Hey Guys
1998 2 Dr Blazer, 4X4, 4.3L Vortek (Vin "W"), Stick NVG3500 transmission with internal hydraulic slave clutch, NV233 transfer case.

Just got the truck a little over a month ago. Shifted terribly (hard) and had a clutch chatter when the clutch pedal was engaged (pushed down). First let me list the replacements and repairs I have been doing the last couple of weeks (just put the truck back together last night):

1. Brand new clutch set (pilot bearing, clutch, pressure plate)
2. Brand new hydraulic slave which also incorporates a new throw out bearing)
3. Replaced both engine mounts
4. Replaced transmission mount
5. Replaced vacuum switch on transfer case
6. Replaced 4x4 actuator under the battery shelf
7. Replaced the vacuum lines
8. Installed missing transmission-to-transfer case braces
9. Installed 3 missing bolts on top of bell housing (mentioning this because someone may feel it had an effect on the problem)
10. Bled the slave

Did some other odds and ends, but above is the gist of it. After putting it back together last night, the repairs made huge differences. Tranny shifts like silk now. However, the clutch shatter is still there when the pedal is pushed down. Not loud, but loud enough for the car next to you to know something is not right. Drives like a champ while in gear. No sound or problem of any kind. Also, when I have the tranny in neutral there is no sound at all...until I push down on the clutch pedal. Any help greatly appreciated.

P.S. "Clutch Chatter" may not be the best description of the symptom. Clutch pedal does not pulse or anything, operates completely normal. The sound is quieter than a knock, but little louder than tick. It's a rhythmical sound...kind of like a ta-ta-ta-ta-ta-ta...

 

1998 2 dr Blazer, 4.3L Vortec Vin “W”, 4WD, Manual Transmission NVG3500
Hey Folks I’m really confused about what I just saw with my flywheel. First off I had started a thread asking about a “Clutch Chatter” after I had done a clutch set replacement, located here https://blazerforum.com/forum/engine...chatter-75490/. Tonight I was trying to pinpoint the sound. So wifey was in the truck with the engine running while I am underneath. My bellhousing has holes so I can very easily see the flywheel/clutch/pressure plate/throw-out bearing. I’m having her disengage the clutch, after a few minutes I noticed that when the clutch pedal was depressed, the flywheel moved forward about 1/4”. When the clutch pedal was released, the flywheel moved rearward 1/4”


We shut the truck off, pressed down on the clutch and the flywheel moved forward. Released the clutch pedal and nothing happened. I’m guessing centrifugal force was push it rearward when the truck is running. I am only a shade-tree-wanna-be mechanic, but since the flywheel is mounted directly to the crank, how is it possible for the flywheel to move forward? The crank must also be moving forward…no? That chattering I am hearing must be the flywheel rubbing on protrusion on the block when I depress the clutch pedal.


The truck runs like a champ…you would never guess it has 218,000 miles on it. I would think if the crank is moving back and forth 1/4”, there’d be all kinds of major problems going on? The engine runs very smooth. I don’t get it. Any thoughts?

 

*Combining threads. Please keep it together so folks can follow what's happening.*

 

So I spoke with someone today that told me worn main bearings will allow the crankshaft to move fore and aft. What I still can't get over is how is it possible for the engine to hum along perfectly if the crank is moving back and forth?

Anyone ever change the mains with the engine still in the vehicle? I'm taking the block for my other Blazer in to be hot-dipped and magnafluxed on Tuesday.

I really don't want to have two engines out at the same time

 

Well, since this thread has appeared to be nothing more than a daily journal for myself since I can't get anyone to answer any questions, I might as well keep asking myself questions .

So I've decided that I have to pull the engine. Right now I am bouncing back and forth on whether I want to:

a) just replace the main bearings and throw the engine back in the truck. This would cheapest and the quickest option.

b) get a full crank kit and replace all the low end stuff. Some more cost and some more time.

c) say screw it and get a "new" re-manufactured engine (I can get one for about $1600), throw all the old engine top end (intakes, sensors, etc) on it. Much more cost and probably only a little more time than option "b".

The the two primary factors are cost and time (in that order). I don't have extra of either. This is my wife's daily driver and it's running well. So I can't really pull the engine and then decide after I look at everything. Basically when I first disconnect the negative cable from the battery and "start the clock", I need to have everything bought and ready to go sitting on the workbench. Now when I bought the Blazer, I fully expected to have to replace the engine...but it runs so well, burns no oil, and all six spark plugs are textbook examples of what used spark plugs should look like. Didn't get around to compression tests because there was really no need.

So, money is tight, time is tight....which option would you choose in my shoes?

 

This thread is worthless. I probably didn't write it well enough or something. For whatever reason I have received zero input or help on my Blazer since I started this thread. So I am killing this one and starting anew without all the "clutch" comments and questions in the way. I'm going straight to some opinions on the engine decision I last posted.