have had my truck a few months. It worked well for about 1000 miles and has been a nightmare ever since. without getting into all the details of all the parts I've replaced and the ridiculous number of times and ways it's left me stranded in about 3500 miles, I'll just focus on the transmission issues here: 

 

it started gradually shifting worse and worse. Initially it seemed to mostly be 3rd gear, but eventually, over the course of a couple weeks, it was all the gears. Grinds the worst and the most consistently going into 3rd  but now grinds in all the gears randomly, and the shifting in general is very hard. Can't get it into reverse without putting it into second and revving it first, and then quickly putting it into reverse.

 

so I initially tried replacing the clutch hydraulics. Got a pre-bled master/slave assembly from Oreilly's and installed it. For a couple days, it was better, and then it went back to how it was before. 

 

tried replacing the transmission fluid with Amsoil MTF, including adding an extra quart. Seemed better for about a day, then went back to doing what it was doing before. 

 

last weekend, I replaced the clutch and flywheel with new ones from Valair. for the last week, it's been driving great. shifting was significantly improved. After a couple days, I was confident I had found the problem. I went out of town for two days for work, came back today, got in my truck to drive home, and it's shifting rough again. grinding in 3rd unless I double clutch, and starting to want to grind in all the other gears again as well. again can't put it in reverse without first putting it in second. 

 

Is it possible I bought a pre bled clutch hydraulics assembly that has air in it? should I try bleeding it before I order a transmission rebuild kit? at this point all I can figure is that the syncros are going out, but it doesn't make any sense to me that every time I've attempted to fix it, it's better for a day or two and then goes back to sucking. 

 

really fed up with this truck. on the verge of selling it for a loss so I dont have to mess with it anymore. 20+ trucks and 11 motorcycles, all except one have been 20 years old or older, have had more problems with this truck than the rest of them combined. 

 

 

The NV5600 is not hard to rebuild, a bit clumsy to do, its completely different than the NV4500. 

I think it could just be the syncros and fluid from the past life. 

I have one of the best parts places for these transmissions here in my home town. Let me know if you need anything, and their super cheap (last time I checked). 

13 hours ago, Stanley said:

The NV5600 is not hard to rebuild, a bit clumsy to do, its completely different than the NV4500. 

I think it could just be the syncros and fluid from the past life. 

I have one of the best parts places for these transmissions here in my home town. Let me know if you need anything, and their super cheap (last time I checked). 

yeah a rebuild is probably where I'm headed. I'm going to take it out and double check the pilot bearing, throw out bearing, clutch fork, and clutch fork pivot, as well as re-bleed the hydraulics. if that doesn't work, I'm going to rebuild it. 

I really don't like prebled clutch hydraulics being 80% you have to rebled again. Then most misadjust the pedal rod length. I typically use NAPA master & slave separate and works 100% of the time.

 

As for that thin MTF it tends to wear out syncros faster than something thicker. I'm also using brass syncro allows thicker lubes, but still 1st and 2nd are carbon fiber syncros. No problems all the way down to -40°F with Mobil 50 SAE trans fluid which is 90 weight gear lube. 

 

Most of my trans issues was wear of the hard facing from using that factory Mopar fluid 75W-85 which is like 10W-30 engine oil. Now ive had most all the gears replaced from hard facing wearing out and breaking teeth.

Edited September 25, 20222 yr by Mopar1973Man

1 hour ago, Mopar1973Man said:

I really don't like prebled clutch hydraulics being 80% you have to rebled again. Then most misadjust the pedal rod length. I typically use NAPA master & slave separate and works 100% of the time.

 

As for that thin MTF it tends to wear out syncros faster than something thicker. I'm also using brass syncro allows thicker lubes, but still 1st and 2nd are carbon fiber syncros. No problems all the way down to -40°F with Mobil 50 SAE trans fluid which is 90 weight gear lube. 

 

Most of my trans issues was wear of the hard facing from using that factory Mopar fluid 75W-85 which is like 10W-30 engine oil. Now ive had most all the gears replaced from hard facing wearing out and breaking teeth.

mine is an oreillys pre bled. it isn't adjustable. I'm going to try one more time to bleed it and see if that helps, then i'll be dropping the transmission for the second time in a month and checking out the other stuff. 

 

Pull the entire hydraulic system out and hang it by the reservoir and pump the slave cylinder. Quickly in, release slowly. You cannot bled in the vehicle because the line has a high spot that gathers air in.

Now you know why I never buy prebled systems. Very low chance it's not got air in the system between manufacture, shipping to a store, you buy it ship it home and expect it not to get air back in the system. Just temperature changes during shipping can draw air in.

22 hours ago, Mopar1973Man said:

Now you know why I never buy prebled systems. Very low chance it's not got air in the system between manufacture, shipping to a store, you buy it ship it home and expect it not to get air back in the system. Just temperature changes during shipping can draw air in.

I dont know anything yet. haven't done it. 

 

I was just reading another thread about not flat towing with the nv5600, and it reminded me that while I was out of town, I had a friend tow my truck to my place. I told him not to flat tow it, but it would be like him to just flat tow it anyway and not want to deal with the flatbed. Would that explain my hard shifting? 

 

 

 

Was it 4x4 with transfer case in neutral  or 2x4. How far and how fast?

The lower shaft in the transmission typically doesn't turn when towed so the oil isn't thrown around much, so the top shaft spins inside the gears and can dry up.

9 minutes ago, Great work! said:

Was it 4x4 with transfer case in neutral  or 2x4. How far and how fast?

The lower shaft in the transmission typically doesn't turn when towed so the oil isn't thrown around much, so the top shaft spins inside the gears and can dry up.

i dunno. I texted him to ask but he hasn't gotten back to me. It's 4x4. I know he would have put the transmission and transfer case in neutral, it's about 2 or 3 miles and the speed limit is like 25 in town. 

Edited September 27, 20222 yr by blacker_canyons

two or three miles @ 25 MPH is pretty survivable.

Transfer case in neutral the transmission shouldn't spin. Also the oil pump in the transfer case is driven by the rear driveshaft.

 

For what I know of the NV4500 even in neutral both upper and lower shafts spin when towed. 

I was wrong the 5600 has two gears on the lower shaft that turn when towed so I don't think towing caused your problems. 

https://www.allstategear.com/NV5600-Diagram-s/3087.htm