They certainly look like the needle rollers, but I suspect that they fell out during last assembly, they can’t get out otherwise. In all but 5th gear, the high gear pair are being driven, I would look particularly at those gears for “spalling”, a kind of pitting you get with poor lubrication.

 

Yes they are parts of the roller bearing. You need to get in there now and change whichever one failed before riding it again. Looks like those have been mashing around in the cogs.

 

Hi,
It’s a full gearbox stripdown and inspection i’m afraid. The needle roller bearings run directly on the layshaft, hopefully that is not damaged.
On replacement of the bearings please pay special attention on how much they stick out of the case. They should stick out enough to secure the thrust washers, but not so far to allow the layshaft to touch the bearing case otherwise the end of the bearing will wear away and the needles will come out.
There is a tool you can make to set this distance, or you need to measure very carefully
The bearings are made by Torrington. You will need one blind bearing and one open bearing.
here is the fitting tool dimensions and the fitting tool I made for myself.

Good Luck

regards
Peg

 

Thanks Mick, Rambo and Peg,
Yes, it was the layshaft drive side needle bearing (the inner most).

Is it possible to change this bearing out by getting access from the drive side? Without having to remove the engine from the frame?
I see heat required but at only 100c, localised heating should work. Challenging my current skillset

The layshaft 5th gear has significant wear and chips, looks like it has been weathering for some time.
The layshaft seems to have scoring and possible wear at the failed bearing end. Will change both. Strangely the rest look fine. The inner Gb housing layshaft needle bearing was also on the way out. I wonder why they gave up? Incorrect fitment? The PO said 'complete rebuild'!

Layshaft 5th gear.

Layshaft (end looks tapered!)

 

Ow! I can't believe that the mainshaft high gear is not damaged in contact with that layshaft 5th. As both are under load in every gear except top. I would change the mainshaft high gear as well, even if nothing else. I haven't tried changing bearings with the engine in frame, as I am invariably doing complete rebuilds, you might be able to do the layshaft bearing, but the high gear bearing would be another matter, if needed.

 

Those small rollers have small pins on to keep them in the outer case. It is common for the small pins to break away and the rollers usually stay in place but can also drop out as yours have done. That is very expensive damage you have.

 

That is horrendous. Sorry, but if that was my bike, and the PO said it had had a complete rebuild, I'd be taking the engine out to do just that. I'd not trust anything the PO had said. You could end up with a lot bigger bill if it blows up. And if it's a matching numbers bike you don't want to end up with a wrecked crankcase.

 

Last time i built my engine i did replace those bearings in the gearbox as they were only about £11 each. I had found the rollers fell out on dismantling. Been lucky with my 4 speed box and just one tooth has snapped off in my ownership but no damage to other parts. Fortunately, after the problems locating a new mainshaft, i have acquired two complete gear sets. I paid £40 for a brand new mainshaft 12 years ago. I think i would agree with Andy that the engine may have other faults hiding inside. Depends if you have the knowledge and tools to strip this engine and build it well.

 

Getting on top of it now. Have both sides almost stripped. Lots of work for a $15 part 👺 Specialist tools were a problem, but luckily fellow members of the vintage MC seem to have everything
Additionally lots of calming advice. Good to know other people who have done the same job - successfully. Lots of great advice on this forum and now I am definitely developing my own skills💪

My main concern now is the raised stub on the inside casing for engaging the layshaft thrust washer (57-1607). It appears to have taken some damage due to the washer rotating before it disintegrated.

It is partially there at least, and may be largely intact. In the photo is is partially hidden by the edges of the torn bearing housing.

How important is this locating stub?

If it was not 100% could it be repaired? Or glue the washer in place?

Thanks, Rob

 

Possibly of more concern is the damage to the face that the thrust washer sits against, it should be flat and smooth. Normally, a don't fret about layshaft end float, but if it is shimmed (if necessary) to give maybe 10 thou float, then as long as the pin has more than, say, 15 thou engagement, it should not rotate - there is almost no thrust involved. You can check layshaft end float with a magnet. I know glue would be a bodge, but I guess it would work.
Ideally, you would get the pin out, face up the thrust washer surface, replace the pin and possibly use an oversize thrust washer, but that's another scenario entirely.
HTH

 

I hope you can get the remains of the bearing housing out. Tapping it through will probably just pop the centre out of it. Possibly, something like JB weld will give you some of the surface back behind the washer. I would prefer knowing i had a pin holding it though.. I expect you know the back of the bearing needs to be sealed up to prevent oil leaks

 

That's quite a mess. were it mine, and I were to strip the engine I'd have the surface re-faced and relocate the pin in a different position with an oversize thrust washer. However, another way without stripping the engine down would be to resort to the older plain bearing arrangement, remove the remains of the pin and any high spots on the face. Obtain, or have turned a top hat bronze bush (phosphor if possible), have a locating hole in the top hat to use as a pin guide.

Perhaps suitable, though with a narrower rim, may be Top hat bush T1367, Peg T912, Blanking disk (core plug cos it's open ended) T981. You would need to allow for 0.0025" end float, and also perhaps check - allow - ream the bush, as the 5 speed layshaft increased in OD from the four speed 0.6845" to 5 speed 0.6875", to tighten up tolerances, though you'd aim for 0.005" running clearance in bronze. better to give the bushes rim at least the same OD & oil scroll as original thrust washer and it would require pinning.

The advantage of bronze, (my choice) is unlike a needle roller, they don't suffer from catastrophic failure like yours, hence specified by the MOD. You really would not notice any difference, except the 5 speed is susceptible to gear change drag if these bearings are worn.

 

Hi Rob,
The previous owner has said fully rebuilt, but he did not say rebuilt by someone who knew what he was doing.

Unfortunately Triumph Meriden does not help, unlike the Japanese, they give you the opportunity to get things wrong by having items that need to be set exactly to succeed making the bike run sweetly, then never giving you the tolerances or detailing the methods to set them up correctly. (Pushrod tube seals is a good example) Fortunately there were some owners and some agents that worked things out, and some generous enough to share their hard won knowledge (John Healy with Vintage Bike Magazine comes to mind here).
Then Tim Berners Lee/ Al Gore and others let the internet escape from a military project into the real world, and here we are.

The Torrington needle roller bearings if set up correctly are very long lived, with enough internal clearance to allow minor misalignment. It is rare they have problems unless set up badly.

Looking at your photo, it looks like most of the debris is from the bearing.
The set up needs to be quite precise. It looks to me that the bearings were not installed far enough into the case.
1)The amount sticking out does two things, it sets the base end float clearance of the layshaft, it holds the thrust washer in position.
2) The bearing edge should never touch the layshaft, the bearing edge should sit just below the surface of the thrust washer. If the bearing does not stick out enough, the thrust washer falls off and can jam or it works off the pin and can either jam or spin.
If the bearing sticks out too far then the layshaft runs on the edge of the bearing destroying it, this is what I believe happened in your gearbox.
3) The photo of the inner case looks terrible, but I think a lot of that detritus is from the bearing, not from the case.
Once that is out of the way I think you will find the surface is not too bad. The case does not have to do much except butt up against the thrust washer, I think you might get away with smoothing it square to the bearing.
4) The pin that stops the thrust washer spinning, like the bearing has to stick out so far so the thrust washer is prevented from spinning, but not so far that it extends past the thrust washer and contacts the layshaft.
If the pin will not come out then drill a new hole opposite the original. I have used a thrust washer as a drill template and a roll pin as a replacement before now. The pin can be ground to length after fitting.
5) Setting up the layshaft, Triumph Meriden are no help here, they give no information, so you get to judge it yourself.
You will need to insert and remove the layshaft several times to set the end float, luckily you can leave all of the gears and selector fork (not 4th/5th).
fit the layshaft and thrust washers including inner gasket. Measure the end float, I use a dial gauge and a magnet on the end of the shaft to push and pull the layshaft. Take the reading.
I like to have between 3 and 5 thou clearance, this is quite tight but gives a fantastic gearchange, and gives confidence that the thrust washer will stay in place, there is no guidance from Triumph on this. The gearbox will still work with much larger end float.

You have two main ways of altering the end float, make (or have made) thicker or thinner thrust washers, or fit thicker or thinner gaskets between the engine case and the outer gearbox cover. Your gearbox was designed for a gasket, earlier models were not.
6) Once the layshaft end float is set, then the gearbox can be built.
If you have altered the gasket thickness, then the primary chain alignment between engine sprocket and clutch should be checked/reset.

regards
Peg.
PS.
If you know the thickness of the thrust washer you need and can find a parts supplier with stock (This is difficult now in these internet supply times), you could ask if you can use a micrometer to check each one, there are some large variations in thickness.

 

5) Setting up the layshaft, Triumph Meriden are no help here, they give no information, so you get to judge it yourself.
You will need to insert and remove the layshaft several times to set the end float, luckily you can leave all of the gears and selector fork (not 4th/5th).
fit the layshaft and thrust washers including inner gasket. Measure the end float, I use a dial gauge and a magnet on the end of the shaft to push and pull the layshaft. Take the reading.
I like to have between 3 and 5 thou clearance, this is quite tight but gives a fantastic gearchange, and gives confidence that the thrust washer will stay in place, there is no guidance from Triumph on this. The gearbox will still work with much larger end float.

Thanks for that detailed set-up information Peg. I will follow as closely as I can. In my Tech data manual, Triumph do give end float for layshaft of 25 to 475 thou" (0.0632 - 1.2065mm) so I will aim for your numbers if I can measure it - have digital caliper📐 Smooth shifting is what I want.

and
(thrust washer locating peg 57-0912).

Outstanding I completely missed that the locating peg is a service item and costs all of $1.17c. The part and number is camouflaged in my parts diagram. So I have many options now. Using part number 57-0912 in search function brings up posts with similar issue - Fastlikejudy and Mr Pete in 2013 - who was able to extract the worn pin.

 

Thanks All for your thoughts and advice
I will have to check when I FINALLY get to the bearing. One cover screw to sprocket cover stuck
Freakmaster - the top hat is an interesting variation.
Epoxy on the back of old bearing (when I get to it) to re-enforce is a good idea
Peg, are 'Torrington needle bearings' especially superior to what may offered from a dedicated Triumph/BSA/Norton shop - 'Made in England' type bearing?

I also suspect the bearings were not set-up correctly.
The outer bearing also has witness wear marks and interestingly, its thrust washer (57-1607), is strangely distorted! Looks partly melted.

 

Check the thickness of the least worn part of the washer. New they are 0.090" or over (they do vary). If the bearing was proud of the washer, you would see the bearing rubbing, as yours appears to have done. Mind you, as Rambo said, the layshaft flopping around would do no favours.

 

I suspect that bearing has worn like that due to the gear shaft wobbling around a lot after the other bearing failure.

 

Hi Bobby -
For replacement of a damaged locating peg in my T120R's gearbox a local machinist made up a little jig to drill the hole for a new peg. Pretty sure i still have the jig. If it would help i could send the jig to you on loan. Let me know by pm.

The tool is pictured on this web page: www.hermit.cc/tmc/technote/gearbox/locating_peg/index.htm

At the end of that page there's also a link that shows a plywood base i made in order to set the engine up for perpendicular drilling of the hole for the peg.

Edit: Actually the base board is not necessary to drill the hole - the machinist's jig insured a perpendicular drilling, which he made with an electric hand drill. As i recall he made a sleeve to put over the drill to get the proper depth of the hole.

 

Hi Bobby -
For replacement of a damaged locating peg in my T120R's gearbox a local machinist made up a little jig to drill the hole for a new peg. Pretty sure i still have the jig. If it would help i could send the jig to you on loan. Let me know by pm.

Bruce thanks so much for the offer for the loan of tool. I really appreciate that I'm in West Aust so long way off the Maple Leaf. I now see (thanks to Peg) - it is a removable pin - {cost $1.17}, or use the thrust washer to drill as a template. Feeling better about it. Cheers, Bobby

 

Peg, are 'Torrington needle bearings' especially superior to what may offered from a dedicated Triumph/BSA/Norton shop - 'Made in England' type bearing?

I believe (but I am not certain) that Torrington are the only manufacturer of this size needle roller bearing, therefore if you get Torrington bearings direct from a bearing supplier (one open both end and one closed end needed) or if you buy them off of a Triumph part retailer under the triumph part numbers (bearings 57-1614 and 57-1606), you should get exactly the same parts.
You will also need as that thrust washer is destroyed:
(2 x thrust washers 57-1607),
and
(thrust washer locating peg 57-0912).

good luck
Peg.

PS: refit and tighten all of the other sprocket cover screws, to take the pressure off the single stuck screw, then remove that screw using an impact screwdriver. (Add heat if no joy)

 

Hi Bobby, The damage may not actually be so bad.
Install new bearing such it protrudes to about .005-.008” deeper than face of thrust washer. The bearing centers washer, not shaft.
Normally you heat case to 100C to drive old bearing out & new in. However sometimes the bearing is loose in case & needs Loctite. On these you can use red Loctite to great success. Later heating case to 100C you’ll dove bearing out no problem with red Loctite.
I see the remains of old steel locating pin. Drive it in a little deeper. With new bearing installed, place new washer over bearing & drill new hole & install new locating pin. Place drill bit hole of new washer as a guide. As/if needed use red Loctite to secure new pin. The pin is not hardened. You can make pin from steel rod if needed.

Drive pin in slowly. Only about .005” below surface of washer. As was stated there is very little thrust on washers so they don’t wear fast at all.

Getting case spot faced for washer will demand removing motor at the least. Probably cases split & stripped.

A shim as thin as you’d need should be hardened.


Look over suppliers such as McMasterCarr. They sell various shims.

getting custom made washer will be costly. I personally made custom washers for my transmission. Bearing bronze is tough to machine flat parting off the washer. I ended up having to sand it to finally thickness. Took me 3 or 4 attempts to get the washer right.
How thick will you need? I have some I didn’t use.

It may well be you don’t need to spot face, use shim, or need custom washer.
So long as you can keep washer from spinning by installing the pin, the motor case should see no further wear.

I would never rely on epoxy to secure washer & keep it from spinning, it must have the pin.

There is a bit more to this than just end float. If gears are too biased to one side the dogs can contact adjacent gear when they should clear.
I purchased new Harris layshaft for my bike. The shoulder for 2nd gear was too far over & allowed unwanted dog contact on 2nd gear. So I made custom thickness thrust washer to recenter shaft. Have cover 6000 miles so far with this shaft, still working good.

Point is: At this time replace both needle bearings, drill & fit new pin. Assemble trans & see how it looks.
Don

 

Hi Don, What do you do to seal the closed end of the DS bearing from the outside to prevent oil leakage. Triumph only say "use a proprietory sealer". i.e. How was it sealed at the factory when built? Can a "wicking" grade of Loctite like 290 be used on the outside after the bearing is fitted?

You mentioned using red Loctite to secure a loose fitting bearing, I assume you mean 270 (high strength), I've used it many times in my former life. It works great, is permanent and is easy to release with heat when needed, but in my experience it takes quite a lot more than more than 100 deg C. Loctite say 500 deg F (260 deg C) to break down Loctite 270. A hot air gun can be used to locally heat the area further to get it hot enough and if you drive the part out immediately, while at temperature it comes out easily.
I found that once it gives way, keep it moving and get it out in one move. If it is a bolt, turn it back and forth a bit as you turn it out, which will come out as a pink powder.

A word of warning to anybody who has not used red Loctite, do not try to remove anything secured with it without heating it up properly. A bolt secured with it can actually strip threads, or break if an attempt is made to force it cold.

One place on our bikes where red Loctite is quite commonly found is on the bolt threads (including the sludge trap bolt) securing the flywheel to the crankshaft.

Terry

 

getting custom made washer will be costly. I personally made custom washers for my transmission. Bearing bronze is tough to machine flat parting off the washer. I ended up having to sand it to finally thickness. Took me 3 or 4 attempts to get the washer right.
How thick will you need? I have some I didn’t use.

Hi Don,
I had the same problem getting the faces parallel at the same time as getting the correct size. I gave up with the lathe and milled a flat sheet of PB1 bronze into different thickness strips. You just need to mill the oil flutes and drill the hole for the pin, then cut out the correct thickness thrust washer.

I have had success with a roll pin to substitute the soft pin, once forced in its springiness keeps it secure, it can be then cut and ground to length in situ using a dremel grinder.

regards
Peg.

 

Hi Terry, I also use JB weld original grey.
What I’ve seen from factory looks like epoxy but is softer. I don’t what it is. Was quite good at stopping leaks.

I’ve removed hundreds of red Loctited bolts. I heat until spit boils. It still has grip, but not much.

I would not use wicking loc. I’ve had very mixed results with it at work.
Don

 

Now have the drift tool. My daughter's partner has access to a workshop and had one of the metal techs knock this one up. Now have a loaner if anyone in West Aust needs one (Now just need a 47mm socket!)
(And no, the end piece is not so long that it will knock the end plate out of the blind bearing)

 

Hi Bobby, We won’t know more until you trial fit gears & outer cover.
I’m away from PC until Late Friday.
I have photos & videos showing end play & the gears/dogs.

I compared my original from new layshaft with the Harris one. Using depth gauge on calipers I measured the shafts. They were not the same. This caused concerns. So very careful trial fitting was needed. I’ve had years of automotive transmission experience. This transferred over. Peg & Mick mentored me. Adding all this together I came up with a plan. I have a lathe, which of course is a huge advantage.
McMasterCarr sold me a length of pre drilled bearing bronze which had ID & OD that was close to what I needed, that reduced cost & machining time. It was not cheap.

I’d like to see detailed photos of the rest of the gears.
Worn or damaged gears are subject to sudden fracture. Especially if objects got caught between teeth as the damage to lay shaft 5th shows.

The high gear roller bearing is odd size. I’ve not been able to find a bearing supplier that sells it. In my area the Triumph parts sellers are selling the bearings at very close to same price as bearing supply houses

To check end play of lay shaft you can bend a hook of coat hanger wire ot the like. Reach in & hook it behind lay shaft 5th. Pull shaft towards you & measure with depth gauge. This holds shaft very tightly so you can’t accidentally push shaft in while measuring. Then push it in & measure. Subtract difference, give end play. I have dial indicator which makes it simple, but depth gauge works fine.
Don

 

Hi Bobby

I will follow as closely as I can. In my Tech data manual, Triumph do give end float for layshaft of 25 to 475 thou" (0.0632 - 1.2065mm) so I will aim for your numbers if I can measure it - have digital caliper📐 Smooth shifting is what I want.

I have used a small clearance figure because I had never seen a figure published by Triumph, so I made one up for myself based on Japanese gearbox clearances.
I have not had a problem with 5 thou clearance , but the Triumph figure of 25 thou is 5 times bigger, this is a large difference.
Quaife, who designed the gearbox have a good reputation for knowing what they are doing.

475 thou is 12mm, this must be a misprint
47.5 =1.2mm this also seems huge to me, having to move the layshaft back and forward by this amount to even start to engage the selector would result in a very sloppy pedal.
I also cannot understand that if you have 1.2mm of end float and the bearing with a rounded edge that only protrudes 1.85mm, having only a 0.65mm lip to retain the thrust washer is a good thing, it seems too close to disaster to me as I would expect the alloy casing to expand at a greater rate than the cast steel shaft.

Regards
Peg.

 

Hi Bobby, Here’s the layshaft work sheet I did.
Also the hook for end play measuring.
Don

 

I find a magnet on a stick works fine instead of a hook, I've got a couple of them in the workshop - very handy!