Trouble mating transmission and engine

I’m working on my mr2 spyder and have the engine and transmission ready to go together before putting them back in the car. I checked the fit of the clutch disc to trans input shaft before assembling things and the fit was good. Trans splines are good. Centering the clutch disc is next to impossible because the car has no pilot bearing so there’s nothing for the clutch centering tool to center on. I’ve got it really close and am able to get the trans input shaft into the clutch disc and can get the transmission up to the alignment dowels but can’t get it to go the rest of the way. The dowels are close to perfectly aligned - within a millimeter or so - but can’t get the trans onto the pegs and flush against the engine. I tried putting a bolt in the hole next to one of the pegs and gently tightening it. It pulled the trans onto the dowel on that side but the other side stayed gapped and as soon as I took the bolt out the transmission sprung away. I have the engine strapped level to a cart and the trans on my engine hoist. Obviously getting them perfectly level with each other is tough. Is alignment the problem? Is there something interfering that shouldn’t be? Should I just put the bolts in and force it together? (Yikes!) Any suggestions for getting this thing assembled??

If you need to go the same direction with both dowels, you are likely slightly off on the disc alignment.  If its not a stepped flywheel, there is usually a space around the outside edge of the pressure plate where you can see or feel the edge of the disc.  Stepped flywheel makes that harder. 

Release bearing is free to slide?

Are you alone?  I find a second set of hands makes that job a lot easier.

Get some longer bolts, cut the heads off and turn them into the block-use them as guides to slide the trans/engine together

Bump the clutch.  That is, with it as close as you can get, press the clutch lever thingie so the pressure plate will release the hold on the plate.  It should center itself at that point, in my experience.

And is there no hole in the back of the crank?  Nothing at all?  The 3S cranks all have something there, even though they don't use a spigot (pilot) bearing either. 

Don't forget the Barry White, very important to set the mood for mating. 

What all change from the last time the engine and trans were together?

@loosecannon: I’ll try that! I do have a good supply of bolts to modify. 

@hess: there is a hole in the crank but it’s bigger than the hole in the center of the clutch so I can’t see how to use it to center the clutch. 

@ECM: awww yeah

@Dusterbd: new clutch flywheel and pressure plate. 

In reply to dculberson :

When I did mine 2 years ago, I used the centering tool that came with my clutch kit.  Seemed to work well.  Are you sure the splines are mating between the clutch and input shaft?

I'd focus on recentering the clutch again?  It should just pop back together

https://midshiprunabout.org/mk3/transmission-removal/5/

Never use the bolts to pull them together, tends to break things. I checked my 1ZZ Prizm (Corolla) FSM and it isn't any help as it seems to think there is a pilot bearing, so do half the clutch kits that come up for a MR2 Spyder. I'm guessing the crank is machined for the bearing, even if the trans doesn't use it. 

In reply to eebasist :

I’ll look at the tool and center of the crank again but when I was assembling it the tool didn’t fit into anything beyond the clutch so it acted more like a handle to help center it rather than an actual centering tool. 

The clutch and trans input shaft are engaged - turning the engine by hand turns the output of the trans. 

Yes, NEVER use the bolts to pull together-that's how I blew up the V12 in the MGB. The trans input shaft was slightly too long and put pressure on the crank, which destroyed the thrust washers and the engine. If necessary, removed the trans input shaft and use that as a centering tool

I would have someone turn the crank while you push the transmission onto the engine. I have see where the trans input shaft was barely engaged onto the clutch but the splines not perfectly lined up. 

Turning the crank while pushing helps in those cases.

They make a "universal" clutch alignment tool.  It has a tapered end that fits any size crank hole.  You put that in, then use the slide part to align the disk.

Note that I have also successfully used a tree branch at a campground.

Did you put a 1zz or 2zz engine in?  When I put a corrolla 1ZZ in my MR-S, I  swapped flywheels (corolla was an auto) and the clutch centering tool fit past the clutch and into the flywheel to keep it center.  If you cant get yours past that I'd be concerned its not centered.  Does your flywheel have a indentation in the center?

Mine went in with no issues after I had it lined up (2nd try)

Have you tried swearing at it?

Clutch plate in backwards?

The tool should bottom the splines on the flywheel and locate firmly with the pilot bearing.

Try loosening the pressure plate and realigning things. 

Also (rwd guy, so may not apply), try rotating the output of the trans with it in gear while you jiggle and push. 

Lastly: confirm that there's no crap in the pilot bearing recess in the crank.

Doesn't sound like a fun job...  Sometimes using some longer bolts can help you align the transmission to get it to mate with the engine.

Does the clutch disc fit on the splines of the transmission input shaft?  You should make sure of this before installing the disc under the pressure plate.

EastCoastMojo said:

Don't forget the Barry White, very important to set the mood for mating. 

Truth. Seriously...you gotta hump it in there.  Get it lined up and close, then mount up and start whispering dirty things and thrusting.

In my experience, the clutch can be centered by eye just fine. If it looks centered in the pressure plate, it's good enough. No need to use a tool other than a long screwdriver. 

Also in my experience, when it gets close but won't go, something is in the way. Clutch plate backward like Dean said, clutch release lever not releasing, throw out bearing not seated, trans not on straight, etc. Clutches never seem to spline right for me, I always need to spin the output shaft a bit to line em up. This is not always easy, esp on front drive cars.

If you want to rule out a centering or clutch disk spline issue, install the trans without the clutch in the pressure plate.

dean1484 said:

Clutch plate in backwards?

 I'll admit to doing this. Spent the better part of a day cussing and stomping around the shop, wondering why the berkin' 'box wouldn't mate up to the block. Once I figured it out, (Doh! ) it slipped together like Barry White was playing in the background. 

Is this the engine from the auto MR2 parts car now being mated to the manual from your good car? Are the dowels longer for the auto? Is the dust shield the same? Is there  really no pilot bearing? This sounds crazy to me. If this is, indeed the engine from the auto car, I recommend a side-by-side comparison. Something has to give. 

Also, clean out all holes, inspect dowels for damage. That's all I've got.

In my experience, the later model Toyota motors are not using pilot (spigot) bearings. At least 2 manual motor/trans from the factory that I have examined did not have a spigot bearing.  3SFE in a manual Y2K RAV4 and a 3SGTE in a manual '97-00-ish Caldina. I was surprised by this as well, but the input shaft is pretty stout and I guess the input bearing is all it needs. These manual transmissions were also not the same, but the same family, and the family known as being bullet proof rock curshers.  Really, the spigot bearing only does something when the clutch is disengaged, so if the input bearing and shaft is a bit stouter, why bother?

Most/all front drive transmissions don't use pilot bearings.

Rear drive transmissions usually do because the input shaft is only supported by one bearing.  The pilot serves as the support on the other end.  Front drive transmissions don't have that kind of layout, the input shaft is the length of the transmission and is supported by two or more bearings internally, so a pilot would be redundant.

The most you'll usually see with a front drive setup is a machined hole in the crank as a courtesy to you in order to give you something to center the clutch disk with.  I'm starting to see engines where the end of the crank is completely flat, or has a depression that is much larger in ID than the clutch splines.  You can't center those disks with anything but your eyeballs.