Any NV3500 Experts? Might Have a Broken One Here...

[USSkoval]

My son has '93 1500 with the 4.3 and nv3500 combo. Let me preface this by saying, he's been driving it for over 3 years and he beats the snot out of the transmission. Like, pretty much everywhere he goes, he's got his foot to the floor and he's bangin gears.

So anyway, last night on the way home from fireworks, he hit 2nd gear and it was a neutral. 3rd gear would pull, but that's it. When he got to the next stop, he had 1st and reverse, but that was it. Then he had nothing. The shifter would only move to the 1st and 2nd gear slots, but wouldn't pull. No other gear positions could be accessed. So I pulled him to my dad's house a couple miles away. When we got there, it would click into 1st, but not pull. It would kinda feel like it went to 2nd, but not pull. Couldn't access 4th or reverse. It would try to go in 3rd and 5th, but act like the clutch was not released (engine was running).

I trailered it home today. It will go into 1st, 3rd and 5th and it will pull in those gears. The shifter will not move to the 2nd, 4th and reverse positions. I drained the fluid and it looks like this:



The pictures make the fluid a little more gold colored than it is. There's no chunks, just a bunch of sparkles. This fluid was new 3 years ago.

Is this a sure sign that something let go in the trans? Or could this be just from 3 years of abuse? It seems to be awful f**cked up to be just a clutch/pressure plate problem.

 

[imiceman44]

My son has '93 1500 with the 4.3 and nv3500 combo. Let me preface this by saying, he's been driving it for over 3 years and he beats the snot out of the transmission. Like, pretty much everywhere he goes, he's got his foot to the floor and he's bangin gears.

So anyway, last night on the way home from fireworks, he hit 2nd gear and it was a neutral. 3rd gear would pull, but that's it. When he got to the next stop, he had 1st and reverse, but that was it. Then he had nothing. The shifter would only move to the 1st and 2nd gear slots, but wouldn't pull. No other gear positions could be accessed. So I pulled him to my dad's house a couple miles away. When we got there, it would click into 1st, but not pull. It would kinda feel like it went to 2nd, but not pull. Couldn't access 4th or reverse. It would try to go in 3rd and 5th, but act like the clutch was not released (engine was running).

I trailered it home today. It will go into 1st, 3rd and 5th and it will pull in those gears. The shifter will not move to the 2nd, 4th and reverse positions. I drained the fluid and it looks like this:

View attachment 507783View attachment 507784View attachment 507785

The pictures make the fluid a little more gold colored than it is. There's no chunks, just a bunch of sparkles. This fluid was new 3 years ago.

Is this a sure sign that something let go in the trans? Or could this be just from 3 years of abuse? It seems to be awful f**cked up to be just a clutch/pressure plate problem.

I am not familiar with the nv3500 specifically but as I understand it, manual transmissions have the same concept. The gears are on a shaft and another shaft has the main shaft connected to an idler gear, to shift, the forks are connected a a splined sleeve the connects the 2.
Sometimes the C clip holding the gear gets damaged and the gear walks with the sleeve and then you connect another and that causes you to be in 2 gears at the same time.
It sounds like that's what you have going on to me based on when it happened to me in my big rig.
When you get it out of gear, does it feel like it is dragging something or it feels like it just got released from something?
There's also the possibility your synchros are worn out, causing the sparkling shake you have for fluid

 

[USSkoval]

Yeah, I was wondering if all the glitter was simply from 3 years of excessively hard use.

Going from say 3rd, to neutral, it feels fine. It's just that it was acting incredibly goofy last night and now today, it seems to have 1st, 3rd and 5th... but you kinda have to monkey with the shifter to get them. 2nd, 4th and reverse cannot be accessed. Like an internal shift rail is fubared or something. I'm just guessing here, I've got no experience tearing down or repairing a transmission.

Maybe I'll pull the shifter and see what I see...

 

[centexk5]

That looks like an awful lot of brass. Something is trashed. Synchros and bushings and who knows what else.

 

[imiceman44]

Yeah, I was wondering if all the glitter was simply from 3 years of excessively hard use.

Going from say 3rd, to neutral, it feels fine. It's just that it was acting incredibly goofy last night and now today, it seems to have 1st, 3rd and 5th... but you kinda have to monkey with the shifter to get them. 2nd, 4th and reverse cannot be accessed. Like an internal shift rail is fubared or something. I'm just guessing here, I've got no experience tearing down or repairing a transmission.

Maybe I'll pull the shifter and see what I see...

If you can remove the shifter tower and see what is going on in the there.
If you put it in neutral first and open it, see if the 3 rails are aligned in neutral or one is off and still engaged.
If they are, then remove the top cover and see if the forks are worn out or broken.

 

[tarussell]

If you can remove the shifter tower and see what is going on in the there.
If you put it in neutral first and open it, see if the 3 rails are aligned in neutral or one is off and still engaged.
If they are, then remove the top cover and see if the forks are worn out or broken.

IIRC there is no top cover to an NVG3500 - they’re a mid-plate design loaded case with integral bell to the main case.
Gotta take it all apart to inspect the rails.

If ya had two gears trying to apply at the same time ( that was mentioned earlier ) it should lock slam up - but it does seem like you have shift rail/fork issues at a minimum according to your description given.
The metallic fluid definitely suggests blocker ring damage and/or most likely bearing cage failure ( sometimes they are brass ) and that means that all bearings have been contaminated at this point.

The NVG3500’s are alright in a 1/2-Ton 2WD but they are not known for holding up to the abuse of young spirited drivers who like to row through the gears like a drag car.
A used trans might be your best option since parts prices will add up quickly with these things.
If it does end up being an easy shifter issue and fix change that fluid and keep in mind that it’s most likely running on borrowed time so plan on a replacement.

 

[USSkoval]

IIRC there is no top cover to an NVG3500 - they’re a mid-plate design loaded case with integral bell to the main case.
Gotta take it all apart to inspect the rails.

If ya had two gears trying to apply at the same time ( that was mentioned earlier ) it should lock slam up - but it does seem like you have shift rail/fork issues at a minimum according to your description given.
The metallic fluid definitely suggests blocker ring damage and/or most likely bearing cage failure ( sometimes they are brass ) and that means that all bearings have been contaminated at this point.

The NVG3500’s are alright in a 1/2-Ton 2WD but they are not known for holding up to the abuse of young spirited drivers who like to row through the gears like a drag car.
A used trans might be your best option since parts prices will add up quickly with these things.
If it does end up being an easy shifter issue and fix change that fluid and keep in mind that it’s most likely running on borrowed time so plan on a replacement.

Thank you, that's kinda what I needed to know. Basically, verification that I need to be looking for a replacement trans. The unfortunate part is, I think it's a version that was only used for maybe 3 model years, with the external slave. Not exactly easy to find.

I threatened to install an automatic trans if he didn't stop beating on the truck all the time, lol.

 

[USSkoval]

I did end up pulling the shifter. What I could see in there looked ok, other than a lot of brass buildup in the shifter cup and on the shifter mounting gasket.