4th Gear grinding

[newyorkin]

mmmm Feels good getting back into wrenching... Except when I spend 4 nights replacing all the brake lines and bleeding the friggin thing just so I can test drive it, and find 4th grinds and pops out..

Does this mean my tranny is shot? I've never seen a manual die, so I don't really know what the symptoms are...

1st/2nd/3rd are fine, perfet. goes into 4th fine, but as soon as I let the clutch out, it squeals and grinds. It may not actually pop out, I put the clutch back in immediately.

Truck is a 92 K1500.
4wd/IFS, 4.3l, 5 speed.


ANy thoughts? Can I do something to fix it?

 

[tRustyK5]

That'd be the Getrag 5 speed. Not known for being particularly strong. Might just be easier to find another from a wrecking yard. They were used from 88 up, so there should be a decent used selection by now.

Rene

 

[newyorkin]

Ah, ok, so it's toast? I was really hoping there'd be a way to fix it so this truck wouldn't be worth what I paid for it...

Thanks Rene

 

[Corey 78K5]

That'd be the Getrag 5 speed. Not known for being particularly strong. Might just be easier to find another from a wrecking yard. They were used from 88 up, so there should be a decent used selection by now.

Rene

I here that all the time about the Getrag. My 96 C-1500 has the NV 3500 and has never once had a problem with 143,000 miles on it. I feel the NV 3500 is a great tranny in a 1/2 ton behind a 4.3

 

[mosesburb]

I here that all the time about the Getrag. My 96 C-1500 has the NV 3500 and has never once had a problem with 143,000 miles on it. I feel the NV 3500 is a great tranny in a 1/2 ton behind a 4.3

I believe that a '92 *should* have the NV3500/MY2 also (the MY2 code should appear on your option broadcast list in the bottom of the glovebox), but I agree. I have two of them (NV3500/MY2) in my S10s. One in my wife's Blazer ('92) and one in my p/u ('93)--both with 4.3L motors. I had an issue early on with mine when the reverse shift fork broke for no apparent reason and I had to drive it for the first 10,000 miles with no reverse because I had no money to fix it, but since it was fixed I have shown it no mercy for 100K and it has not let me down. It actually took a long time to get fixed because the trans guy that was building it kept calling it a Getrag and he kept receiving the wrong parts for it and it wasn't until I gave him the vin that he realized it wasn't a Getrag and the part was found in town and fixed that day. They are noisey, and the shifting preciseness leaves something to be desired, but all in all it is a good trans. I think that alot of their issues come from lack of maintenence (my owners manual states that the lubricant in the trans NEVER needs to be changed--I can't bring myself to even consider believing this statement, so I service mine about every two years or so, more often if I am towing/hauling) and people using the wrong lube. These transmissions MUST(!!) have the correct Syncromesh fluid (GM# 12345349--it runs about $9.00/qt but you only need two) because they use a synthetic lining on the inside of the synchro rings that get aggravated when the wrong lube is used. Beyond that, I think they are as good or better than anyone else's light five speed offerings for a 1/2 ton.

As far as your 4th gear issue goes, yeah, it's probably time to call it done or just skip fourth gear when driving. I do this quite often, but I do use 4th quite a bit also, so that may not be a viable option. As far as a wrecking yard trans goes, this is your only hope of getting out cheap--possibly. If you get a good one, you're good, but if not, here you go again. They are not terribly priced new, but it wil probably be way out of budget. The last one we installed cost about $1200 for the trans, if I'm remembering correctly.
Good luck with it.

 

[kennyw]

I've seen similiar problems with the SM465 that turned out to be a worn out shift fork not allowing the tranny to fully engage a gear. This would be something you could check/fix by removing the top cover of the tranny and inspecting the shift forks.

 

[newyorkin]

I'm thinking it may be an NV3500 also, only because evrything I'm running across on the net is showing that as the standard equipment on the 92 half ton.

Not that it matters which it is, if I can't get lucky with it being a shift fork, I still have to either replace the unit or see if I can get it inspected (dyno) without 4th...

The clock shows 223k on the truck. I'm guessing at some point the rear was replaced because it has junkyard-ish markings on it (grease marker labelling). I suspect the motor was rebuilt at some point just because it looks so clean under the oil fill cap and the oil I drained from it was pretty clean.
The tranny I have no real clues to indicate it was ever swapped or even serviced. It has a big wet spot that looks like a leak at the TC adapter, but otherwise it's pretty clean on the outside. I actually can't even find the fill plug on it...

The glove box label is lonnnnng faded, so I pretty much have nothing left to go by. Maybe I can find some letters/numbers stamped on the case...

Thanks for that dim ray of hope, Kenny, I'm going to see if I can get in there today or sometime this week.

 

[mosesburb]

Well, unfortunately, there is no cover to remove like on a '465. All of the shifting mechanisms are internal and trust me, you do not want to get into those. I purchased all of the Kent Moore tools to build one of these transmissions and they look like items that would be used to assemble something along the lines of a nuclear reactor. Way-odd looking stuff. Unfortunately, at this point, it is really time to start shopping for prices and warranties as there is not much that can be done to bandage one of these without getting into serious cash for someone to tear it down and inspect the remnants just to tell you that it is worth less than scrap value.
I wish it was easier than that, but I don't believe it to be.

 

[newyorkin]

Well I pulled off the shifter ring and boot today, and yeah, there's no cover that can be removed, just the shifter tower, and I doubt that would give me enough work room or visibility.
I messed around with it with the transfer case in nuetral. If I hold the shifter down in 4th with some force, there won't be any noise when I pop the clutch, but as soon as I let off the shifter a little, it grinds and pops out. I'm guessing 4th is definately done.

Thanks for the warning. I don't think I'd get into the rebuild myself. Doing the brake lines this week was so crappy concerning time allocation, I doubt I could rebuild it in less than 3 months if I even tried.

So for now, my plan is to see if I can get it inspected without 4th, and if so, drive it til more gears go. It's a weekend warrior, so I don't want to start dumping cash and time into it unless I decide to make it my wheelin truck at some point... And then I'll probably try to go with heavier equipment anyway.


Any way I can ID the tranny from the top? I'm not sure if it's a Getrag now or an NV3500. I'm hearing both were stock equipment for this model truck. Any distinct features of either tranny that can help me ID it while it's in the truck?

 

[tRustyK5]

The Getrag is an all aluminum tranny with an integral bellhousing. It splits lengthwise down the middle IIRC. I've never seen a NV3500 so I dunno how similar they are. The Getrag I had was in an 88 C1500.

My buddy has an 89 C1500 with the 4.3 and getrag and the tranny still works like it always did. It has 270,000 miles on it.

The motor is finally done though, and the heater core just puked so it's parked now.

Rene

 

[newyorkin]

Bummer that you're across the continent, I'd see if your buddy wants to part it out and see if that tranny would adapt to 4wd... I don't recall a split down the middle, but I'm pretty sure it was a one-piece aluminum case from bellhousing to tc adapter.

Thanks for the replies, all!

 

[mosesburb]

The NV3500 is an integral bellhousing unit also. On the forward 1/2 of the trans it has a "grid" texture cast into the case. The case splits at the 1/2 way point (you should be able to see this quite easily if it has it). After the split the case is relatively smooth (no more grid pattern). The rear 1/2 of the trans also constitutes the transfer case adapter. There is a fill plug on the passenger side in the forward 1/2 of the case and a drain plug in the very bottom that threads in vertically.

 

[newyorkin]

Ok, that sounds like it, I'm at work, so I can't check again til I get home.

I started driving it to the shop for inspection today (he was going to try it, skipping 4th), and everytime I let my foot off the gas no matter what gear, it would grind and squeal. I got about a good mile over some hills and stuff, and turned around and went home.
I only drove it up and down the block before, no hills.
I'd say this thing is COOKED, I don't think I can get away with the skipping 4th idea very long. And apparently, now the law is different, and the guy I bought it from has to register it, which means I have to get it inspected and dyno'd first, which means I have to get the tranny done before I can even make it legal.

I called 6 different local junkyards, and nobody has it so far. I'm waiting for a callback from one yard, but I'm not optimistic anymore.
I'm sure a rebuild will be over $1k, which means I will have sunk more money in this f*%&^$# truck than it's worth at all. If it's too good to be true, it probably isn't.

****
Never buy used from a dealer if you can't test drive it. I should've figured there was a reason this guy didn't just fix the brakes to make a better profit on the truck. I really am just a sucker for expecting honesty from the scumbag. ("The motor is great, and my mechanic drove it there, so the tranny works also").

Stoopid me. Eating crow now.

 

[diesel4me]

Might try in MA....

You might find a tranny in my area...I know of several yards that have quite a few trucks like yours...has any of the junkyards you tried put it in the "intercom" thing that connects the yards to each other???...I bet I could come up with a tranny around here,but first you'd have to identify what one yours is for sure...

 

[newyorkin]

Yeah, I know the intercom thing, can't remember what it's called eitehr... I don't think they use it around here anymore. My uncle's used to run a yard, and they about never used it.


If you wouldn't mind calling a couple yards, I'd owe you big time for the favor, but I don't know if I even have the cash for it right now, or if I can make the drive up there anytime soon.

It's a 92 K1500, 4x4, 4.3l, 5-speed (overdrive).

I'll try to ID the tranny tonight and post up what I think it is. I might as well pull the friggin thing soon anyway.


I'm just depressed about this truck now. I blew off other trucks that didn't need this much work but were right in my work-truck budget, just cause this one was 4wd. Now this truck is eating my budget even worse than one of these other trucks would've (I think).

Thanks for the offer!

 

[diesel4me]

I'll see whats available...

I might be headed to the junkyards tomorrow to scrap some stuff,I'll ask around and see if they might have any available...the price probably wont be that cheap for a 90's truck unfortunately,especially if its a common one to crap out..one reason I've avoided buying any 88-up trucks yet,the price of parts and many of them are dealer only,or junkyard..

.I passed on a 1989 K3500 with a 454 my friend had for sale,the same guy I bought my 82 K20 and 79 C10 from,for 1500 bucks!--and it had a plow,brand new gas tank and lines,and much other recent work like a rebuilt tranny,shocks,exhaust,etc--but it was getting real rusty underneath,and a few rotted spots on the cab and rockers..

.I wanted that EFI 454 so bad I was drooling--but my lack of cash in the bank made me pass--that and many of the others I asked here voted I should pass...kinda glad I did in a way,I have enough troubles with what I own already--but since it was such a rough winter here,I bet I could have paid for it using it to plow--but would have salted it to death in the process....would have been worse than the ones I already have....

I hear you when you say you got it because its a 4x4!--when I bought my C10,the last thing I needed was a 2wd truck,but I figured I would not find another one in such good shape as cheap as I got it for,and the 250 six promised better fuel mileage--well,that motor blew with only 113.000 original miles,and had just had a valve job and many other repairs,and it got LESS mpg than my 400 small block in my 74 K20!

--so I had to buy a van,strip the 305 out of it,put in new timing chain,gears,and oil pump,screen,oil pan,gasket.AND install it,just so I could still drive it!(and all of this was done with hardly ANY money to spend! )--now I hate too,but I'm selling it soon--I need a 4x4 more,and I have the 82 diesel K20--and I need MONEY more than I need a truck I wont be using much!...its a disease,wanting every GM truck you can get--I have it too,dont feel bad!...

 

[newyorkin]

Cheapest junkyard tranny so far is $650... I'll have to hock some junk to get it... And the dealer is now giving me crap about the title, he's refusing to give it to me, saying he can only get it to me by registering it and having DMV mail it to me. I spent some time on the phone with some DMV people today, though, and apparently, he was supposed to hand me the title when I handed him the cash. Something fishy going on there...

Rene, you da man, it's a Getrag MG5. I called the dealer today and read a parts guy the vin, he told me the getrag is the tranny it left the factory with.

Looking up parts kits for it, and all the calling out I'm doing on it, I'd almost say people call it an NV3500 also. It requires the syncromesh fluid also.

I may have lucked out on a tranny, too. I talked to my uncle, who used to run a junkyard but is now a heavy equipment mechanic. He said there's an 88-90 1/2 ton abandoned in his equipment yard from another mechanic's friend. It needed fuel lines, and the guy never came up with cash and never picked it up, so they were going to push it out into the street over the summer. He's going to check on the tranny tomorrow, and then maybe hook me up with it. Heck, I'll take the whole truck if the frame is less rotted than mine...


Thanks for the help fellas.

 

[tRustyK5]

The getrag gets a bad rap, but isn't a bad tranny IMO. It does not stand up to a ton of abuse, but driven normally it'll outlast the truck and it's a very nice shifting tranny. They are a little noisy in neutral, but that is normal. My 88 C1500 I bought as a demo and it was noisy like that from day one.

I wonder if you could make a 2WD Getrag work...I'm not sure on output splines or lengths etc etc.

Rene

 

[newyorkin]

I wonder if you could make a 2WD Getrag work...I'm not sure on output splines or lengths etc etc.

I don't think so, it looks like the whole back half of the tranny is different. I wouldn't not-try, though, if one were offered to me...

As much as I've been waiting to get back into a stick, at this point, if automatic's didn't take so much electronic modification, I'd just get an auto and convert. The auto's seem to be all over the place.

 

[mosesburb]

I actually did a manual to auto swap on a '92 K1500 for a guy, but he had the early 6.34 first gear NV4500 in it (yes in a K1500) that I wanted. Really, electronically there isn't much to do, just change the PROM and re-wire the backup lights and neutral safety switch, but trust me on this one, it is MUCH easier to replace what you have than trying to swap in an auto.