What caused my tranny pump to go bad?

[J4GRAND]

Finally found out from the trans shop that the nose of my torque converter pushed into the pump and made it fail; clutch plates burned up after that. What could have caused this on a TH400?

[reddog]

I am no expert here but is it possible that crank play put pressure towards the trans??

Kerry

[J4GRAND]

Freshly rebuilt motor so I can't believe the crank is moving. Would the lack of the crank sleeve be a problem? I can't recall if it was there or not.

[Crazy_Jeepman]

When you mated the engine and trans together, Did you have the Torque Converter bolted to the Flex Plate? If so that would most certainly do it.

[J4GRAND]

Mated the trans and engine together first then tightened converter to the flexplate.

[Crazy_Jeepman]

No idea then. I figured it would have been done right, was just checking. I know nothing of Transmissions and do not want to!!! LOL

[Rogue]

bolts loosened on pump housing (have seen it b4)
crank end play
or power braking cheap torque convertor ballooned
these are the only reasons i know of

[gsmikie]

check the crank play

[J4GRAND]

Pulled out the old parts manual. I don't know if this has been answered before or not, but the diagram in the parts manual shows NO crankshaft bushing for the 360 with a TH400. As for the crank play; like I said before, freshly rebuilt motor with a new crank. I just can't see the crank having play.

[joe]

Originally posted by J4GRAND:
I don't know if this has been answered before or not, but the diagram in the parts manual shows NO crankshaft bushing for the 360 with a TH400. Patrick,
It doesn't show the ref number in the pic but it does list the bushing in the part number section.
This is from my 74-80 AMC Parts Manual in Group 1/Engine.

Ref number: 1.043-3
Description: Sleeve, Crankshaft Insert, WHT(with hydramatic trans).
p/n 535 2374.

[J4GRAND]

My 62-73 parts catalog doesn't have that section, in my book the bushing is in section 1.043-1. That section is titled BUSHING, Crankshaft Front (Bearing, Clutch Shaft Front). Maybe the later TH400s had this bushing, but not from 71-73 according to my parts manual. I went to the trans shop at lunchtime and got a better explanation as to what happened. It seems that when my friend and I installed the torque converter, it wasn't seated all the way causing a binding which led to the pump failing.

[joe]

I still think there should be one in there Patrick. Granted the page you're looking at says "BUSHING, Crankshaft Front (Bearing, Clutch Shaft Front)". That "seems" to apply to only manual trannies with the wording "bearing, clutch shaft front". I also have the factory 1963-73 PM besides the 74-80 PM. And under the same section you see, are the 230 and 232 motor listings. One bushing is listed as for LHT and one WHT refering to both the 230/232 etc Less Hydra Trans and With Hydra Trans meaning that AT's are also included under this same section. It doesn't just list manual trans/clutch only stuff. For the 232/358/304/360 up to 1972 it only states "ALL" no saying LHT or WHT which to me means "All" with manual or AT. Same for the 304/360 1971 listing..."ALL". I don't know why 73 wasn't mentioned but it may have been a publication date(Feb 72) thing of the PM and info was yet unavail for 73 model year at time of printing.
I'm not telling what to do Patrick nor am I an expert on this stuff but I personally would not assume it doesn't have a bushing because the section header says "clutch, shaft front" in it because AT bushings are listed in the same section. Nor would I assume 73 doesn't have one because on up to 72 360's are only listed.
I've never heard of a 304/360/401 w/TH400 combo that didn't have a pilot bushing in the crank. I guess my point is don't assume anything here. "To me" the 1962-73 and 1974-80 PM's say the 360 w/hydramatic trannies have a bushing. FWIW my 73 J-4600 360/TH400 had one. I would keep searching for more info one way or the other before you put it all back together. I'd also mic the shaft end and the inside of the crank and see how much space there is.

[Crazy_Jeepman]

It seems that when my friend and I installed the torque converter, it wasn't seated all the way causing a binding which led to the pump failing.[/QB]That is the most probable, sorry to say. :( I have done the same thing in the past. Now I set the converter in and then push it back, spin it while putting pressure on it, CLUNK! Then I spin it the opposite way to be sure it is back all the way. I was told if the pump goes bad shortly after a engine or trans swap........It was done incorrectly :rolleyes: I believe the early cranks did not have the bushing, however to be sure!!! Have the Trans Shop set hub of the converter into the end of the crank, to verify a snug fit. ;)

[letank]

If you just grab the harmonic balancer (engine off) it should not nudge...... it can go as much as 1/8...... then you need a new thrust bearing

Joe is correct, they are all the same 360 w the TH 400

Michel
74 wag

[J20 project]

J4grand, Just to clarify something for me, which th400 do you have. In 73 they still used some of the buick cased th400's w/ the qtrack tcase. Is it this one or is it a amc cased th400?
J20

[flyboy]

Are you talking about a different bushing than the pilot bushings used with a manual trans? Is this bushing more of a cup that covers the end of the crank?

[Crazy_Jeepman]

Originally posted by flyboy:
Are you talking about a different bushing than the pilot bushings used with a manual trans? Is this bushing more of a cup that covers the end of the crank?It is a very thin bushing that presses into the end of the crank, this brings the diameter of the end of the crank down the the correct size for the torque converter to fit into. ;)

[J4GRAND]

My trans is the old buick cased th400 with the adapter ring if that makes a difference. I talked to the guys at the trans shop and they said that they're not showing a bushing for the crank and I don't remember one being there when I removed the old crank during the engine rebuild.

[J20 project]

J4 grand, Glad to see you brought this back up. My 1973 J4000 which came with the th400/qt setup utilized the Buick case and....and.... a approx 1/2in thick crankshaft spacer.... If you do not have this and the flexplate and tconvertor are bolted together then the tips of your tconvertor are not comepletely meshing w/ the oil pump on the tranny. When this happens it allows the the tconvertor to ride up onto the tips of the oil pump causing it to bind and rub on the rear face behind it. This then in turn allows for a fluid pressure loss resulting in the failed forward clutch pack. This crank spacer was used w/ the 327 rambler engine and the 360amc. I don't know if it was used with the 350 buick.
J20 project