Barnett clutch

[warp9.9]

Bummer, the torque on them little buggers is light are you using a inch pound/NM torque wrench?
Once you take it off you caqn drill the bolt out from the back side. The bolts miss going completely thru thr hub by .625" so there will be plenty of pilot hole for a good machine shop to drill it out for you if your not set up for it. I would use 45 mm long bolts to replace them. Or that is did what I did with mine, I use grade 8 equivalent. I believe mine let loose due to the short bolts or at least the spring towers snapped below the bolts in the area that was hollow.



here you can see how far the bolts go in. You can see they stop before the filet radius on the spring tower.

I

below is a bolt placed up to the vernier that is set to the length of thread in the spring tower.



I ordered my bolts from Fastenall, and I knocked the washers off the old bolts so I could use them. The washers on the bolts are larger diameter then I could find for sale.

Here s a look see at my damage so you won't feel so bad about yours.



wasted the blower cover also which was a good 1200 plus shipping from the UK



Four of the five spring towers broke up and the fitfh one is all bent up. Don't read to much into my breakage as I am running a wee bit more HP then stock.

 

[Battersea]

................... as I am running a wee bit more HP then stock.

NO, really.

 

[warp9.9]

Many times us HP junkies find ways to improve on what is a god design. Although there could be factors that made my hub fail one being maybe the centrifugal force of the lock up weights strained the spring tower over time weakening them and sometime after eliminating them along with the increase of HP to over say 300 hp. It failed. It also could be good traction and a large amount of torque over time weakend them also.
My point is you can see where the towers broke





in the area just after the bolts ended.
I see know reason why the bolts could not be longer as the thread goes all the way in.



I can not help but wonder if they had gone thru would the towers have broke?

Either way it is not going to hurt anything by filling the threaded holes with bolt in my opinion.

 

[nomnob]

Thank you for your deep insight and comforting post. I understand the bolt thread go thru the drum completely and it's better to fill all the way with longer bolt for more tolerance although I probably don't need for now with stock engine power.
Luckily I found the fastenal just around my neigber, I'd easily find the bolt and will no longer pay $11 for a piece of missing stock bolt for plastic head side cover anymore. All I need to do now is take out the inner drum and find mechanic shop to drill the hole and tap it if necessary.

By the way, I found that the service manual is different from what I have seen in my clutch. It's probably because of design update, needle bearing, thrust washer in the manual were not there anymore. bearing was attached with pressure plate. In addition I have wave washer on the bottom of lifter piece which I don't know how it works.

 

[warp9.9]

the wavey washer is between the lifter piece and the input shaft of the tranny it is there so oil that flows thru the tranny shft lubricates the lifter piec and internal clutch stuff the are a couple ways ol get over everthing.

The hub comes off easy find the keyway in the shaft and use a punch to knock the mashed nut section up and out this helps protect the threads when you take the nut off.

The triumph tool



locks the inner hub with the outer clutch drum.

You can also use some old steels and fibers by drill a coulpe bolt holes in them to lock them together. (bolt together while installed so they are in alignment)

Of course the easy way is if you have a good air impact wrench. You just hold the inner drum with one hand and spin the nut off with the impact wrench.

 

[STRIPES]

Being that bolt is not bottomed out, it should have no residual torque. It should be easy to drill a hole in it and use an "ease out" to get it out. It should back right out. I do it all the time.

 

[nomnob]

Yes, I have known that nut has something unfamiliar to me. But Punch is easy to find. I will find impact wrench to do it instead of special tool for one time use.
Thanks!

 

[warp9.9]

The nut is fairly cheap from Triumph I would replace it. Also there is a thick washer that is on th eback of the hub it sticks to it from the oil. do not loose track of it. That and the front washers can be re-used. If you get to where you think you need the special tool let me know I can loan you mine.
If you try the easy out be carefull its a 6mm 1.00 pitch thread. if you start drilling with the tap dril from behind it might start spinning the bolt out the front so you can get a hold of it. Don't be afraid to take it to a machinist as you do not want to damage the threads. Once the threads is screwed new hub will be the answer.

 

[nomnob]

Thanks for the kind offer, I will PM you if necessary. I will try the impact wrench first. I think the dealer might allow me to borrow it once they extract the shaft. Yes, Dealer agreed to try it.
I ordered Lock nut (T1170101) because locked part of the nut has teared already. I've ordered Belleville Washer (1170091-T301), too which was instructed to use new one in service manual.

By the way, I have questions about gasket.

when you open and close the crank/clutch case cover, how do you clean the gasket and what do you use to install new gasket?
It's very difficult to clean it. I think I need to use oil stone to clean up glue-like residues and finish light scratches from scraper and flat head driver. I used break cleaner to make it ease but did not seems to work.

Also, when you install new gasket, do you put oil to seal it or easy pealing for the next time? manual does not say about it but some people say it's good to put very slight oil on engine side not for the next time.
I found liquid gasket in auto shop, too. I don't know if those are good product to use instead of/together with stock gasket.

 

[warp9.9]

I used a razor blade to scrape the gasket off the cover. Applied permetex to the cover and stuck the gasket to it. Then left the other side dry and lightly oiled the egine side. This allowed me to pull the cover a few times before having to change the gasket.