Issues reinstalling trans after oil leak ruined clutch
 

HI all - at the risk of getting burnt again from the flames, I thought I would posted a question to the most responsive miata subforum I know. I recently had an oil leak from my vvt feed line get into my trans bell housing and ruined my clutch. Rather than bringing it to a shop which didn't previous even have the courtesy to reinstall all of the trans bell housing bolts, I figured I would take on the job myself (first time obvi). I took it in small chunks 30 to 60 minutes at a time every few days over the course of the last month. Got everything apart and even took the time to replace the motor mounts will the trans was out. I got sick deal on a used ACT 6 puck, pressure plate and fidanza flywheel and got it all installed up to the point of installing the trans which is where I'm stuck. Tonight is my 2nd 2 hour session trying to get reinstalled.

I'll skip the drama and basically get to the point from here on out. I bought some m12x1.5 100mm long bolts to help me line up the trans once I got it close. Currently I have 4 of those bolts with the trans on it, in what appears to be perfectly alignment with the engine block. I used a floor jack to lift the crank pulley to rotate the engine down for easier alignment. I have the weight of the trans on a floor jack below. I can slide the floor jack forward and feel the slip in of the input shaft and off and the same. However, as much as everything is lined up, the bell housing is still 1/8" to 1/4" of an inch from the engine block when simply pushed in. I have/am considering using the trans bolts to "pull" it in the rest of the way. I have played with moving the engine as I thought perhaps the splines weren't lining up. To test that theory I put the drive shaft back on the trans and turned the engine crank pulley while the car is in gear and the drive shaft turns.

I googled some stuff and came into an ls1/3 forum that had half the guys on there talking about that's how they finish off their trans installations every time, so I'm here to get your guy's experience on the matter before I end up destroying something I've spent about a month of here and there's trying to put together. Am I just being too cautious or not cautious enough? I can't imagine that the splines are misaligned at this point otherwise the driveshaft wouldn't turn.

Is it snagging on the locating sleeves found on a couple of the bolt holes in the block? That would be greater than your gap I think, but check it anyway - may require some aggressive juggling/shoving to get it over those. Otherwise it sounds like there is some obstruction in the spigot hole, or the faces of the block/bellhousing.

The other thing that could cause problems is some issue with the TOB, is that arm free to move when you have it in as far as it is going? If it is contacting the pressure plate, it might point to a pressure plate/flywheel issue. If they are correct, you may just have to adjust the actuating rod by shortening it - but that suggests they are different dimensional specs to what you took out - double check these are not going to cause any other issues.

I haven't replaced many clutches/gearboxes, but they have always gone home relatively freely - after a lot of cursing shoving and general carry-on.

FWIW, there are dowel pins in the block that do the final alignment of the trans to the block. THey are short, about 1/8" or so. I wonder if you're catching on those because they are not perfectly lined up? Once they are, it will pop into place flush.

My advice is to put every bolt in the bell housing, push it as far forward as it will go, and then grab the trans is move it up/down until it "pops" into place. I wouldn't draw it in with bolts. But if you do use bolt, I mean just BARELY apply any torque. If a dowel pin was dented for example, it would catch, but light torque would easily overcome it and pull it together. If you're using more than 5 ft*lbs, something is off and the chance of breaking something expensive is very high.

Thanks for the advice fellas! I think I might've been misaligning with the dowel pins. I put every bolt in hand tighted and then basically just circled the trans slowly tightening up making sure to do my best to maintain the same gaps all the way around. Eventually the trans/block mated up and did so while putting only very small effort of torque on the bolts. I think @patsmx5 was right. Man, seems silly thing to get stuck on, but I guess when it's your first time, its always hard to find the hole! heh....

Gave you a cat for figuring it out
#compensation

On my BP there is a sleeve concentric with one of the LH bolt holes (looking from the rear) as I recall, same function as the studs Pat describes, but they can be dislodged fairly easily, and would be less rounded than a stud making them harder to slip into the receiver. Might be two sleeves, might be one of each, hopefully it will be a long time before I can check.

You may have also misaligned the clutch plate a smidge, this can cause similar issues

i use the alignment tool, but always do a visual check to ensure the plate is centered before I give the pressure plate final torque. Too much slop in the plastic tool. You can put a few turns on the PP bolts and still slide the plate around.

At any rate, glad you got it in, and are taking a cautious approach.

Glad using the bolts didn't go sideways for you. Attached is how it worked out for me, and I never felt like I was torquing hard on the bolts at all to be honest. The result was a complete inability to shift/disengage the clutch. Like you, this was my first time taking the transmission off, except I was on a tight deadline. On the plus side, the job is a lot quicker the second time.

What worked better for me was to make sure that the plastic alignment tool was really, truly centered. There's slop in it, so that required moving it around some with the bolts kinda-sorta holding things together. Then you can nudge things around until the alignment tool goes in/out without any resistance whatsoever. Still no idea how to get the tranny back on easily... I just manhandled it with the tail being held up by a transmission jack and/or my legs, cursed for a good 30 minutes, gave up, cursed some more, and it finally popped right in.

Congrats on getting it to seat finally!
I frequently have used the "bolts to pull it in" approach, having done dozens of trans swaps on RX7 and Miata race cars.
As long as one is as careful about it, as you describe being, it works fine, with no damage to the pilot bearing.
Other times it simply pops right in to seat well, seems a bit random.

It is also possible your nice replacement clutch spline had a burr on in it, or the input shaft does, which caught it and made it harder to push on.
I have had that happen, and now make a practice of sliding the clutch plate onto the input shaft out on the shop floor, to test it, before putting it on the fly wheel.