Rebuilding a NV4500. Insight?

[ZXT 2,394]

Early last year, I picked up an '01 Dodge 2500 parts truck with the 8.0l V10 and NV4500 transmission, with the vision of swapping it into my '95 Dodge 2500 8.0l V10 with a slipping automatic. Got it put in, and found that the 3rd gear synchros were shot. No problem, I learned to double clutch to combat the issue. Recently, it has started popping out of 2nd gear at takeoff (1st gear is a granny gear, I've never used it other than to see if it was still there) unless I hold it into gear. I could put up with the 3rd gear issue, but forgetting to hold it into gear when taking off and having it violently jarr the truck when popping out is quite embarrassing. Since I know the trans needs overhauled anyways, I picked up another NV4500 from a local salvage yard that I frequent with the intention of rebuilding it. The guy running the place likes me, so he sold it to me for less than what he gets for a core. The shifter/top plate bolts were loose, so we figured it needed something done internally. Got it home, and turns out I was right. The gear on the input shaft was chipped, and the gear on the counter shaft that the input shaft drives is missing 3 teeth in a row. Ordered a new input shaft, counter shaft, bearing/seal/synchro kit, and a mainshaft with splines for a speedo gear, since the trans is from a newer truck that runs the speedometer off of the ABS sensor in the rear end, and mine drives off of a sensor in the trans. 

I plan on tearing into it this weekend if time permits. I still need to pick up a bearing puller/separator from HF. When all is said and done, I should have in it about what a "good" used trans costs. I've never been inside a MT before, but I've watched several videos and feel confident. I've been into AT's before with success.

I don't have any pictures at the moment, but I will do my best to take pictures and document the process. If anyone has been inside one of these trannys or has any pointers, I'd love to hear them. I know @pullstart and @PeacemakerJack are Chevy guys, so maybe they'll have some experience with them. Also, if any of you have recommendations as to what MT fluid you've run in the past, I'd love to hear it too. The original fluid specified by both Dodge and Chevy was Castrol Syntorq, which has been discontinued. Apparently Dodge and Chevy owned the rights to the fluid. Neither of them produce it anymore. I am running Royal Purple MaxGear fluid in my current trans. The trans is dying, but It was when I put it in, so I can't blame the fluid. Some people swear by the RP fluid, some by the Redline Mt-85 fluid, and some by the Amsoil MTG fluid, all of which carry the same spec number that Mopar requires. Googling and looking over forums for hours, you'll find instances of people both swearing by and warning against the use of each of the mentioned fluids. After I was done reading through it all, I'm more confused than before I started. I wasn't as concerned with my current trans, but I want my new one to last.

Thanks guys.

Edited January 15, 2021 by ZXT

[Pullstart 59,728]

I think the last manual trans I was inside of was for a VW Jetta Jonah.  I think @PeacemakerJack knows of “the fluid” to use as he’s got the NV4500 in Warrior.

[PeacemakerJack 10,671]

Thanks for pulling me into this guys.  Amsoil has this product specifically developed for the NV4500...

I have run this for several years with good success.  Make sure if you decide to go with their product that you don’t grab one of the 15 other gear lubes in Amsoil’s catalog that won’t work with the NV-4500.  They are picky “eaters”.  Good luck...

[ZXT 2,394]

1 minute ago, PeacemakerJack said:

Thanks for pulling me into this guys.  Amsoil has this product specifically developed for the NV4500...

I have run this for several years with good success.  Make sure if you decide to go with their product that you don’t grab one of the 15 other gear lubes in Amsoil’s catalog that won’t work with the NV-4500.  They are picky “eaters”.  Good luck...

Thanks! That's the one I was leaning towards; seemed I saw less "bad" about it than the others. If you've been running it for years, that's good enough for me. I'll order 5 quarts for it tomorrow. Thanks!

[peter lena 8,067]

ZXT, my son is a regular maintenance  guy , regularly changing gear oils and related rustproofing , has MAGNATIZED  ACCESS / DRAIN PLUGS IN ALL AREAS . its the total lack of quality gearing that causes failures. remember when gear boxes and rear ends hardly ever failed ? a lot of the stuff today is italian or chinese made. typically my sons magnetized plugs are loaded with metal spikes , even with regular oil changes . use good stuff  , like amsoil , and change it on a regular basis , pete   

[ebinmaine 63,141]

[shallowwatersailor 3,213]

Besides a magnetic drain plug, I also place magnets on the oil filter. Some might say that is the job of the filter, but it prevents the filter from loading with the metallic particles and offers additional protection for very little money. HF has different shapes that can be used..

[ebinmaine 63,141]

5 minutes ago, shallowwatersailor said:

Besides a magnetic drain plug, I also place magnets on the oil filter. Some might say that is the job of the filter, but it prevents the filter from loading with the metallic particles and offers additional protection for very little money. HF has different shapes that can be used..

Good idea.

 

I keep a neodymium magnet on the drain of Cinnamon. 

[ZXT 2,394]

Well, I got off work early enough today that I decided to tear into it. Getting the guts out of the case was pretty easy - I had it apart in about an hour and a half.. And I took pictures! Lots of them, mainly to aide in reassembly. 
I knew that there was carnage on a couple gears, but I was surprised to find that the plastic caged bearing on the input shaft was lacking its cage; the individual rollers scattered when I pulled the input shaft out. No sign of the cage until I got into it a little deeper.. I found it!

It apparently got rather hot - hot enough to melt the cage and have it melt down into the nearest cavity, which was inside of this synchro. Not sure if they ran it low on oil or what, or maybe were pulling too much weight. So far everything else in the transmission (bearing and gear wise) looks just fine. 

Got the mainshaft out, and I could now see the extent of the damage on the gear on the countershaft. That might make it skip a bit!

 

My picture of the chipped gear after I pulled the shaft from the trans wound up being a blur, but it is blackened, which leads me to believe that it got hot! This picture isn't as close up, but if you look, the gear contacting the concrete on the shaft towards the bottom of the photo is black. I don't think it was factory heat treating, but I could be wrong.

 

Here's the disassembled product. I might have part of the day tomorrow to work on it, and I'll focus on cleaning up the case and disassembling the mainshaft, and assembling the new mainshaft. 

[fast88pu 3,313]

On January 14, 2021 at 10:41 PM, PeacemakerJack said:

Thanks for pulling me into this guys.  Amsoil has this product specifically developed for the NV4500...

I have run this for several years with good success.  Make sure if you decide to go with their product that you don’t grab one of the 15 other gear lubes in Amsoil’s catalog that won’t work with the NV-4500.  They are picky “eaters”.  Good luck...

That's a cool package to solve the issue with filling some of the hard ones

[ZXT 2,394]

1 hour ago, fast88pu said:

That's a cool package to solve the issue with filling some of the hard ones

I thought so too. I ordered 6 qts from Amsoil. Should be here in a couple days!

[ZXT 2,394]

No real updates as of yet. On Sunday I started re-assembly. Got the countershaft back in no problem, and unstacked the mainshaft to find that the plastic cage on one of the bearings that my "rebuild" kit didn't come with was cracked. Not wanting to risk it, I decided to order a bearing kit for it. Supposed to be here Thursday. Hopefully will continue assembling and get it back together by the weekend.

[ZXT 2,394]

Well, it took me a while, but I was successful!

Biggest issue was Amazon. Bought the bearing kit I needed with Prime, and it didn't ship until a week after the "guaranteed" delivery date. 

 

Friday after work I got back on it. Got the mainshaft stacked, with the help of the pictures I took during disassembly. I'm not sure what the correct snap ring pliers are for the style ring that this transmission uses, but I will definitely purchase some before I rebuild the next transmission. I wasted probably 4 hours total getting the snap rings off and reinstalled with the incorrect tool. 

 

The snap rings were a pain, and getting this race out of the front bearing retainer wasn't a cakewalk either. There isn't enough meat exposed to get a puller on it to yank it out. I tried grinding through it but went through the few tiny Dremel cutoff wheels I had before i got through. I was hoping that if I scored it, I could hit it with a punch and shatter it since it's extremely hard metal. No dice. I tried welding a piece of metal across the race, but the flux core wire welder i had access to wouldn't penetrate the race, as can be seen by the splattery crap that I "welded" on. Finally, I cut up a number of washers and placed them inside the race where they would catch the lip, and then I welded a large washer to all of those pieces to hold them together. Welding that got the bearing retainer rather hot, so I got some ice cubes and cooled off the race. That shrunk it enough that it fell out with a couple of light taps. 

 

Once I got that on, I checked and set the main shaft end play to about .0022". The manual specs .002-.006", and I sat it towards the tighter end as I know it'll open up over time. Did the same with the counter shaft and got it to about .003". 

 

Here's the finished product. Don't mind the not perfectly clean tailshaft and the dirty top cover. At this point, It was a little past midnight last night and I was past the point of caring about cosmetics. 

 

I pulled the sad looking thing in the shop at about 10:45 this morning and rolled it out right at 2pm. I really need to get it painted.

 

Took it on a test drive and WOW! Every gear works, and I can upshift and downshift with ease. It also doesn't pop out of second gear when accelerating from a dead stop. I drove it probably 20 miles and it didn't grenade and it didn't get hot so hopefully I assembled it correctly. I caught myself a couple of times double clutching to get into third.. I'll have to learn to get out of that habit. 

 

I wanted to see just how bad the transmission I pulled out looked inside so I popped the top cover off and... Well, it looks just fine. I at least expected to see a chipped 3rd gear, but nope! Had I pulled the cover off and inspected it before I put the trans in the truck the first time, I would've assumed that I was good to go. There isn't anything visibly wrong from what I see. Just needs synchros since someone ran the wrong fluid in it. Should be a much easier rebuild!This was definitely a chore, but I learned a lot and can now say that I've rebuild a manual transmission.. I just hope it stays together!

Edited February 1, 2021 by ZXT

[ebinmaine 63,141]

6 hours ago, ZXT said:

learned a lot

THAT is the most important thing!

 

 

EXCELLENT job Sir!

 

 

[Pullstart 59,728]

Awesome stuff Jonah!  Like most things, it’s easy

ier to do something than to think about how it’s gonna fight ya!  Unless it’s in my shop.. then it does fight!

[ZXT 2,394]

On 2/3/2021 at 3:16 PM, pullstart said:

Awesome stuff Jonah!  Like most things, it’s easy

ier to do something than to think about how it’s gonna fight ya!  Unless it’s in my shop.. then it does fight!

There's always something that fights me... and I've come to expect it! I will say that this is the easiest transmission that i've ever stabbed. Jacked it up there, and it slid right into place. Didn't have to turn the output shaft or anything!

 

Thanks!