mhuppertz

Update on a previous post, pulled the transfer case and extension housing, the large 5th gear is missing teeth as I suspected.

All the other gears felt fine.

I have a spare NV4500 (unfortunately 2 wheel drive main shaft) that I guess I can pull the two gears from, but don't want to hurt any more parts until I figure out the cause.

Thoughts? The nut backed off a couple of times before I put in the permanent fix, so maybe the small gear riding on the edge of the big gear weakened the teeth on the edge?

sooty

that's on the back extension, sucks they cut the gears toward the way they spin, normal rotation directs pushing the small gear off, you don't have the channeled mainshaft? the upgrade, uses a lock washer with a lock cog, the correct way, ive seen 3 other upgrades that fail, but the 5th gear cant be compromised from quickly spitting off, its usually blamed for normal wear over the long run. I have new part sources, but places like quad 4x4 even have oem, im fine with aftermarket parts, that im replacing during rebuild, knowing 5th will get 80% load, replace...the mainshaft thrust is more important, check for around .006"- .009" as I remember. when thrust goes, its usually the input shaft that's always spinning, roller bearing plate breaks through hardened surface and destroys thrust, cool thing on these, the input can be removed without the countershaft being moved underneath, do you have the info for disassembly?

thrashingcows

But if you remove the input shaft and replace, you have to reset your end play (thrust) on the mainshaft. Very important, and a reason many of these trannies fail per-maturely.

mhuppertz

It looks like perhaps the spacer washer behind the small 5th somehow let go and damaged the teeth on both gears. I pulled the fork and the 5th gear assembly from my spare and hopefully can get them installed today. Putting a neodymium magnet in the extension housing or the sump of the tranny to catch anything we missed.

gorms

These trannies are pretty easy to deal with, if you have a spare trans with good gears I'd get new bearings for main and counter for peace of mind. End play on both shafts is via shims under the rear bearing caps, quad sells shim kits.

As for disassembly, remove 5th gears from rear, unbolt bearing caps and roll the shafts out the top from memory.

I did this to my NV when I first got it as the case was cracked and welded when I got it, so I swapped the guts to a new case. I put the factory split nut back on 5th gear, followed the directions and covered it in red locktite. 90k on it so far and no problems. Firm believer in not lugging it under 1500 in 5th for best results

mhuppertz

The bearings are quiet, so I'm leaving that sleeping dog lie. Already have the replacement parts pulled, just have to pull the broken stuff and replace.

sooty

I was going to ask if it was making noise, if you don't have one, now is a good time to add a magnet, inside the pto cover, I gots a big one, I change the oil every year, before my summer tour, running amsoil, besides the dodge and chevy oil options, has anyone ever seen the Castrol syntorque recommendation? ive not.

oliver foster

I have about half and oil change worth of the now unavailable Castrol Syntorque left.
I bought it from Quad 4x4 3 or 4 years ago. I was buying some at that time and they said it was their last 55 gallon drum so I ordered several oil changes worth.

mhuppertz

I have had great luck with Syntorque and am chicken to switch.

sooty

none of my suppliers, oreillys, azone, napa, pep boys, even list it, amsoil was making synthetic oil way back, been in racing forever, because I have a supplier that even delivers in my local area, saves me 30 mile round trip shopping for it. my trans shop here locally recommends it highly, and after a few hundred k, I got no complaints. another example, our Polaris ranger has 4 different lubricants for ft locker diff, rear switchable locker diff, trans, tcase, engine, all synthetic, and very Polaris pricey, amsoil has all the compatible equivalents, saves lots of trouble.

thrashingcows

I am using this fluid....They claims it the OEM stuff, but not sure.

Manual Transmission Fluid for New Venture 5 Speed Chevrolet or GMC NV4500 | eBay

I did one oil change with the expensive OEM stuff just after I bought the crewcab, and the tranny was 2wd, and this stuff doesn't smell the same. I bought the 10 quart jug, and have been running it since Patches went 4wd and the tranny got rebuilt. Not had any issues for over 20K KMm's.

mhuppertz

Standard Transmissions of Arizona has Syntorque, Standard Transmissions of Texas recommends Amsoil.

mhuppertz

Going to have to wait a week. Raining turning to snow, and I am working outside.