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Old 07-12-2018, 05:05 AM   #1
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Join Date: Oct 2013
Location: Santa Paula, CA
Posts: 355
Th350 done for???

1972 c10 350/350 LWB
I rebuilt the engine back in 2014. I have about 25k miles on it since then. I didnt touch the th350 other than a filter and fluid change. At that time the trans had about 85k miles on it. Engine bored .040 over, flat top "eyebrow" pistons, comp cams XE250H Hyd.flat tappet "RV" cam, 1.5 prw roller tip rockers, edelbrock performer intake, rebuilt stock Qjet 4MV from '72, reman "882" heads, hedman headers, super 40 3" true duel flowmasters, stock 3.08 rearend, u joints and center support bearing wear replaced last year, new prothane and energy suspension motor/trans mounts.

Replaced the detent cable with a plastic sleeve type OER brand ( I guess they dont make the metal sleeve type anymore. Not happy with it. Leaks like a sieve just sitting there on level ground.) Trans leaks from 1-2 accumulator cover, vacuum modulator has black and red band and is adjustable from autozone about 3 years ago. Just replaced the pan gasket with a felpro one, found one of the filter screws in the pan, fresh fluid after straightening pan rail, new derale trans cooler mounted in front of everything supplied by stainless hardlines, trans fluid does not enter the radiator at all, because i dont trust the internal cooler's integrity.

It's been 100+ every day around here since last Thursday. On that first day my engine coolant gauge inside the truck got to about the half way point, never got stuck in traffic but I do have a pretty steep grade about a mile long on my way home from work (6% grade).
I used to put a quart of fluid in the trans once a month or so about 2 years ago, now I put 3 quarts in it in the last 2 weeks. Always catching it right about the "add a pint" line. On Sunday it was 107 outside, I had driven the truck for about 20 minutes easy going, then I was stuck at 2 traffic lights in a row for what seemed like an eternity, parked the truck to get the lady some frozen yogurt, tried starting the truck about 5 minutes later, no go. Cranked but wouldn't run. Removed air cleaner, worked the throttle a couple of times to try and get the fuel vapors out, went and left the cleaner off and the truck started, replaced cleaner drive the 1.5 miles home. Drove ok. Temps were a little cooler yesterday and today. Fresh tank of 91 on monday evening and truck was lovin it. I was cruisin, took the long way home. Stoplight with a straight and clear lane, mashed that pedal til it wouldn't go anymore, truck launched and I was happy as hell and impressed to say the least, but that's when it all changed. No obvious noises, no crunching, scraping, banging, probably wouldn't even have been rememberable except that I noticed the truck no longer had that snappy response to my pedal efforts. Revs started going higher before shift points, which I thought was a good thing( staying in the power band longer) so much to the point that today I had 1/4 tank of gas left after maybe 80 miles of driving total. Usually I can drive 80 mph and have my rpms right at 3,000. Tonight I was driving 75 and had 3,000 rpms. This is after I poured in a bottle of Lucas trans fix. I did this because I started the truck and I could definitely hear something hitting something else. Not continuous, but rather like something metallic revolving and hitting against a stationary object. I thought my starter had fallen and the bendix was hitting the flexplate, but then i remembered i have a starter brace. And i verified it wasn't the starter. This weird and unbearable noise happened while the engine was running and the transmission was in park, it happened when i shifted into drive but slightly less frequently until i started to give it more throttle then it would grow in frequency and in pitch, so i shifted back into park and the sound went away until i stabbed the throttle, it really didnt like that.
So i shift back into drive because I'm about 2 miles from my dads house, as i start moving i find i can slightly give it throttle to get the truck moving without making the sound, if i give it to much throttle that metallic revolving sound is back again, so i give it more throttle to build momentum so i can relax my pedal effort. I make it to the local autozone grab the bottle of Lucas head right out and proceeded to get about half the 32 oz. Bottle into the transmission in about 20 minutes. Truck was not on at this time. I get in the truck turn it on, no weird sounds, idle is normal, shift into reverse no bad sounds, shift into drive and pull out of the parking lot and I mash the throttle, no bad sounds just really loud flowmasters
Truck seems "fixed" right? That's how this stuff in the bottle works isn't it?
I know it's not fixed. But I can convince myself of somethings if I try hard enough to ignore the facts. Lol.
So I go to my dads pour the rest of the bottle in the trans, add a quart of oil because it needs it, and I go for a mellow cruise around the neighborhood 25mph and less. Seems like the truck isnt responding to my acceleration NOR my braking efforts like it normally does. Idle seems slightly higher, shifting seems less engaging, i.e. smoother less noticeable shifting, less change of rpms between shifts. Drive the 30 miles back home which has that steep grade I mentioned earlier. And I have to admit there was a slight feeling i had of not being able to make it to the top. But luckily i did. I had the throttle at about 3/4 down to the floor while on the grade, normally this would put me at 75-80 while on the grade and not even questioning my trucks ability and not lugging down the engine. Tonight however the truck was doing barely 60 mph at the same throttle position while on the grade.

I made it home but the truck doesn't sound so well. No bad weird sounds since putting the Lucas in. Even after multiple starts and no wrench turning at all.

Now the sad sack story, this is my only vehicle. My daily driver, in addition to being practically flat broke, even though payday is Friday, and having a short paycheck, in addition to all of lifes hurdles that you and I all have. It still sucks to have happen to you. I was quoted by a local reputable shop $700 for a bench rebuild with torque converter and a shift kit installed. 2 day turnaround, remove and install myself.

Opinions?, comments?, smart-alike answers? I'm all ears. Thanks for reading. I feel better venting at least.
1972 C/10 LWB
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