Horn-O-Plenty

[NoInterstates!]

Well, not the good kind!

My truck is like a Cornucopia, the more you go in to fix, the more you find to fix. But is this really what I wish for? Anyways, I noticed while doing some investigative disassembly on the timing chain and sprockets for my rough idle/power reatarded timing condition that my oil cooler lines had some substantial leaking. Ok, hoses age, went to take them off. I removed the front driveshaft, and oil cooler lines and find this little treasure! How about a cracked Bell-housing to brighten you day! The previous owner told me that he put in a "aftermarket" "high performance" clutch. Who knows what caused the crack, overtorquing or the clutch and flywheel itself. When you are done laughing at my misfortune, if you have the time, please throw some ideas out there to these 3 questions;

1. Does my truck, a 94 K3500, VIN F 6.5, supposed to have a dual mass flywheel for torsional vibration control?

2. How many bolts hold the bellhousing to the transmission, just the four I see on the outside?

3. do you recon that bad motor mounts, the aftermarket LuK clutch without the dual mass flywheel, or overtorqueing of the bolts could cause this?

Thank you all for your time and take care!

 

[Bullseye240]

Well at least it was the bellhousing and not the engine block. You can at least put a new/used bellhousing in pretty cheap and easy. Its only cast aluminium. As for the dual mass flywheel I'm not sure perhaps others here will know.

 

[schiker]

1. Does my truck, a 94 K3500, VIN F 6.5, supposed to have a dual mass flywheel for torsional vibration control?

From the factory you had a dual mass. Depends on who you ask which is better. I think most prefer the solid flywheel conversion due to price. The key is to use a better pilot bearing and make sure the snout of the input shaft is good. Either a kevlar or bronze bushing is better than GM needle bearing. I seriously doubt the change over from dual mass to solid flywheel & Luk clutch /pp broke the bellhousing by itself. Later years the Luk was OEM and what many use now. Not many other options.

2. How many bolts hold the bellhousing to the transmission, just the four I see on the outside?

Yep only 4 bolts But I can't remember if its doweled or not like on the back of the motor. If I remember correctly the diameter of the through hole in the back of the bellhousing was kinda tight to a lip on the front of the trans like the steel rims are to the hub on the axles but not exactly sure memory is fuzzy. The four bolts are stout. Its the same basic configuration for the NV4500 behind the 5.9 just a different bellhousing size, with different input shaft, gear and misc differences. The trans housing is the same.

3. do you recon that bad motor mounts, the aftermarket LuK clutch without the dual mass flywheel, or overtorqueing of the bolts could cause this?

Mabye the failure of the original dual mass if it catastrophically failed proably maybe ??? Too much wrench torque maybe. Bad motor mounts and or transmission mount plus abussive shifting and loading???? Maybe repeated turning with 4x4 on dry pavement. Mud slinging or other. The 6.5 has decent compression braking power and can buck pretty good sometimes if get out of sinc with fuel control and spring wrap. I have jumped bucked and skidded tires with my truck in a parking lot a few times. So there are several ways you can torque up the drivetrain and stress it. Another I just thought of taking the cruise off by clicking it off running over 65 mph will jolt the heck out of the drivetrain. I love my manual and wish they made more of them but they are not for everyone and I have ridden with some that really should not drive them.

Could have been from disassembly or other stress not supporting the motor or trans and or jacking the other. Or tightening up the mounting bolts and they were in a bind etc. too.

 

[schiker]

I imagine up north the more frequent spinning the tires on icy wet or black ice then grabbing pavement is heck on a manual where as an automatic could absorb some of the shock better????

But probably it was big movement and not just just quick loading. Turning sharply in 4x4 on dry pavement or with good traction is one of the hardest things I can think of and it moves my stick a lot and twists up the drivetrain and body pretty harshly. It should be avoided at all cost. Up north with icy roads and some mismatched cleaned parking lots I am guessing its more common and harder to avoid. Previous owner might not have cared and left it locked in 4x4 a lot.

 

[Matt Bachand]

I am guessing its more common and harder to avoid. Previous owner might not have cared and left it locked in 4x4 a lot.

I agree witht he abuse. On Icy/snowy surfaces that you are using 4x4 in, Usually are slippery enough to avoid that harsh grab. At least my front tires are

I'll do a 7 point turn before trying a 3 point in 4x4 on dry/wet pavement.

 

[TurboTahoe]

Could you use these to fix that crack? http://www.locknstitch.com/

-Rob

 

[NoInterstates!]

Forward Progress

Took down the drivetrain. New Bellhousing on order, $305. Got new motor mounts, new seals, in particular the rear main seal! New exaust coming. Just wanted to put the pictures in here so you all could see my progress into this as an non-professional mechanic. Ask any questions and I will gladly answer. Check out that down pipe, did they put it in with a pile driver?!!
Take care fellow 6.5 owners.

 

[JiFaire]

Oh man, you have one of the ugly 1994s...

Here's the best hint you'll ever get... change out your downpipe and crossover while you have things apart... put in a mandrel-bent 3: downpipe and a mandrel-bent (constant radius) crossover. More power (like, LOTS more), better mileage, cooler EGTs, and then you;'re set up to add a chip and more fuel if you want to.

Do me a favour; when you have the crossover off, try and roll a golf ball through it - the stock ones were double-wall back then, and the inside wall had a bad habit of collapsing and partially blocking off the pipe. If yours is collapsed, we'd appreciate a good cutaway pic for the FAQ reference section.

Jim

 

[fastjohnny]

Dog gone Jim, I should have done that to mine before I tossed it.

 

[fastjohnny]

Oh man, you have one of the ugly 1994s...

Here's the best hint you'll ever get... change out your downpipe and crossover while you have things apart... put in a mandrel-bent 3: downpipe and a mandrel-bent (constant radius) crossover. More power (like, LOTS more), better mileage, cooler EGTs, and then you;'re set up to add a chip and more fuel if you want to.

Do me a favour; when you have the crossover off, try and roll a golf ball through it - the stock ones were double-wall back then, and the inside wall had a bad habit of collapsing and partially blocking off the pipe. If yours is collapsed, we'd appreicate a good cutaway pic for the FAQ reference section.

Jim

Yeah, definetly change that crossover with those bolts so easily accessible. Mine was major micro surgery with the torch to get those out, at the expense of an oil filter in the way of the flame.

 

[Bullseye240]

Oh man, you have one of the ugly 1994s...

Here's the best hint you'll ever get... change out your downpipe and crossover while you have things apart... put in a mandrel-bent 3: downpipe and a mandrel-bent (constant radius) crossover. More power (like, LOTS more), better mileage, cooler EGTs, and then you;'re set up to add a chip and more fuel if you want to.

Do me a favour; when you have the crossover off, try and roll a golf ball through it - the stock ones were double-wall back then, and the inside wall had a bad habit of collapsing and partially blocking off the pipe. If yours is collapsed, we'd appreicate a good cutaway pic for the FAQ reference section.

Jim

X2 on that, made a huge difference on my Blazer when I installed the 4" stainless steel with no muffler. Even got a great comment from a BMW driver one night on the way home from work about how good it sounded after he stayed on my starboard quarter for like a mile listening to it. I wanted to cut my crossover open to see if it was like that but it got lost by the guy who did the work for me while I was deployed. Oh well. He installed the crossover and I did the exhaust.

 

[MILD BILL]

clutch

I have been told by several people to stay with GM clutch I had the luk heavey duty, and lost the throw out bearing, and the teeth on the clutch. At 1100.00 a pop, I'm tired of it. So have caution and study well, there is a dude on this site who is up to date, but I can't remember his handel..

Well, not the good kind!

My truck is like a Cornucopia, the more you go in to fix, the more you find to fix. But is this really what I wish for? Anyways, I noticed while doing some investigative disassembly on the timing chain and sprockets for my rough idle/power reatarded timing condition that my oil cooler lines had some substantial leaking. Ok, hoses age, went to take them off. I removed the front driveshaft, and oil cooler lines and find this little treasure! How about a cracked Bell-housing to brighten you day! The previous owner told me that he put in a "aftermarket" "high performance" clutch. Who knows what caused the crack, overtorquing or the clutch and flywheel itself. When you are done laughing at my misfortune, if you have the time, please throw some ideas out there to these 3 questions;

1. Does my truck, a 94 K3500, VIN F 6.5, supposed to have a dual mass flywheel for torsional vibration control?

2. How many bolts hold the bellhousing to the transmission, just the four I see on the outside?

3. do you recon that bad motor mounts, the aftermarket LuK clutch without the dual mass flywheel, or overtorqueing of the bolts could cause this?

Thank you all for your time and take care!

 

[schiker]

I have been told by several people to stay with GM clutch I had the luk heavey duty, and lost the throw out bearing, and the teeth on the clutch.

As far as I know Luk did make the clutch for GM in the late 90's. I believe the 6.2 had a solid flywheel. Early 6.5 trucks had a dual mass flyweel that broke. Its also expensive to replace. Later truck had single mass flywheel but the clutch disk hub failed. Several found the GM needle roller pilot bearing destroyed along with the broken Luk clutch disk hub. And it its theorized that the failed pilot bearing allowed the input shaft to wander a bit more and stressed the clutch disk to the point of early failure. This pilot enduced disc hub failure was seen in the 6.5 and Dodge trucks too.

Visit southbend clutch website and see what they say. The Dodge guys machine the crank to accept a bigger pilot bearing. Since the GM crank is smaller its advised to go with a Kevlar or bronze bushing as you don't have the meat to increase the bearing size.

Now there is some debate whether or not you should add the harmonic dampener when running SMF and that hasn't been proven much that it matters. I think its mainly for sound and maybe long term wear.

I will advise using Castrol Syntorq for the tranny fill. Or appropriate GM or Mopar lube. At a minimum get a high quality synthetic.

Look at NV4500 dot com, or quad4x4 dot com for good tech stuff on the trans.

 

[packratt]

Zoom also makes a good one

 

[jbsaxman]

The NV4500 requires Syntorq. At least that's what it says on the side of my tranny.

 

[Slim Shady]

The NV4500 requires Syntorq. At least that's what it says on the side of my tranny.

Redline makes a good synthetic lube for the NV 4500, I have been using it for over 30,000 miles. I also have a LUK clutch and pressure plate with the Kevlar pilot bearing and have not had any problems yet. Just my 2 cents, ):h

 

[schiker]

Not to tangent the thread but its important and will relate to your finishing the job.

Slim is it a new product by Redline? 2 +/- years ago they recommended mixing 2 of thier products together. Again 2+/- years ago Amsoil was developing a product similar to Syntorq. Not sure if any they followed through Some have recommended Mobil synthetic as ok. I went with a Mopar brand stuff as it was a little cheaper than GM stuff. It says its specifically made for the NV4500 on the bottle.

None of the good stuff is cheap. So you can pick your flavor but try and double check it is really equivalent to Syntorq. Syntorq was kinda new back when the NV4500 came out. Actually I think Castrol formulated the lube after NV started experiencing trouble in the field with cold shifting or something like that. Castrol developed it specifically for the NV4500 for New Venture Gear and or GM and or Chrysler. Its popular in Europe for other manuals too. Being some kind of partnership Castrol probably got a little inside scoop on some stuff probably maybe??? Anyway its a really good match for the synchro's of the tranny and helps ease cold shifts.

Its been out a while and the other mfg's have probably matched it ok by now but don't take it lightly and use any ole manual transmission oil/gear lube.

 

[packratt]

Amsoil has one for the NV4500. I'm running it in mine. Don't recall the name of it but they list it on their site.

 

[NoInterstates!]

Hey all, I haven't taken a look at the down pipe yet, and I do agree that changing the the crossover now is a good idea, but unfortunately the torque holding my wallet closed is substantial! The crossover I have is not mandrel bent, but had no leaks and is pretty solid. I do have a 4" turbo back on the way, and I finally convinced my wife on the advantages of a Fluidampr considering that our truck is supposed to have a dual mass flywheel, and that the damage that I spent a year tracking down was from vibration. I will have the truck apart for at least another 4-5 days. If you all want me to take any pictures for reference now is the time. There is a lot of bad info online, and those being new to the 6.5 may end up being screwed because of that. For example, the whole "when the guy changed the IP, the IP gear moved a tooth off" on the gear because the IP gear just floats in there. Thats a bunch of nonsence, the IP gear's teeth are a quarter inch long, and the gear only has about an eigth of clearance on the sides and around the top. So in order for it to "be off a tooth" it would have to press into the timing cover an 1/8 of an inch or so. I don't think that can happen as accidentally as some make it sound. I imagine the timing cover would break long before that happened!

 

[NoInterstates!]

Another quick post, when you guys say I have one of the "ugly 1994's" are you suggesting that the pictured down pipe is from the factory? That is hard to believe the factory could be so sloppy, if this down pipe was intalled in Wisconsin by GM, I swear I will make the drive to thier headquarters and find someone I can blame for this, slap them across the face for ruining the name of Chevrolet! No way that mangled thing drove out of an American Manufacturing plant.