Is this a deal-breaker?

[plfking]

I may have found my bus....1996 Int conventional, Thomas body 6 window, 115K miles, DT466, AT545 (yeah, I know ). However, there's a crack in the transmission housing, and I don't know how critical that is. It sure doesn't SEEM like a good thing.

DSCF0704_zpsv9w2ijxe.jpg Photo by plfking | Photobucket

DSCF0705_zps7vq9xfex.jpg Photo by plfking | Photobucket

When I arrived at the site, there were no leaks at all under the bus (had been parked there for about 3-4 hours). First thing I did was crawl under to see which transmission it had, and saw the crack. I then asked to drive it. Couldn't take it out on the road (the school transportation director wasn't there, and the mechanic said he couldn't drive it because it wasn't licensed, but said I could drive it around the lot), so I basically did exactly 6 burn-outs on their 125-yard long paved driveway......parked at one end, then floored it from a standing start and kept it to the metal. The bus shifted very smoothly through at least 3 gears before I had to quit the gas and hit the brakes, and shifted into reverse smoothly as well (actually as smoothly as my Dodge Dakota). I then parked it and spent another 45 minutes inside and out, and there was still no leakage or even seepage from the crack.

I need thoughts from the experts, please. The crack is just forward of the transmission fluid pan. Could it be sealed somehow?

[Brad_SwiftFur]

That appears to be the bellhousing where the torque converter is. There's no fluid (or at least not supposed to be any) in there. You could probably drive it for months ... years ... with no ill effects ... or it could crack further tomorrow. However, that "crack" looks awful smooth. Are you *SURE* it's not just a casting line?

[plfking]

I'm not SURE of anything.....that's why I'm asking y'all !

[New2Skool]

That looks like a casting trail to me but, that is just a guess really.
Given the shape of the housing, I don't think a fracture would follow such a gradual curve. Especially in a casted piece, I would bet it would fracture nearly straight or in two directions.

I cant say ya or na but, if it were me. Given what I know now, I wouldn't have bought the bus I have now based on rust. Doesn't mean, I gave up on it.

[2kool4skool]

IMO no crack.

[milkmania]

Put the straw of a wd-40 can against it and spray...
Watch it and see what happens. If it's the bell housing, the wd-40 will spray into the crack... If it's a casting line, everything you spray will be on the surface.

If it's the main transmission body, it should spray into the crack also, if you're above the fluid level.

I'm guessing no crack... I'm on an iPhone, but it looks like cast flashing the didn't grind clean at foundry

[milkmania]

So I can see it mo betta and not get that danged Snickers bar popup

[milkmania]

Googled bell housing crack... Although it's aluminum

[cadillackid]

IF it is in fasct a crack.. remember that a 545 is typically only supported by its bell with no rear cross-member on most applications... so it could break..

if its not a crack then no issues .. I cant tell from the teeny pics on the page..

I also wouldve expected a crack to travel along to the bolt hole and t othe edge since a bolt hole is a weaker spot anyway and the stress of a fastener there.. the fact this didnt makes me more believe that its a casting trail as others have mentioned....

-Christopher

[Tango]

FWIW...some of the early Allison's got a bad rap for cracked cases. Problem wasn't so much the tranny as the way the chassis builders installed them. All the newer cases have much more webbing built in to compensate for dumb mounting practices.

[Jolly Roger]

A crack on the bottom? That's a casting/mould mark not a crack and as Chris pointed out it would be around the bolt holes and to me would start from the top down. Unless of course someone had taken it muddling and bottom out on a stump or something but you would see other problems if that was the case?

[Tango]

Typically...if its' not leaking fluid...its' probably not a crack.

[ChiliChzPoopTart]

Steelworker QA guy here: That's a casting mark, not a crack. If you want to be sure you can pick up some penetrant/cleaner/developer and test it. Short instructions on this, spray cleaner, wipe off all crud. spray penetrant wait a few minutes, wipe off as much as you can with lint free rags(bedsheets), wet a rag with the cleaner and wipe it till almost no red is showing up on fresh rags, spray developer wait a few minutes. You won't get all the penetrant off so the developer WILL have red spots, but unless any of the spots grow off the "crack" you're good, if the casting mark turns into a giant red blob you have issues. hers a link to some penetrant thats pretty cheap, I don't use this brand at work but 3-36 is everything WD-40 wishes it was https://www.amazon.com/CRC-Weld-Chec...+penetrant+kit its got the cleaner and developer tagged as the bought with. Feel free to pm me with further questions.

[plfking]

Thank y'all for the insights, gentlemen......much appreciated.