NV4500 Countershaft question

[Akaiser21]

Hey everyone,

     So where do I start.. So about 30,000 miles ago I had a transmission built for my truck since my last one imploded. This transmission has never "felt right." The problem I'm having is as you probably guessed it 5th gear loss. What keeps happening is I keep losing the countershaft retainer (snap ring.) This is a 1999 dodge and I do that the thicker version of this snap ring. I have replaced this 4 times now. Which is getting expensive due to gear oil prices. I have had just about enough of this failure. Has anyone found a reason why this happens? What I have checked is 5th gear nut tightness, splines and just the usual over look of everything there. What I haven't checked is end play. Not real sure how to correct this if it is end play. Im hoping to tear into this this weekend if I can get all the parts in on time. On the verge of swapping this for a g56. 

 

 

[Mopar1973Man]

5th gear nut torque is like 520 to 660 foot pounds depending on shaft design. Like mine is the upgraded main shaft torqued to spec. 

 

If you beating that nut with a hammer you'll never reach the required torque. This is why you losing the battle. Torque it right and fix the problem.

[Akaiser21]

1 minute ago, Mopar1973Man said:

5th gear nut torque is like 520 to 660 foot pounds depending on shaft design. Like mine is the upgraded main shaft torqued to spec. 

 

If you beating that nut with a hammer you'll never reach the required torque. This is why you losing the battle. Torque it right and fix the problem.

 

Well I know I didn't get to that kind of number. I called a local transmission shop and the told me 320-350 would be more then plenty. I used a 1/2" breaker and a cheater and gave it what I could. I will get it as tight as possible next time and hopefully to will hold up. Each time Im in there I make sure it hasn't loosened up but I will give it a shot and attempt to get into that range. I also have the upgraded main shaft, locking nut and I installed the splined locker that keys into the nut. Ill give her the onion!!

[Mopar1973Man]

Find out the exact number. I want to say Weller truck told me 600 foot pounds. But I suggest double checking.

[Akaiser21]

I will for sure. Ill call ATS and see what they say. Ill be getting the parts from them anyways since Im close by. Ill post what information they tell me

[Mopar1973Man]

Thanks ill make sure the numbers are posted as an article.

 

I've got to ask what sized tires are you running? Then what gear ratio?

[Akaiser21]

Well I posted some overheating issues a while back and one of your recommendations was to go to smaller tires. Well I ended up putting the stock wheels on with 285/70/16 to give it a shot. I also dropped injector size assuming that wasn't helping the situation lol. I had to put a new snap ring on before I left. While pulling my 5th wheel not even touching 5th gear for the sake of myself I still lost it. 

3:54 Gears also. Sorry I missed that

[NIsaacs]

9 hours ago, Mopar1973Man said:

5th gear nut torque is like 520 to 660 foot pounds depending on shaft design. Like mine is the upgraded main shaft torqued to spec. 

 

If you beating that nut with a hammer you'll never reach the required torque. This is why you losing the battle. Torque it right and fix the problem.

 

It don't sound like the OP is having current issues with the 5th gear nut, just the snap ring on the counter shaft 5th gear. Is the needle bearing in good shape, the 5th gear bearing surface and shaft bearing surface? Good snap ring groove? I have not run into this problem before.

 

The FSM says 270-280 for the nut. I recommend 400. 

[Mopar1973Man]

Upgraded torque king shaft requirement more.

 

I've got to ask what size tires is the OP running and what gear ratio in the axles?

[NIsaacs]

48 minutes ago, Mopar1973Man said:

 

 

I've got to ask what size tires is the OP running and what gear ratio in the axles?

 

He said 285's and 3.54's.  https://mopar1973man.com/topic/15013-nv4500-countershaft-question/?_fromLogin=1#

[Mopar1973Man]

Sorry I missed it on my cell phone. One of the few reasons I prefer the desktop computer. Mobile devices are fine in a pinch.