RichardB Posted January 17, 2023 Posted January 17, 2023 Like many I've been trying to source some good quality bearings and today some KSM branded ones arrived in the post. The part is labelled 'KSM RMS8N JAPAN LOT .190822' I don't have any of the allegedly poor quality KOR ones to compare it to but later this week I'll take a photo of it next to the RHP one I've got. Just posting this in case it's useful to anyone else. Without specialised equipment or time I can't comment on the quality, but having more sources for these parts is always helpful and hopefully these perform well. I got them here - https://www.autogear.uk.com/triumph-spitfire-1500-mk4-gearbox-input-shaft-bearing.html Not cheap at 23 pounds plus postage but they arrived quickly at least. 1
yorkshire_spam Posted January 17, 2023 Posted January 17, 2023 Previously I've been able to source FAFNIR branded MJ1N (note: no R, so no snap-ring you have to save your old one!) from Hendersons (https://www.hendersonbearings.co.uk/mj1n-1x2-1-2x3-4-single-row-ball-bearing-brand-fafnir.html) but now listed as "Availability: On Request - Please add to quote" I think @wimpus previously build a 'box for FQX using KSM bearings, he might express an opinion on their quality. My notes on x-fer for these are: Quote front/rear bearing - 8MJ1N (RHP) Or rms8n or 8/MJ1NR (MJ1NR Imperial Open Snap Ring Brg 1x2-1/2x3/4 inch) Fag MS10K Bmc 104433 But use at your own risk! 1
RichardB Posted January 17, 2023 Author Posted January 17, 2023 Yeh the snap rings weren't included with these either. I don't think Wim has visited here for some years but I'll see if he's mentioned it on the Triumph Exp forums as I recall he is still occasionally posting there.
RichardB Posted January 20, 2023 Author Posted January 20, 2023 (edited) Not easy photographing these with a phone but I can't see anything that suggests they're any weaker by design than the RHP version. Suppose you'd need specialist equipment to test their strength properly. What's obvious though is they are different to the KOR ones sold by suppliers. I did have a slight concern they might be rebranded KOR ones but the design is different from the photos I've found online of the KOR bearings. Edited January 20, 2023 by RichardB
Nick Jones Posted January 20, 2023 Posted January 20, 2023 Size and number of balls is a good indicator usually. Bigger is better. ISTR a previous discussion on this matter (though possibly not on this forum) where someone reckoned that it was much easier to source them without the external groove (even original spec RHP?). In these days of tipped tooling, getting the groove cut would be no big deal, though undoubtedly more economical to do a reasonable size batch of them….. Or do I imagine this….? 1
JumpingFrog Posted January 20, 2023 Posted January 20, 2023 (edited) On 1/17/2023 at 3:15 PM, RichardB said: Just posting this in case it's useful to anyone else. Without specialised equipment or time I can't comment on the quality, but having more sources for these parts is always helpful and hopefully these perform well. I got them here - https://www.autogear.uk.com/triumph-spitfire-1500-mk4-gearbox-input-shaft-bearing.html Not cheap at 23 pounds plus postage but they arrived quickly at least. Interesting, I bought bearings from this shop before, and was also suspicious. It was back in 2017 and they sent me NTN ones, I was also worried they were counterfeit (since you can't buy NTN RMS8N anywhere), but like you decided they looked nothing like the KOR ones, and everything about the machining on them looked decent to me: (This is the only photo I have of them) FWIW those NTN were still fine at 20,000 miles when we sold the car. I now have some SKF ones that need a groove cutting in them, like Nick says. Maybe one day soon I'll finally build up the close ratio gearbox I've spent almost 4 years collecting parts for... I recently needed LJ1 bearings for a driveshaft rebuild, seems like all imperial ball bearings became increasingly expensive and hard to find other than from budget manufacturers with no reputation. Edited January 20, 2023 by JumpingFrog 1
RichardB Posted January 20, 2023 Author Posted January 20, 2023 (edited) @JumpingFrogThat's good news regarding the NTN ones and thanks as I think I found the firm from your link on the CT forum! I've found it quite hard finding anything useful online about bearing manufacturers but it seems like Japan is full of them. I suppose not having a western consumer facing presence doesn't mean they wouldn't be capable of making decent quality things. Even with the Chinese offerings it's usually poor because its made to a price point, not because they can't make them well. For these particular ones the firm KSM are quite widely sold as 'branded' for other vehicles and Heathrow Transmissions sell them as a premium offering for 1275 boxes. All I could initially find about the firm when searching 'KSM' is "Minamiguchi Bearing Mfg. Co. was established in 1958, in Sakai City, Osaka, Japan." which seems to check out as theres old looking boxes of their 'KSM' bearings knocking about for sale on eBay. But once you search for the name Minamiguchi their website comes up -http://www.minamiguchi.co.jp/en/ Osaka is on my list of places to visit next time I go to Japan, maybe I could call in? You're right on RHP bearings @Nick Jones, I can easily find the same bearing without the groove from them or SKF. I wonder if Triumphs were the only places the groove was required, or whether this particular bearing was used on something else. Edited January 20, 2023 by RichardB
RichardB Posted January 23, 2023 Author Posted January 23, 2023 (edited) I found another source for the bearings. I spoke to Bearingsrus and they quoted me just over £17 each posted for 4 which is pretty competitive, putting them close to what the Triumph suppliers charge for KOR. They don't normally stock them but are able to order them. One thing to mention, these probably are CN rather than C3 fit like the original Triumph bearings, but I dont know whether the others on the market (SKF, KOR, NTN) etc are C3 either. If the SKF bearing was the same as their RMS8 then it was CN. Edited January 23, 2023 by RichardB
RichardB Posted January 27, 2023 Author Posted January 27, 2023 My order of KSM bearings from Bearingsrus arrived today, interestingly they're different! In a good way though. These are labelled RMS8NR and come with the snap ring already installed. The fit is still correct but the manufacture appears slightly different. Not sure why that would be but you can see in the photos they have a different shape of nubs in the ring over the ball bearings and the face is very slightly different. Neither bearing is the same as KOR fortunately. These also came with KSM boxes and sealed bags, giving further confidence that these are genuine.
Hamish Posted January 27, 2023 Posted January 27, 2023 When I worked for a classic car company we used this local (to us) company. https://www.macclesfieldbearings.co.uk they helped a lot with special links and rose joints for the wolf race car that was in for rebuild. They may be able to help with sourcing bearings. 1
Martin Posted January 27, 2023 Posted January 27, 2023 Be careful with the topic of clearance. If C3 is required, CN might be too tight when mounted. 1
RichardB Posted January 27, 2023 Author Posted January 27, 2023 What's the car in the photo @Hamish? New Batmobile?
JumpingFrog Posted January 27, 2023 Posted January 27, 2023 (edited) Richard, interesting how different they are. Are you sure that the original gearbox bearings are C3? I know that the 6205 output bearings in the diff are C3, but I've never seen any RMS8 or MJ1 sold as C3 and all the original bearings from gearboxes I've dismantled were just marked "Hoffmann MS10K". Edited January 27, 2023 by JumpingFrog
yorkshire_spam Posted January 27, 2023 Posted January 27, 2023 18 months or so ago I had not problems sourcing the non-snapring (no groove) bearings from good branded makers. Now, they also seem relatively expensive. I was lucky enough to get the last 2 RHP RMS8 bearings from my local supplier years ago when I actually rebuilt my current box. I've never used C3 bearings, I think @wimpus has though.
Nick Jones Posted January 27, 2023 Posted January 27, 2023 AFAIK the gearbox bearings are not C3. No need to be as they are not especially tight on the shafts. Unlike the diff output shaft bearings which certainly are! KSM bearings look decent in the pics. 1
Hamish Posted January 27, 2023 Posted January 27, 2023 9 hours ago, RichardB said: What's the car in the photo @Hamish? New Batmobile? 1980’s custom for wolf race wheels when the fiesta pepper pot wheels came out. Twin v8 twin gear box but driving one rear wheel each very complicated sync-ing 1
Nick Jones Posted January 27, 2023 Posted January 27, 2023 1 hour ago, Hamish said: Twin v8 twin gear box but driving one rear wheel each very complicated sync-ing Hmm…. Sounds horrific….. not surprised it hasn’t caught-on!
RichardB Posted January 28, 2023 Author Posted January 28, 2023 I may be misinformed about them being originally spec'ed as C3, I think I read it from a well known character on a post here but good news if they're not. That was from someone building them for high revs which would I guess subject them to more heat and subsequently expansion.
coperlio Posted May 20, 2024 Posted May 20, 2024 It's great that you shared your experience with KSM bearings! This information could be helpful to others looking for good quality replacement bearings. You received KSM RMS8N JAPAN LOT .190822 bearings. You haven't compared them directly to the allegedly lower quality KOR bearings, but you'll be comparing them to an RHP bearing later. Without specialized equipment, it's difficult to definitively assess quality, but having more suppliers for bearings is a positive thing. You can also check quality ball bearings from https://en.tradebearings.com/clist_7.html
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