T160 lazy gearchange

Freshly rebuilt T160, no discernible damage to the gearbox when I fitted it, but have to confess I wasn't looking very closely.
If I'm just cruising it goes up the gearbox just fine, but if I'm trying to do a quick shift I sometimes miss 3rd gear.
Similarly, on down-changes when dropping from 4th to 3rd I sometimes get a false neutral, most times it then drops into 3rd of its own accord.

It never jumps out of gear, just sometimes doesn't like going into 3rd.

Any ideas?

On my old T160 the inner gearbox cover had not been machined correctly and was not allowing enough movement of the pedal / quadrant.

I found it out by chance simply by noticing that it allowed more movement one way than the other, when I observed the dismantled inner cover. Trail and error filing and fitting was required, but it was quite an easy and very successful fix.

Mine had clearly been like it all it’s life hitherto. So was obviously an original machining error. It’s therefore unlikely that mine was the only one!

Also, due to the similarity of parts in Triumphs, parts can get miss matched. If 4 speed gearchange plungers are used in a 5 speed they also cause strange partial shifting problems. It’s not impossible that these could have been inadvertently fitted at some point down the line.

Both are easy to check but do need the covers to come off...

Thanks Eddie - certainly worth checking while I'm in there.

I was leaning towards worn selector plungers, quadrant (particularly) and possibly camplate, as all other gears are sweet, and it's sort of logical that the most used gear would get the most wear. As it doesn't jump out of gear I don't believe the gears themselves are a problem, and if the camplate is OK I don't have to strip the primary out to get the job done - big cost & time saving.

First plan is replace plungers & quadrant and see if that fixes things before pulling the camplate out. I presume it's not like a Norton camplate where the drive gear can be indexed around to use un-worn teeth...?

If you haven’t seen this one already, you might wanna...

Update...

Pulled the gearbox and had to dismantle the primary drive to get the camplate out, which was a bit annoying
At least it gave me an opportunity to check everything out properly. Nothing was visibly worn as such other than the usual 'used look'.
the third gear selector fork did have a small amount of play in the camplate, but nothing out of the ordinary.
selector quadrant and pawls all looked OK but for the price of the stuff I replaced them and the camplate.
Unfortunately it's become apparent that the primary chain is tossed and the duplex chains are pure unobtanium, so I'm now waiting for the triplex chainwheel kit to arrive from Clive Scarfe.

I sold my last Trident in 1988 and swore I'd never have another... I just don't learn!

B+Bogus said:

Update...
Unfortunately it's become apparent that the primary chain is tossed and the duplex chains are pure unobtanium, so I'm now waiting for the triplex chainwheel kit to arrive from Clive Scarfe.
I sold my last Trident in 1988 and swore I'd never have another... I just don't learn!

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Hi B+

You are not alone, I am just working through gearbox and primary drive on my t160 I have replaced layshaft second and third gear all bearings and kick start axle it was cracked I bought a starter motor from Dave Madigan, and Like you I purchased the triplex sprocket conversion from Clive, though I went with the Merc duplex chain from "Jason The Chain Man". When I opened up the primary shock absorber the cush drive rubbers, what was left of them drizzled out on to the bench. As a consequence of the lack of cush drive rubbers, the rivets holding spider and centre together rattled their appreciation at being set free. After drilling out the rivets I found that all of the holes were elongated , I bored all the holes over size and turned up rivets to suit I can't tell you how much I enjoyed whacking those rivets up tight The clutch was as expected shot some clown had fitted a grey spring the thickness of which combined with a knackered plate made it close to impossible to pull. I was to say at least surprised at the price of an orange clutch spring from the usual suspects assuming you can find one with one in stock, after looking around i found a company in Oxford making classic Mini a cover plate fitted with an orange spring for £60 delivered. New Surflex friction plate and and a trip to the local bearing factors for a sealed angular bearing for the jolly old clutch pull rod to nestle up against. I measured and remeasured the the stack height before machining the clutch basket fingers I hope I have achieved the elusive flat spring required for the over centre clutch. I have turned up a clutch slave cylinder with a 38mm piston and a 12mm travelling spigot (made up name) to run the pull rod through fed by £35 worth of sh 13mm brembo master cylinder from ebay.

Triples eh, who would have them.

Esmerela said:

Hi B+

Triples eh, who would have them.

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Great to hear they're giving so much enjoyment to so many people
Have to say I'm relieved that the clutch on mine was in decent order and hasn't been an issue - yet... It's light enough and with the Hyde plate it works great.
Norman Hyde did a stronger spring but having just checked he is out of stock . He still has the sintered plate, but it's pricey.
The videos from Classic Triumph have been a good source of info (as per Eddie's post above), and it's great to find there's always more to learn!

Having said this, I'm really liking the bike now, and I have another awaiting a refresh as my Wife has rather taken a shine to it. She hated her old '68 TR6 simply because she was scared she wouldn't be able to start it if she stalled it.

I've also noticed that Trident owners seem to be the biggest bunch of p*$$ takers on the internet! Essential to have that sense of humour

B+Bogus said:

I've also noticed that Trident owners seem to be the biggest bunch of p*$$ takers on the internet! Essential to have that sense of humour

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Yep, Trident owners can take the piss out of ourselves. However non triple owners can't , none of them know the true meaning of misery

trident sam said:

Yep, Trident owners can take the piss out of ourselves. However non triple owners can't , none of them know the true meaning of misery

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You can't say that on a Norton forum!
I also ruled out future A65 ownership after a 90mph crank lockup on the M61 back in the '80s. Maybe I should be looking for another one of those?

B+Bogus said:

I've also noticed that Trident owners seem to be the biggest bunch of p*$$ takers on the internet! Essential to have that sense of humour

Click to expand...

Smoke fumes go to their heads after a while...

][QUOTE="B+Bogus, post: 433497, member: 1419"ou can't say that on a Norton forum!Y
I also ruled out future A65 ownership after a 90mph crank lockup on the M61 back in the '80s. Maybe I should be looking for another one of those? [/QUOTE]

90mph ? A65 ? surely not !

trident sam said:

][QUOTE="B+Bogus, post: 433497, member: 1419"ou can't say that on a Norton forum!Y
I also ruled out future A65 ownership after a 90mph crank lockup on the M61 back in the '80s. Maybe I should be looking for another one of those?

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90mph ? A65 ? surely not ! [/QUOTE]

And he wonders why it protested !!

Fast Eddie said:

90mph ? A65 ? surely not !

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And he wonders why it protested !![/QUOTE]

Ha! Yes, it only did it once

Update...
So I picked up the triplex primary kit & new thrust washers from Clive Scarfe (who was on his way to the IoM with very nice Rob North T150 in his van) and on dismantling my cush drive I found the rubbers had turned to mush after 500 miles
One highly plausible theory is the gap between the outer tips of the vanes on the spider and the chain wheel acts like scissors and chops up the rubbers, so minimising the gap is important.
As it turns out, my spider is a late type with longer vanes and needed skimming on the lathe to fit the new chainwheel, so it's gone from a 0.050" clearance to 0.004".
Now waiting for a set of polyurethane rubbers from Tony Hayward.

At least I can crack on with my 'S' Type while I'm waiting...

Polyurethane rubbers I got from Tony didn’t last 5 minutes.

I’ve always stuck with rubber since.

Well I'm another long time 3X owner. But I'm one of those less than manly types that stuck with the T150V avoiding the weight and bother of the
leg assistant. And in fact that I like it because it is easy to start. The easiest of my four old boat anchors at that.
Oh, the clutch? What a heavy, stupid POS.
There, I said it.

Onder said:

Well I'm another long time 3X owner. But I'm one of those less than manly types that stuck with the T150V avoiding the weight and bother of the
leg assistant. And in fact that I like it because it is easy to start. The easiest of my four old boat anchors at that.
Oh, the clutch? What a heavy, stupid POS.
There, I said it.

Click to expand...

Welcome to the madhouse!

My previous experiences were all T150V, one a bog standard '73 model and the other a Rickman which ended up in France. The Rickman was proper fun but the brakes were scary - in the days before re-sleeved master cylinders.
Both were great to start, and I have to say I never had any bother with the clutches; all mine have been pretty light (especially compared to the Bevel Ducatis…); as with Commando clutches, the stack height is key.

I'd strongly recommend having a look at yours as they really shouldn't be heavy if everything is within spec - even with a heavier Hyde spring my T150 clutch was still pretty light. Unless you're talking about the sheer weight of the thing? In which case... Yes, it's utterly barking.

I noticed P&M's race solution looks very much like a Maney Commando belt drive...

The actual clutch system is way too heavy. The pull on mine as it is now is too heavy. To some extent this is because I have a later lever and mount
that allows for more travel. It is not always possible to get the clutch to release with the standard amount of pull travel. Had mine apart and on
the lathe to true up and found that I could improve it but never get it to be right. It is entirely possible that factory clutches were selectively
assembled and mine is a DPO replacement of mismatched parts.
Perhaps next winter Ill pull it down and have a good go with it. Right now time to ride and build up those wrist muscles!

Onder said:

It is not always possible to get the clutch to release with the standard amount of pull travel. Had mine apart and on
the lathe to true up and found that I could improve it but never get it to be right.

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It does sound like you're fighting with a fundamental issue. If you could get the separation sorted the other problems would go away by default.

One of the Classic Triumph videos was a great education on clutch setup.
The trick with paper strips and measuring lift for clean separation was something I hadn't seen before - the Triumph workshop manual is pretty useless in this respect.
I checked mine in the lathe and it seems OK, and when I checked the separation at 0.021" lift all the paper strips were free. I reduced the lift and it started holding the strips at around 0.012", so well within spec.

Hopefully I'll get it back together today and see what improvement there's been. Based on the Facebook TR3OC group chat the third gear issue seems to be 'just the way it is' and slow, deliberate gearchanges are the answer, and I recall my T140 being similar, although it never seemed to fluff down-changes into 3rd, which is what prompted me to get this sorted as it's potentially dangerous.
Deleting the inner gearbox gasket on the T140 made a big difference, so it would seem that minimising backlash has a lot to do with it.

Andy, come on, don’t let the Face Ache crowd fool yer...

A well set up 5 speed Triumph (Quaife after all) box is about as sweet as they get.

Yes, a million and one things can prevent this, but that doesn’t make it “just the way it is”...