[Hermit47]

In his post to "Blown Head Gasket", Stuart says the part number for the aluminum washers on the allen head screws inside the rocker boxes of the '73 T150 RPC is a misprint and that it should be 70-8175.

No RPC, Page, Fig., or Ref. given. Detective work indicates the following manuals

RPC 99-0955 1972 Trident T150, T150V
RPC 99-0972 1973 Trident T150 Series I USA Edition
RPC 99-0972 1973 Trident T150 Series II USA Edition
RPC 99-2252 1974 Trident T150 Series ! USA Edition
RPC 00-5738 1974 Trident Model T150 commencing CJ41610

Have the same PN for
Fig.4 Cylinder Head and Rocker Boxes Ref.38 PN 60-4245 washer, which appears to be the most likely culprit to me.

So my question is:
Is 70-8175 the correct part number for Fig.4 Ref.38 PN 60-4245 washer in the five RPCs listed above?

And if not, which tree should i be barking up?

TIA

PS
I don't think any of these are the error, but there are four other washers listed for Fig.4:
Ref.31 PN 70-1575 plain washer
Ref.37 PN 70-9239 plain washer
Ref.40 PN 70-9240 washer
Ref.45 PN 82-2184 washer

 

[StuartMac]

Hi Bruce,

Stuart says the part number for the aluminum washers on the allen head screws inside the rocker boxes of the '73 T150 RPC is a misprint and that it should be 70-8175.

No RPC, Page, Fig., or Ref. given. Detective work indicates

Firstly, apologies for lack of a direct post to you for your database, it was on my to-do list ...

However, your post having prompted me to prepare a reply with all the aforementioned missing details, I'll have to do some more research ...

What prompted this post was @BMF Brett's post; both my T160's and my T150 have the same "little aluminium washer seals for the Allen head screws inside the rocker[-boxes]". BUT (and it's the proverbial J-Lo), preparing the reply for you, I realised:-

. as Brett's T150 is a '74 Series 2, it has the same rocker-boxes as my T160's; these are different part numbers (71-4245/6) from rocker-boxes in all other T150 RPC from early '69 SPC4 to '74 Series 1 99-2252 (E6561/2);

. although my T150's a '70, it isn't beyond the bounds of possibility it too has the later rocker-boxes, that take the "little aluminium washer seals for the Allen head screws inside the rocker-boxes".

To try and clarify the detail for you:-

. Every T150 RPC, from early '69 SPC4 to '74 Series 2 00-5738 has either S25-1 or 60-4245 (same washer) under specifically the six 14-7004 (Ref. No. #18?) Allen screws into the head below each rocker-box Inspection cover. This washer is plated steel nominally 1/4" ID, 9/16" OD, 14SWG (0.080") thick.

. Certainly the later 71-4245/6 rocker-boxes, the bottoms are counterbored around the Allen screw holes so the tops of the screws' heads are pretty-much flush with the rocker-box bottoms; the counterbores are a smaller ID than the 9/16" OD of S25-1/60-4245; it's these counterbores that definitely require the 70-8175 aluminium sealing washers; also these washers are deformed by tightening the Allen screws, making the seals.

. The S25-1/60-4245 washer is used widely; just on the "CYLINDER HEAD AND ROCKER BOXES" illustration (always "Fig. 4"?), it's also shown on the 1/4" bolts at each end of the rocker inspection covers and on the 1/4" bolts into the head at each end of the rocker boxes.

I need to find out for you whether:-

. S25-1/60-4245 washers on the 14-7004 Allen screws is wrong in every T150 RPC;

. or 60-4245 washers on the 14-7004 Allen screws is wrong just in the '74 Series 2 T150 RPC.

four other washers listed for Fig.4:
Ref.31 PN 70-1575 plain washer
Ref.37 PN 70-9239 plain washer
Ref.40 PN 70-9240 washer
Ref.45 PN 82-2184 washer

70-1575 are the 1/2" ID plain washers either side of each rocker; 70-9329 are the copper sealing washers under the four Sleeve nuts in the middle of the rocker inspection covers; 70-9240 are the 5/16" ID washers under the bolts through the rocker-boxes and head into the cylinder barrel; 82-2184 are the 3/8" ID washers under the nuts on the tops of the studs from the cylinder barrel protruding from the head either side of the outer cylinders' plugs.

Hth.

Regards,

 

[Hermit47]

Thanks for the reply Stuart. Good thing i asked before just slamming an error into all those RPCs, which may well still be the case, but we'll stay tuned for further info.

Also, from your reply, one little question: Would RPC 00-5738 1974 Trident Model T150 commencing CJ41610

be the same as the "'74 Series 2 T150 RPC" you mention?

Cheers

 

[StuartMac]

Hi Bruce,

RPC 00-5738 1974 Trident Model T150 commencing CJ41610 be the same as the "'74 Series 2 T150 RPC" you mention?

For T150's, the '74 model year is divided by the Meriden sit-in that began in calendar September 1973:-

. All triple engines, Triumph and BSA, were built at BSA's Small Heath, Birmingham works; before the sit-in, Triumph engines (T150 and X75 Hurricane) were trucked to Meriden to be assembled into cycle parts, tested and dispatched from there.

. The '74 model year began in calendar June 1973 for Triumph triples and twins; earlier than usual in a calendar year but I suspect it had to do with Triumph becoming part of NVT. RPC 99-2252 for 1974 T150V's is actually titled "Series 1", covers the '74 T150's from GJ40101 dispatched from Meriden.

. Once NVT management determined the Meriden sit-in wasn't ending quickly, the plan to move all T150 production to Small Heath (that was part of the original cause of the sit-in) was simply brought forward, either by installing new machine tools at Small Heath or making the release of tools at Meiden part of the negotiating process that drip-fed funds to the Meriden strikers. RPC 00-5738 "1974 Trident Model T150 commencing CJ41610" covers the '74 T150V's assembled entirely at Small Heath, tested and dispatched from there (RPC 00-5738 does detail a number of changes from RPC 99-2252).

Hth?

Regards,

 

[Hermit47]

Thanks for that clarification, Stuart. I've updated my RPC library index.

Regards,