New clutch woes - trouble getting into gears

[max71]

Steve and I renewed the whole clutch assembly in my MGB due to a faulty pressure plate. Now I can't barely get it into 1st and reverse grinds like crazy even if I set the gears first. This is a 4 synchro box with OD. I have never experienced anything like this in the 35 years I've owned the car. We also renewed the spigot bushing. So here's the story. We're both mystified.

New Clutch assembly - pressure plate, throw out, disk, spigot bushing

Checked disk on input shaft first by sliding it on splines no issues although I don't recall sliding it the entire length of the splines maybe just the front half. Spines looked fine. Disk was installed in proper direction.

Checked fork bushing and pin which I renewed 18K miles ago - still fine just greased it up. Put in new nylock nut and checked to make sure the fork moved freely.

New spigot bushing which had oil pushed through it - checked pilot bushing on shaft prior to install and used the proper tool to install it. Went in straight.
Greased input shaft lightly

On reassembly we had some alignment problems which we tapped the grearbox with a rubber mallet from behind. We had to reset the clutch disk and try again. Slid in further but the last inch or two required more tapping. This happened last time so I didn't think much of it.

After it was back in the car and the engine running first is very hard to get in. Reverse is just about impossible. It grind even If I set the gear. It grinds like I don't have the clutch in.

I checked the slave and its moving the pin full travel. I bled it just to see and while the peddle is slightly firmer there's no difference.

Through a week of driving with not much change I tried feathering or burnishing the clutch - no change. Holding the clutch in and reving it to maybe loosen a tight spigot bushing - no change.

More background --

Here are some interesting observations:

1. It was cold here (well for Cali) and it was much better going over to Steve's. Didn't grind as much and went into gear easier. Halfway through the canyon when it got hot it went back to its old bad ways. This gave me hope thinking metal expansion maybe alignment (loosening the bell housing bolts and shifting the tranny) would do it.

2. We had the car on jack on all points. After nothing helped alignment wise I later started the car again while it was on jacks and kept the clutch in and asked Steve if there was drag on the wheels. He could stop the rear wheels with one finger. I rev'd the engine while the clutch was in and he said there was a barely perceptible increase in drag but one finger kept the wheel from spinning.

I am really giving up. Is it the pilot bushing? Is it not too bad cold but when it heats up it binds? Or is it something else?

We noticed that the old one we removed which was only in the car for 18K miles looks like it spun in the crank once of twice. It was such a tight tolerance that it polished the input shaft. However, aside from the funky pressure plate I have no trouble getting it into gear.

IF its the pilot bushing will it wear into tolerance? Or will it eventually spin like the old one?

Further testing:

Here's what I believe can be discounted and why:

1. Hydraulics. The throw of the pushrod in the slave is fine. Its identical to 2 MGBs I've measured. I also rebuilt the slave.
2. Flywheel is fine even though it was surfaced several times. I bought a Midget push rod for the slave which is .20" longer (although comparing it to the standard MGB one it looked longer than that). I put it in today thinking the xtra throw would hopefully solve it. NO change what-so-ever
3. Pilot bushing. As mentioned Steve could stop the wheel with one finger when the clutch was in and even when I raised the RPMs with the clutch in. When I'm on just the slightest grade and I have the clutch in the car will roll forward or backwards depending on the grade.
4. TO bearing. I did measure the new one against the old one and they were identical.

So that means its something in the clutch/pressure plate assembly. Without simply buying a new set and replacing this one I have no idea what we will see. We would have to take it to a clutch shop and see if they can find something. Its a Borg and Beck by the way.

Steve said he doesn't know how much drag can still affect the synchro in first and reverse. Meaning maybe a little.

Help?

[Steve Simmons]

I'm out of ideas for Gary other than drive and see if it loosens up, or pull it out and look for something amiss. I still don't think the old bushing spun in the crank, but there were signs that maybe it was damaged during assembly.

The only thing I can figure at this point is a warped disc or mushroomed / damaged / faulty pilot bushing.

Incidentally, the rubber mallet came into play because the packing blanket the engine was on had become pinched between the engine and gearbox. Once removed, the gearbox went together fine until the last little bit where it got tighter. Gary said the same thing happened last time and everything worked once together, so we used the gearbox bolts to pull it the last little bit together. Sounds like the pilot may have compressed below tolerance once installed in the crank?

[Jimmy]

I had to use a rubber mallet for the last two inches when reassembling my Beater's motor and trans, with no apparent ill effects.
The pilot bushing was a very tight fit in my case, too, but that doesn't seem to affect operation any.
Perhaps the main difference between the two installations is that I chamfered the input shaft before attempting assembly, never having seen a blunt cut shaft before, and it didn't make sense to me.
If some shavings came off the pilot bushing during the install, they should wear off/in rather quickly, I'd think.
But it won't take much force to turn the gears, making it hard to shift into gear. That's why trucks have a clutch brake, to make it possible to engage a gear from a dead stop.
At this point, getting mine into Reverse often requires letting the clutch up a bit, getting things to turn enough to be able to engage Reverse.
Let's hope it self heals!

[Steve Simmons]

I just had another thought...

With your engine OFF, and without pushing the clutch, shift into any gear. It may be difficult but it will go in. Now that you're in gear, still without clutch, shift to neutral and back into the same gear. Did it get easier? If so, the gearbox is fine. If it's still just as difficult then something is amiss with the gearbox, or something is affecting the shifting. Maybe even a problem in the shift tower. Have you tried what I mentioned the other day - pulling the shifter out and putting in back in yet? Make sure the shifter and all parts are assembled correctly and not blocking travel somehow.

[max71]

With engine off I can shift through the gears fine. I don't think its the shift toward as it only goes in one way and you can only tighten it so much before the bolts bottom out to the pin center.

Again, apart from a small issue with third the gear box was fine. If you recall the very first time I put it in gear when I was leaving the night of the re-install I immediately mentioned it was hard to get into gear.

At this point unless someone comes up with something brilliant we overlooked I'll drive it for a couple more tankfulls and if there's no change I guess we'll have to do what I really don't want to do - pull it. Ugh. Double ugh.

[malcolmr18zoy]

Hi Max,
It sounds like you have problem with your clutch pressure plate. Is it spring, or is it diaphragm? Either way, sometimes the manufacturers put clamps in the pressure plate for shipping. If these are not removed prior to assembly, the clutch will not clear properly.
Malcolm

[max71]

It's springs that look like a diaphragm. Don't know if that makes sense. We read through the instructions and there was no mention of parts to remove. Here's a picture.

[Steve Simmons]

I didn't read nuttin'. I was just the extra hands and moral support. No brains here.

[max71]

Yes you did. As I recall your exact words were "Everything you want to know is here in the instructions" At which point I actually bothered to read them.

[malcolmr18zoy]

Hi Max,
That's a picture of a diaphragm clutch. I the hydraulics are good, as you described, then you have a problem with the clutch itself. Having to hammer it home, and then draw it in with the bolts, doesn't sound quite right to me. If you didn't have the first motion shaft quite lined up with the pilot bushing, you may have damaged the pilot bushing causing it to be a tight fit over the shaft. This would give you the drag that you are describing. I think you will have to take it out again. Don't be tempted to leave it and hope that it improves. You may damage your gearbox, and still have to remove it.
Malcolm

[Jimmy]

Malcolm, whatever happened to your sense of adventure??
Suppose the pilot bushing is a bit unhappy at the moment...there's no way it won't wear in.
It could put some undue pressure on the input shaft in the meantime, I suppose, but if going through all the trouble of pulling the trans again, one might as well do it for a reason. Like that the transmission is bad.

I'll be changing the clutch in Annette's B as soon as I get home again, and I know how fun it isn't to do.

[Steve Simmons]

Clutch day at Jimmy's! Everyone bring a wrench!

[malcolmr18zoy]

What are you talking about Jimmy,
On MGBs you leave the transmission in, and pull the engine. It makes the job twice as easy.
Malcolm

[Jimmy]

Uh, shouldn't we try to figure out Gary's dilemma first?
Annette's car still works fine, it's just that the poor excuse for....er, the throwout "bearing" is toast.
Or, are you just trying to get on her good side?

[malcolmr18zoy]

Jimmy,
It's still easier to pull the engine than the gearbox, to work on any component of an MGB clutch. That's what Max is going to have to do. I wouldn't risk trying to wear it in, incase it happens to be something else.
Malcolm

[Jimmy]

What are you talking about Jimmy,
On MGBs you leave the transmission in, and pull the engine. It makes the job twice as easy.
Malcolm

While my tranny indeed went back in easier the second time (with the engine still in place) than when joining them on the garage floor, I'd think that the pilot bushing stands a much greater chance of getting creamed by pulling just the engine.

And I guess that by "twice as easy" you really meant half as hard? Which for a no-fun job translates into basic "hard".

[malcolmr18zoy]

Not if you're careful. I've done a lot of MGB clutches, and the easy way is pull the engine.
Malcolm

[max71]

I've heard about this - pulling the engine not the trans too. I would dearly love to try that but I do think if there were hassles getting it mated on the floor it would a nightmare on a lift which we angle anyway.

Although I'll bet Steve and I would be happy to learn if you want to teach us.

Guys - If this were to happen where is a good local clutch shop near Steve that we could take the disc and pressure plate to be inspected?

[malcolmr18zoy]

Hey Max,
If you lived closer to me, I could probably be more helpful. I'm the other side of Pasadena from you, and I spend most of my week-ends in Big Bear. During the week I work on other peoples British cars for payment. If we were closer, I would be happy to show you my method of doing it. The clutch shop that I use is in North Hollywood. I can give you their details when I get back to Temple City if you like.
Malcolm

[Steve Simmons]

Try Valley Friction Materials. If they don't do clutches then they may know who in the area does.

[Martin Keller]

Hi Max,
Having to hammer it home, and then draw it in with the bolts, doesn't sound quite right to me. If you didn't have the first motion shaft quite lined up with the pilot bushing, you may have damaged the pilot bushing causing it to be a tight fit over the shaft. This would give you the drag that you are describing. I think you will have to take it out again. Don't be tempted to leave it and hope that it improves. You may damage your gearbox, and still have to remove it.
Malcolm

I have to agree with Malcolm on this as I have done many MGB clutch changes and if the pilot bushing is bad you will have the problem you have described if the clutch slave is operating correctly. You could also have a throw out bearing that is not installed correctly (one of the clips could have disloged or the bearing is not the correct one), the clutch disk could have been installed backwards by accident and that would also cause the binding and the simptoms that you have described.
Pull the engine and trans as one unit as it is much easier to work on that way (four nuts and bolts on the driveshaft, two ground straps, two motor mounts, two radiator hoses, remove the radiator and mount, remove hood for better access, disconnect electrical, disconect throttle and choke cables, disconnect oil cooler lines and drain oil to reduce weight of engine and mess on floor, pull engine and trans. No set order for removal of items listed)

[Jimmy]

I've heard about this - pulling the engine not the trans too. I would dearly love to try that but I do think if there were hassles getting it mated on the floor it would a nightmare on a lift which we angle anyway.

Gary, if you have access to a tilting device for the hoist, it'd help immensly.
Either way, it's a whole lot easier with an extra pair of hands.
I wouldn't even try reinstalling the just the engine (or transmission) by myself. Come to think of it, I have tried.

No need to remove the hood, really. Just disconnect the hood prop, then hold it wide open with a ratchet strap.The trunk release works well for the anchor end.

[malcolmr18zoy]

Yes, Valley Friction, that was the name that escaped me. Pull the engine and gearbox as a unit, or pull the engine alone, your choice. Pulling the engine alone saves about an hour on the job, if you're used to doing it. I alwasys do them on my own, but I've been doing it for a long time.
Malcolm

[max71]

Clytch slave is fine - I even rebuilt it. Same throw as Steve's cars.

Clutch disc 100% the right way around.

Neither Steve or I have ever done just the engine without the trans. Could possibly lead to more pilot bushing problems.

Ok, time for a poll.

How many of you think its not going to correct itself with driving/wear and possibly damage the synchros?

How many think it can be driven to correcting itself.

A new pilot bushing opposed to a gearbox rebuild are very different options.

Anyone ever heard of All Valley Clutch? Its closer to Steve. I want to line someone up if we do pull it.

[malcolmr18zoy]

Hi,
If you put the car in gear, then step on the clutch pedal, and start the car. Run it like that, stationary but in gear with the clutch disengaged, It may free off, if the problem is with the pilot bushing. Worth a try. In case you don't understand, that would keep the first motion shaft stationary, while the crankshaft and pilot bushing are turning. You can call me if you like 626 260 1403.
Malcolm