Reconnecting Engine

OK, so my JD 2640 tractor with the 276 4-cyl engine needed rebuilding. So we split the tractor. While we were splitting it, it was very difficult to separate the engine from the back half of the tractor.......it came apart, but it was quite difficult to get it apart. We finally did, and rebuilt the engine.

Now it's time to re-bolt the engine back on. We have a new clutch, new pilot bearing, new throw out bearing. It is very difficult to get back on.....we spent a good half a day trying to get everything to align so that it will go back together. Re-align, re-align, etc. After hours of trying, we finally get it aligned with the bolts on....but it is still going together very difficult.

We are to the point that the clutch is on the splines, but it is so difficult that we are afraid that the trans shaft will force out the pilot bearing.

Is there some secret that we do not know about getting this back together?

Have you guys experienced a similar problem?

What to do?

Thanks in advance.

Make sure the end of the shaft is not buggered up, feel it.

Did you examine/clean/wirebrush the splines on the pilot shaft(s) and test-fit the new plates on the splines before assembly to make certain everything fit/could slide together smoothly including the pilot into the bushing?

Forcing out the pilot bearing is the LEAST of your worries. (NOT sure where it can even go.) If you have put ANY force on the lined clutch plate(s) they are RUINED.

Go back, figure out what the actual issue is, check the clutch plates for being warped, when all is checked out and well, put it back together GENTLY.

Ditto on checking/cleaning splines & pilot brg area on shaft. Did you rotate engine a little when gap got smaller between halves while pushing together? Did you utilize a clutch disc alignment tool? Is gap between halves equal top & bottom?

Did you test fit the clutch disks on the input shaft?

Yes, make sure the clutch is happy with the shaft,,file a slight taper to the end of the shaft to help it find it's way into the pilot bearing, shine the dowel pins up and champher them a bit, use a measuring stick to make "sure" the housings are perpendicular.."don't pull it in with the bolts",, some times I put a ratchet strap on each side to put some tension on them,,some times I will put it in high gear and shake it good this lets the trans shaft turn a bit to find it's way,,turn the PTO shaft as you go also,,and as always practice makes perfect...

Concerning the problem above, here is what we have done:

--Before tyring to fit the engine, we test fit the new plates on the splines. They slide on easily and perfectly.
--Roated the engine, several times, attempting refit each time.
--The dowel pins are not yet engaged, so they are not the problem.
--There is already a taper on the end of the shaft. It has no large noticable burrs, but it tapers enough that it should not matter.
--We have been using a tape measure to try to determine the gap between the engine and trans housing. Comparing both sides and the bottom, they are very equal. Sure, they might be a few thousandths off, but it is the same down to a sixteenth of an inch on my tape. We cannot get to the top to measure.
--One suggestion was to turn the PTO.....we did not do that, but the plates are already engaged onto the shaft....we can see through an access hole that they are engaged. It is the last half-inch that is giving us trouble.
--We have all four mounting bolts installed but were hesitant to use the bolts to pull the engine up tight.
--We do not have an alignment tool for when we mounted the clutch plates onto the engine. However, we aligned then visually, then left them slightly loose so that we could adjust them as we pushed them together. We can see through an open access panel that the plates are engaged correctly.

With all of this, the engine is still very difficult to push together. We cannot do it by merely pushing on the engine.....although we did not want to force it for fear of damaging the clutch.

Is is the case that once aligned, the engine should slip easily onto the trans shaft? How much force is usually required?

Thanks in advance.