Mainshaft transmission bearing

[Suzuki_Don]

I need help on this one guys and gals. As many of you know I have the cases split on my '77 550 while I am in the throws of boosting the capacity to 700cc. The 550 has a six speed transmission and I would like to replace the main bearing adjacent to the sprocket on the mainshaft. The problem being I cannot find out which bearing to use. On the parts fiche this bearing is not identified. I cannot find a part number for it.

I know I can measure the bearing seeing as the transmission is disassembled at the present time, but I need to know the internal tolerances, C1, C2, C3, etc. There are many options available in any given bearing size. Most people suggest using the bearings with the 2RS seals either side which is OK for wheel bearings, but I would think not for transmission shaft bearings.

I thought I would use a 2RS bearing and pick the inner rubber seal out so oil can get to the balls in the bearing and the other seal left on the outside of the bearing plus the other two seals that are originally on the mainshaft just inside the sprocket should make sure the oil stays in the transmission. Or should the oil be allowed to flow through the bearing to properly prevent wear.

What are your thoughts? Give me some feedback please. And does anyone know the part number for this bearing.

P.S. What does the B1 in front of the bearing size mean?

 

[GearHead]

Most of the bearings i have worked with have a part number stamped on them. You could probobley use that number to order another one ( thats too obvious a solution ). Also, Most of the good auto parts stores still have the paper catalogs, you could try using those to cross reference that part number. Hope this helps.
Gearhead

 

[Nessism]

The stock bearing has a groove cut around the OD which holds those crescent pieces. I don't think you will be able to find anything off the shelf with those grooves.

 

[Calvin Blackmore]

I need help on this one guys and gals. As many of you know I have the cases split on my '77 550 while I am in the throws of boosting the capacity to 700cc. The 550 has a six speed transmission and I would like to replace the main bearing adjacent to the sprocket on the mainshaft. The problem being I cannot find out which bearing to use. On the parts fiche this bearing is not identified. I cannot find a part number for it.

I know I can measure the bearing seeing as the transmission is disassembled at the present time, but I need to know the internal tolerances, C1, C2, C3, etc. There are many options available in any given bearing size. Most people suggest using the bearings with the 2RS seals either side which is OK for wheel bearings, but I would think not for transmission shaft bearings.

I thought I would use a 2RS bearing and pick the inner rubber seal out so oil can get to the balls in the bearing and the other seal left on the outside of the bearing plus the other two seals that are originally on the mainshaft just inside the sprocket should make sure the oil stays in the transmission. Or should the oil be allowed to flow through the bearing to properly prevent wear.

What are your thoughts? Give me some feedback please. And does anyone know the part number for this bearing.

P.S. What does the B1 in front of the bearing size mean?

Is it this the B1 26X62X17 bearing?
i see there appear to be two identical bearins on each shaft
one Identified as number 11 on bike bandits parts fiche the other not.

if the dimensions are correct then this is likely your bearing

I looked up B1 and it is referenced in a multitude of bearing listings
but no explanation is given.....nasty thing..

 

[rcp]

I would like to replace the main bearing adjacent to the sprocket on the mainshaft.

First question: you'd _like_ to, or you _need_ to?
The "If it ain't broke, don't fix it" rule might apply here - this is, I believe, a good-sized sturdy bearing running in a well-lubed environment.

If you're bound to replace it, verify if it has a slot for a c-ring, or a locating pin on the outside race. If it does I'm doubtful you can find a general-purpose replacement. If, however, you can find a general-purpose, you can buy them sealed only on one side.

Perhaps you could cross-reference similar model fiches for the missing part number?

- Richard

 

[Suzuki_Don]

Thanks Ed. Yes, one small item I overlooked is the large "C" clip that holds the bearing in place. That's why the Suzuki part costs much more than the bearing off the shelf. I also saw that other bearings in the transmission are 26x62x17. And it is not a very common bearing. I will check any imprint on the bearing when I get home tonight to see if that gives any light on the subject. Thanks for the input guys, you each had relevant helpful information.
As far as I know this bearing is not failing, but if it does then I need to split the cases again, don't want to do that. And the added strain on that bearing, because it takes the load of the rear chain drive, and with added capacity, flat slides, etc, there will be about a 20% boost in power and just thought it would be a good thing to do.
Thanks again. And please add any more thoughts, suggestions you might have.

 

[49er]

Don, how are you bumping up the capacity by 150cc? Sounds like a pretty big over sleeve job!!

How many kms has the engine done? If they are moderate, you should be safe re-using the original bearing. Having said that, I would replace all the bearings and drive dogs myself, if I was splitting the cases. All OEM is a pretty expensive exercise, but if you're planning to hang on to it, worth the peace of mind.

 

[Suzuki_Don]

Don, how are you bumping up the capacity by 150cc? Sounds like a pretty big over sleeve job!!

49ER, I am fitting 650 cylinders and quench chamber head from a 650 which is actually 672 with the standard bore. With a 1mm overbore and 4th size pistons and rings it brings it up to 696cc.

 

[Suzuki_Don]

Well I finally got the number off the bearing and it reads 8358OA and I cannot find anything on the web that even looks like a bearing. It is a deep groove ball bearing (7 balls).
I have looked up many other diagrams of the exploded view of the mainshaft and in none of them is the bearing itemised as a separate part. And all exploded diagrams have this bearing still attached to the shaft although all other parts (including other bearings) are exploded and not on the shafts (main or lay).
It looks like this part will only come with the mainshaft. So I guess I will not be replacing it. Also I cannot see how to remove the bearing. No circlips or other retaining gear to hold the bearing in place.

 

[49er]

Well I finally got the number off the bearing and it reads 8358OA and I cannot find anything on the web that even looks like a bearing. It is a deep groove ball bearing (7 balls).
I have looked up many other diagrams of the exploded view of the mainshaft and in none of them is the bearing itemised as a separate part. And all exploded diagrams have this bearing still attached to the shaft although all other parts (including other bearings) are exploded and not on the shafts (main or lay).
It looks like this part will only come with the mainshaft. So I guess I will not be replacing it. Also I cannot see how to remove the bearing. No circlips or other retaining gear to hold the bearing in place.

I just had a look at the 550 drawings on the Alpha site. They don't list that bearing separately, but show item #17 as a shaft set. Looks like it includes the bearing and maybe a spacer/sleeve on the sprocket side of the bearing.

The bearing will be an interference fit and would need to be pressed off the shaft. If it's not worn, I'd reuse it. How many kms has the engine done? That should guide your decision whether to replace it or not.

 

[hampshirehog]

Don, can you measure it? If I remember correctly (which is highly unlikely ) that's the same bearing as fitted to the 750 (and even the GSXR750?) so if you wanted to replace it you can find the part number.

Having said that I've never known one of those wear out - and one of the lads I used to work with had a pretty hot (mad?) 550 that he thrashed the pants off. (The only gearbox bearings I can ever remember replacing on a Suzuki was on a GT550 where a guy had sandblasted the motor and filled everything with sand).

B1 by the way is the bearing quality descriptor and in this case it's classified as low precision (makes it cheaper).

 

[toolman]

i have run into this alot, it is oem spesific. odd balll sizes and nothing you find in the after market will work . the best thing to do is if the bearing isnt bad dont replace it. but if you have to suzuki is the only place to find that bearing.you might get lucky in the snowmobile world they have some wierd sizes with groove or pins.
good luck .....toolman

 

[Suzuki_Don]

The bearing will be an interference fit and would need to be pressed off the shaft. If it's not worn, I'd reuse it. How many kms has the engine done? That should guide your decision whether to replace it or not.

49ER, I don't know how many kms the motor has done, but as you will see in the pics below there is very little wear if any on the transmission parts, dogs, etc. So I think I will go with retaining this bearing as it probably has very little wear as well. Have a look at the pics and tell me what you think.

Don, can you measure it? If I remember correctly (which is highly unlikely ) that's the same bearing as fitted to the 750 (and even the GSXR750?) so if you wanted to replace it you can find the part number.

Having said that I've never known one of those wear out - and one of the lads I used to work with had a pretty hot (mad?) 550 that he thrashed the pants off. (The only gearbox bearings I can ever remember replacing on a Suzuki was on a GT550 where a guy had sandblasted the motor and filled everything with sand).

B1 by the way is the bearing quality descriptor and in this case it's classified as low precision (makes it cheaper).

Hi HOG, thanks for the reply. I cannot measure the internal diameter of the bearing or the shaft it sits on. On one side of the bearing there is a raised collar that the bearing rests up against and on the other side is the spacer that the two oil seals run on that sits up against the bearing. You will see by the photos I have attached.

I am not a transmission expert so any comments on apparent transmission wear would be appreciated.


http://s226.photobucket.com/albums/dd105/donclifton/Transmission/

 

[hampshirehog]

Don, everything looks fine in the photos but more importantly have a feel of everything as well. I bet it's all tickety-boo (it's a Suzuki box don't forget!).

I'm sure that spacer comes off by the way (with a little gentle persuasion).

 

[49er]

Don, everything looks fine in the photos but more importantly have a feel of everything as well. I bet it's all tickety-boo (it's a Suzuki box don't forget!).

I'm sure that spacer comes off by the way (with a little gentle persuasion).

I agree with Hoggy. The gears and dogs look good for another life.
How do the big end bearings check out for side play/clearance?

 

[Suzuki_Don]

Don, everything looks fine in the photos but more importantly have a feel of everything as well. I bet it's all tickety-boo (it's a Suzuki box don't forget!).

I'm sure that spacer comes off by the way (with a little gentle persuasion).

Wally any tips on getting that sleeve off. I have a feeling that the transmission has not done that many kms looking at the gears, shafts, dogs, etc. I bought the bike with a claimed 7,000 kms on it. But I found that the head had been off before and other things (damage) done to the bike that indicated many more kms than what had been claimed. So now I don't really know.

I agree with Hoggy. The gears and dogs look good for another life.
How do the big end bearings check out for side play/clearance?

49er I have a roller bearing bottom end and the side play on the crankshaft journals is OK.

 

[Suzuki_Don]

BTW is it suggested by most members to use OEM valve guide seals and cylinder head gaskets over the after market ones like you buy on EBAY like VESRAH.
Any suggestions greatfully accepted.

 

[49er]

BTW is it suggested by most members to use OEM valve guide seals and cylinder head gaskets over the after market ones like you buy on EBAY like VESRAH.
Any suggestions greatfully accepted.

Don, I did realise that we were talking roller bearings. Side play/clearance at the rods still needs to be within spec.

I would recommend using OEM gaskets and seals. I have sucessfully used a MLS head gasket on the 850, but some others have had oil leaks with them. If you use OEM, you can guarantee that the head won't leak oil or compression, even if the mating surfaces are slightly marked or bowed. The only draw back is that should you need to go back into the engine at a later date, you are up for some serious surface scraping to get ride if the old gasket material.

Vesrah had a good reputation too, until they were copied by a Taiwanese outfit using inferior gasket material and rubber seals. 3 of us got caught with these sets last year, all having base gasket failures.

 

[Suzuki_Don]

49er, thanks for the info on the gaskets. I happen to know a guy here in OZ that used to own a Suzuki dealership and has since passed it on to his son who is big on modern and dirt bikes. So he asked his dad to get rid of all the old spares. he has sheds full of the stuff. Last time I spoke to him he said he had a couple of OEM 650 head gaskets for around $50 each. I will need to get back in touch with him and arrange something.

It is a while since I had the side clearance on the con rods checked and cannot remember the exact figures of the tolerances. The guy who checked it for me rebuilds Velocette engines and is a whiz on replacing the big end bearings on the pull apart crankshafts and reassembling with new bearings and balancing the crankshaft on a jig. He said everything was within spec. I know there was a bit of sideplay on the journal but no play at all when the top of the conrod was rocked from side to side in an arc fashion if you know what I mean. But I will check again as the crank is on the work bench ready to go in the cases when I get them ready with another coat of VHT high temp paint.

 

[hampshirehog]

Don - you have to persuade it off with a thick screwdriver or a chisel (driven in as a wedge, get some penetrating oil in there and work it backwards and forwards) but you could well booger it when doing so I'd leave it on if the bearing feels ok.

If I am right about it being the same bearing as in the GS / GSXR 750 you've obviously got bags of leeway for putting more power through it.

Regarding whether to use OEM gaskets and seals - I've never found any problems the other guys have with loads of different gasket sets but I put valve stem oil seals on my 1000 last year from a pattern gasket kit and they were toast within 6 months / 3000 miles so I'm strictly OEM in that area from now on.

Oh - and don't worry about your crank at all. As long as the motor hasn't been sitting in a desert with the top off it'll be fine - you can't give away 550 cranks as nobody ever needs them!