Exhausts

T244 exhaust systems are prone to problems. The culprit seems to be that the whole design is flawed and that it can’t cope with vibration.

Failure of mounting brackets and the standard-fit flexible bellows section just downstream of the manifold (shown as ‘C’ in the image) is well known: even new trucks in active service apparently suffered a lot. As well as brackets breaking, heat shields self-destruct and mounting bolts are also prone to loosening.

On our truck the bolts that attach one of the mounting brackets to the mounting bracket that attaches to the gearbox (shown at 6 in the image) regularly worked loose: the addition of a couple of spring washers helps to prevent this.

Whilst on one trip in the Baltic States, we suffered a split in the flexible bellows section referred to above. This wasn’t a showstopper and was only noticeable by a ‘woofling’ at certain revs but clearly it need sorting. Once back from the trip, a little research revealed that the flexible section was eventually subject to an OEM upgrade and was replaced by a solid piece of pipe. Additionally, part of this upgrade meant different silencer mounting bands were used, presumably to try to take some stress out of the weaker parts of the system.

I managed to locate one of the upgrade kits, fitted it, and so far all is hanging together well. I still don’t trust it though…

One owner I know has gone to great lengths to beef up all the mounting points and has essentially custom-fabricated new brackets to take advantage of more fixing points by recruiting more of the standard-fit bolts to be found around the gearbox and bell housing areas. So far, all appears to be working well. I'll try to obtain some images of his work at some point and post them.

The two relays pictured in the gallery are master switches for the 24 and 12V systems and when travelling they were - by original design - required to be permanently on. I did some testing and found they draw approx 165mA each when energised. This might seem inconsequential but when extrapolated can be an eye-opener - it was for me, anyway.

We normally travel each day when out and about but usually 'camp' from somewhere late afternoon to mid morning the following day, usually a period of around 17hrs. In that time the relays were 'costing' us almost 6A in quiescent load. Now, because we travel each day we've never really succumbed to huge battery capacity or auxiliary charging solutions so our 24V battery capacity is comparatively small. As such, 6A is just about 6A more than I'd like to be losing for no good reason. I'd much rather that 6A be available for the compressor fridge. Even worse, though I never designed our truck to be used for shows, it has been to a few and parking up late Thursday to Sunday afternoon would see the relays alone suck 24A. Ouch.

To improve system efficiency, I tweaked them to enable a manual override function. With the knurled screws 'out' the relays still operate just as Durite intended but once the relays are switched on, I can now tighten the knurled screws in and lock the contacts closed. When that's done, turning the relays' energising coils off saves all the power previously required just to hold them in. I now 'lock' them when setting off on a break and 'unlock' them on our return.

It seems like a decent work-around and it's saved me from having to disturb my original wiring looms. Lesson learned: if I built again, I'd utilise purely manual switches instead.