Britbike forum Forums British Motorcycle specific Brands Triumph bulletin board TR6 clutch woes and shifting problems

Hello all,

Finally got out on the road with my Triumph project and have experienced some issues during the "running in" process, related to the primary and gearbox.

This is a 1969 unit 650, sealed primary. Single carb head with T120 cams.

Using-

75/90 Mobil 1 syn gear oil in gear box.

Type F ATF in primary

Problems are-

Originally started out as slipping clutch when in higher gears, 3rd/4th and the first gear "crunch". Clutch had been freshened with new frictions and glass beaded steel plates.

Decided to "solve" the problem with a 7 plate clutch and fresh 650 springs. In hindsight, my adjustment probably wasn't the greatest, but decided the 7 plate and fresh springs wouldn't hurt.

Installed 7 plate and springs, adjusted by manual.

Pressure plate run out adjusted- top spring coil/button is just showing, run-out about .015.

Push rod adjusted- Backed off cable going into gear box, tightened center until contact, backed off 1/4 turn. Adjusted slack at cable base until 1/8 play at lever and lubed cable. Lever action is great, and clutch seems to hold where the old set up slipped. now I have these issues...

First gear crunch, not every time but most times.

Neutral is impossible to find unless shifted into when still rolling.

High RPM shifting 2-3 and 3-4 gets false neutrals.

Other than that seems to shift and go great! I only have 14 miles on this new setup today.

Looking for advice on where to look/what to try next, not sure if I have adjustment issues or gearbox issues or both.

Thanks!

Could be any number of things, selector quadrant springs and pawls,
cam plate, selector forks worn gear dogs etc.

Clutch dragging and not being able to find neutral can be notches in the chainwheel slots. Certainly somewhere there is drag on the components. Poor clutch spring adjustments could do it, (uneven)
It could even be the oil in the gearbox. Sometimes a change to lightweight gear oil, especially synthetics can help.
I would look at every component from the lever to the clutch cover plate for something that isn't to spec.
With the 7 plate conversion, there's no reason your clutch can't be like any modern clutch.
Cheers,
Bill

Are you using the correct 7/8th pivot clutch lever (just a thought, my clutch was possibly over extending giving me problems)

With only 14 miles it could just be settling in. Cable stretch, springs settling, plates evening out etc.

Crunch into first is typically Triumph. Depends on how bad yours is. Some do, some don’t.

High rpm false neutrals is not usual. Maybe in the pushrod or general adjustment. Pushrod for 7 plate the same as original or different?

Somethings not disengaging somewhere.

If it was mine I’d worry less about the clutch/gear issues and more about seating rings if it is a new build. If you are happy that the rings are bedded in then do a few more miles on it and see what settles and what doesn’t.

Make sure you are getting the full lift from the clutch cable. My bike sometimes doesn't select properly between gears when doing more frantic higher rev changing. Just letting the revs drop a bit solves this. Crunching in first can be cured by having a slow idle of about 750rpm. Allowing the revs to drop to idle, pulling the clutch and pausing for a short time and then clicking in makes for a quiet engagement as long as the clutch is not dragging.

Dave

In the same vein as Dave, sometimes you can get first gear more smoothly by going up to second from neutral and then down to first.

Do you free the clutch plates before taking off?

When installing the 7 plate I did notice the very first friction plate that goes against the chainwheel was difficult to get in, but figured once it was snug up against the drum it wouldn't pose any issues, I can re-visit that.

The center hub and basket are not new, but didn't appear to be grooved beyond use? I'm not sure how sensitive it is to be honest. (lack of Triumph experience)

The spring adjustments were relatively even, I'm not sure if my pressure plate was stepped on or what but it did have pretty substantial run-out when I started the adjustment procedure.

What light weight gear oil would you suggest? That would be the easiest thing to try first.



No idea, they are cheap "Triumph style" levers that came with the bike. To measure I go from the pivot bolt to the cable lug?




Yeah, I thought about that as well. I'm not sure This is my first vintage bike, British at that. I'm not exactly sure what is "normal" or what type of shifting the bike is capable of to be honest.

Pushrod for the clutch is the same. I'm using an aftermarket version, two piece with the ball bearing in-between.

Correct, seating rings is first priority. This is only my second time away from the house on the bike, ride previously was about 12 miles and the 14 I did last night. Seems to be running well, no smoke, minimal leaks.



Basically describes it exactly. It seemed after a failed attempt or two on the 2-3 shift, the RPM's came down and I was able to make the shift. Same with the 3-4. My expectations of the 7-plate conversion might have been a little high right out of the box.

I can double check the idle speed, though I do not have a tach at the moment. It does seem a bit* high once the bike is actually hot.



I did not "free" the plates yesterday as everything was new.

Thanks all for the replies so far!

I’m thinking of doing what your doing , going with a 7 plate setup. I really want the lighter lever pull. I’ve been told to use these springs 57-1560 with that setup. Did you use these springs ? If not was your lever any easier to pull ? I’m running the map no drag clutch now. I also have the problem with neutral and first gear crunch at times. My basket and all are new. I was also told to use those 57-1560 lighter spring in this to get a lighter lever. So now I’m not sure what to do. Go with the 7 plate or not.

I was interested in the lighter springs, but when I bought the 7 plate they were out of stock so I just used standard replacement 57-1830 springs.

I do have to say the lever pull is not bad, better than before but I know I'm running less pre-load on the springs now. I also lubed the cable and that probably made the biggest difference.

One of the jokers around here said that the Triumph first gear crunch has a Triumph part number.
Ha, ha.
I've found that rolling forward, even just a tiny amount will allow for a silent engagement. So, perhaps he's right. Goes with the territory.
The 7/8 lever reduces lever pull effort dramatically, but doesn't do anything for full disengagement of the clutch.
I used to have a '67 Bonneville and I thought the gearbox was horrible. So did Triumph and within a couple of years of your bike's manufacture, Triumph changed everything in there to make it a better gearbox.
The main thing I think that made difference was the change from fine to coarse engagement dogs. This makes for much cleaner shifts with less crunch, especially on the move. Speed shifts under full throttle were dodgy at best. I used to pound the gear lever with my boot when shifting. It always made a nasty bang when I did. (I was young. I don't ride a Triumph like that anymore)
So, maybe it's just the nature of the beast.
Having said that, the same rules apply to your bike as every other Triumph. The clutch is the weak link in the whole design. Every single component of the clutch needs to be in good condition and adjusted properly or it won't work right.
Cheers,
Bill

Wear on the clutch spider will give dragging too. Few people check this item.

Hi UGOTBIT, What brand 7 plate do you have?

What brand basket do you have or do you know?

I just ran into the first friction plate not fully settling into basket. New LF Harris Uk made basket. Aerco 7 plate. Looking at genuine baskets the back corner is very square, but on new basket, it's a little radius. Also the tangs on the Aerco friction disc are slightly longer than genuine Triumph tangs or Hyde tangs. (some Hyde have this too long tang issue also). It's imperative the first plate sits flat & freely into basket. File tangs & back side of friction material and steel of that first plate as needed to set flat.

This is my first experience with Aerco 7 plate. I have done many Hyde 7 plate. Aerco plate has same friction material, but the friction pads are much larger which changes the effective pad pressure. I won't road test for a week or so on the job I'm doing now. (my bike).

The adjuster screw on clutch rod should be set to 1/2 to 3/4 turn out. 1/4 is not enough. On brand new friction plates, I'll use 3/4. After 20 miles or so & many take off & shifts I recheck/adjust rod. I tend to use 5/8 turn out as my normal setting. I find 7 plates last fine, but tend to wear faster than the original cork. Rod clearance goes smaller as plates wear. If rod clearance is less than zero it actually holds plates apart, which causes slip & smoked plates. A little extra clearance is fine.

As you have done most important to have huge free play in cable when adjusting rod. The #1 mistake I see is adjusting rod without enough cable slack.

I would adjust lever free play to about .115" lift measured at the primary adjuster hole to end of adjuster screw. Sometimes over lifting can for some odd reason increase drag. If you have 7/8" pivot lever this would pretty much automatically work out with 1/8" lever play motor cold. Play will increase with heat soaked motor. That is normal.

As was stated too much side play in spider can cause drag as well as too much play at thrust washer behind basket. Grooved basket & hub will cause drag also.

Regarding slip the springs must be adjusted to the thickness of the clutch stack. A new genuine Triumph stack will be very close to 1.400". That's all the steel & friction plates stacked together squeezed tight in your hand & measure with Vernier calipers, being sure your on top of the friction pad of 1st plate, not in the groove between pads.

The new Aerco clutch I purchased 7 new frictions & all new steels. They measure 1.380" stacked. So I know I need to go .020" deeper than stud top of dome to be nominal. I will then go deeper on one or two nuts to set wobble. The spring tension is critical. Too loose & you will get slip. I've found with Hyde plates I started going with studs flush with bottom of nut slot. This worked good when new, but when plates wore some, the effective spring tension became too loose. This resulted in what I call micro slipping. Not really a slip, but not as positive of grip as should be. In a few thousand miles this micro slip results in actual slipping when accelerating hard in upper gears. Very quickly the friction pads will wear to zero then.

Will see how the Aerco does. I usually cover about 5k miles a year, so it will take some time.

Just tonight I was checking pressure plate diameter in relationship to friction pad circle diameter. The original steel pressure plate is pretty much centered over pads which is good. It's less than centered with Hyde. I've noticed it appears a larger diameter pressure plate might be more desirable with Hyde. Most alloy plates are actually smaller than steel plate, which is a step backwards.

Sounds like you did a good job correcting wobble. .015" off on nuts is not bad. Often will take more. The amount nuts have to be adjusted to correct wobble is not so important as the trueness of the pressure plate.

Always adjust clutch rod every oil change after clutch has bedded in. So every 1000-1500 miles. A tight rod will smoke a 7 plate very quickly. Less than 50-100 miles. The friction pads are only about as thick as a playing card so no room for error from slipping.

Also I found synthetic oil in trans gave less resistance to spinning gears, actually making shifting a little rougher while moving & also more clunking into gear. Not so much harder to get into neutral.

As was said lower idle rpm reduces clunking into gear, but it can cause other problems such as stalling & reduced oil pressure at idle. I tend to never go lower than about 900 with motor heat soaked. Going into neutral at stand still is sometimes easier if you lightly blip throttle & select neutral as rpm crosses the peak back to normal.

As was stated if you can anticipate the change of the light you can pull clutch & wait maybe 5-10 seconds to allow gears to slow down. Of course that's not always possible. So select first, quickly & firmly. Also when shifting move lever fairly quickly & firmly. Unlike a car, there are no synchronizers to ease into gear. They must just jam together. With practice you can match shift speed, rpm, to get the smoothest you can. Freeing clutch before start up should still be done with 7 plate. It should free very easily.

I'd recommend going over rod adjustment & lever adjustment again. Evaluate the clutch & shifting doing some experiments with the above suggestions & see how it goes.

I've a lot of experience on '69 Bonnie with Hyde 7 plate, ATF in primary. It works quite well, but will clunk into gear often. Not really bad, but as was said some is normal. If the gears are totally at stand still, not spinning at all sometimes (often??) will not go into gear. You have to clutch it to get gears turning, then it clunks worse.

Give it a good few hundred miles & see how things settle in. Let us know how it goes.

Your bike is now same as '69 TR6R. A very desirable bike! They had same cams as T120. Some feel single carb head is the better setup.

I'll give full report on Aerco compared to Hyde 7 plate after I get several hundred miles on the Aerco. I'm keeping 100% open mind.
Don

Hi, just to add my bit, my 1972 TR6 with standard clutch crunches into first when hot but not from cold. From cold my clutch does not stick ever, neutral is no problem whether hot or cold. I have suffered from clutch slip in the higher gears under heavy throttle even with correct adjustment and T140 springs, I have now measured the plates and they are worn so just waiting on a new set. Clutch pull can be made easier if you set the handle bar lever below the horizontal, i used to suffer from wrist cramps due to the heavy pull but not since setting the lever lower. A mate gave me a book "Triumph Tuning by Stan Shenton" from about 1972? Which is about tuning for racing but one paragraph reads "Triumph standard bonded clutch plates are quite satisfactory but avoid those with cork linings. We increase clutch spring pressure by using three Norton Atlas springs. Clutch springs should be tightened until they are just coil bound at full clutch lift on 500 and 650cc models. This setting will occur when about two threads show proud of the adjusting nuts." I have done this with mine and the lever pull does not seem to heavy, and we have the stronger T140 springs to play with these days! Changing direction slightly while looking at a 1982 T140 workshop manual 99-7059 I noticed that the clutch spec lists six bonded plates of standard thickness 35/45 thou and seven steel plates so giving you 12 working surfaces rather than 11! Clutch springs 9 1/2 coils, 1 13/16" long, 62lb load. I presume this was Triumph trying to produce a lighter clutch, I did wonder whether the clutch basket is deeper to accommodate the extra plate and also if two rows of teeth on the triplex basket would line up with a duplex chain set up? Any one know any thing about this late Triumph set up? When I get my new plates I'm going to check to see how much room I have to see if I can get another steel plate in with out the outer one disengaging with the hub! Cheers Steve.

Did t they have friction material bonded to the inside of the basket in the later madras ? Not sure though.

Hi Mori55, not by the drawing in the manual I looked at, it looked like a standard clutch basket to me. I tried to find a parts manual for the later bikes to check part numbers but had no luck, cheers Steve.

So one of things I hear about the 7 plate clutch is you don’t need as much spring tension ? How do you figure that out without constantly pulling the primary cover. Some say use the 500 springs. It’s just confusing me. I never did it like Don said by checking the stack height then adjusting the springs accordingly

I used 500 springs in one clutch and 650 in another. Can't hardly tell the difference, but the 500 springs almost needed a return spring for the clutch lever. It was the lightest clutch I've ever experienced on any motorcycle and didn't slip at all.
On stock and lower powered bikes, it could be the way to go. I suspect with more power, you'll need stiffer springs.
Cheers,
Bill

Hi Mori, For model year 1981 Triumph finally decided to lighten the 750 clutch lever pull. That was needed to my fingers.

They had their own version of doing a 7 plate. This allowed the use of 650 springs in place of the 750 springs. They glued thinned friction pad to inside of basket. The made the other pads thinner as well. Since the friction pads were glued to the inside of basket, that's what allowed the use of friction pads that were no so thin as Hyde or Aerco kits. The basket was the same depth as a normal basket not including the friction plates. I think the thicker pads is a very good plan, but... when basket pads are worn, you need a new basket. It would probably be grooved anyway so maybe that doesn't really matter that much. This was the first time I've ever seen Triumph list friction pad thickness specification. I expect, but don't know for sure this clutch & related parts could be retro fitted to earlier T140 type motor.

As we've discussed prior both Hyde & Aerco 7 plate have very thin friction pads to make up the space for the extra 2 steel plates. Not much thicker than a playing card! Remember the first plate against basket is basically wasted space. (Thickness of 1 friction pad & steel of the plate).

I've only talked to one owner of an '81. He didn't really know exactly what clutch was in it, but it worked good. I personally felt lever. Felt like mine with 650 springs.

I don't know how hard it is to come by these later plates & baskets.
Don

On my 650 could I use the lighter 500 springs if I go with the 7 plate clutch ? Or would you be afraid if it slipping ? I’ve seen where this has been done. I actually heard aerco recommends this. I just hate pulling the primary on and off.

Hi Bill, I've found over the last 18k miles the 650 work best when dome is screwed flush with the studs. I used to back them off to the bottom of the grooves but that promoted premature wear.

I measure the stack of all steel & friction plates. I've found over time new genuine Triumph plates stacked average 1.400" Measuring lots of aftermarket plates they can vary by more than .060". I've found even .020" makes a difference. So I measure new stack & then calculate the difference. I then go flush & use depth gauge on Vernier calipers to make the correction as needed.

I've found this works very, very well. Even with very worn plates, you can get near new performance by setting the springs to compensate for thickness of stack. Remember pressure plate is that amount deeper, so it doesn't effect spring binding one way or the other. Recently went about .120" deeper.

It was listed on a few sellers sites, Hyde being one, you could use 500 springs. Speaking with Hyde about 4 or 5 years ago, they said that didn't work for most riders & recommended 650 springs, but you could try backing 650 off. The 500 springs I've felt on the bench are a fair amount softer than 650 springs, so I would think most riders would find them too weak & slip worse.

I found backing 650 off didn't give me the life I expected. I've never tried using backed off 750 springs.

750 springs are shorter & way stiffer. I'll have to give it some study, but I recall something about a formula for pressure vs compression comparing a longer thinner spring compressed more to a shorter thinner spring compressed less. I think the shorter thicker spring would still make lever pull harder at the same actual pressure installed. Meaning the short thick spring is less linear during compression. Anybody know about this?? I may be way off!

In any case lever effort goes up very quickly as spring tension is increased, by turning nuts deeper. I still recently have been going deeper with 1 or 2 nuts to correct wobble, unless it's way too deep. Then I'll back off 1. Once to fuzz wears off a new plate it's slightly thinner so you'll loose a little spring pressure there. If you are very sensitive at feeling clutch rod clearance using witness marks, you can get a rough calculation of how much wear is occurring on the plates. But.... Thrust washer wear will show as plate wear using the rod screw. Crazy fun stuff!

That would be a good experiment to install backed off 750 springs. That won't be me at this time.

On a good note, the new clutch basket & tensioner showed up today, so I might.... get bike running late tomorrow.
Don

Thank you ALL for the thoughtful and detailed responses.

TR7RVMan- I'm not going to quote your post due to size, but thank you for the detailed response.

I'm using an Aerco 7 plate kit.

After reading the responses here and searching out and reading everything I could find, I began to suspect my adjustment was not as good as I thought it was and that I did indeed have some dragging issues. I also put another 10 miles or so on it and decided I should take a look.

I believe my education of Triumph clutch operation has come at the cost of my new 7 plate clutch

Once I got the primary cover off I could see and smell the clutch was slipping/dragging. I took the plates out and had to dress the tabs on 2 or 3 friction plates to get them to float in the basket correctly.

I inspected the basket and hub, for grooves and like I originally thought, they are both in usable condition. The basket has a hard square edge in the rear. I scuffed up the steel plates, and inspected the frictions. They are a little dark, but there was still plenty of friction material.

I believe I did not have enough spring pressure on the pressure plate. When I adjusted it the first time I started flush with the domes and backed off until I had the pressure plate run-out dialed in. I believe I wound up too far out with not enough clamping force. The dragging plates I believe are what caused my other issues (first gear crunch and impossible neutral)

When I re-assembled I adjusted the pressure plate correctly (springs turned in) and once again was able to achieve .015 in run-out.

Adjusted push rod adjuster to 1/2 turn out.

1/8-1/16 play at lever.

Quick run around the block resulted in great clutch action, NO first gear crunch, NO slipping, positive "clicks" selecting gears AND neutral has returned. I don't want to yell victory yet as the ride was very short, just enough to get the pipes hot enough to give me a nice kiss on the forearm

I'm not sure how much life I took out of it with the improper adjustments, I may freshen everything up once the season is over.

Plan is tomorrow to get out on the bike and attend a local event. It's a decent ride from my place so I can get some time on everything to see how it works.

Thanks again to all for the ideas, tips and tricks. The detailed replies really helped and were all spot on!

Let me k ow how it’s working as I’m thinking of doing the same thing as u. I also was thinking of using the 500 springs. Now not sure as I don’t want any slipping.

Hi UGOTBIT, What did your clutch stack measure?

If you don't have Vernier calipers you need them. Digital ones are $20 eBay or Harbor Freight.

Been there done that what you've experienced. I've learned the hard way to measure the stack. It's a key component to good clutch like & operation. Guess work bits you in the rear every time.

Back in the day, life was simple. We went to local dealer & got genuine Triumph parts. The fit & worked. Simple!! Not now. Every new part must be examined. Quality control seems marginal with even the best sellers. Everything must be inspected & measured if you want bike to work like you want it to.

You learned a very valuable lesson, that will serve you well for Triumph ownership. This bikes might be simple, but are finicky about assembly. If you really want to ride both there & back, everything must be right. Once sorted these bikes are fairly trouble free & very reliable.

Good luck on your trip.
Don

Hi Morri, Don't even think about 500 springs. I can't imagine they wouldn't slip with the power your bike puts out.

Let me know what your clutch stack is when your calipers arrive.

I hope to have my bike running later today. Working on 3 row chain alignment next. Looks like it's out .030" I hope I have enough shims.
Don