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Discussion Starter #1
Rebuilding the engine on my buddy's 1972 TR6RV and made the determination that the clutch assembly had more play than it should. I bought a new thrust washer and 20 new rollers. Upon reassembly, the bearing would not go back together. I tried heating the housing but it still would not accept the hub and rollers. I measured the new rollers and they are .255 inch diameter and the old ones are consistently .2485 to .249. No visible wear or lip on the race in the housing. There is .001 difference between the new thrust washer and the old, the new one being thicker. New and old rollers both measure .233 in height. Are there two different size rollers and I received the wrong ones? I have not reassembled with the old rollers to see if the thrust washer improves the play I was looking to eliminate. Suggestions?
735562
 

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Rebuilding the engine on my buddy's 1972 TR6RV and made the determination that the clutch assembly had more play than it should. I bought a new thrust washer and 20 new rollers. Upon reassembly, the bearing would not go back together. I tried heating the housing but it still would not accept the hub and rollers. I measured the new rollers and they are .255 inch diameter and the old ones are consistently .2485 to .249. No visible wear or lip on the race in the housing. There is .001 difference between the new thrust washer and the old, the new one being thicker. New and old rollers both measure .233 in height. Are there two different size rollers and I received the wrong ones? I have not reassembled with the old rollers to see if the thrust washer improves the play I was looking to eliminate. Suggestions?
View attachment 735562
I would try with originalrollers as the std size is .249/.250" so if you have 20 all measuring +.005" that equals o/d being +.080" or 2mm bigger which is considerably larger than std.Cheers
 

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I would try with originalrollers as the std size is .249/.250" so if you have 20 all measuring +.005" that equals o/d being +.080" or 2mm bigger which is considerably larger than std.Cheers
oops maths wrong this early in the day here. . It is .100"/2.5mm of course. Just testing.
 

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It's 0.01" = 0.25mm. Regardless still too much.
 

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Hi Happyfeet, The rollers should not be larger than .250" in diameter. I bought a set of 20 a year ago from Vintage Triumph Supply & they replicated original rollers perfectly. Fit perfectly with old parts & new parts. Hub was LF Harris, New basket was LF Harris. I pay attention to all this stuff & fool around with trial assembly just to see what difference new & old parts make in real life. Old rollers were good, but I decided to replace since I was using new small hub and basket.

I don't know what your actual measurements of new rollers is as both posts don't quite seem like the values make sense. Or you got bum rollers somehow. So far as I know the rollers are the same on all unit motors.

I've had a lot of clutches apart. I find the rollers tend to wear very little. On these primary breather motors with constant short trip riding, I've seen 2 bike that the rollers rusted & pitted, but I'd not call that wear per se.

The new hub had very very tiny burrs on the 4 holes where thrust washer sits. It chewed the ID of thrust washer up in 100 miles, putting brass chips in bottom of primary case. I've seen this recently again on fellow's bike on BritBike forum. So maybe this is problem. In any case, I'd lightly chamfer the 4 oil holes on new hub.

In any case very unlikely you'll feel much difference with a .001" thicker thrust washer. The basket with clutch plates removed is very, very wobbly. Installing all new parts is still very wobbly. The chain is on line with rollers so it doesn't really wobble much in actual operation.

However the actual end play of basket with the hub all torqued up does matter. For both release & slip under heavy load. Putting a large bolt through assembled basket, cush hub, small hub & tightening it. Turn over & measure end play of thrust washer/basket. Good will be about less than .018-.020" You'll need 3 feeler gauges of same size to keep the basket level & get accurate reading. When you get up into the .030-.040"+ range it starts causing problems with drag & slip. However, there is more to end play than the thrust washer. The other part is the spider leg side wear & back plate wear. Radial wear of spider in bores can cause wobble also.

If you look at Lunmad video on YouTube of wiggling the basket, it wobbles a lot. That is not out of line. He speaks of this wobble as normal. He is correct. I can't seem to locate it quickly at the moment.

What are you doing with cush hub. The back plate is hardened so not easy to refinish & machine down hub to remove clearance. Cush hubs are quite costly, but if worn, they prevent good clutch operation. I'm speaking of the spider area. Worn grooves are bad too of course. They can be filed, but the internal wear requires replacement.

My spider had about .020 wear at least. Hard to measure as it wears tapered. My back plate had .005" wear where the arms rub. Using straight edge over plate & narrow feeler gauge at worn area.
Don
 

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Only replaced one set of rollers and thrust washer. That was during a rebuild but since then, those rollers and washer are not wearing so re-use each time the clutch is out.
 

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Discussion Starter #9
My parts source offers the roller bearings in .005 oversize from standard and mistakenly gave me 20 of the .255 inch. They are shipping the correct ones to me this week so I should be set!
 

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Hi Happyfeet, I didn't know they sold .005 over rollers. I guess there are people honing the bearing race in basket?

Kind of funny how we used to go to Cycle Salvage & get good used parts cheap! Triumph owners seemed to crash a lot & totaled their bikes. I got several complete primary drives with only a few thousand miles on them. Cheaper than new cultch plates from dealer. Notched baskets & hubs were as common then as now. We never considered filing them when you could get perfect used for so cheap. They were cheaper than Honda parts. I bought a pair of new take off mufflers from the local Triumph dealer for $15 in 1976. He was so happy to get rid of them. New parts very hard to get due to the strike which we knew nothing about. Local dealers were dropping Triumph line.
Don
 
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