Panhard Rod Crossmember Replacement
During our pre-MOT inspection of RM1872 we found a number of things
which needed addressing such as windows that didn't open and corrosion
on the PanHard Rod Mounting Crossmember. The former were easy, if
tedious, to fix but the later needed further investigation.
Since removing the PanHard Rod Mounting Crossmember results in an immobile 'bus we tried, to no avail, to get a spare before we took the original component off so we had no choice but to park RM1872 up over a pit for a week so we could remove the old crossmember and have it repaired. We are lucky that the South Devon Railway Trust's main workshop has high enough doors at the Ashburton end to allow RM1872 to be backed in. It was a bit of a squeeze with GWR steam locomotives 4160 and 3803 over the pit at the same time as RM1872 but it was achieved by the workshop staff. We only had a limited time to effect the repair because 3803 is due to have her wheels dropped out because it's 10 years since they were installed and we're in the way for it to get over the wheel drop.
Unfortunately the corrosion was much more extensive than we'd first thought and a total replacement was required. We had hoped Imperial Engineering could assist and so arrangements were made to get the component up to them first thing Monday morning, but upon arrival they realised they couldn't help though they did put us in touch with Arriva's depot in Enfield who had a redundant spare for sale.
To give you an idea as to why we replaced the crossmember look at the following photographs. The rest of RM1872 is in very good condition, particularly when you consider her age. For those interested there are 15 off 3/8"UNF bolts holding the PanHard Rod Mounting bracket to the crossmember, 24 off ¼"UNF bolts, 10 off ¼"UNF countersunk screws and 4 rivets holding the crossmember to the 'bus. This list doesn't include those fixings for the floor panel over the axle which has to be lifted to gain access to the 10 countersunk screws!
In order to simplify construction and installation Arriva don't use rivets but bolts so we also needed an extra 60 off ¼"UNF bolts 1inch long each with two washers and a nyloc nut to hold the components together. The bolt together construction makes fitting easier too because the internal bolts can be installed without having to use "key-hole" surgery through the open end of the crossmember. We suspect that if the crossmember is fully assembled as per the original London Transport version that the nearside rear wheels need to be removed for access. We didn't need to and completed the job over the pit in two days.
If you need a new crossmember then The South Devon Railway workshops can provide a kit based on our old unit for £288* (plus bolts, carriage and VAT) or you can try Arriva Bus Garage, Enfield. Both will supply the crossmember as a bolt together kit containing four aluminium components in natural finish manufactured to order.
The South Devon Railway Workshops
Dart Bridge Road
Contact Rob LeChevalier
Tel: 01364 643461
Arriva Bus Garage
The contacts are Tony Skinner or Jimmy Kent
Tel: 020 8271-3317
|The view down from the passenger compartment shewing 'B' frame & no crossmember|
|PanHard Rod mounting bracket with nothing to attach to !||The crossmember goes here.....|
|The crossmember had completely rotted away where the PanHard Rod mounting bracket goes|
|The front face isn't much better; look carefully and you'll see the holes are joined together !!|
|Some of the inside was good, but every component had a rotted hole in it.|
|The replacement Crossmember after priming - Note bolt together construction|
|Compare this with the rotten view above - these holes have metal between them!|
|These are the internal parts recovered from the old crossmember - all were re-usable after cleaning and painting.|
|New crossmember part assembled and in position|
|Panhard rod securely attached to the Routemaster via the new crossmember|
|Finished crossmember with all bolts in place.|