Merc 1124 4x4 Auto

Hi,

Have Merc 1124 4x4 Auto 1994 Double cab ex fire engine. Just getting used to it and don't have any information with it so trying to figure things out as I go along. Has plenty of power through the range but is up at about 2400rpm at around 55mph (88kph). Thought it would sit better at motorway speeds. Does this sound normal. Not got much experience with trucks so trying to figure out whether I'm missing something or whether this sounds normal.

Thanks for this.
Cheers Tobias

Hi Toby.

Post a pic! Love to see what we're talkin about! V6? Hub reduction rear axle? 55mph/90kmh is about right.. My 1222 is the same!

My 917 drives all day long at 55-60mph.

Revs @ 55

Thanks for the comments guys. What sort of Revs are you at at 55 on your two trucks?

Will sort pictures

must be different gearing in the 4x4 trucks. My 1823 is at 1,700 rpm at 55 mph (90 km/h)

Yup, recon you're on the money re 4x4 gearing.. My 1222 is dong 90kmh at the end of the green band.. 2100rpm from memory. I planned to change the diff ratios, but that's not as easy as I first thought.. The front and rear diffs don't match as one is a different ratio to suit the hub reduction axle! Now looking to change the 6 speed for an overdrive 8 speed.. It would be handy having closer gear ratios, and a better top speed.. Only mods needed are prop length between gearbox and Transferbox, gearbox mounts and gear linkage.. (In theory)!

I'm also of the belief that some of the GB/Euro Powerliners had a different diff ratio, giving them long legs (high top speed)! I drove a 1617 4x2 and a 2421 6x4 for Dragoman.. The heavy old 1617 had good top speed of 100kph +, whereas the V6 2421 was flat out at 95kph.

I have the opposite problem. I have the G85 6 speed box which has a good top speed thanks to the 0.73 ratio in 6th gear, but has no crawler gear. My truck is 4x2 so has no transfer box to add low range. I have been keeping my eye open for a transfer box in the wreckers but the 1823 4x4 trucks mostly found use as gritters for local authorities and they normally keep the old trucks to rob for spares. They sold the 1823 with a G131 9-speed box but as it has no overdrive in top gear, I'd need to swap the diff out if I fitted it. Also the gear linkage isn't hydraulic on the 9-speed so it'd be more work to fit.