Correct way to mate motor and transmission???
 

When I mated the motor and transmission I tried to leave the clutch release fork in the same angle as when they were removed. I have replaced the cable and helper spring assembly.

Finally got car started (timing issue) and warmed her up. I tried to shift into gear and noted the clutch pedal did not grab for about 1/3 of the travel. I checked the pedal and noted that it was resting about 5/8" from the stop. I tightened the cable all the way to the end of the thread, tightened the adjusting bolt against the clutch positioning lever and removed the pedal cluster board to increase my throw. Started car and could not shift into gear.

I tried to put the clutch positioning lever closer to the clutch release lever but could not get an easy fit.

I cannot position a mirror in order to be able and look down into the hole on top of the mating point.

Should I try and get the clutch positioning lever closer to the clutch release lever or should I unmate and remate the motor and transmission? Thanks again,

I like to play some Barry White music to get them in the mood and let nature take it's course.
If the release fork is engaged with the throwout bearing, rotation of the release fork shaft (sticks out bottom of transmission) back and forth should be limited to a few degrees of free play, maybe 2-5 degrees. It will make a clicking noise as it hits the limit of its travel.
Did you remove the release fork shaft from the transmission? I think I reindexed things wrong once doing that but I can't remember.
I'm curious do you leave the transmission in the car when you removed the motor?
-Chris

You need to check this as the engine and tranny are going together. Typically when the engine is out of the car, or the engine is not raised all the way up into the car. At this point, you can use a mirror and see down the small little hole. The fork must fit within the small channel in the TO bearing...

-Wayne

Chris,

That must be where I went wrong. I was playing Sinatra and Bennett!! Barry White!! I'll pull some of his stuff out to the garage with me. I do not feel any free play in the shaft. I must have knocked the fork from it's location when I mated them.

Wayne, Chris,

I followed the progress of the fork during the mating via the hole in top. It appeared to be going in well. Felt some resistance to mating, lowered the motor in relation to the transmission, pushed a little, and it slid right in without a fuss.

The only thing I can think of is that the fork is not in the throw out bearing channel. In other words, I will need to drop and re-connect. Insert your favourite string here.

So Barry White, a little bit of wine, some grease, and more patience. $#*%!!!

Re: Correct way to mate motor and transmission???
 

Groesbeck,
It sounds like the fork is engaged to the throwout bearing. It if weren't, you would had a very difficult time mounting the trannie to the engine. Indexing the arm might be the problem, but the spline is rather coarse, giving you 20-30 degrees of latitude. Is the clutch disk/pressure plate new? If not,did you measure the thickness of the disk?

There should be a slight amount of backlash when it is properly mated. From experience, improper mating means you can't wiggle it at all. Do you have any backlash?

-Wayne

Dave,

I did not measure, but the clutch disk/pressure plate, throw out bearing, and fork were all replaced by PO about 30K miles ago. The white lettering is still visible. Before taking the motor out this time, the shifting was smooth and gentle.

Wayne,

No backlash at all. I have disconnected the battery, then the electricals, then the fuel lines. Tonight and tomorrow I am doing the oil and will lower the motor and start over. Too much fun for one day? Eventually, I will get this right.

Thanks to all,

No backlash = bad. It means that the fork is probably mashed either in front or behind the groove that it's supposed to fit in. When you finally get it together, you will see what I mean about fitting into the groove, and having a little bit of backlash...

-Wayne

I admit, I stuggled with this the first time I put the tranny/motor back together. You will need to check your TO fork and make sure its not bent. It may be a good idea to replace it if you have forced it against the bell housing while trying to disengage the clutch.
My $0.02.

Troy

Wayne, regarding the backlash. I have my engine and tranny mated, the fork is happily in its grovve, the small lever has some freeplay, but it is not loose or freemoving freeplay, it is kinda stiff. Is this normal? Thanks

freeplay = backlash - yes this is normal...

-Wayne

Just to clarify, I know the backlash is normal. I need to know if it is normal for that play to be kinda stiff. It feels smooth, just stiff.

Throwout mis-aligned
 

Hello Guys,
I am doing a rebuild and somehow got the tranny/engine in the car with the trowout bearing mis-aligned('85 930). Can I slide the tranny back enough to do this with a screwdriver, without removing the engine/trans from the car?

Les

sorry, no. the 930 takes some extra care when mating the fork to the bearing. unlike the regular 911 bearing which has a groove all around it, the 930 bearing only has 2 ears, which tend to rotate out of position as the fork is engaged behind them. the hole in the bellhousing gives you enough room to watch with a mirror and flashlight, as you move the engine toward the trans carefully. you can turn the fork by the lower end of it's shaft.

Throwout fork issues
 

Ok... I'm stuck on this one.

I had my engine and transmission in once, but pulled it do to a lack of motion in the transmission throwout fork.

I reviewed my throwout bearing insertion (from the transmission peek hole) and the fork appears to be properly seated in the TO bearing groove. I went ahead and separated the transmission from the case to ensure everything else looked proper. It did.

So... I put the two back together and, again, very little motion in the throwout fork. I have read something about using a screwdriver to move something or rather around through the peek hole, but the descriptions I have read lack a good description.

Are we supposed to used a screw driver to thrust the throwout bearing and fork forward (towards the transmission)?

This is confusing... to say the least. The throwout bearing doesn't seem to want to move more than a very tiny bit on my install... Maybe 5mm at the most. :confused:

I need some direction on this.... thank you in advance for your help.

Eric J.

At least on a 1970-1971, you need to turn the little ears of the throwout bearing 90* to lock it to the pressure plate.

With the tranny and motor mated you should have minimal movement of the release lever
(by hand). Your 5mm is probably good. No screwdriver needed. As the trans. slides onto the studs turn the release lever shaft ( from underneath) so that the arms fits in the grove on the T/O bearing as you push the trans. on. You won't be able to move the lever by hand enough to release the pressure plate. Once the cable is attached and adjusted all should be good.

Did you mean to turn the ears on the throwout bearing 90* to lock to the clutch fork? That's how I do it on my 914 track car, which uses the 70-71 style clutch.

Eric - You can turn the throwout bearing with a screwdriver through the opening in the bell housing.

Scott

Reply...
 

Thanks everyone for chiming in.

I think I need to follow Pete's direction on this since we have similar transmissions (915).

So... Pete are you saying the throwout fork doesn't move more than 5mm by hand (almost seems more like slack than any real movement), but should move a greater distance when the cable is installed and you step on the clutch?

I actually did not think my fork lever was moving at all when I stepped on the clutch after my initial install. It seemed like it just stayed straight. Perhaps that's what it does, but I would think it has to move at least an inch to engage and disengage.

Thanks again for your responses.:)

Yeah, that's what I meant. ;):D

IME, you can't move the fork by hand if it is installed correctly or incorrectly.

If you install incorrectly, you can't move it with your foot either. A PITA to get right till you figure it out.

I got mine in the car with the TO bearing and clutch fork not engaged properly. Real pisser!

Guys - some of this is getting overcomplicated.

First off, what happens with the 911 (or 901) - or G50, for that matter - TOBs has nothing to do with the 915. No rotating of anything, no screw drivers, etc. Haynes failed to point out that various nice pictures it had related to the 911 tranny, misleading a whole generation of DIYers.

Secondly, the most common problem with getting the fork not quite in the right place is that the engine won't slide all the way in. This is a kind of self-correcting problem. It is clearest if the fork points straight back, so it hits the diaphragm spring at about a perpendicular.

That's not too bad, because you know it, and can back the engine out a little and move the fork (by fingers on the bottom of the shaft) more toward the centerline. At least you know which way to go.

Third - you get the fork between the spring and the TOB.

Fourth - you get the fork too far to the centerline, and as you move the engine in the fork gets pushed back so it sits outside, so to speak, of the TOB. Not in the groove.

I can't remember (repression of painful memories is not a bad thing) which of #3 or #4 will allow you to mate engine and tranny fully (putting on all the fasteners etc) without leaving the fork loose such that you can twiddle it back and forth. If you can twiddle it back and forth when mated, something is wrong and try again. There just isn't much "slack" between the fork and the sides of the TOB groove, but the bearings for the vertical shaft aren't all that close a tolerance and there is some wiggle there which can confuse things.

But the difference between getting it in the groove (where sometimes there is just the slightest back and forth) and one of the misalignment options (the most evil one) is very small.

When in doubt, before doing much else, after a successful mating I hook up the lever arm and wiggle that. But I then hook up the clutch, get in the car, and step on the clutch. If things aren't hooked up correctly, the pedal won't move, or will only move a little as it takes up slack. And you know it is back to the drawing board. But at least you haven't hooked up the oil lines, etc.

Of course, the easiest is to have the tranny out on your floor when doing this mating - so you can easily look through the hole and see if the upper ear of the fork is in the groove. But for those of us who tend, at least on occasion, to leave the tranny in this is not so easy. It is one of the reasons I lust after a 5.5" pressure plate with a push TOB that doesn't need to mate with anything.

If you do have the tranny in, start by eyeballing the angle of the fork. You will note that the TOB's engine side groove flange is wider than the one on the tranny side. So you try to, before things get out of sight, get the fork aimed a tiny bit to the center of the engine side flange. So it will miss the tranny side flange, hit the engine side flange at an angle, and slide into the groove.

Sometimes this works just fine for me, sometimes #$#@%#%@ emanates from the garage.

Walt

I guess this is where I become an expert at motor removal and installation... Ha. Perhaps I can get a job on the pit crew when I'm done. I'm pretty fast at dropping and installing now.

Anyway... thank you for the response Walt. I think I've got it in correctly, but what I am learning from you and the others is I will probably have to install the motor and transmission again to find out for sure.

I hate to sound like a shade-tree mechanic here... but it seems like we should be able to hook a ratcheting strap to the fork lever and see if it engages or moves properly before the big install. I don't want to break anything, but isn't there a better way to check it before installing?:rolleyes:

Speedy Swiss

On reviewing this, do I understand that you have engine and transmission out of the car but mated at this very moment?

If so, there simply is no reason to come up with some complex method of seeing if the clutch arm will disengage the clutch. Because you can just look in there and see that the fork is where it should be.

The small LED flashlights are good for this.

I don't know if the hole on the top left (driver's side) of the tranny bell housing is there for vision or for ventillation, but it serves well as a viewing port. If really concerned, pull the starter and look in there.

It is only when you have the tranny in and the engine out that things get trickier. Because on a stock bodied car it is hard to see in this hole. Hence the discussion of using a mirror. Still difficult.

I have no excuse, other than not being tall enough, because my track car (whose engine comes out at least once a year for this or that, and sometimes, alas, more often) has no sheet metal in that area and I can, if a bit awkwardly, look in. But that calls for getting out from under the car, etc.

Look at it this way - it is easier to put the clutch lever arm on with the engine/tranny already in the car than it is to fumble around with it under things on the floor.

Walt

Hi Walt,

Thanks again for the input. It sounds like I should be fine with the installation again.

Although, I did check my throwout fork to see that it was in the proper groove after after my recent removal and it was in the right location, but still did not move.

Hopefully this time it does.

We shall see... thank you again.

Eric J.

Remember: install just enough to put the tranny and engine holder bolts in, then hook up clutch, adjust, and step on the clutch pedal. With the experience you have gained doing this, whipping it in and out is the quick part. It is hooking up all the other stuff, and unhooking it, that takes the time.

You would think that you should be able to twiddle the upright splined shaft with your fingers, and feel the fork boink against each side of the TOB groove. Sometimes mine feel just like that. But not always. Not much movement to begin with, and unless freshly greased the splined shaft may have some internal resistance. And then there is spline slop to complicate things.

But if your tranny/engine unit is in a fairly stable position, you could slip the clutch arm on (I forget if this is the later clutch with the long and short arm and harp spring, or the simpler earlier style with just one long arm) without bothering, for the moment, with the circlup. Then, while looking in the viewing hole, move the arm back and forth, and watch the top of the fork move a bit one way and the other. Just to confirm.

Walt

Well.... I finally had time to reinstall my motor and transmission. Everything went smoothly, but I don't notice that big of a difference in the clutch.

I am beginning to realize, I may have done an extra removal and install for nothing. :mad:

I have never driven a Porsche (bought mine inoperable) so I really don't know what a brand new Sachs clutch feels like.

I would describe the feel of my clutch pedal as a normal clutch when I first step on it. Then when I reach about 1/4 of the way down, it engages the throwout fork and it's all helper spring from there. I believe the throwout fork only moves a tiny bit.

I wonder if I should have the clutch cable tightened even more with a new clutch? My cable is currently tightened at about the halfway point.

On a side note, my transmission seems to shift very smoothly into all gears and reverse with the clutch engaged and not engaged. Is this normal?

Thanks in advance for your responses.

Just got it in correctly. I believe the entire issue was just the clutch cable adjustment. I just needed to tighten it all the way with a new clutch.

Thank you everyone for your help. I must have been standing too close to the forest on this one. ;)