FlaVert

I am trying to install the M21 transmission in my 68 BB. The tranny stops going in about an inch from mating with the bellhousing. What am I sticking on, the clutch disk or the pilot bushing? I test fit everthing before reassembly, so I know everything fits.

Thanks,
Rick L.

bashcraft

Did you align the clutch disc when you bolted on the pressure plate?

FlaVert

Yes. Used the alignment tool that came with the clutch kit. Is it possible to knock the disk out of alignment while trying to install the transmission?

bashcraft

Possibly, but it would be pretty hard to do. The pressure plate is exerting quite a bit of clamping force.

You may want to try and align it again. Those tools are usually pretty sloppy.

FlaVert

Oh joy! When I first tried to test fit the clutch disk to the input shaft I thought it was the wrong one, but then discovered that it is a really precise fit. I can't imagine how I am going to be that precise while trying to install the tranny. Should I be doing this with the transmission in gear or in neutral? It's in gear right now.

Gordonm

What I have done on occasion when this happens it hook up all the clutch linkage. When you have the transmission almost in, have someone push in the clutch. This will release the clutch disc just in case you have not lined it up perfectly. Once the disc is free the trans should slide in very easily. I have done this many times when someone, me included has not lined up the disc and pilot bushing just right. It has to be almost perfect to get it to all go together.

FlaVert

I thought about this, but I was afraid the clutch disk would slip completely out of alignment and I'd have to tear everything apart again. I may end up trying this.

I pulled the tranny back and slid the alignment tool in and it goes right in all the way and seats in the pilot bushing. I know it is seating because the pilot bushing I put in has a slight lip on the inside, and I can feel that lip with the tool, and then feel it go all the way in.

How about the angle of the engine and transmission? I am doing this on a scissor lift and I have the back of the engine supported so that I can raise and lower it with the lift. Any tips on getting the angle correct?

Gordonm

Only have some push in the clutch when the transmission is in far enough where the splines are engaged. You are working the trans in and when it has that last inch or so to go have someone push in the clutch. The disc cannot fall out or down if the trans is in this far.

As for the alignment yes try to get the trans and motor on the same plane. I know it is tough when you are wrestling the trans but don't be afraid to give it a little wiggle up and down and side to side.

I also use guide pins to make it easier. Get yourself some long bolts and cut the heads off of them. I use 2 of them. Thread them into the bellhousing and use them as guide pins. Once the trans is "home" thread in the other two bolts just snug so the trans does not go anywhere. Remove the guide pins and put in the other 2 bolts.

I never liked the alignment tools either. They have to much slop. I have always used and old input shaft from a Muncie. The fit is much tighter for alignment.

firstvett69

If trying to get someone to help is almost impossable or by the time you find someone to help you could have put the trans in 5 times, this is what i do. Oh by the way guide bolts are a good way to. I get two longer bolts one on top and one on bottom snug them up abought a half turn after snug get in the car push clutch in, then give the bolts a nother turn and repeat this untill the trans is in. No problem Ha Ha, always works for me, Id rather do it myself. Every time i have someone help me it takes twice as long

todds74

When i installed my 4 speed it would not go in all the way. the problem was that i did not drive the pilot bushing in all the way and would not allow the trans. to go all the way in. Drove the bushing in all the way and trans. went in just fine.....

FlaVert

How can I tell if the splines are engaging the clutch disk? I don't think they are, but I could be wrong.

bashcraft

Put the tranny in 4th gear and try to turn the output shaft.

FlaVert

Shifter isn't installed. How do I set it to 4th gear?

bashcraft

I think you move the front lever back, but it doesn't matter what gear it's in. It'll just be easier to turn in 4th.

Gordonm

Just put it it any gear. Turn the shifter fork to put it in any gear. If the trans is only an inch away the splines are engaged. They engage pretty quickly. Tightening the bolts to draw it in is risky no matter how you do it. Many have done it with no problems and had success but you would hate to hear a CRACK and break off an ear of the transmission.

FlaVert

Worked on this some more today. I tried everything you all suggested, guide bolts, having someone push in the clutch while I tried to feed the transmission in. Nothing worked. So, I figured it had to be something screwed up inside the bellhousing. I pulled the bellhousing and just for ****s and grins I slid the transmission in to the pressure plate/clutch disk. Guess what, it went right in all the way into the pilot bushing. No problems. So, what in the bellhousing could be keeping the transmission from going in? I am starting to suspect the part that the through-out bearing rides on. Seems like it is kind of a tight fit between the bellhousing and the flange at the transmission. I ran out of energy today, but I think I am going to try putting the tranny in with the bellhousing loose and see if that will work.

Any other suggestions?

Thanks,
Rick L.

tonyv123

Are you bolting a new bell housing to the engine? It sounds like your bell housing isn't dialed in to specifications, and needs off-set locating pins. If it's the same bell housing going on the same engine, this probably isn't the problem. If it is a different bell housing, or different engine, do a search here for dialing in a bell housing. Let us know.

FlaVert

Everything is original except for the pilot bushing, the clutch disk and the pressure plate. I am starting to think that maybe a wire for the starter got caught between the bellhousing and the block.

BBCorv70

Sounds like the throw bearing may not be sliding onto the sleeve. When you hit the 1 inch stop, can you move the arm back and forth? The throw bearing should slide back and forth a bit. If it's not sliding onto the sleeve the arm may not move freely at all.

You may try wiggling the arm up and down just a bit as you insert the transmission, try to get the throw bearing to slip onto the sleeve.

It's been a while since I've seen the input shaft on my transmission but I think there's a
slight taper which should allow a slight misalignment with the pilot bushing. If the bushing were the hang up I think you'd get closer than 1 inch.

FlaVert

Worked on this some more tonight. Tried getting it to go together with the bellhousing mounted but loose. Still no go. So I stripped it down to the flywheel with the intention of knocking the pilot bushing all the way in, instead of the 1/8" or less it is sticking out. Whacked on the bushing a few times with a socket and hammer and it wouldn't budge, so I figure it's seated. So just for the heck of it, I tried sliding the input shaft into the pilot bushing with nothing else interfering and it WON'T GO IN!!! I know I test fit the bushing on the input shaft before I started putting everything together and I compared it to the one I pulled out. The only difference was the bushing I took out was steel colored and the new bushing is bronze colored. They are both definately bushings and not bearings. I froze the new bushing and tapped it in with a hammer and socket. The alignment tool that came with the clutch kit fits in the bushing just fine.

The clutch set is from Luk model 004-049. I ordered it from AutoZone.

Anybody got any ideas before I rip this bushing out and try another one? Anybody know a bushing that will definately fit a 1968 427/400 that is all original, as far as I know?

Thanks,
Rick L.