I have 1990 S-10 Blazer, 2WD, 5 speed manual transmission. I've had to replace the 4.3 L engine due to a blown head gasket. The job has gone smooth so far - I'm replacing the blown engine with a 4.3 L from a '91 S-10 Blazer. This replacement engine was hooked to an auto transmission...I removed the old flywheel and mounted the one from my blown engine. I've got the engine in place and on the motor mounts, tranny seems to be lined up fine, but the two won't pull together. I can jack the tail of the tranny up a little and close the gap at top of the transmission/engine block, but the bottom's not pulling together. There's still about a 1.5 inch gap at the bottom - i can barely get the bolts to reach the holes in the engine block through the transmission. I thought i had the one on the driver's side, just above the dowel pins (which are lining up) started, but the tip of the threads on the bolt stripped when i turned it instead of pulling the tranny to the engine. What am I missing?

 

Did the crank have the hole machined into it for the pilot bushing/bearing? If so, did you install a pilot bushing/bearing and was it the proper size?

 

Makes sense...the crank was machined with a bearing inserted, but I did not check the size of the bearing. I'll pull the engine back out this evening to check - should be a quick thing to check. Thanks!

 

always install a new bushing/bearing when replacing the transmission (or engine).

The easiest way I've found for removing the pilot bushing from the back of the crankshaft is to get a piece of dowel rod the same OD as the ID of the pilot bushing. Take a cake of soap, cut off small slices with a knife, use the dowel rod to push the soap through the bushing. Once you can't push anymore in by hand tap the rod with a hammer. It will begin to push the bushing out of the crankshaft. Add more soap as needed and keep tapping the dowel rod with the hammer. The hydraulic pressure of the soap being pushed by the dowel rod will force the bushing out of the crankshaft. Once its out scrap the soap out and install the new bushing/bearing.

This may not work so well on a bearing. I've never seen a pilot bearing in a Chevy crankshaft, but all my stuff is old.

Oh, never use the bolts to try to force the transmission to mate up to the engine. If the alignment is right they'll "pop" together almost before you know it. Trying to use the bolts to crank them together can break a piece off the transmission. I've seen bellhousings at swap meets with the broken pieces of the bolt hole welded back on the housing.

 

I used longer bolts to line up the bell housing and used them to bring the engine and the bell housing closer than used the correct bolts. I know that was not your issue but the longer bolts really made lining things up a lot easier.