Thread: Underbody protetion for Defenders

The engine & transmission are snuggled pretty high up in the chassis to avoid damage. But you could try some heavy aluminium plate (4mm+ chequer plate) bent into a square U section, where the bottom covers the vulnerable parts, and the sides come up and "hug" the chassis rails. While you're at it, why not build a hull with elongated slots with rubber sleeves for the tail shafts to protrude and travel along, fill the chassis with closed cell filler, make sill tank pontoons and turn your Landy into an amphibious car . Sorry - getting carried away with ideas again.

Originally Posted by DRUT

Has anybody got any after market ideas for underbody protection for a 99 defender tray back. Preferably stuff I an get made or make myself to save $$$$. Looking for engine, gearbox and t'fer case and steering gear protection. Its only a tourer but better safe than sorry. I have Bearmach diff protetion front and rear already but am looking for cheaper ideas for other areas.

cheers
DRUT

I have difficulty seeing anything apart from the front diff and steering links that is at all at risk. Certainly never damaged anything except the track rod myself (in 400,000km including a lot of off road). Everything else is pretty well tucked up - the front axle will shield nearly everything. I am not sure whether the Defender has a guard on the fuel tank, but if not a skid plate there could be an idea - although the plate under my fuel tank has no dents in it, it has the odd bit of paint scraped off.

For the steering gear the best solution is probably a heavy track rod (several varieties available or you can get a reinforcing tube that goes over it - I've also seen advertised a bracket on the diff that stops it bending too far, but I'm not keen on that idea) and possibly drag link, although the drag link is fairly well up out of danger.

I have seen u-joint guards advertised (no point in having them on the front unless you make a habit of driving backwards), but they look to me like they would cause more trouble than having the open joints - imagine trying to untangle a bit of fencing wire wrapped round that, jammed between it and the joint. Be bad enough with small sticks and other kindling, which could ignite from friction. The rear prop shaft is prone to damage if you really try, but it is difficult to see how it could be protected without reducing clearance - remember it travels down a long way on rebound.
John

Tis a difficult area as you don't want to enclose as it will retain more heat from the boxes and you can't go long as the propshafts need their travel space..
I have a Troutbeck 8mm alloyset up for my steering and front diff, a bearmach Sals rear diff protector and a 70x70x90, 5mm mild steel angle and 2.5mm chequer plate protecting my fuel tank. nothing else seem to take a knock and I do try some nasty off roading Main consideration is do not detract from you ground clearance when adding armor.

Originally Posted by DirtyDawg

<snip> a bearmach Sals rear diff protector <snip> Main consideration is do not detract from you ground clearance when adding armor.

removed 3/4" from the bottom of the Sals and used a Rockcrusher Dana 60 diff cover (nodular iron, 8mm thick, gusseted/finned and very strong) suitably chopped. Removed the very bottom bolt, screwed in a blind stud and drilled and tapped a new 10mm bolt hole slightly further up/around. Diff is ground/chopped to the very bottom of the lower bolt hole. Only around 5-7mm lower than the front diff now.

you can get this for around $500

For a tourer, there just isn't a history of problems. Diff guard, steering protector bar, that's about all you'd need.

As to the alloy plates, skid thingies etc. I was advised not to do it. The car relies a lot on the airflow under the car for cooling. Reduce that airflow, & you could have gearbox etc issues. Not a problem in the UK, it is here.

And they fill up with mud anyway.

Regards
Max P

Originally Posted by Tusker

For a tourer, there just isn't a history of problems. Diff guard, steering protector bar, that's about all you'd need.

As to the alloy plates, skid thingies etc. I was advised not to do it. The car relies a lot on the airflow under the car for cooling. Reduce that airflow, & you could have gearbox etc issues. Not a problem in the UK, it is here.

And they fill up with mud anyway.

Regards
Max P

Another problem with them is that if you go offroad at all (and why would you get them if you don't?), they will accumulate a nice thick bed of grass seeds, chaff and small sticks, stuck together with your oil leaks, just waiting for the exhaust to get really hot on that steep, slow hill, on a typical inland day with the temperature in the low forties and the humidity down to single digits. Or for a stone thrown up to strike a spark on something. If you are still off road when this happens, the local bushfire brigade is not going to be happy, and even if you are on a road, YOU are not going to be happy.
John

or you could keep them clean.