The Stovebolt Site Forums The Shop Area Engine Shop problems putting engine back in..need advice

I'm writing for my husband who is at work at the moment so excuse my lack of knowledge if it seems I'm not sure of truck/ engine lingo.

he has a 1950 chevy 3100. he just had the motor rebuilt (235) when he took it out everything came out no problem. but yesterday as he and a friend were trying to put it back in they ran into some problems.

they can get the engine in almost all the way but are left with a gap under 1 inch between the bell housing and where they need to bolt it in.

it seems as tho the transmission won't fully go into the crank shaft. they took it out and tried 3 times and just keep getting stuck with that 1 inch space. it is engaging because when they tried to push the truck it was in gear from them turning the clutch plate, just not going in all the way

he called a friend who said to just try and start the bolts and that would help draw them together but when he tried the holes were not perfectly lined up so he couldn't.
they've tried different angles, rocking back and forth, side to side, greasing up the transmission.

he did have his crank shaft replaced as his was really worn down. could that affect how they fit together since the tranny is the original?

any tips or tricks would be so appreciated. after work we will be out trying to get it in again!

It sounds as if they are trying to install the engine with the trans still in the truck. Is that correct? If so, remove the trans, attach the bellhousing to the engine, install the flywheel then install the engine in the chassis. Following that, install the pressure plate and clutch with an alignment tool, install the throw out bearing than install the trans. Make sure the crank has the correct pilot bearing.

yes the tranny is still in the truck. he was trying to avoid having to take it out because they only have the cherry picker and thought it would be impossible to get the right angle with the transmission attached to the engine.
never thought of putting the engine in and then attaching the trans... the same issue can't happen where it doesn't go in all the way?
this is his first time doing all this so a lot of rookie mistakes happen, but he's learning. he does have the plastic alignment tool.

what would make it go in so far except for that last inch?

I would check to make sure the pressure plate and clutch are properly aligned and as noted above that the pilot bearing is correct and fully seated in the crankshaft. When I installed my engine years ago I cut the heads off bolts and slotted the ends. Then I used these as guide pins to align the trans to the bellhousing. Once aligned I replaced the guide pins one at a time with bolts and tightened them equally to draw the tranny to the bellhousing. I also had the sheet metal off The front and radiator removed which made life easier.

you can use the cherry picker to lower the tranny to the floor by going in through the passenger door. with the floor panel removed its a straight drop to the floor. install it in the same manner after the engine is bolted to front and rear mounts. i had an issue when i put my first motor in, it wouldnt fit and i was an inch away. after pulling the engine back out i notice i left the tranny bolts in the bell housing so they wouldnt get lost. once remove it went right into place.


if it was from someone knowledgable with 235's the pilot bushing should of been replaced. should be easy to tell. if its somewhat shiny then most likely it was replaced since they are bronze.

thanks guys. I'll pass all this info on to him! wish us luck

Probably the reason it won't go the last inch is the pilot bushing isn't accepting the end of the input shaft of the trans. One can buy plastic input alignment tools(cheap) to help get this done, or use an old clutch shaft. Everyone should have one lying around.

Loosen all 6 clutch bolts, slide the tool in while moving the clutch disc around until the tool slides in all the way-Don't force it by beating on it with anything. It might take a few tries. As was suggested, make up some headless bolts long enough to insert through the trans. into the bellhousing to guide the trans in.

No reason to remove trans. to attach the if input shaft tool slides in. To line up the splines on the input shaft w/ the clutch disc, put the trans in high, so one can turn the rear u-joint flange on the trans. while gently pushing the trans into the bellhousing.

Good luck.

Those plastic line up tools are not accurate. I measured one once & compaired it to the trans shaft & it was .007 smaller. An old trans front shaft works best if you can find one. Like Pruss says, loosen the clutch bolts & put the iron alignment tool in & then tighten them.

The three plastic line up tools I have received with clutch assembly kits over the past 5 years have been as tight as my trusty and venerable front shaft. I do, however, prefer the front shaft.

I do exactly the same thing and it works really well. I use that method on anything that's heavy and awkward like tractor final drives and such and it makes the job much easier.