NV4500 5 speed

[Hansh]

My K3500 NV4500 (L,1,2,3,OD) trans is beginning to grind again going from 1 to 2 and 3 to 2. The trans was rebuilt about 90,000 miles ago. Is that all I can expect to get out of the NV4500? Is there something I can do to make it last longer? I only use it for light duty towing of boats and a car trailer.

[a5150nut]

Ive got 191k on mine. It will make noise when low on oil. They have problems with the seal between the trans and transfer case. They also have fiber syncros that wear. Do you use the clutch other than starting? Mine shifts real well without, just don't hury it.

[trbankii]

Are you using the specified gear oil?

Castrol "Syntorq" - GM part #12346190

Syncros will have a short life if you don't.

[Hansh]

I am using Amsoil Synthetic gear oil, should be the same spec as the Castrol. I have never had a problem with the seals. I am just wondering if this problem goes back to the original rebuild, which they made numerous mistakes on. Maybe I got a used unit? Just wondering what alternatives I have to get more life out of the transmission. I do use the clutch all the time when I shift, and I have shifted without, when the shift fork pivot wore out. Rebuilt (??) trans only has 90k on it.

[mark45678]

If you didnt do the rebuild , I take the word " rebuilt with a grain of salt! Most shops only do whats needed , they dont replace all wear items! If you drive without the clutch and can do it smooth this will make it last a long time. Worn shift drums and sliders will make a new synro bite the dust much sooner then it should. most of the time the lower gear drums and slides have been toast on the trans that I have had apart. what was replaced at the time of rebuild? My guess is only the syncro and main bearings at best.

[Hansh]

I asked for the parts to be saved, but they mistakenly tossed them out....yeah right! Bad experience from the day I picked up the truck. They probably only changed the syncos and ft. bearing, but it is the same problem I had 90,000 miles ago. When I replaced the engine, the old pilot bearing was in little pieces and dust. May have been cause of early failure also. I can live with it for now, but will have to repair soon and I want to make it better if I can.

[trbankii]

You know, this sort of thing is why I do most of my own work. Granted, I realize that I am fortunate to be in a position to do that between time, skills, and such. But it always seems that when I have someone else do the work I'm unhappy with the results, it ends up costing too much, or I end up redoing the work myself anyway... Or a combination of all three.

Case in point. My daily driver - the Saab - was in for state inspection and such this past summer. While it was in I mentioned some issues with the heating/cooling system. Seemed that it was running cold the previous winter. I asked them to flush and fill the coolant and check things out. While they were messing around, I told them to look over the engine to see if there was anything else I should be concerned with. The bill for the service was a bit salty, but I figured it saved me the time from messing around with things and that it was taken care of and I was good to go for awhile since everything had been looked over. The bill stated that everything was flushed and filled and that the thermostat operation had been checked.

Well, the other week I end up with no heat. The engine just never warmed up. It was in the teens at first, so I just thought it was too cold to warm up in the short distance from home to work. Then the outside temp warmed up and I had to take some longer drives. Still no heat. So I clear out some time and pull the thermostat one evening. The gasket was obviously never touched and the t-stat was stuck open. So obviously they didn't really check the operation...

Get that all fixed up and about a week later I start the car up and within a mile lose power steering and charging. Then the temperature starts going up so I know I lost the water pump as well. Those are different belts, so it seemed a bit odd that I'd lose all of that together.

Limped back home and checked things out. First, the belts were in horrible shape (guess they didn't bother even looking at them), but what it turned out to be was that the crankshaft pulley (which is also the harmonic balancer) had disintegrated. The outer pulley with the belts was totally separated from the hub.

The belts and all on a Saab are at the back of the engine, right up against the firewall, so it is sort of hard to check things. But after being told to go over things they should have at least checked the belts...

That's the other problem with having someone else do the work. I should have looked things over myself, but figured that a "professional" had just looked everything over so I didn't go to the trouble.

Guess I was reminded of my lessons once again...