727 front bushing

Posted By: cermac

727 front bushing - 05/26/12 07:34 PM

This is 2nd new bushing And it's worn again. Trans leaking from front pump. New ATI 8" treemaster hooked to 416 ci with 620 hp and 550 fpt. Motor line bored and built 2yrs ago. Same tranny housing with block on new build. Only diff was old Lupo 9.5 " converter. Just switched to ATI, 7 passes, leak! Pressure tested converter. Ok! Tranny rebuilt this past winter. Put back together and bushing worn again and leaking. Are there manuals to show how to align housing with crank or any other suggestions. Thanks. Ps want to get to track!!! BSD in Pa

Posted By: MR_P_BODY

Re: 727 front bushing - 05/26/12 08:31 PM

With a dial indicator mounted to the crank and the
indicator on the outer pump bore(no conv or pump in
it) slowly turn the crank and see what you have...
might need to get a set of offset alignment pins...
also check the conv for run out on the input hub...
conv mounted to the crank and indicator mounted to the
block with the indicator on the hub... turn the crank
and see if its out

Posted By: jamesc

Re: 727 front bushing - 05/26/12 09:25 PM

when the engine was align bored the crankshaft moved up in the block a small amount. as mentioned you need to check the crankshaft/transmission alignment

Posted By: John_Kunkel

Re: 727 front bushing - 05/26/12 09:32 PM

Bronze bushing or babbit? Is the wear pattern all on one side or all around?

Posted By: turbobitt

Re: 727 front bushing - 05/26/12 11:57 PM

I had a problem similar to this about 20 years ago. The problem ended up being that one of the alignment dowles was in the block a little to far. The chamfer on the pin combined with the chamfer on the bellhousing allowed the case to move around and not properly locate.

Allan G.

Posted By: cermac

Re: 727 front bushing - 05/26/12 11:59 PM

Quote:

Bronze bushing or babbit? Is the wear pattern all on one side or all around?

The wear pattern seems to be on opposite sides. For example at 12 o'clock and 6 o'clock. It's a clevite babbit.

Quote:

when the engine was align bored the crankshaft moved up in the block a small amount. as mentioned you need to check the crankshaft/transmission alignment

The engine was rebuilt 2 years ago. We ran all year last year w zero problems. It seems weird that we would have problems now by just changing the converter.

Posted By: cermac

Re: 727 front bushing - 05/27/12 02:34 AM

Dowel pins are 1/4" out from block. Should be more?

Posted By: MR_P_BODY

Re: 727 front bushing - 05/27/12 02:39 AM

Quote:

Dowel pins are 1/4" out from block. Should be more?

Yes about 1/2"... tap them out some

Posted By: cermac

Re: 727 front bushing - 05/27/12 02:45 AM

How do I attach dial indicator to crankshaft. I have a magnetic mount for my gauge but not sure how to make that work.

Posted By: MR_P_BODY

Re: 727 front bushing - 05/27/12 03:01 AM

Quote:

How do I attach dial indicator to crankshaft. I have a magnetic mount for my gauge but not sure how to make that work.

Put the magnetic base on the back of the crank and
use a long arm to get the indicator out to the pump bore

Posted By: turbobitt

Re: 727 front bushing - 05/27/12 03:28 AM

Quote:

Quote:

Dowel pins are 1/4" out from block. Should be more?

Yes about 1/2"... tap them out some

If only the chamfer part of the dowls are sticking out than you know its going to be trouble.
Allan G.

Posted By: rickraw

Re: 727 front bushing - 05/27/12 04:57 AM

with mr.p, i made my own dowel pins using a 1/2 bolt shank. mine are sticking through the trans case about 1/16". also use the trans case u are indicating to the crank.

Posted By: 440Jim

Re: 727 front bushing - 05/27/12 02:17 PM

Quote:

With a dial indicator ...
check the conv for run out on the input hub...
conv mounted to the crank and indicator mounted to the
block with the indicator on the hub... turn the crank
and see if its out

I like to see 0.003" TIR or less, 0.010" TIR is bad, inbetween is marginal.

Attached picture 7223439-Converter_runout9_1024.jpg

Posted By: cermac

Re: 727 front bushing - 06/16/12 12:40 PM

For info, found crack at hub in converter! Originally tested with 20# pressure and found nothing. One company rep said that should be enough. Finally took contractor chalk and powdered converter and crack showed immediately. Called company again and rep who sold it to me said pressure test I did probably wasn't enough. They found crack and now deciding what to do! Under warranty! Only 15 runs! Having removed trans SIX times and replacing front pump and seals and bushings hopeful to get fixed.Thanks to all who helped here for input!

Posted By: MR_P_BODY

Re: 727 front bushing - 06/16/12 01:27 PM

Quote:

For info, found crack at hub in converter! Originally tested with 20# pressure and found nothing. One company rep said that should be enough. Finally took contractor chalk and powdered converter and crack showed immediately. Called company again and rep who sold it to me said pressure test I did probably wasn't enough. They found crack and now deciding what to do! Under warranty! Only 15 runs! Having removed trans SIX times and replacing front pump and seals and bushings hopeful to get fixed.Thanks to all who helped here for input!

The crack at the hub is SORTA common... it cracks
right next to the weld(heat affected zone).. I usually
check the converter with 125 psi... thats all the
pressure I have.... glad you found your problem

Posted By: racerx

Re: 727 front bushing - 06/16/12 03:54 PM

Quote:

Quote:

For info, found crack at hub in converter! Originally tested with 20# pressure and found nothing. One company rep said that should be enough. Finally took contractor chalk and powdered converter and crack showed immediately. Called company again and rep who sold it to me said pressure test I did probably wasn't enough. They found crack and now deciding what to do! Under warranty! Only 15 runs! Having removed trans SIX times and replacing front pump and seals and bushings hopeful to get fixed.Thanks to all who helped here for input!

The crack at the hub is SORTA common... it cracks
right next to the weld(heat affected zone).. I usually
check the converter with 125 psi... thats all the
pressure I have.... glad you found your problem

Mr. P what tool did u use to test the conv.?Is it something u fab. r purchase?......Thax