Thread: Firewall - Bulkhead Modifications

Hello All,

Is it a legal requirement that firewalls/bulkheads in Series Land Rovers are welded together, single piece units?

I am currently delving into the bowels of a late model 2A shortie to replace the clutch slave cylinder. I have previously worked on Series IIIs to access things like starter motors and to just add electrical switches for added components like driving lights.

Having taken off the two covers that make up the transmission tunnel there is still restricted access to get to the 2A's clutch slave cylinder. The area above the transmission tunnel has a flat vertical face and is located in between the driver and passenger's foot well. This flat vertical face immediately above the transmission tunnel is spot welded together. Ease of single-person access to work on various components is not an in-built characteristic of this area.

Would it still be considered as a functional firewall if I drilled out the spot welds on the vertical face and used nut inserts (rivnuts) to detach and secure that panel face? The nut inserts would allow easy removal and much improved access within the uncovered area. Then the panel could be easily secured back on the main firewall panel by refitting the bolts.

As the vehicles have been off the road and unregistered for a long time - if I did make the modification to the firewall would the car be knocked back by a vehicle inspector during a roadworthy? Because if my suggested modification was performed the firewall is no longer a welded together single-piece panel. The firewall's integrity could be considered as compromised by a vehicle inspector.

Logic suggests that Land Rover welded together that part of the firewall for a reason. For example, to hinder a fire in the engine bay making its way into the cabin where people are sitting. Hence, one of the names associated with this panel .... 'firewall'. The term 'bulkhead' suggests to me something nautical in origins that forms a structural panel that seals out water ... Land Rover Series ... holding out water via a seal ... tee-hee.

Kind regards
Lionel

Hello Colin and John,

Thank you for your replies. I went for a stroll between the 2A and one of my Series IIIs. The Series III is waiting for me to put a seal kit through its replacement gearbox. When I bought the Series III it came with a Holden 202 motor. The adapter plate must have been misaligned because the previous owner said that it jumped out of high gear when it was coasting along and the accelerator pedal was lifted up. It also had some broken springs inside the box. I have a gearbox taken from an original Land Rover powered motor. So I am in the process of putting new seals and gaskets through the gearbox before I fit it back into the Series III. I also have a dial indicator to check the alignment of the adapter plate.

Anyway, the firewall on the Series III is a bikini version of the 2A firewall. Yes, the clutch slave cylinder located in a different position than it is in a 2A. No, I do not have to modify the 2A firewall to access the clutch slave cylinder.

I also learnt that the thread on the dual clutch/brake master cylinder on the 2A is a different thread than the Series III's clutch master cylinder. This means the cap on my Motive pressure bleeder does not fit the 2A's master cylinder. Lucky for me I was just walking past one of my vehicles in the shed and I spied something sitting on the bonnet. The only survivor of a very rusty dual master cylinder - its cap. I will be off to get a barbed fitting to fit to this now sacrificial cap so I can use the pressure bleeder on the clutch and its brakes.

One of those - I had better hang on to this part because it might come in very handy one day situations. The bonus is that I did not even have to go looking for it.

Kind regards
Lionel