Britbike forum Forums British Motorcycle specific Brands Triumph bulletin board Drive side rocker spindles leaks

When the oil pressure is high during hard acceleration it’s the worse, fine hot oil droplets hit my left leg. I have tried Permatex high temp copper sealant, muffler repair, and high temp JB weld. 🤷🏼‍♂️🤦🏻‍♂️🙆🏻‍♂️

Stuffing tissue in the the cooling fins is the only way to somewhat slow it down. How much work is it to replace and properly replace O ring?

The muffler repair works on the intake side but exhaust side has always been worse.

Hope you don't mind me saying but that looks bloody horrible! Please fix it properly. The workshop manual tells you how. You just need some new O rings and you'd be best to also buy the O ring compressor tool (it's in the manual - should only cost a few dollars).
You can knock the rocker spindles out towards the drive side IF you're careful, and after slackening the valve adjusters off completely (turn the engine so the cam lobes aren't lifting the pushrods, then slacken the adjusters so there is definite play at each adjuster). Then you can tap the spindle out to about 1/8"" past the groove for the O ring without disturbing the rockers.

I've practically said how to do it, but please do refer carefully to a genuine manual.

Oil is fed off the return so high RPM is pushing more into the rockers.

Hi Splash, You must pull gas tank & rocker boxes. The key to easy rocker box remove/install is setting cams in correct position. Then back off valve adjuster screws. Now you have no spring tension on rocker boxes. Don't turn motor with box removed. Do only one box at a time. Expect to take all day.

The real fix is is to replace the orings with viton. I've found the viton rings from Steadfast cycles have worked good for me. Again ONLY viton!!

Fitting them is not easy, All surfaces must be well smoothed, including oring grooves. A fitting tool can be a real help depending on the chamfer you have on your box bore. The bore must not be damage or scratched. However the tool must fit perfectly & held very, very tightly to box as you push shaft in. Or the ring will expand & push tool away. Getting the ring in without a trace of damage can be a fight & take some practice. I'd get 6 rings. We'll call the first 4 practice rings. If you get it on first shot, we'll call that luck the 4 extra rings gave you. There are 2 wall thickness of rings. A '70 will take the thin ring which Steadfast will supply under 60-3548.

It is a fiddle to fit the shafts with all the springs & washers. Practice several times without orings until you get the feel for this.

Micro scratches on the rings from improperly prepared surfaces or forcing the shaft will soon result in seeping.

The orings are not under oil pressure. Just normal crank case pressure & vacuum. Even at idle the rings will be flooded with oil. As was stated faster rpm the more the flood. You do this right I can promise you a good 6+ years of zero leaks. Don't use viton or not prepared & installed properly, I can promise you will have seeps.

If oring is torn, shrunken, or cracked, It's staggering how much oil can come out the shafts.

The dirty cure is get some silver Yamabond or the like. Scrub the area super clean. Wipe with acetone. Smear the silicon as neat as possible. I've done this & has held well for a few years anyway. Before leaked profusely.

Don't even think about pushing rocker shaft out a little & slipping on new ring. That might slow leak, but don't expect it to stop leaking. Also very hard to get shaft back in as thackery spring often falls down & gets trapped by end of shaft.

Truth be told. I've done lots of these orings. Every time I've done it & cross my fingers. Take bike for 100 mile ride. I've learned the prep work is critical as well is the practice. Very sadly every tool I've seen on market must be reworked to be used successfully. If you have good tool it actually works. On the larger chamfered boxes like mine you don't need tool. You smooth all surfaces the ring will just go in. You must smooth oring groove in cap on shaft as well. The ring must be lubed. P-80 I've not had such good luck with. I can't work that fast. I just use thin smear of oil. Don't fill groove with oil or grease. The ring must expand into the groove, so we don't want it to have to force oil or grease out to expand. Also make sure ring is nice & straight in groove. Wind it around with smooth tool so there no twist.

Good luck. Every time mine don't leak I thank God. This is only seal on the motorcycle I fear. So far I've had very good success. Use ONLY cov-seal rocker box gaskets. A smear of loctite 574 on cov-seals is a really good plan on those also. See if you mechanics at the airport has any. It's $40 a tube plus shipping.
Don

John Healy put up a detailed post on this somewhere, dont know how to find it though.

Getting the correct "o" ring seems to be the trick.

What does the O ring compressor tool do? I imagine it compresses the O ring so it can slide in without ripping. A hose clamp? hmmmm, I'm gonna get scorned here for thinking hose clamp.


I tried a search also for subject but only found the timing side leak.


Is there any other later engineering methods which are above this O ring engineering? Like uh, new closed end rocker boxes??? Horizontal wet band saw the ends of the spindles to fit the new closed end??? Maybe there is something I don't know that Triumph engineers were thinking here which I am pondering over? How are new bikes made here?

When disasters happen in aviation usually an AD (airworthiness directives) are issued. This happens when a part fails. The part is engineered again so it doesn't fail. I feel to believe this would have gotten an AD put out long ago but it's just a classic motorcycle we are dealing with. We crash all the time, HA. Airplanes that is. You hear about them. Classic motorcycles and cars not so much open ears around the world at all. I'd rather crash an airplane any day of the week to a motorcycle. I'm so much more defensive on this thing.

The O-ring compressor tool doesn't work. I cut or grind a 45 degree angle on the opening in stead. More often than not you'll still cut a sliver off of the O-ring, but it'll usually seal anyway. If it still leaks I've had some success with Loctite thread sealer or similar products. If that doesn't work either I've resorted to cutting an additional O-ring groove on the shaft head. In one instance even that didn't work due to an axial scar in the housing itself, so I had to resort to cheating, sort of like splash did, only a bit neater. As I own a lathe, cutting these buttons was easy, and I simply glued them on with a suitable sealer. The inlet shaft didn't need it, so the button is just for symmetry. It's been on there for 4-5 years now and stil seals.

SR

That's awesome SR!!! That's what I'm talking about. Do the buttons tapper and pressed in? Lets talk more about those.

The O ring compression tools vary a lot, they must have a smooth bore and be quite a close fit at the end of the internal taper where it fits over the spindle thimble. That at least will compress the ring into the groove. A slight countersink in the end of the rocker box is a very good idea, but it must be smooth, fine emery on a countersink bit will work. Obviously, any scars in the bore of the rocker box are going to give a leak path, fiiting clean and dry with sealant will help.

The O ring and its groove do not comply with engineering design standards set by the O ring makers, the grooves x sectional area should always be larger than the x sectional area typically by 10 to 20%. The groove is normally wider than its depth and the depth smaller than the thickness of the O ring so the O ring is compressed on the OD but expands on the edges, the compression provides the seal. There is not enough space in the groove for the O ring the way Triumph engineered it hence the shaving of the O ring on insertion. One of these days I will machine the correct sized groove and use an X ring and see if it seals.

As those thimbles press off, I got Ralph Allen at Motalia HERE to copy them in stainless. Maybe I should have specced the differently!

Yes! A static circumfrential seal such as this should have zero leakage, and be simple to assemble with just good surfaces and a spot of silicone lubricant. How hot does this jount get? The only advantage (and there are many disadvantages) that I can think of in this case for Viton would be high temperature. Buna-N (nitrile) o-rings are much more resiliant, hold that resiliance longer. They are limited to an upper working temperature of 120C however. Viton is good to 205C.

You can get Viton in soft (60A) rather than the standard medium (75A) which seals better in low pressure applications. Silicone are 70A and high temperature soft silicone are 50A. McMaster gives Viton temperature to 400 F and silicone to 450 F, soft silicine to 400 F. If you get anywhere near these temperature you have a problem. Buna-N is available in soft (50A) which would be better than standard medium (70A).
The problem is the groove dimensions as mentioned. Somewhere I worked out that a metric O-ring will fit the groove better than inch. Many different diameters available in metric.
The seal compression tool is supposed to have a chamfer on the outside of the nose that fits the chamfer in the rockerbox. This way there is no interruption in the O.D. of the seal as it goes in.
New rockerbox spindle caps with the correct groove would be the way to go. I thought about making these, however, the bore has to be reamed for a close fit on the spindle and the outside machined to a tight tolerance which drives up the cost and no idea if anyone would buy them.

Hello Dave,
The early rocker boxes don't have a chamfer, thus the advice to create a nice smooth one. If I can remember, I'll measure the groove in the caps that Motalia make and compare with the standard ones to calculate a siutable O ring size. I think I did it in the past and bought O rings, but that brain cell has departed. Certainly, I don't have a problem wit leakage on the motors (very plural) I build.

I was thinking triples.
My drawing has the groove as 0.050" x 0.032" and the cap diameter 0.625". A 14 x 1mm O-ring will work. The groove I.D. is 0.561" (14.249mm).
I use Loctite Gasket Eliminator on static O-rings to help them go in and seal any imperfections in the surfaces.

Thanks for the info, I only get involved with B range stuff, wonderful as the triples are. Right now my workshop is literally freezing, no heating, so I’m avoiding it like the plague, current jobs are engine bottom ends and gearboxes. That, and looms, so I might be a while in checking!

The buttons are just for looks, stuck on top to hide the hideous sealer! You can use anything you want, a coin or a bottle cap or whatever, as long as it fulfills the aim of beautifying a bodge...

By the way, I arrived at the same conclusion as kommando on the O-ring groove, it's too narrow so I actually cut it wider, along with the second groove. Even if I used a rubber lubricant, it still shaved off a tiny sliver. I must be doing something wrong.

SR

Hi Splash, Hmm… If you did AD on Triumph you’d end up with an entire different motor!!

The rocker shaft is shaped such it must be installed from left side.

As you think the installation tool compresses the oring to allow it to slide in. The tool MUST be precision made. It must mate with rocker box perfectly & be held tightly, very tightly to box. 2 people makes this fairly easy.

In the work shop we help each other, lift, steady, mold things several times a day. Not to mention sharing knowledge. It takes a village! By yourself is much harder.

If even a trace of rubber peels you can expect at least seeping.


I agree oring groove is small. This no room for extra oil or grease or even P-80 rubber lube.

As was stated, a scratch in bore is problem.

Maybe you can hook up with very skilled aircraft mechanic & tag team the job.

All the installation tools currently on market will need the end reworked & bore smoothed.

Factory got these in very successfully. We can too.
Don

Triples and T140 use the same seal ring : 60-3548. '71 A75 parts book shows 75-0124. Both T150 and A75 use the same spindle 70-9558.
The cap is not shown as a separate part.

The buttons are just for looks, stuck on top to hide the hideous sealer! You can use anything you want, a coin or a bottle cap or whatever, as long as it fulfills the aim of beautifying a bodge...

By the way, I arrived at the same conclusion as kommando on the O-ring groove, it's too narrow so I actually cut it wider, along with the second groove. Even if I used a rubber lubricant, it still shaved off a tiny sliver. I must be doing something wrong.

SR[/quote]

Oh, my misunderstanding. I thought the caps were doing the sealing (ID +- .003 or so) and tapper cut on the outside of cap to be pressed in. Could it work with out the hideous sealer? I'm thinking aluminum cap so as it is pressed evenly and slowly it can smash into the imperfections of spindle or valve box. It would be like smashing an aluminum can rather than sealant. Maybe some redneck engineering here but I may try a slither of aluminum can tapped between the spindle and box.

The proper solution is simple enough, but if you're stuck in the middle of nowhere, wrap some thread/fine string round the spindle groove.
It would probably do until you get to the other side of the Sahara desert.
As you're in a "civilized" place, just do it properly, I would suggest.

It’s a bit of a PIA, but those O-rings can be replaced in situ. Release valve spring force on both rockers and gently tap the spindle out until the cap and old O-ring are exposed, then replace.

Of, course if the Thackeray/Thackery washer mod hasn’t been done yet (T140’s with grooved spindles) this would be a good opportunity to pull the rockerboxes and do both jobs at once.

I’ve not tried, but would the “wicking” loctite (green) work for this type of application?

Steve

Even without the special tool, it's not a difficult job. I t just requires patience. I use a little grease and a blunt screwdriver blade to press round the O-ring as it enters the hole. Takes quite a while, but no shavings. No rocket science.

Same as above but I used some fine emery cloth on my finger to round over, just a little, the sharp edge on the rocker box hole. A smear of red, hi-temp silicon on the "O" ring and shaft to make it slipperier and some patience and it all works fine and has for many years.