CK5
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so IF it is the pump, and the engine was running for say, 15 minutes without the pump pumping, could it have damage some other internals, like the torque convertor :eek2::eek2::eek2:, or bushings up front?
 
Seems like the tabs on the gear would be broken off or that gear shattered. So TH-400 has no screen on the output to catch debris because it's a gerotor instead of ring/vane design? I was wondering if the gear could have been installed upside down and not engaging fully, but I think the opposite would happen and the torque converter couldn't seat all the way.

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Are you 100% sure the yellow pickup tube was sealed up in the case?

If you can't find any evidence in the pan then you might as well pull it. It would of been nice to get a pressure reading first. Hopefully the problem will be obvious but if it isn't then you'll wish you had that pressure reading (or lack thereof).
 
That sucks Dave. I have nothing constructive to add here. How much time did you get in the dunes before it let go?
 
Too soon to suggest a 465?



Ok, maybe tomorrow

Its already been suggested...putting in a 465 would be taking the easy way out!
I'm committed to making this T400 work, and kick ass doing it! and I have no use for a 465 in the Maiden.....so :flipoff10:

Haha! I was going to say it too but Dave will just tell us to Fork off anyway! :haha:


Sorry about the luck Dave! :dunno:
great line Dean! thanks man!

Are you 100% sure the yellow pickup tube was sealed up in the case?

If you can't find any evidence in the pan then you might as well pull it. It would of been nice to get a pressure reading first. Hopefully the problem will be obvious but if it isn't then you'll wish you had that pressure reading (or lack thereof).
Pan is clean, fluid is still purplish/pink. (FORD type A) I pulled off the filter, and the pickup tube is still stuck in the case, so yeah I'm pretty sure that was OK. Its still in the truck, so maybe I'll get a gauge and long enough hose to read through my shifter hole what press (or lack of) in each gear.
Seems like the tabs on the gear would be broken off or that gear shattered. So TH-400 has no screen on the output to catch debris because it's a gerotor instead of ring/vane design? I was wondering if the gear could have been installed upside down and not engaging fully, but I think the opposite would happen and the torque converter couldn't seat all the way.

s-l300.png

I gave the torque convertor a trial fit on the pump on the bench...it seemed to engage the tangs correctly and when the pump was in the case, I installed it again and rotated until it "seated" into the tangs on the gear. When the trans was bolted to the engine block, I had to pull the t/c forward maybe 3/16 to mate to the flywheel....seemed normal.


That sucks Dave. I have nothing constructive to add here. How much time did you get in the dunes before it let go?

thanks AJ! I ran it around my 10 acres for a lap before loading it on the trailer...then drove around the streets of Silver Lake maybe 10 miles, then onto the dunes for maybe a mile or two. then hit the hills with it under full throttle for a few seconds at a time, then while under steady part throttle, it stopped working.
 
I have the exact same gauge set Dave, works great, and the hose is plenty long to go under the body and up through the window if needed. Although its easiest on ours to just go through the Tcase shifter boot. Although since this is likely just a stationary test it won't matter.
 
So having some time today to get back at this I got to inspecting this a bit more and poured the rest of the oil out of the pan and found what I believe is an oil pump gear tooth and a bunch of glitter in the pan.
After letting the mostly drained pan sit and then tilting it slightly there is a dark edge of very fine steel/iron glitter.
I’m not going to do a pressure test as I believe the problem will be evident when it comes apart again and it will save the possibility of more damage and the hassle of filling running and draining again and taking it apart hot.
those are the old set of pump gears for comparison

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It seems like you definitely found a problem Dave! I would agree, save your time on the pressure check...
 
Here we go again.....1st look at the pump while still in the case shows no drive tangs on the pump gear.
Now to find out why.
@Greg Ducato , I’ll be shipping out that bitchin convertor today.

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Sucks, but it should just mean a rebuilt pump and converter and it's back up. Hopefully you can figure out if the parts don't match or what it was that caused the failure. I assume the bellhousing bolts had stayed tight, etc. Did Greg take a bunch of measurements from you? Is that the same pump you ran in the past or a new one?

I've seen 4L60 pumps break the tangs off like that just from putting pressure on sides of the ears. They can run for hours or days, whatever, then bang. Don't know if the TH400 gear is that same brittle stuff.
 
Unless there is a midplate then we wouldn't need any special measurement, all 400 converters use the same assembled height. GM pump gears are cast iron, they work great unless you put them in a bind then they fracture easily.
 
everything went together as normal so I don’t know why but the small gear speaks for itself.
The large gear is seized in the pump, not sure if it’s from broken bits wedged in there or what. When I initially put the converter in it spun freely so I don’t think the new gear set was an issue as far as fitment is concerned
I will take the pump and gears to the trans shop for his opinion as well.

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