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Discussion Starter #1
First off, although 'new' to this forum, I was once registered before but lost my login details, so here I am with a new identity.

Last winter I rebuilt the gearbox in my S2 Spider, and thanks to all of you on AlfaBB who unknowingly gave me help with the many previous posts and photographs. I was a car mechanic back in the 70's, but never built a 105 gearbox, so the help I got here was invaluable.

The reason for rebuilding the box was a worn/noisy first motion shaft bearing, all the syncros were OK, including 2nd. I got a donor box, so replaced dog gears and syncro rings with the best of what I had, all just about perfect were used. I also used the selector forks from the donor as they were better than the original. I managed to get a genuine new first motion shaft bearing from Germany and the output shaft bearing was replaced with one from Alfaholics. As those bearing would be above the oil level, so I used some grease in them to give them a good start in life. I refilled with Redline NS oil.

So, the parts that were 'new' to my 'box were: New first motion shaft and output shaft bearings, a couple of dog gears and syncro rings plus the selector forks.

I have been getting an oil leak, a table spoon of oil on the garage floor after a run out, we've done around 7 - 800 miles since the rebuild. The oil leak has continued, first off I thought it was overfilling coming out of the breathers so it would settle down, as there is no signs of 'throw' across the underside of the car which might indicate a duff output shaft oil seal. I just drained the oil to see how much is in there, just over 1 litre!

I need to check the breathers are clear, but if anyone has any ideas I'd be pleased to hear what might cause this to happen. This is the real issue though, the oil I drained out was very dirty, dark grey in colour plus it had a metallic sheen to it, a bronzy colour. The only thing I can think of is that the 'new' selector forks are bedding in, but should they? There is nothing not working, the gear change is a delight. I intend to flush the 'box with a 40# oil for 100 miles then drain and refill with more Redline. I need to fix the oil leak before the Redline goes back in.
 

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Discussion Starter #2
First off, although 'new' to this forum, I was once registered before but lost my login details, so here I am with a new identity.

Last winter I rebuilt the gearbox in my S2 Spider, and thanks to all of you on AlfaBB who unknowingly gave me help with the many previous posts and photographs. I was a car mechanic back in the 70's, but never built a 105 gearbox, so the help I got here was invaluable.

The reason for rebuilding the box was a worn/noisy first motion shaft bearing, all the syncros were OK, including 2nd. I got a donor box, so replaced dog gears and syncro rings with the best of what I had, all just about perfect were used. I also used the selector forks from the donor as they were better than the original. I managed to get a genuine new first motion shaft bearing from Germany and the output shaft bearing was replaced with one from Alfaholics. As those bearing would be above the oil level, so I used some grease in them to give them a good start in life. I refilled with Redline NS oil.

So, the parts that were 'new' to my 'box were: New first motion shaft and output shaft bearings, a couple of dog gears and syncro rings plus the selector forks.

I have been getting an oil leak, a table spoon of oil on the garage floor after a run out, we've done around 7 - 800 miles since the rebuild. The oil leak has continued, first off I thought it was overfilling coming out of the breathers so it would settle down, as there is no signs of 'throw' across the underside of the car which might indicate a duff output shaft oil seal. I just drained the oil to see how much is in there, just over 1 litre!

I need to check the breathers are clear, but if anyone has any ideas I'd be pleased to hear what might cause this to happen. This is the real issue though, the oil I drained out was very dirty, dark grey in colour plus it had a metallic sheen to it, a bronzy colour. The only thing I can think of is that the 'new' selector forks are bedding in, but should they? There is nothing not working, the gear change is a delight. I intend to flush the 'box with a 40# oil for 100 miles then drain and refill with more Redline. I need to fix the oil leak before the Redline goes back in.
 

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Richard Jemison
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Lube

Only use 3 pints of lube. If you fill to the bottom of the fill hole they will leak. As well the overfill will cause 5th gear to sling lube up the shifter tower which is the most common source of leaks.

Sealing with ultra grey sealant on all the surfaces, studs and nuts, and shifter bushings is the correct way to seal. With other sealants the lube can weep past very small openings.
 

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Have you determined the actual location of the source of the leak? That should be the first order of business. Depending on the volume, it might be something simple like a poor seal on the drain plug. If it is dripping from the flywheel cover plate, it could also be motor oil leaking from the rear engine seals, and not gear oil at all. Smell the oil that is leaking. Gear oil has a unique, kind of stinky aroma, while motor oil has very little scent.
 

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I'd be worried that your 800 mile old recon tranny filled with 1.8 litres of shiny new Redline NS, is now "...very dirty, dark grey in colour plus it had a metallic sheen to it, a bronzy colour"

when I change my tranny oil say every 2 or 3 years, it is still clear (makes me wonder why I change it sometimes! That redline stuff costs a blasted fortune over here in europe!)
 

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Discussion Starter #6 (Edited)
Hi spiderserie4, you know me from another forum, you should recognise the avatar, when my name change there catches up you'll know! ;-) I think it was you who sent the Ebay link for the bearing I bought from Germany, remember?

Your right about the colour issue. I've refilled with some oil to flush the box out, I'll see what colour that is. You'll see from my OP, there were not so many parts renewed, its like not much has changed.

Norseman, thanks for your post, it is gearbox oil of that I'm sure.
 

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Discussion Starter #7
Thanks for your reply Richard. I used Loctite 574 on the joints, I'm not sure if Ultra Grey is available in the UK, I did look and someone else suggested the Loctite, all the joints seem Ok, but this leak is no weep and where it drips on the garage floor is right under the back of the gearbox. I did wonder if it might have been the rear oil seal but youd expect to see the oil thrown off the rubber doughnut under the body, but nothing. I cleaned the breathers and refilled with flushing oil, just the amount you suggested, which I did before using a measuring jug, pouring it down the shifter tower.

Any ideas on the oil colour?
 

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Richard Jemison
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Oil color

Discoloration is caused by heat. Something internally has a clearance issue most likely. I suspect if you changed shift forks they were not correctly adjusted to center the slider between the gears syncro bands. That`s the typical issue on builds done by owners.......
 

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Did you replace the seals on the shift rods at the front of the case? if these are not replaced, then you will get a weep from them that leaks down inside the bell housing. If it is a 2 liter gear box then they are not needs as the bell housing seals the shift rods.
 

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Discussion Starter #10
Discoloration is caused by heat. Something internally has a clearance issue most likely. I suspect if you changed shift forks they were not correctly adjusted to center the slider between the gears syncro bands. That`s the typical issue on builds done by owners.......
OK, but as the shifter forks are fixed with a bolt right through the shifter rod, wheres the adjustment made? I was rigorous in the build, placing both gear sets in one half of the case and the sliders had movement both ways, they were not tight against a syncro ring, they were right in the middle of both hubs, what else could I have done?

Gear changing is as sweet as you would want it, even into first now I added a two way syncro set.

How does that sound?
 

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Hi spiderserie4, you know me from another forum, you should recognise the avatar, when my name change there catches up you'll know! ;-)

aah! of course....sorry A-R-B
I remember now;)
 

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This is the real issue though, the oil I drained out was very dirty, dark grey in colour plus it had a metallic sheen to it, a bronzy colour.
Something is wearing away. The dark grey colour is surely due to metal impurities.

I'd pull the box out and open her up and have a look. Best to save it now if you can :)

Also if you have a leak at the rear of the gearbox but not from the output seal, then I assume it is from the gearshift tower and running down ... as Alfa7 says.
Pete
 

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OK, but as the shifter forks are fixed with a bolt right through the shifter rod, wheres the adjustment made? I was rigorous in the build, placing both gear sets in one half of the case and the sliders had movement both ways, they were not tight against a syncro ring, they were right in the middle of both hubs, what else could I have done?

Gear changing is as sweet as you would want it, even into first now I added a two way syncro set.

How does that sound?
The shifter fork will slide back and forth a little bit so you can set the slider in the middle. There is a measurement in the shop manual. If its off it will rub against one of the synro rings.

As to the leak did you replace the seal in the speedo cable drive?
 

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Discussion Starter #15
`OK, The box will have to come, that is for sure. I will update the thread once I've done so, however, so far.

Yesterday evening we put some straight 40 oil in the box to flush it out and ran the car up to speed, wheel free on stands, there was quite a pronounced noise, more of which later. So, we dropped the oil out, and refilled with some Penrite 80. We had taken the cover off the gearlever tower inside the car, so we refilled through the tower with a measured amount of oil, with the cover off any noise was clearer to assess. I took the car for a short drive and the noise was worrying loud.

The noise, well if you spin up a roller or ball bearing that has just been washed out, no oil, just paraffin, then that how it sounds. It is present when the car is in neutral, so my thoughts are that one of the layshaft bearings I passed as OK is not. Here I'm looking for your views. with the engine running, the first motion shaft is turning (new bearing), that drives the layshaft and the individual gears will rotate on the main shaft, until a gear is selected the mainshaft is not turning, right? so with the car in neutral the only moving parts are going to be: first motion shaft, layshaft and gears on the mainshaft, those gears are on plain bushes and nothing has changed there since before the rebuild. So my money is on one of the layshaft bearing, we'll see.

The issue of the selectors and possible wear. When I put the shafts into the case half with the selectors the sliders were free, there was some free movement with them in the central position. They were not pushing up against the selector folk at all.

I also washed out the breathers and blew an air line through them. After my short drive, there was no sign of oil from the top of the tower, Jim, I'll check for leaks around the speedo drive, but there was nothing on the garage floor, I'll watch that one.
 

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Richard Jemison
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Bearing noise

most likely, if it is a bearing, you lost one of the rollers in the mainshaft bearing in the shift tower. Easy to do.
I pack them with axle grease to keep the rollers in place to insert in the race in the case. Easy to bump one out on insertion.
 

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Discussion Starter #17
Yep I packed them with grease to. I reckon it must be the layshaft and could well be in the end housing. The noise is there with the car in neutral, correct me if I'm wrong, but only the first motion shaft, layshaft and gear sets are turning, not the mainshaft itself when in neutral.
 

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My guess is 5th/reverse shifter fork is out of alignment and maybe rubbing. Good news on that one is you can see it with just the front cover off and don't have to crack open the clamshells.

Take this speculation from a guy that's only worked on 2 of these boxes and both in the last 12 months -- but when I rebuilt one I saw how this could easily occur if that shifter fork got loose (or the actual shifter yoke was loose)
 

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Oh yeah that is the rear cover! Duh... anywho the cover that has the shifter tower! Dunno why I mixed that up....:)
 
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