So I decided to swap over to amsoil when I did the clutch and ever since then, the trans makes a really loud grinding noise in 4th from 1250-1500. The more load on it the louder it gets. I like to try different things out but this noise is just ridiculous. I made a vid but for some reason all you hear is the engine so I might have to tape the cam underneath or take the shifter boot off or something. Anyone got a reason as to why switching made it do this? I used the gold plated stuff before and it never made a sound. I've heard nothing but good stuff about the redline GL4 stuff so I might try that next. Think my trans has so many miles it makes all the flaws in fluids stand out.

I ran it in my 4500 and it seemed to do alright, but that is not to say it did any good, i did destroy 5th and 3rd in it before it came out for a 6-speed, it will be nice now that i dont have to run that special gl-4 stuff. I would recommend the filter kit from Genos as precautionary measure.DD

Hmm, so you didn't notice anything overly special about it over the golden stuff either. I'm having a lot of doubts with it. Hard to fork over more money to swap to redline but hard to listen to that grinding and think of how much longer whatever is grinding will last. Sure doesn't inspire confidence.

Which fluid did you get?Are you positive its not a vib in the shifter then takes that rpm to manifest?

I got the stuff in the pic, and yes it's not a vib, it sounds like a cinderblock being drug across a cement slab.Eh, let me go see if I can somehow get it on cam. Cam blocks out that sound for some reason.

I got the stuff in the pic, and yes it's not a vib, it sounds like a cinderblock being drug across a cement slab. Eh, let me go see if I can somehow get it on cam. Cam blocks out that sound for some reason.

Hmm... quite interesting.. .I guess the easiest thing it to change fluid and see if that fixes it. I have ran Amsoil fluid in many different trans and the only issue I ever had was with Toyota truck syncro's.. They don't like GL-5, but that was long before Amsoil came out with manual trans specific fluids.

Man I thought I had it this time. Took shifter covers off and held camera right next to it and the grinding was deafening, all you hear on cam is the engine. On a side note, there was a cinderblock in the parking lot, it sounded a lot better than my trans

I recently made the switch to amsoil on my NV5600 and I am really impressed with the much improved shift quality. Before I made the switch I talked to Dan @ Quad 4x4 and he said that several years ago the 5 speeds tended not to agree with the amsoil fluid but didn't have anything negative to say about using it in the 6speed. He sells the right gearlube for the 5 speeds (i think his is castrol) and also has the filter kits too. I would recommend the filter kit also, plus you can put a couple magnets in the cover to pic up any ferrous material. Chris

Man I thought I had it this time. Took shifter covers off and held camera right next to it and the grinding was deafening, all you hear on cam is the engine. On a side note, there was a cinderblock in the parking lot, it sounded a lot better than my trans

Yeah I'm going to have to do something, the grinding is getting better but I am thinking it's more that it's eating whatever is making the noise away. I'm going to order some redline stuff one of these days and see how that stuff works. I have been reading a lot about amsoil and the nv4500 and it's interesting just how many people say it isn't that good in the 5spd, of course theres those who say it's really good in them too, but I would rather try out redline since I have yet to see any people at all say it didn't work well. I like amsoils stuff but I use what works and this stuff just makes you cringe when it's doing it's grinding thing.

manual trans are not hard to work on(if you know what order everything goes in). drop it and take the top cover off. most trans top covers will have the forks attached. the "dog collar" is what selects the gears. if you "cant find it and grind it" you are not grinding gears but the collar and sycros. you will have to disassemble the main shaft if you have to do anything other than 5/reverse.when my ranger's trans "grinds" in gear, it was the teeth broke on the input shaft. it drove fine. but made awful racket! of course it took the counter shaft with it!

ISX, You'll be ok....Just crank up the stereo!

Yeah I'm going to have to do something, the grinding is getting better but I am thinking it's more that it's eating whatever is making the noise away. I'm going to order some redline stuff one of these days and see how that stuff works. I have been reading a lot about amsoil and the nv4500 and it's interesting just how many people say it isn't that good in the 5spd, of course theres those who say it's really good in them too, but I would rather try out redline since I have yet to see any people at all say it didn't work well. I like amsoils stuff but I use what works and this stuff just makes you cringe when it's doing it's grinding thing.

i know this is an old thread but i just bought a truck that makes the same noise that you are explaining. Did you ever determine what the cause was?