fine since. At the time I didn't know about the splined shaft fix, but it's been working good since.

 

[QWaller]

These special tools seem to be hard to find, around me anyway. And expensive for a single time use. Is there any other option with this tightening this round nut?

 

[SRath]

It only cost me $300 to have the local transmission shop do the whole job: labor, parts, and expensive oil. And mine is a 4x4, meaning t-case r&r to do it. If you could take your transmission, already out, to a good shop like that, it should be much less and probably wouldn't be worth investing in one-time-use special tools. Call around and check into it.

look at it this way: the odds of it going out are greater than the killer dowel pin, though usually less devastating. But when it does go, you will now either be repeating or paying for extra labor at the least. And having no 5th gear really limits the truck. It will NOT go out while sitting in your driveway, either. You will be going somewhere and maybe far away from your shop and tools. You may even end up paying "out-of-towner" prices for a rush job from an unknown transmission shop. It's not worth it for a couple of hundred bucks now, imo.

 

[Joseph Donnelly]

The best fix is the fully splined mainshaft kit and new nut. 800-std-tran has them. The gear hammers into the OEM mainshaft which isn't splined under the toothed portion of 5th gear, and then it rocks and will spit off any nut.

 

[CumminsPower98]

The ultimate fix is Quad4x4's shaft/gear that has an interference fit smooth pilot section under the gear. I have read here on the TDR of fully splined shafts failing as well. See the full details here on Quad4x4's site.

 

[SRath]

I think the ultimate fix is doing the NV5600 conversion like you did.

 

[snappy]

That is the trouble with the updated nut fix. There is no guarantee that it will last. It did not work for me. I bought a 5th gear nut wrench years ago. Can not remember what I paid for it. My NV4500 has a fully splined mainshaft; over 400,000 km since install and no lost 5th gear. I can and do use 5th while towing, but I don't lug it and the rev's are up.

 

[dansdodge]

Ok, I am a little new to TDR and bought my first dodge cummins recently. I have the nv4500 transmission. This fifth gear issue has me concerned, not as much as the KDP which I just had taken care of, but what is the NV5600 conversion? Is this the 6 speed transmission that is in the newer/early 2000's dodge cummins? Will this bolt right up to the 12 valve cummins?

 

[snappy]

Welcome to the TDR. The conversion, is just that. Swapping out the NV4500 for a NV5600. They will bolt up but some mods are required. A quick way to tell the 6 speeds apart, the nv5600 has reverse "up and to the right" on the shifter.

 

[dansdodge]

What are the mods and how complex are they to do this conversion? Also what is the price on the 6 speed?

 

[CumminsPower98]

see Ram Modifications for information on the upgrade. The NV5600 is no longer being made so you can't buy a new one. Used or rebuilt are the only options at this point. Some parts are also not so easy to get anymore. A few people have installed the current G56 but it's a bit more work.

 

[SMorneau]

Do the reading on the quad4x4 site. The fully splined shaft will only last if the gear doesn't have any play on the splines at all. Even if it is fully splined. That said I have seen the stock ones go for a long time. I never had that kink of luck.