Torque Converter or Trans Issue

[84K5]

So here's the run down (skip to the next paragraph if you wanna skip the story). this would be my 3rd squarebody K5 I've ever owned. I've sold my last 2 when gas prices went sky rocketing up about 8-10 years ago. I'm currently building a 383 Stroker Vortec for this K5 which i planned on finishing up this summer. the block was dropped off at a reputable machine shop mid Dec. and I currently have enough parts to build it up to a short block. On to my issue.

I've never done an engine/trans swap on any of my previous K5's as they already had great running 350's and smooth shifting 700R4 trans. The issue that just ended my joy ride is while driving my K5 on occasion i noticed lose of power and a faint grinding noise which seemed to be coming from the bell housing. then all of a sudden while driving only a few blocks up the road the truck lost power as if it slipped into neutral while it was still in motion in drive. I coasted onto the side of the road and put the truck in park and back into drive and the truck was able to move again. A few more blocks down the road and the truck lost power as if it were in neutral again. I pulled on the side of the road and this time it wouldn't move. I turned the truck off and waited only and minute and turned the truck on and tried again. This time I turned around and headed home but while driving the faint grinding sound became much louder. On the way home I played this pulling off the side of the road and waiting for the torque converter (which I think is the issue) to catch and began my slow length quest home. I must also mention that the grinding is much louder and noticeable when the truck is at a stop in drive.

Thoughts on what might be the issue? I'm assuming my torque converter is toast but since I've never actually replaced a V8 chevy engine or trans I thought I'd get some thoughts from the masses. I've done a ton of aircooled VWs in my life and I'm a firm believer in if you want to learn do your research and dive right into it. Plus I have a few motorheads in my area for educational purposes

 

[yevgenievich]

Sounds a bit more like oil starvation/pump issue. Check trans fluid level and mybe drop the pan. If it is making noises that are due to internal issues there is likely answer inside the pan either as shavings or pieces of material

 

[84K5]

Sounds a bit more like oil starvation/pump issue. Check trans fluid level and mybe drop the pan. If it is making noises that are due to internal issues there is likely answer inside the pan either as shavings or pieces of material

I checked the fluids yesterday. Everything was full. I'll drop the pan this weekend. What exactly am I looking for?

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[yevgenievich]

More along the lines of what hoping not to find. is the fluid level changing when running vs not running?
Here is last noise making 700r4 that I have taken apart.

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[84K5]

More along the lines of what hoping not to find. is the fluid level changing when running vs not running?
Here is last noise making 700r4 that I have taken apart.

The fluid is dropping when the truck is running and hot. Am I looking at that shards of metal in your pan in those photos?

It's also hard to see what's wrong in the last photo.

 

[yevgenievich]

Fluid level dropping is a good sign. One easier way to check before dropping the pan is to remove torque converter cover and look over the converter as well as checking for overheating signs. Also can run it again and listen the pan and case with a screwdriver to verify noise location. The pictures posted was of a transmission that starved for fluid and ground most shafts/gears inside

 

[Matt69olds]

Next time it stops pulling, move the shifter to manual 1st or second. If it moves then, but won’t move in drive or overdrive, the input sprag is junk. Putting the shifter in a manual gear brings the overrun clutches on, locking parts that the input sprag would normally hold. The overrun clutches normal use is to provide engine braking in the manual gears.

I agree with dropping the pan for inspection. Hopefully you find just a little “dust” or crud in the pan, with no big chunks or shavings. However, if the filter is clogged enough to starve the trans and prevent the truck from moving, it’s probably all downhill from here on. The damage is done and will only get worse