Britbike forum Forums British Motorcycle specific Brands Triumph bulletin board Top pushrod seals T100R

I am having trouble getting the upper pushrod tube seals on my 73 T100 motor to go into the proper position. They basically twist, resist, tear and squish. Any suggestions? The ones I am using are white rubber-(Viton?) Thanks to all!
Dave

P-80 is a rubber lubricant that helps assembly, good for o-rings, oil seals, JOHN HEALY talked of P-80 in a article, "THOSE PESKY PUSH ROD TUBE SEALS"! VINTAGE BIKE MAGAZINE! Make sure you have the correct squish washer @ the bottom, upon dry assembly you do have 30-40 thousands for proper sealing?

A related problem that I have had ( 66 to 68 T100 )is that the pushrod tube doesn't always fit freely into the head and the head, tube or both need some trimming so that the tube is free to fit and doesn't end up metal to metal before it actually engages with the seal. Cheers, Wilf

Not sure what seals your using but I used imperial #120 viton O rings at the tops and metric 24 x 3 viton O rings at the bottom on my '73 Daytona engine and they go in without problems and are still completely leak and seepage free after 6000 miles.
Didn't use the flat white rings that came with the gasket kit and had 40 thou crush on the rings.
Use glycerine as an assembly lubricant as it dries out completely once they are fitted.

davy

Thanks All for the guidance. I did notice that in my parts book the seals are listed as O rings, and I did install the white ones that were in the gasket set I'm using. The bottom set fits nicely though, so I will try an OR on the top.
-Dave

Hi Dave,


Are these "white" ones square- or oblong-section? If so, they're the wrong ones for a '73 - check the parts book. Triumph had several goes at trying to make the prt seal properly, and the head, tappet blocks, tubes and seals aren't always compatible, so you need to make sure all the bike's bits are from the same year, or you've likely got two hopes of making your bike leak-free.

Btw, if "P-80" or "glycerine" aren't available, cheap spray-on furniture polish makes a good lube. :bigt

Hth.

Regards,

I used the o rings on the top with a smear of permatex and left the white outers and O-ring inners on the bottom and it all went together nicely! Thanks to all!

Hi,


Errrm ... how can I put this without possibly spoiling your day? ...Ok ...have you considered you might've put the rocker boxes on the wrong way 'round? ... Spindle domed nuts should be on the timing side? ... The parts book does show the inlet and exhaust rocker boxes with different part numbers ...

Also, have you thought about where the head steadies are going to attach to the frame? Fwiw, on my '69, I couldn't connect them from the exhaust head/rockerbox bolts, the coils were in the way; I connected 'em from the inlet head/rockerbox bolts to the bracket at the rear of the main frame loop. However, I appreciate the parts book picture does show the bolts with the relevant extension through the exhaust rocker boxes.

Hth.

Regards,

You never really know about PRTs until the bike runs

your right they are the wrong way round but it wont matter.

It would matter an awful lot to me.

davy

The rocker boxes will work ok, but Stuart is right about the head steady bolts/studs. They need to be on the inlet boxes.

I like to put things together the way they came apart, same tappet to same cam lobe, same pushrod end to same tappet, same rocker to same pushrod end, same rocker to same shaft, same shaft to same rockerbox and same rockerbox exactly where it came from on the head.
Fitting them on the wrong sides changes the contact pattern between the rocker ends and the valves tips and even the thrust between the valve and guide that has been bedded in over time so the parts will all have to bed in together again from scratch causing further wear.

Why would you do that when it's a simple job to swap the rockerboxes around to their correct original positions?

davy