Gearbox selector /engage

[Chilliman]

Yes,  what you are describing is the cup for the 1st/2nd gear selector. 👍

[Mike C]

It might be obvious, but I always set the selectors to be in neutral before I put the G/B top back on with the  gear lever in neutral.

[stevenphillips]

Thank you Mike, Yes I will make sure that I'm in neutral.

Waiting on parts now and fingers crossed it will not happen again.  Though I find its always better to find a reason 😐

I'm going to try the Quad seals that was suggested by Roger, and packing them with grease, fortunately the selector shafts have not corroded in that region and with a bit of wire wool they have polished up nicely..

If anyone has any experience with the quad seals I'd love to hear about it as I have both ordered.

Steve 

[Mike C]

I have a set of quad seals waiting for the next time I have the top off the box so I can't help with that, but make sure you seal the hole in the middle selector shaft that bleeds oil while shifting while you are at it- they're generally covered together in recent posts on this topic in  this forum.

[stevenphillips]

Ok thank you Mike I will do.  Any suggestions on what is good to fill it with ?

Do you know the title of the thread regarding the hole I would be very interested to read it but sometimes I find the search gives a plethora of stuff to wade through when all that is need is the specific post lol.

Thank you  

[Mike C]

From memory the UK posters seem to use JB Weld to seal the hole.

I don't have the thread saved in my links, but it was active in the last month or so. The people on this forum are pretty good, I'm sure they will come out with advice and pointers overnight (Melbourne time).

[TR NIALL]

Think it was RogerH for the JB Weld solution and TRier for the original Quad Seal idea.

[RogerH]

2 minutes ago, TR NIALL said:

Think it was RogerH for the JB Weld solution and TRier for the original Quad Seal idea.

very very close.

I think it was Marco with the JBWeld or the German equivalent. I tend to go with Araldite products.  JBWeld cures much faster.

Make sure the quad seals are packed well.

 

Roger

[stevenphillips]

Thank you Roger and All

Roger I assume when you say 'Packed well' you mean with a general purpose grease ?

I will look at the thread and thank you all for finding the correct one.

Steve

[RogerH]

1 hour ago, stevenphillips said:

Thank you Roger and All

Roger I assume when you say 'Packed well' you mean with a general purpose grease ?

I will look at the thread and thank you all for finding the correct one.

Steve

Hi Steve,

it wi;ll need grease but the packing is/are plastic/nylon plates/shims that stop the rings sliding back and forth

 

Roger

[JohnC]

On 6/15/2025 at 5:49 PM, Mike C said:

make sure you seal the hole in the middle selector shaft that bleeds oil while shifting

Why was it there in the first place? Or is sealing it going to cause a problem Triumph put it there to avoid?

JC

[Mike C]

2 minutes ago, JohnC said:

Why was it there in the first place? Or is sealing it going to cause a problem Triumph put it there to avoid?

JC

I don't know. Maybe a self cleaning , unblockable vent? Maybe the hole was needed i the assembly process?

[JohnC]

Just now, Mike C said:

I don't know. Maybe a self cleaning , unblockable vent? Maybe the hole was needed i the assembly process?

I was being cute. Sorry. The drilling wasn’t needed in the manufacturing process, at least as far as I can see. And I would be happy for anyone to point out why a hole would be needed there! I can only assume that Triumph put it there to avoid pressurisation and worse oil leaks elsewhere. I’m reminded of the plague of outbreaks of external rocker oil feeds on original cars (that don’t have roller rockers, and therefore don’t need an external feed). The Triumph engineers really weren’t idiots. And they would never have put in drilling (adding cost) without reason. Save your Araldite, JB Weld, etc.
JC

[Mike C]

2 hours ago, JohnC said:

I was being cute. Sorry. The drilling wasn’t needed in the manufacturing process, at least as far as I can see. And I would be happy for anyone to point out why a hole would be needed there! I can only assume that Triumph put it there to avoid pressurisation and worse oil leaks elsewhere. I’m reminded of the plague of outbreaks of external rocker oil feeds on original cars (that don’t have roller rockers, and therefore don’t need an external feed). The Triumph engineers really weren’t idiots. And they would never have put in drilling (adding cost) without reason. Save your Araldite, JB Weld, etc.
JC

Even if  the drilling  was intentional, it still drips oil as my local roadworthy inspector noted on his list.

[RogerH]

Hi JC

It is common practice when welding an otherwise closed vessel to have an airvent.

The welding process produces a good deal of heat and the expanding air needs to escape.

The hole casn be sealed - JBWeld etc.

 

Roger

[Drewmotty]

I can’t believe that Triumph were daft enough to drill a vent hole in a position where it would transition and compromise an oil seal when it could be almost anywhere else without consequence. 
The hole is pretty effective at dragging a very small quantity of lubricant across the seal and spreading it about the external moving parts. Perhaps that was the intention. 

[RogerH]

Hi Andrew,

 you really should believe that not only TRiumph but ALL manufacturers of everything are quite capable of the craziest things.

It may be that a 3rd party were making the selector rods and didn't know where they were being put.

TRiumph may not even be aware of the hole.  Hard to believe tho'

 

Roger

[stevenphillips]

Hi All

Firstly, let me thank all that participated in this thread, the wealth of knowledge was invaluable.

So the update is that I've installed the quad rings and packing, all seems good and not leaking.

I decided not to plug up the middle shaft hole and accept that the little bit of oil that may disperse is acceptable.

The only thing that I found which I suspect may have caused the initial "jammed gear shift" was possibly that I aligned the reverse selector fork in front of the pin that it should engage with.  The reason being that I found some witness marks on the back of the fork that aligned with the pin on the selector arm.

The gearbox is now back together with a new rear shaft seal, gasket etc.

Been on a couple of runs now and all good so far with all gears working lovely. 

I'm determined to drive the TR more this year to stop the possibility of the clutch sticking again !!!

I note the thread on the clutch SC rod and may over the winter investigate that more, as I have had to put the SC rod pin on the lower hole to get it to disengage enough.  I suspect (as per the thread) that the master cylinder push rod my be incorrect.

On a side note since driving I have noticed a hum/whine from the Bosch fuel pump that I had fitted at least 10 years ago and only done 10-15K in mileage.  I'm pretty sure its not the pump because I have realigned the Stainless Steel braided hose which runs from the pump to the PRV and the noise is now quieter though not gone completely.  If I push on the hose the noise disappears, figure that out ?  

Question (and I may start a thread unless there is already one that looked at this issue, point me in the right direction is there is please) does the braided hole increase the chance / possibility of cavitation or whine in that area.  I note that on the Rimmer catalogue it says, regarding upgrading the fuel pump "that because the pump to PRV hose is not ridged, it can cause some noise which is often misdiagnosed as a problem with the Bosch fuel pump".

Any guidance so that I can really make the 6 quite would be much appreciated, though I will look for a thread.

Thanks again Y'All all who replied are genuine stars.        

[Waldi]

If your “braided ss hose” has a ptfe (teflon) liner this could be contributing to the vibrations. Neil Revington has written a very good description/explanation on his website about this issue (and other issues). The major advantage of ptfe hoses is they are not permeable so do not emit fuel vapors (in the boot). 

One solution is to install a membrane type prv (like Malpassi); this acts as a vibration damper. It can also be more easily adjusted without having to open the system. 
 

Another solution to reduce vivrations is to install a rubber hose from pump to prv. This also dampens vibrations. The rubber hoses that are available through our suppliers are not made from low-emission grade hose (like Gates Barricade Fuel Injection Hose), so unluss you make your own from good quality hose (which I did), you could experience some more smell in the boot.

Waldi