Anyone have an exploded view schematic of manual gearbox?

esray

esray

Member
Dear Forum,

I have replaced all four bearings in my gearbox. When the four bolts that secure the main gearbox casing to the bellhousing are slack, all gears work fine. When I tighten those bolts, neutral disappears, third/fourth seizes up and everything goes to rat sh*t :!:

My HBOL completely misses several thin, delicate roller bearings and spacers/washers from its diagram - Please, does any forum member have a quality exploded-view schematic of the manual 4-speed gearbox with particular emphasis on the mainshaft :?:

Best,

Ray
 
You need to fit the speedo drive gear & rear flange to the mainshaft, and then tighten the rear flange nut. Then tighten the bellhousing bolts. You can remove them afterwards to fit the rear housing.
 
harveyp6 said:
You need to fit the speedo drive gear & rear flange to the mainshaft, and then tighten the rear flange nut. Then tighten the bellhousing bolts. You can remove them afterwards to fit the rear housing.
Click to expand...

Thanks Harvey - I'll try it.

Not absolutely sure that I have several thin, delicate roller bearings and spacers/washers etc assembled correctly on the mainshaft?
 
raylish said:
colnerov said:
I don't imagine there are many differences between these schematics and those for a four-pots manual box?
Click to expand...
Click to expand...

The mainshaft build up should be pretty much the same, it's the laygear bearings that are totally different, which shouldn't be a problem as far as the problem you're experiencing.

One other thought, which rear mainshaft bearing did you use? (In other words, who did you buy it from?)
 
harveyp6 said:
raylish said:
colnerov said:
I don't imagine there are many differences between these schematics and those for a four-pots manual box?
Click to expand...
Click to expand...

The mainshaft build up should be pretty much the same, it's the laygear bearings that are totally different, which shouldn't be a problem as far as the problem you're experiencing.

One other thought, which rear mainshaft bearing did you use? (In other words, who did you buy it from?)
Click to expand...

Harvey, my new main shaft bearing came from a firm in Nicosia in Northern Cyprus (think it is Jap); if it becomes a problem, I will refit the original bearing (which I replaced because I wanted to replace all the bearings due to the disappointingly noisy nature of my box, not because I thought it needed to be replaced).

Harvey, I have had the main casing off and on and the gears in and out of this box so many times now that (on this occasion) I had not fitted the circlip at the front of the primary input shaft and now that I look at it, I see that it does not bed in correctly, and so I need to dismantle (yet again) in order to drive the primary home properly, then I will report back; in other words, I understand where you were coming from with your advice to tighten the flange nut at the rear to drive the shaft forward, but the problem may well be of my own creation at the front end!

I have no doubt that I will be getting back to you to ask for your further help again :!: :!:

Best regards,

Ray
 
raylish said:
Harvey, my new main shaft bearing came from a firm in Nicosia in Northern Cyprus (think it is Jap);
Click to expand...

If this is the rear bearing, did it have a sleeve inside it to reduce the internal diameter so it is the correct fit on the shaft?

If so: Those bearings will not work.

If not: We'd all be very interested to see the bearing make, and part number.
 
harveyp6 said:
raylish said:
Harvey, my new main shaft bearing came from a firm in Nicosia in Northern Cyprus (think it is Jap);
Click to expand...

If this is the rear bearing, did it have a sleeve inside it to reduce the internal diameter so it is the correct fit on the shaft?

If so: Those bearings will not work.

If not: We'd all be very interested to see the bearing make, and part number.
Click to expand...

Hello Harvey,

Yes, it does have a sleeve fitted - I will have to put the old bearing back (did not seem to be much wrong with it anyway); do you know why it will not work, please?
 
raylish said:
do you know why it will not work, please?
Click to expand...

When you tighten the rear flange nut, the step on the mainshaft comes into contact with the spacer, and instead of stopping as it would when coming into contact with the inner track of the proper bearing, the spacer moves backwards into the void in the speedo drive gear, and that allows the large flat washer on the rear of the mainshaft gearset to move forwards and lock the mainshaft up.
 
harveyp6 said:
raylish said:
do you know why it will not work, please?
Click to expand...

When you tighten the rear flange nut, the step on the mainshaft comes into contact with the spacer, and instead of stopping as it would when coming into contact with the inner track of the proper bearing, the spacer moves backwards into the void in the speedo drive gear, and that allows the large flat washer on the rear of the mainshaft gearset to move forwards and lock the mainshaft up.
Click to expand...

Harvey, brilliant - I very nearly understood that!

Please just describe this step to me - Are you telling me that there is a step left at the end of the mainshaft assembly - My combination of 'washer (with small curved 'cut-outs')', roller bearing and finally a thickish spacer before the main bearing leaves a flush fit to the end of the mainshaft?

I am tapping the large flat washer on the rear of the mainshaft gearset until it seats flush (it is a good tight fit) - Is this wrong?

You can tell how lost I am!!

I have replaced the new (but flawed) rear main bearing with the original and I have to say that the casing goes into the bellhousing more easily, but tightening the bellhousing is still locking everything up?

Loose, everything works fine.

I have a horrible suspicion that you are going to tell me that the problem now lies with my new primary shaft bearing, and that I should replace it with the original and that I have completely wasted my money on entirely unsuitable bearings!!

Incidentally, the V8 drawing of the primary input shaft shows a spacer after the oil seal (washer) and before the circlip (within the bell housing) - I do no have this spacer? The V8 drawings and my Haynes also show a bush on the reverse gear shaft which I do not have?

Harvey, if it solves my frustration and problem, then I can take any bad news regarding my replacement bearings from you!

Ray
 
raylish said:
Please just describe this step to me - Are you telling me that there is a step left at the end of the mainshaft assembly - My combination of 'washer (with small curved 'cut-outs')', roller bearing and finally a thickish spacer before the main bearing leaves a flush fit to the end of the mainshaft?

I am tapping the large flat washer on the rear of the mainshaft gearset until it seats flush (it is a good tight fit) - Is this wrong?
Click to expand...

That sounds right. There is a step, because if there wasn't then as you tightened the rear flange, the mainshaft would get pulled back through the bearing, and then force that large rearmost washer/spacer forwards, locking the mainshaft. The step stops that happening, until you fit a bearing with a sleeve in the middle, then the same thing happens, but for a different reason.



raylish said:
I have replaced the new (but flawed) rear main bearing with the original and I have to say that the casing goes into the bellhousing more easily, but tightening the bellhousing is still locking everything up?

Loose, everything works fine.
Click to expand...

You need to fit the speedo gear and flange, and then tighten them, to pull the mainshaft rearwards, until the step makes contact with the bearing.

raylish said:
I have a horrible suspicion that you are going to tell me that the problem now lies with my new primary shaft bearing, and that I should replace it with the original and that I have completely wasted my money on entirely unsuitable bearings!!

Incidentally, the V8 drawing of the primary input shaft shows a spacer after the oil seal (washer) and before the circlip (within the bell housing) - I do no have this spacer? The V8 drawings and my Haynes also show a bush on the reverse gear shaft which I do not have?
Click to expand...

Most of the time bearing suppliers get the front bearing correct, so that's probably OK, but it should have a spacer/washer between the bearing and the circlip, the same as the V8 box does. Without that, if the circlip is up against the bearing, that means the bearing isn't seated on the shaft correctly, and will make the shaft sit about 1/8" too far back, (the thickness of the washer), and that could be another reason why it all locks up when you tighten the bellhousing bolts.
 
Most of the time bearing suppliers get the front bearing correct, so that's probably OK, but it should have a spacer/washer between the bearing and the circlip, the same as the V8 box does. Without that, if the circlip is up against the bearing, that means the bearing isn't seated on the shaft correctly, and will make the shaft sit about 1/8" too far back, (the thickness of the washer), and that could be another reason why it all locks up when you tighten the bellhousing bolts.[/quote]

Harvey, thanks.

Neither of my two boxes had a washer/spacer behind the circlip and nor does the drawing in Haynes? I do see what you are saying - My problem may well be a combination of primary shaft not far enough forward and mainshaft not far enough back, thus compressing the whole array?

I will remove the primary (yet again) and refit the old bearing to see if it allows more shaft into the bellhousing (and perhaps enough to fit a washer if I can find one that fits) - Then I will know that the problem is the new primary shaft bearing. As you advise, I will also pull the mainshaft back with the flange to ensure that the step is against the main bearing.

And then I will cross my fingers!
 
raylish said:
Neither of my two boxes had a washer/spacer behind the circlip and nor does the drawing in Haynes?
Click to expand...


I had a look in the factory WM and that shows the spacer/washer between the circlip and the bearing.
 
harveyp6 said:
raylish said:
Neither of my two boxes had a washer/spacer behind the circlip and nor does the drawing in Haynes?
Click to expand...


I had a look in the factory WM and that shows the spacer/washer between the circlip and the bearing.
Click to expand...

The spacer we are talking about here (primary shaft) is/was available in different thicknesses to set the float of the primary bearing, and it needs to be there.

Yours
Vern
 
Harvey, Vern - Thank you for your patience.

I eventually found (thanks to Harvey's persistence) that I had the washer/spacer (that is not shown by Haynes AT ALL) BEHIND the primary bearing and it was this that was compressing the primary and mainshaft and locking them up!

Now that the spacer is where Harvey told me it should be (in the bellhousing, behind the circlip), my gearbox is working perfectly (albeit the mainshaft seems a little loose), but NOW, when I tighten the bellhousing to the engine-plate, it locks my crankshaft up and my clutch will not operate!!

Before you say it - My two crankshaft shims are fitted, with the oil-ways facing outward!

So it would appear (at this time) that I have a choice between placing the spacer behind the primary bearing and locking up my gearbox, or placing it in front of the primary bearing (and behind the circlip) and locking my clutch & crankshaft up?

At least I have moved the problem......
 
You know that the spacer is in the correct position now, so I think you can discount that as the cause of the locking up when you tighten the engine to the bellhousing. If it frees off when you slacken them again, then I'd look at the spigot bearing, and the clutch centre plate to see if they give any clues as to the cause of the problem.
 
harveyp6 said:
You know that the spacer is in the correct position now, so I think you can discount that as the cause of the locking up when you tighten the engine to the bellhousing. If it frees off when you slacken them again, then I'd look at the spigot bearing, and the clutch centre plate to see if they give any clues as to the cause of the problem.
Click to expand...

Thanks Harvey - I'll do exactly that tomorrow!
 
Hello Harvey,

Get ready to have a good laugh at my stupidity!

I have a habit when dismantling of trying to refit and leave bolts etc to in their correct locations. I had done so with the two bolts that secure the clutch slave cylinder to the side of the bellhousing. During the many times that I assembled and dismantled the gearbox, one of these bolts had tightened itself into the bellhousing without me noticing it. The seizing up of the crankshaft when the bellhousing was tightened was being caused by this intruding bolt jamming against the flywheel :oops:

Ray
 
raylish said:
I have a habit when dismantling of trying to refit and leave bolts etc to in their correct locations. I had done so with the two bolts that secure the clutch slave cylinder to the side of the bellhousing. During the many times that I assembled and dismantled the gearbox, one of these bolts had tightened itself into the bellhousing without me noticing it. The seizing up of the crankshaft when the bellhousing was tightened was being caused by this intruding bolt jamming against the flywheel :oops:
Click to expand...

That'll do it! Many people have experienced the same thing after using too long a bolt to retain the slave cylinder.
 
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