Crank Walk? Balancer Failure?

[Zeppelin264]

Wow, lots of reply's!

When I noticed the issue, the whole pulley was moving in and out(belts were almost coming out of alignment).

I let the car sit for a long while(4 months) and just yesterday fired it up and everything looked perfect. No issues with the pulley moving in or out at all.

This video( ) shows exactly what I was seeing. Granted this is a serp. setup and the belt is riding on the outer ring which can make sense, but this is exactly what I saw but from the top of the engine. I dont recall seeing the outer ring moving with the pulley, but the pulley and belts moving in and out.

So how can it do this one day and then not the next?

Gong to take a look at it this weekend.

 

[BSB67]

Wow, lots of reply's!

When I noticed the issue, the whole pulley was moving in and out(belts were almost coming out of alignment).

I let the car sit for a long while(4 months) and just yesterday fired it up and everything looked perfect. No issues with the pulley moving in or out at all.

This video( ) shows exactly what I was seeing. Granted this is a serp. setup and the belt is riding on the outer ring which can make sense, but this is exactly what I saw but from the top of the engine. I dont recall seeing the outer ring moving with the pulley, but the pulley and belts moving in and out.

So how can it do this one day and then not the next?

Gong to take a look at it this weekend.

Because your test method is flawed. Seeing once and not seeing it the second time while its idling doesn't mean anything.

 

[dadsbee]

How much alcohol was involved the time you saw it walking??

 

[MOPOWER871]

Had same problem, turns out it was the torque converter. the converter was pushing on the crack had to install an anti ballooning plate in the converter solve the problem

 

[hangn0ut]

Brother had this same thing happen to his ford pickup with a 312 v-8. Crank was broke at the snout. Break was irregular which kept everything working.

 

[Zeppelin264]

Well, finally got a chance to look at the car and its the Thrust Bearing that has gone bad. The crank is badly worn down. Looks like the pressure was coming from the rear so either the torque converter was ballooning(which I doubt, PTC 9.5" w/ billet face) or when the 4 speed was in the car the tip of the snout was pressing against the crank for long enough to do damage over a long period of time and I just happened to miss it getting worse all these years.

At this point I need either a new crank or a new engine all together. 440's seem hard to come by from my searching around. Unfortunately I dont have the room to pull this engine and rebuild like I used to, I need to just swap engines so I can keep the car mobile. Guess this project has turned into the ol' "I'll get to it someday" slogan.

Atleast for now it runs and I could drive it in a pinch if I had to.

 

[HEMI-ITIS]

So the thrust bearing is there,,,,just wiped?? If that is the case than you should be able to rebuild that short block.Crank endplay should always be set and checked!!

 

[Zeppelin264]

Wiped the bearing surface and the crank has a deep groove in it.

Not sure what happened but talking to a buddy last night he feels the 9.5" converter may have been putting much greater thrust load on the crank due to its smaller size. I've heard of line pressures in transmission causing this problem with th400's but never a 727 and this is a John Cope trans, so I'd hope it was setup correctly.

Either way, its time for a new build.

 

[HEMI-ITIS]

Did you build the engine last time?

 

[Zeppelin264]

I built the top end last time. The bottom end I had assembled. Everything was good with the 4 speed for years, then I do the auto and thrust bearing failure.

 

[Garys1969RR]

Was the converter fully seated on the input shaft? It needs to be about an inch inside the housing mating surface. I've never seen a converter cause a thrust bearing failure.

 

[bearman]

Crank play comes only a couple things I know of and the biggest problem is not checking end play when crank installed. Most people don't know how or just don't do it. That's why I ask at the machine shop to set in play or tell me how thick of a thrust bearing needed. Second problem is convertor issue. You said you had a 4 speed first then an automatic. 4 speed have less inpact on a crank then a automatic does. I think like hemi says replace thrust bearing to proper setting and you should be o.k. just my thoughts