Engine and tranny don't fit together!!!

Sometimes they mate quickly and other times it can take hours, for no apparent reason. So, how far apart is the trans from the bellhousing when it 'quits'? If only an inch or so, it could be a wrong size input bushing in the crank, hence the input shaft won't go in. Or, it sometimes requires a slight turning of the input shaft to align the splines with the clutch disc splines. Inserting a yoke on the output shaft and turning usually does the trick.

 

No, its not the crank, but the bushing that goes into the crank.

I'm assuming your clutch alignment tool goes into this bushing. It pretty much has to, to align the clutch disc properly. If so, check the alignment tool size against the trans' input shaft. They should be identical.

If the alignment tool is one of those cheap plastic ones, I found they really are not all that accurate with aligning the clutch. Being off just slightly is enough to cause the problem you're having. Try to use an old input shaft as your alignment tool.

 

Did you try to put the motor and transmission together out of the car? The yoke is the input ...front of the driveshaft. Sometimes we have extra parts laying around like this separated for use as tools. Its very possible you have a late model bellhousing for the T5 transmission and there is about an inch difference in bell housings that won't work without an adaptor/spacer. Check the part number on the bell housing to confirm its not late 80's 90's part numbers.

 

When you say your clutch alignment was okay, how did you check? I'm assuming with an alignment tool, however that would not require pulling the motor. Are you mating a 289 or 302 with a toploader or T-10? Because of the slight taper on the nose of the toploader input shaft, I've found that a precise clutch alignment is not necessary, so one of those plastic alignment tools should be sufficient. You're not putting a T-5 behind a 289/302 with an early (pre-80's) bellhousing are you? the T-5 input shaft is 3/4" longer and you'd bottom out if that's the case.

Give us all the info on the motor, the bellhousing and the tranny, and we can certainly get you on track.

BTW - the reference to the yolk is referring to using a spair driveshaft yolk on the tailshaft of the tranny to rotate the input shaft in an attempt to get the input shaft of the tranny and the clutch to mesh. I've never used that method, I've always just rotated the transmission slightly, but if you have the tranny on a tranny jack, that would work wonders (I've always either had the car on a lift with the tranny held overhead, or been in my garage with the tranny laying on my chest... which sucks).

Josh

 

Did you remember to install the separater plate between the motor and trans?
Not sure if that will make much of a difference.

I would also take steveshelbysmustangs advice and install the motor and trans outside of the car then install as a whole unit.

 

The tranny pilot shaft has to align with 2 things; 1- the pilot bushing which the end of the pilot shaft needs to fit into, and 2- the splines on the clutch plate. If these 2 parts are not lined together, the ass'y will not go together and act like you are describing. If they are off from each other, you will be able mesh the shaft splines with the clutch, but you will not be able to seat the end into the pilot bushing. Turning the crank will not change the relationship of the pilot bushing to the clutch and the misalignment will remain. If your new aligment tool does not provide the proper alignment, try depressing the clutch and moving the tranny around to get the last inch properly lined up.
Jay

 

This is key. Make certain that "small diameter shaft at the point" is the same size as the pilot bushing in the crank. Most likely it is but its worth checking.

 

If you were using a wood dowel that didn't taper at the tip, then it probably wasn't slipping into the hole of the pilot bushing and it wouldn't have been aligning the clutch to the crank. It sounds like you're on the right track using a real alignment tool.

As far as the splines on the clutch and the tranny input shaft, you are correct in that it's not rocket science... just rotate the tranny back and forth until it slips in (rotating the crank seems like a more complicated two person operation).

Remember to have the tranny well supported when slipping it in. If it's hanging on the clutch splines, the prying action of the weight of the tranny is enough to flex the clutch and kill the alignment.

One other thing I thought of... make sure you've got the alignment tool fully inserted into the pilot bushing. If you're just stabbing it in there until you feel resistance, you may be pushing on the face of the bushing and have not aligned it. After you think you've got it, get a flashlight and visually verify the clutch looks to be aligned with the hole in the pilot bushing. Speaking of, you installed a new pilot bushing and throw out bearing, right? You don't want to pull all this stuff back out when you're done because you didn't throw in a new $10 part.

I used to align the clutch by eye, and then if I couldn't get the tranny to fit up, I'd have a buddy depress the clutch pedal while I monkeyed with it. Not the ideal way to do it, but my point is; the alignment doesn't have to be perfect, just good enough to get the tranny in. Once it's installed, the clutch will move into position the first time the pedal is depressed.

My money's on the wood dowel not actually fitting into the pilot bushing and the new splined tool will do the trick. Keep us informed and good luck.

Josh

 

I know I need pictures to see what I'm doing. I made a crude sketch that might help but my upload keeps failing. I'll send ya an email.
Nevermind I can't attach anything to emails or private messages. Darnit

 

I'd check a couple things, #1 that the input shaft slides into the bearing in the back of the crank without anything else there. 2 I'd slide the clutch disk over the splines on the input shaft to make sure nothing's buggered up. 3 I'd bolt the bell housing to the trans and make sure the collar is the right size (I ran into that on a 289 cobra when we put a toploader in it, the collar was just a hair too big, had to get one for an earier bell housing.

An old mechanic told me when I was doing the clutch in my 70 fastback I had at the time, get some cheep bolts and cut the heads off and bevel the ends and cut a groove in them and use them as guides to slide the tranny in. Also when I had the tranny about 1" or so out and couldnt get it to go the rest of the way, he said to hook up the clutch and just lightly tap the pedel, I did that an it slide right in! Sometimes they go in easy sometimes, not so much. I put a 5 speed back in a Panoz GTS car and couldnt get it in only to find out whoever built the car beat the hell out of the roller bearing and split it, that was an easy fix once we figured out what the problem was. Good luck.

 

Good advice. Also, if the trans splines won't engage into the clutch disk, put a 15/16ths socket on the bolt on the front of the crank and turn the engine over until they line up. Usually you turn the crank about 1/4 turn and the engine suddenly moves back and everything lines up. We had to do that all the time when installing engines in the race car. Tapping the clutch petal with the linkage hooked also works to line up the input shaft to the pilot bearing. DO NOT pull the bellhousing up to the block with the bellhousing bolts. I know a guy who did this once. There was a bind in the input shaft, when he started the engine, the crankshaft was being forced forward and wiped out the thrust main bearing.
Good Luck

 

In the past I also borrowed a real input shaft for a top loader to get them to line up. Some trans shops might let you borrow one if you leave a good deposit.

 

Just proves the old saying "It helps to have the right tools".
Congrats and good luck, now get out there and drive that baby!!!!