Gearbox troubles!

Maestro, SEI-V

Re: Gearbox troubles!

Postby morini_tom » 10 Oct 2017 20:09

A couple of years ago I bought in America some new bearings, with the correct morini part number (70250061A) listed as for 501 Excalibur/'92, in a Ducati blister pack, and when they arrived they were not the original spec 33mm 4PAC bearing (SKF 633250C) but were 30mm QJ 306MA/C3 (still 4 point angular contact)

Perhaps stock of the 633250C ran out towards the end, or Cagiva/Ducati decided it was cheaper to supply a bearing perhaps common with one of their other engines at the time?

It does at least give an extra lease of life to a crank if the primary side journal was damaged, or a decent machine shop could probably grind the inner race out to 33mm. In the absence of stock of the original spec 4PAC bearing I doubt there's a better alternative.

I bought a couple of those Ducati bagged qj306 bearings assuming there were the 33mm ones. Since they're not, and I'm unlikely to need them both I'm happy to move one on if anyone's interested. I think I paid about £60 a bearing but they're not doing me any favours on the shelf so I'm open to offers, especially if it keeps another morini on the road.

Tom
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Re: Gearbox troubles!

Postby penman » 11 Oct 2017 09:20

I came to the same conclusion, the simplest way forward is going to be a one-off modification of a standard bearing, as you say there are plenty of small engineering shops capable of doing it, though no doubt at a price!

Harrymuffin - do you have some document which translates those Morini part numbers to a bearing specification? I will make a few enquiries beforeI strip it down, just so I know what I might be in for and so I have a way forward. I don’t suppose this is a specially demanding application, so standard bearings should be OK (?). Of course I may not need to replace any bearings, the engine is mechanically quiet and the only ominous noise is confined to 3rd gear. Fingers crossed!

Joe.
1985 Morini 350 K2
1978 Triumph T140 E Bonneville
1975 Triumph T160 Trident
2014 BMW F800GT
1978 Morini 500
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Re: Gearbox troubles!

Postby harrymuffin » 11 Oct 2017 13:12

I see that Tom was ripped off by Ducati who supplied the spare for Morini after they closed/bought by Cagiva. I never by anything from a dealer when you can buy direct from the manufacturer e.g. just replaced the front discs on the car, they cost me £33 where the BMW dealer wanted nearly £200 both pairs were ATE discs.
I have been through the SKF and FAG catalogues and for me to explain how the service life suitability of bearings are arrived at would take all day. For those of you who may have noticed, the original engines had ball bearings on both sides of the crank, but no allowance was taken into account for expansion, as the drive side bearing positively located the crankshaft rigidly and was or is a standard 6000 bearing. They had to modify the timing side to account for expansion by fitting a plain bearing which works perfectly. The 500 series of engines needed a heftier drive side bearing by fitting the special 633250C which assuming Morini were going to make 10000+ was economically viable to have these specials made. Why did Lambertini not increase the mainsheet diameter by 2mm so that standard bearings would fit? Same goes for the gearbox bearing. Unfortunately little thought was given when these engine were no longer made and SKF could not be arsed to make these bearings in the quantities that Morini were buying them in at, so marked them as obsolete to the chagrin of all us 500 and all the variation owners when the bearings eventually do need replacing. So the question arrises, why does the little engine get away with a standard £5 bearing and us big engine people have to pay upwards to a £100 for a bearing that does not fit?
If the QJ 306MA was to be modified by increasing the inner diameter to 33mm would there still be enough 'meat' between this inner diameter and the track of the balls? The original 'meat' is 2.8mm but modified it is 1.8mm but as it is a precision fit on the shaft would this suffice to provide the stability? I would suggest that it is by virtue of SKF modifying the smaller gearbox bearing a 6204 to 21.8mm the 'meat' reducing for 3.5mm down to 2mm.
I think I have mentioned before, this problem over bearings does not concern me as I had the foresight when I realised to obtain a pair of these bearings; contact my executers if you want them, but as I relish problems such as this I have contacted a division of Hoffman Bearings that specialise in modifying bearings to replace obsolete ones to see if it is feasible to modify as above and what would the minimum order and cost be. Whether they will be able to help I will wait and see. Depending on whether they can help then perhaps the club would like to assist in the purchase of a minimum order and hold in stock as other motor clubs do, and put a mark up of say 10%, or would there be enough owners prepared to club together, as they did regards 500 pistons and buy a pair for their executers to sell on?
I will keep you posted on this saga as and when I hear good or bad news.
If I were you Penman, I would simply dismantle the engine so that you will know what exactly is the problem with the gearbox whine. All the other bearings and seals are ten a penny from bearing stockist either online or local.
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Re: Gearbox troubles!

Postby penman » 11 Oct 2017 14:03

Another small update. I spoke to NLM this morning and they do stock all those bearings, though the last one of item 59 was just sold a week or so ago(!) Rob tells me he gets them from Italy and although the supply has been reliable, they are expensive - £46 +VAT. He is intending to try an alternative supplier in the UK, though I have no other details. One way or the other he expects to have stock fairly soon. All the other bearings are currently in stock. So although not cheap, this is an option.
1985 Morini 350 K2
1978 Triumph T140 E Bonneville
1975 Triumph T160 Trident
2014 BMW F800GT
1978 Morini 500
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Re: Gearbox troubles!

Postby harrymuffin » 11 Oct 2017 17:52

The two specials were made in Italy, but all the other bearings are common e.g.. camshaft bearings 6202 around £5, GB layshaft other end NJ 203 from Chinese £18 to SKF £30, GB output shaft end NJ304 from Chinese £8 to SKF £35. I do not pay these prices for SKF or other reputable make bearings, if you ask for trade than you would expect to see a discount of at least 60% off the marked prices.
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Re: Gearbox troubles!

Postby harrymuffin » 12 Oct 2017 09:55

I have received a quotation from Hoffman bearings regarding modifying the standard bearings to replace the original specials as below:

We thank you for your recent enquiry and have pleasure in quoting as follows.

This quotation is based on you supplying bearings to us free issue. Please note, prices do not include carriage
and this quotation is valid for 30 days.

Our Reference QB 12.10.17

Free Issue Bearings 6204 to modify to 21.8 x 47 x 14 5 off £16.00 each nett
Delivery 3 - 4 weeks

Free Issue Bearings QJ306MA to modify to 33 x 72 x 19 5 off £26.00 each nett
Delivery 3 - 4 weeks

Please note, if you wish alternative prices please do not hesitate to contact us. We can quote 1 off each to 50 off each

Best Regards
Alison

So, you sort the bearings yourself from wherever you like, send them to Hoffman and they will modify for the quoted price. The total price therefore is purchase price + modification price so on the gearbox bearing you would be looking about £25 including P & P and VAT which is a damn sight cheaper than the original bearing when I bought mine 15 years ago.
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Re: Gearbox troubles!

Postby penman » 12 Oct 2017 14:44

Harrymuffin- good work! Ijust had a quick look on Simply Bearings and the 6204 from whichever manufacturer and in whichever variant is under a fiver ex-vat. The QJ306MA is another story, they only quote the SKF bearing and it’s £81.11 + VAT. All the same, this looks like a good option if needed. I really need to take the engine apart and see what I’ve got now. It’s done 32000km and as I’ve said, it runs quietly. I like the idea of replacing bearings irrespective, but that one will be well over £100 which does make you hesitate!

I also took the 350 K2 for a run this morning for comparison, though it’s very different - 6 speed box and L/H gearchange. I’m ashamed to admit that I struggled a bit with the L/H gearchange, changing gear with the brake pedal is remarkably unsuccessful and actually a bit scary at times! That aside, the K2 gearchange is much more positive. You can really feel the “click” as the index arm drops into place and there is no overshooting or false neutrals or any nonsense like that. It doesn’t whine either!

Regards,
Joe
1985 Morini 350 K2
1978 Triumph T140 E Bonneville
1975 Triumph T160 Trident
2014 BMW F800GT
1978 Morini 500
penman
 
Posts: 260
Joined: 08 Mar 2016 09:20
Location: Milton Keynes

Re: Gearbox troubles!

Postby harrymuffin » 12 Oct 2017 17:05

Yes, my first Morini was a K2, best of the 350's as it received the development the previous ones did not get; much stronger crankshaft, 140w generator better riding position, bigger tank, the left hand American gear lever was a bugger being brought up on the world right hand change not the Harley Davidson one. I found it worst when getting back on a proper gear change bike as I would occasionally change gear with the foot brake. Never had a problem with kick starting when I had to with the left leg, balance is all wrong if you try to use the right leg, but then the starter motor always worked.
Just done a quick search for the 306 bearing and I am getting prices around 50 quid plus vat but also looked at more alternative bearings that could be used as they are rated at 14300 in oil and that is a 6306 as low as £3.00 or an angular contact 7306 at £21 - SKF or a 21306 at £54 - SKF which is a spherical roller bearing. I went back to Hoffman to see if they could supply on an ad hoc basis the bearings already modified, will have to wait and see.
If you think I sit here all day looking at the computer then I am not, I am busy in the workshop building up a complicated engine, I just pop in for a quick cuppa and now I am going to cook the tea.
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Re: Gearbox troubles!

Postby penman » 12 Oct 2017 21:46

I'm glad you like the K2, I think it's a pretty sorted bike and I was lucky to get mine with less than 2000 miles on the clock. For a 350 it's pretty amazing, though I must say, the extra bit of grunt you get with the 500 makes a big difference.

I will await your next bearing bulletin with interest. Realistically it'll be a week or two before I get a chance to strip the engine down but in the meantime I might just order all the common bearings so they are ready and waiting. There's no great amount of cash involved. I've used the mid-priced "Codex" bearings from Simply Bearings before with success, though I'm not too sure about their slogan "Spinning into Infinity"!
1985 Morini 350 K2
1978 Triumph T140 E Bonneville
1975 Triumph T160 Trident
2014 BMW F800GT
1978 Morini 500
penman
 
Posts: 260
Joined: 08 Mar 2016 09:20
Location: Milton Keynes

Re: Gearbox troubles!

Postby penman » 13 Oct 2017 10:48

Another update. My eBay gearbox arrived this morning and I'm pleased with it. I can't see any wear to the gears, in fact the teeth are barely even polished. There is a small polish mark to the "leading edge" of some of the dogs and that's about it for wear and tear. I slipped the second gear layshaft gear off and had a good look at the bush which has no visible wear and what feels to me like a good running clearance. Hopefully all the bushes are the same. There is no visible wear to the pawl tips or the index arm tip and all the springs appear to be perfect. There is some light corrosion to the chain sprocket splines. Without a doubt that will clean off OK. There is slight polishing to the cylindrical "teeth" on the selector wheel and to the indexing detents, but no actual wear that you can feel with a thumbnail. This is a low mileage gearbox.

So I'm happy, I still need to see the state of my engine internals, but clearly I could do a lot worse than to give this gearbox a clean and lube and drop it straight in. Back to the bearing hunt!

Joe.
1985 Morini 350 K2
1978 Triumph T140 E Bonneville
1975 Triumph T160 Trident
2014 BMW F800GT
1978 Morini 500
penman
 
Posts: 260
Joined: 08 Mar 2016 09:20
Location: Milton Keynes

Re: Gearbox troubles!

Postby Angelo » 13 Oct 2017 10:53

Perhaps I can help you for the SKF bearings.
If interested, please PM me
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Re: Gearbox troubles!

Postby simonnorthroad » 13 Oct 2017 14:14

Hi,
I have a copy of a 6-speed 501 parts book, if you need the exploded diagram.

I also have a 5-speed gearbox sold me by the Man From Luton as a good spare, if anyone needs it
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Re: Gearbox troubles!

Postby penman » 13 Oct 2017 17:37

simonnorthroad wrote:Hi,
I have a copy of a 6-speed 501 parts book, if you need the exploded diagram.

I also have a 5-speed gearbox sold me by the Man From Luton as a good spare, if anyone needs it


Thanks, but this is a 5-speed and I do have the parts book - essential reading I think!
1985 Morini 350 K2
1978 Triumph T140 E Bonneville
1975 Triumph T160 Trident
2014 BMW F800GT
1978 Morini 500
penman
 
Posts: 260
Joined: 08 Mar 2016 09:20
Location: Milton Keynes

Re: Gearbox troubles!

Postby fastharry » 19 Oct 2017 08:35

Could you advise where i can get a copy of the 501 parts book please.
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Re: Gearbox troubles!

Postby 'It must be a .....' » 19 Oct 2017 17:29

Hi, the club should be able to supply a copy of a 501 parts book.
'It must be a .....'
 
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