Weekend Rails

what we do for our kids

Of propshafts and UNFs

22nd April 2012

On Tuesday at 8.00 sharp I set off for South Wales and after the first 50 minutes I was 30 minutes down the M1. Nonetheless after a detour for a cup of tea and a chat with Bryan Lawson at Alan Keef’s, I was down almost to the South Wales coast by 1.15 pm and collecting a smart new prop shaft that one man can (just!) lift but two find much easier and would just fit in the van, which I had mostly emptied to make room.

Then I sauntered back along the M4 to collect some bits Andrew had won on e-bay and in fact then headed over the bridge and south into Exmoor, but that’s another story. The short fact is, with over 600 miles accrued on Tuesday, and other excursions on Wednesday, Thursday and Friday, come Saturday morning, Andrew in London and me intending to head to the DVLR and investigate Pluto’s problem, I stared at the computer screen, my vision did a shimmy and I knew all too well that a migraine was on its way. The DVLR was scrubbed and I retired to bed.

Sunday: Andrew reappeared prompt at 10.00 and disappeared to “check his e-mails” leaving me impatiently pawing the ground waiting to get off to Scunthorpe. Eventually we arrived at 11.45, to find a team of 3 fettling the 07 with a view to having it running at the AFRPS gala – an event we hear is already over-subscribed and causing concern as to how to find the necessary additional seats. The AFRPS’ rolling stock is basically dmu trailers and “ordinary” loco hauled stock have subtly different corridor connections!

Anyway, we started by unloading the propshaft – aah, but I see I’ve omitted an important bit. As the gearbox drive flange was intended for a Layrub coupling, it was not compatible with the prop shaft we were using, which was dictated in part by the flange on the back of the transmission – the other end. In an ideal world I’d have had a spare gearbox flange of the appropriate pattern to swap, but this is not the real world and anyway, I opted to use the parking brake disc as an adaptor flange. The propshaft requires 12 bolts which, being of automotive origin, are 7/16″ in diameter, and would normally be UNF. (American Unified National Fine if you don’t know). As the disc must butt up flush with the existing drive flange, I had the holes countersunk on the gearbox side, but when I came to order up 7/16 UNF countersunk setscrews this week, I was disconcerted to be told by two suppliers that they were no longer listed by the manufacturers. Andrew came to the rescue, pointing me to a small supplier in Shepshed who stocks them (probably imported from the States), but the requisite length was not available in time, so for the moment one end only of the propshaft is in place, but no matter, for the uninitiated it looks OK (the other end is hiding under the cab floor) and I am pleased to say that Andrew conceded that his previous concerns that the prop-shaft would not clear the top of the oil reservoir were unfounded: it does, pretty much as my drawing forecast. He did however, insist that he was right to wait until the prop was in before installing the battery tray, as it would have been difficult. I just point out that, one day, hopefully when I can be tucked up with a blanket in my bath chair and merely direct, someone might need to take it out again, battery tray and all.

Anyway, we moved forwards, Andrew to the left hand side and me to the right. I had to come across to aid him undo the bolts that secured a cover plate over where his new filler pipe arrangement would emerge. But with the pipework suitably tweaked, it lined up correctly and he went on to install a “clear” plastic pipe from top to bottom of the rad which will give us something resembling a sight gauge (we’ll secure the pipe with P-clips or summat later).

img 0778 edit
At the top is the filling connection, with the plastic pipe down the side to act as a sight guage

On my side I put together the remaining bottom coolant connections and by-pass line before starting to pull wires through from the connection box to various switches and senders. Sadly, our remaining problem with the cooling system – the “loose” thermostat housing (detached when we acquired the engine) needs a visit from a UNF tap to clean out the 4 deep threads, and the two boxes of taps we’d brought out from home, plus the vast collection of AFRPS taps we checked over, all seemed to be BSW or BSF. So no fill-up to look for water leaks yet. Andrew meanwhile got out the welder, and attacked the matter of the battery tray, which comprises two angles (you’ve seen them lying around waiting) spaced to accept the batteries. after which we loaded them and I made the two main feed cables thence back to the switch before returning to my slow task of pulling wires through conduit.

img 0776 edit
The bottom coolant connections in blue silicon, with by-pass in red

img 0779 edit
The propshaft passes through while the batteries now live on their tray above

Andrew then returned to plumbing the air system. Although the compressor cylinder head is away being commercially overhauled, sooner or later a pipe must be arranged from it to feed the air tanks, and after a quick conference a simple layout was agreed on and put in hand, complete with non-return valve. I had hoped to be well on with hosing this week, but that has hardly been started, though with Andrew allocating both days next weekend to the loco, maybe we’ll catch up.

This site runs on a system that employs Cookies to establish a link between your web browser and our site. This link is required to deliver to you the page you requested, let you see any photos or videos or to use the contact form. The Cookies that allow this to happen are automatically downloaded to your device (pc, mobile, laptop etc) when you click onto our site. If you set your web browser not to accept Cookies then its probable you will be unable to use Weekend Rails properly. Click to Accept (or the message stays visible). To find out more about the cookies we use and how to delete them, see our Privacy Policy.

I accept cookies from this site