Transimission housing cracked, now what?

[VIKING_MECHANIC]

I don't even know where to go at this point. Nothing but bad luck with this damn truck. Me and my brother were trying to install the transmission to the engine, using @Schurkey advice and removed the oil pan. We got the trans on, but noticed that only one side of the trans was flush with the engine. No matter which way we moved the trans and engine around, a gap was always present on the on side but not the other.

After carefully tightening both side little by little, we got the gap down to less than 1/8 of an inch on both sides, but then a loud pop rang through the garage.

Two things I can think of that made this happen:
1. The transmission housing was warped from the factory or some interesting abuse happened with the previous owner. I do remember that the trans was rather difficult to get off the engine when I first pulled it off, almost as if it was stuck on the dowel pins.
2. The pressure plate that came with my clutch set is "OE original", but not actually the same as the original design. I'm thinking that the new pressure plate was preventing the trans from actually being flush with the engine.

I don't know, these are just my thoughts. Pictures to follow.

 

[VIKING_MECHANIC]

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[VIKING_MECHANIC]

This is the old pressure plate.

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This is the new, "OE original" pressure plate. Notice the fingers on the new one are recessed and the overall design is slightly different.

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[Supercharged111]

With the trans halfway tight you should have been able to jerk it home by the tail housing. Something wasn't lined up or seated correctly. How was the pilot bushing/bearing looking? I don't see a pressure plate snapping a bellhousing.

 

[VIKING_MECHANIC]

With the trans halfway tight you should have been able to jerk it home by the tail housing. Something wasn't lined up or seated correctly. How was the pilot bushing/bearing looking? I don't see a pressure plate snapping a bellhousing.

The pilot bearing looked good. No damage that I could tell.

I don't know wtf is going on. I'm going to swap out the two pressure plates tomorrow just for ***** and giggles and see what that does.

 

[Frank Enstein]

You may be able to have the bellhousing welded. Regardless I recommend measuring from the block face to the top of the pressure plate where the release/throw out bearing touches. Then measure from the front face of the bellhousing to the front of the release bearing. The release bearing should be a little bit farther away from the bellhousing face than the pressure plate is from the block. A tiny bit of clearance is all that is needed. Also check the pressure plate for shipping blocks. Never saw them with a diaphragm pressure plate but it won't hurt to look.
Check the pilot bearing measurement the same way that you did for the throw out bearing.

Make sure the splines on the input shaft have no rough spots or burrs. Repair any rough areas with emery cloth. Check to see that the clutch disc slides up and down the splines of the input shaft.

Lubricate the splines with a regular pencil. Just run the pencil up and down the splines. That is all the lube they will ever need. Do not use liquid lubricants.

Quick tip: Shim the starter before you put the bellhousing on. It's about 1500 times easier that way.

The trans should slide up to the engine by hand. A TINY bit of lubricant on the dowel pins can do wonders. Clean the pins and the corresponding holes in the bell housing but DO NOT undersize the pins or oversize the holes. A light wire brushing is all you need to remove corrosion (a battery terminal cleaner is pretty good for this). Any nicks or burrs can be filed down flush but no more. New ones are readily available.

The dowel pins need to be snug to align the transmission input shaft to the crankshaft centerline. Get the bellhousing on the dowel pins and get the bolts started no tighter than finger tight preferably just a few turns in. If the trans won't fit up to the engine by hand STOP and find out why. Take your time.

You may already know 99% of this but I didn't want to leave anything out. You've had enough trouble already.

Also you may be tempted to use the Fake aluminum "welding rod" you can get at the hardware store. Don't. The stuff works great for small items but you cannot get the bellhousing heated evenly enough to work. Same for JB Weld. The repair won't hold up.

Good Luck!

 

[Frank Enstein]

This is the old pressure plate.

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This is the new, "OE original" pressure plate. Notice the fingers on the new one are recessed and the overall design is slightly different.

You must be registered for see images attach

You must be registered for see images attach

The fingers are recessed because the clutch disc is new. The fingers will raise as the disc wears.

 

[Supercharged111]

The clutch pressure plate fingers will give way long before the bell cracks or else the bell would blow every time you pushed the clutch in. Something else is definitely wrong here.

 

[VIKING_MECHANIC]

You may be able to have the bellhousing welded.

I've thought about that, but I don't know how well, if at all, it will work.

I was able to slide the trans onto the engine fairly easily, but it there was a gap on one side no matter how we moved the engine/trans around.

I figure this is mostly human error, but something wired is at play to me.

 

[VIKING_MECHANIC]

The fingers are recessed because the clutch disc is new. The fingers will raise as the disc wears.

I didn't actually know that. This is the first time I've been able to actually work on a manual.