Technical Knocking in bottom end?

Customer friend came in with his truck and stated it sounds like the engine is knocking on the lower end for a couple days.put it up on the lift and sure enough loud knocking from the torque converter not the motor. Disconnect the converter and sound us gone.can manually spin it and can hear something. Pulled trans back and converter out to find this! Pulled the front seal and got the 2 fragments out with a magnet. never seen or heard of this before. 350 700r4 combo in a 41 ford truck.

 

Converter not seated enough into front pump gear?

 

When I pushed back the converter, it did have too much space for me, but it was probably fine.

 

^^^^^ More about that…https://www.google.com/search?q=set...te=ive&vld=cid:9f5a805b,vid:afzBif5snOg,st:93

 

I usually shoot for an eighth of an inch gap. Adding washers usually helps that. The local race transmission shop Mike's Transmission advises eighth of an inch and gives you a sheet that tells you how to do it, in case you don't know.

 

When converter completely seated there should only be 1/8 between converter & pads on flex plate

 

Sounds like a story that isn't being told with all the details. But if we are throwing guess's to the missing details, Buddy did a transmission swap, didn't have it set in properly but tightened it down anyways, a bit of driving and it fixed itself into place? That last little bit is always the charm.

 

As well, there was an old thread about the finger on the pump gears can be of different lengths complicating matters even further.

 

How many miles on it since the conversion? Was it recent?

 

This setup has been in the truck over 10 years.

 

I think on some auto transmissions the lugs on the pump drive gear are flush only to one side of the gear. If the gear could could be installed the wrong way in the pump it could bind the converter from seating fully, or only allow partial engagement between the pump gear and the converter hub.

 

It was driven to Pomona fairplex and home and into my shop.about 120 miles. Everything worked fine just the knocking noise

 

I’ll throw out one of my late uncle’s favorite sayings when something broke……..metal fatigue.

 

Been together 10 years, drove with the knock 150 miles and this?
If true, it's been a ticking time bomb the whole time and finally went boom.

Going to be very difficult to examine the pump drive and figure out what is old damage, failure and then run damage after it broke. Real hard to get in there when ***embled and impact it without tearing up surrounding stuff.

Fresh trans, fresh convertor, flush lines and cooler, and if you want to look for root causes that might be there, check runout between engine crank and new trans. I guess you could strip down the old trans and check this too. 10 years says it's something not very 'off'. What kind of miles does it have? 10 years on a daily is 120K. A once a month donut run could be 10K or less.

 

i'm telling on myself. i had a sbc start knocking and thought i had lost the engine. as i was taking things apart i noticed the converter had to much play. i had installed the flex plate backwards. converter was still good but the pump was done.

 

@26Troadster you are not alone! I didn't but a friend did.
One of those little things a hobbyist might not spot especially if in a hurry or haven't done the job before. The trans should slip onto the alignment dowels and the converter should have a gap between it and the flexplate after the bellhousing and engine are cinched down but before the converter/flexplate are bolted up. Considering this is often done laying on the ground, wiggling big heavy parts into alignment in 3 axis.

 

I've got a weird one, I bought a 65 Impala SS, 327, 4 speed car from a coworker 73/4, he bought it new. The story, he was driving, heard something, saw it had no oil pressure, shut it off, had it towed home, stored it in his garage, everyone told him the engine was junk and it sat, he offered to sell to me $200, I had to look at it for that price. Car was beautiful, I bought and now it's in my garage, I did not need a project. the oil did not have the death smell I got the oil pan off the engine in the car, PIA but doable. Oil pick up fell off the oil pump, pulled a rod cap at front, looked pretty good, nothing discolored, minor scuffing Next step, pull engine, rebuild kit, and had a very nice Impala SS for around $ 350 total. I was racing as much as I could, working every hour I could of OT , plus started remodeling my second home, So it sat, finally in conversation with my Dad, he took it home and finished it, I did the engine ***embly, he did the rest, He and I drove it around some and I sold it for $ 1500, a low mileage Nice car, put the profits put in the racing fund, I already had purchased an Edmunds ch***is, later bought a new SESCO race engine. Gearing up for 75, I was ready to kick *** and take some names.

 

The stater could of locked up in converter & broke the snout on converter,
Some times usually will brake input shaft ,
The lug by pic look to be face correct
Towards flexplate ...
If drove in shop ,
Pull pump , check & lugs ,clean install new bushing / race ,seal converter.
Drop pan check, check what's in the pan

 

That might fix the issue, but if driven 150 miles broken, I wouldn't trust the fluid or anything inside not to have shrapnel.

 

When I say drop pan , do not roll train over , keep pan down , see whats in side
, what type debris , I guess just comes from experience what you see ,
& fluid color , smell is also reference .
I think issue caused by inside converter

 

Another weird deal, I had many things going on rebuilding carbs was a great/profitable side hustle, installed intake and carb set ups, mostly new stuff, used stuff I rebuilt the carbs. I do a Mopar 383 deal, kid brings it, all new stuff, swap it out, no start, no spark, take the distributor to a shop, he had the sun spinner machine, checks good, reinstall no spark. Hmmm, go back, get my continuity checker out , spend time and do not find a bad wire, back to shop, put it on spinner again, checks good, Hmmm wtf, thinking, wiggled the wire coming out on side if distributor, that wire was the problem, new wire, ready to rock. Not the first or last time I dealt with a pro/expert and was disappointed.

 

Mike's Transmission...sounds like he should be the guy to call being an expert on the subject? Well it's NFG now, how about you cut that convertor in two so we can see if it's ****ped the bed inside?

 

I'm not cutting any converter open, I could care less what's inside of it. The customer just wants me to put the new converter in and roll the dice.

 

Hard to tell for sure, but in one of your pics. It looks likes the pump rotor may be sheared.

In the last Pic, you can clearly see the top rotor drive lug. In the previous lower pic, no drive lug is visible. And it looks like the rotor may be sheared.

 

Possibly the picture you're seeing is the 2 pieces that were stuck onto the pump hub before I got them out with a magnet. There's nothing sheared off that I can see in the pump.

 

All back together and working great. different stall converter is a better match too. We will see how it does

 

Well I can't speak for anyone else, but it appears to me you threw the obvious broken part at it, it being the torque converter, and it stuck. Did you call Mike's Transmission for an opinion or just go for broke?

 

I didn't ask them, I know they would say to tear it down.they are right,but the customer wanted to roll the dice.