This morning about half way home from work, the truck started shifting extremely hard into 5th gear. It drove just fine in all gears but I just had a hard time shifting into 5th. Once i got home i played with it and found that reverse was the same way. It is only on that 5th/reverse shifter rail that has the problem. It goes hard in and out of the gates.

I pulled the console and shift tower out and there is metal shavings coating everything. I pulled both PTO covers and the one with the magnet on it had at least 1/8" of metal piled on it.

From what i can see, the gear teeth all look good, so i suppose it is synchro material coating everything. My question is, is it bad sychro's that are causing me to have hard shifting into 5th/rev, or something else like the shifter rail hanging up on something. I know that i really need somebody to row thru the gears while i lay underneath and look, but i need some advice too.

Oh and before i forget, the tranny was completely full of AMSOIL synthetic that i put in it in July when i changed the clutch. At that time i pulled one of the PTO covers and the top cover and there was no metal shavings on anything then.

Is there anything else i can check or do before i pull the tranny again and get it rebuilt, and do you think the Amsoil caused this. Regardless, Castrol Syntorq is going back in it. I just put Amsoil in my rearend last week, so i hope it is not next.

Any help is appreciated as I am down for this and will be back to the 84 big block as my daily driver b/c my Saturn is down thanks to Bambi.

Thanks, Adam

 

can you check the 5th gear nut? i lost that in my old nv4500...dont remember if it affected reverse though?

brett

 

How long has Amsoil been making the nv4500 specific oil? Thats why I think syntorq and mopar are the only two that should be run... But it also just might be a syncro got old... 5th gear has a tendency to fall off the splines of the mainshaft, u can weld the nut on, or upgrade to the fully splined mainshaft... But it sounds like a rebuild is in it's future with all those metal shavings...

 

No i dont think i can see the 5th gear nut from what i have to work with. But my understanding is, it only takes out fifth gear and nothing else. I can still drive in fifth, but 5th and reverse are hard to shift in/out of. I think i am going to wind up pulling the tranny again anyhow, so i'll know soon enough.

I'm just looking for some other ideas, and if nothing else to let people know that I had 2 months worth of Amsoil and about 2 lb of metal shavings piled up. It was probably something entirely different, but it was enough to make up my mind about the stuff. For the time that it was in there, i did not notice any difference in shift quality. I did pick up about 1.5 mpg, but at the same time I also moved closer to where I work and cut out 20 miles of interstate driving. And with 4.10 gears when you can drive 45-55 mph with no redlights to work, I'd say that was where my mileage came from.

Anyways, just something to think about and keep the ideas coming so I have something to think about.

 

i dont even drive on the freeway because the revs get so high above 65....it sucks

 

When 5th fell off in my tranny, I remember having fun with shifting into/out of reverse.

Sounds like the tranny is due for a rebuild. If it went ages without metal shavings building up, and in two months of Amsoil built up a load of them, it pretty clearly did some damage.

 

Just an update incase you were wondering. The tranny is at the shop now, and only the input shaft bearing is bad. i found that before i took it in, but i'm getting all new sychros and bearings.

 

Synchros don't magnatize I don't think.

I've run Amsoil in my 5600 for the last 100k and it seems fine.

 

There's a lot that can go wrong with the nv4500, I know from experience. If you can reduce the chances of trouble by using syntorque, I'd do it. I know Amsoil is great, but why risk it in your nv4500?

 

Standard Transmission in Ft. Worth used to sell Syntorque in bulk, about $50 a gallon. More than a year ago the GM switched to Amsoil transmission & transaxle gear lube. According to the label on the bottle it replaces GM and DC syntorque by spec #s. Charlie, the GM, still uses it which indicates to me that he hasn't had any negative feedback on it. I've only put about 3k on this transmission, so I can't comment on it. I can say the most I have got out of a NV4500 is about 97k using syntorque.

 

I had the rear bearing on the main shaft fall a part and drop the rolers in the bottom of the case happened a block from home started making noise 150,000 miles on it two days before was grossing 24,800 lb lucky it didn't let go then. I am running a 50/50 blend of Redline MTL & MT90

 

Another update.

Got the tranny rebuilt with new bearings and synchros for $660. Guy told me he cut me a break on the labor, which i believe because another shop ballparked it would be $1000 over the phone. It was a local shop, not a national chain. He found the input shaft bearing to be toast. If anybody is in the Fairmont/Morgantown Area you can PM me and i'll give you the name of the shop.

I also asked him about the Amsoil, if that caused it since I had just put it in about 2 months earlier, and he said "Its the best stuff you can buy, I'm a dealer". So i dont know what to do. Right now I'm running 75-90w Mobil 1 synthetic for the next couple thousand miles and then i plan on changing it.

I've got $100 in a gallon of castrol syntorq sitting in the garage that i can replace it with, or put about $40 worth of the Amsoil stuff back in it. I just hate to think about paying $100/ gallon for anything. I'll take it back and buy the Amsoil....Just tell me what you all think.

As for the guy who rebuilt it, he said it didnt matter what i put in it. He said to run 50w racing oil in it if i didnt get Amsoil. I asked him to get me a gallon of the Amsoil when he rebuilt it but didnt have any in stock when i picked it up, so i just went on.

any advice appreciated.

 

If you mean by "Amsoil stuff back in it" you would reuse the oil you had, I'd say don't. There is no way to filter out all the metal that is suspended in it. I sure as heck wouldn't use Mobil 1 or 50 wt racing oil. Neither one is formulated for the metals used in the synchros. If you have syntorque use it. When it is time for a change, then get some more or switch to the Amsoil substitute.

 

I was meaning that i'd get new Amsoil to put in it. I already threw the old stuff out. I've got Mobil 1 Synthetic in it now. But what i cant figure is why (or if) this transmission is so sensitive to Castrol Syntorq. What is the difference between that and Amsoil/ Mobil 1/ Pennzoil/ Lucas. Except about $10/ quart? Not starting a fight, just a question from somebody who is ignorant.

 

I agree that amsoil is the best oil out there, but I think anything other than syntorque will damage the syncros material. Look up quad4x4 and call & ask for Dan. He knows more about these trannys than anyone. Ask him what he recommends.