TECH: Diff Drop Kits

If you have investigated putting a suspension lift into your IFS equipped 4wd, chances are the subject of a diff drop kit has been raised. In Edition 49 of Dirtcomp the team from Roadsafe 4wd climb under the front of a modern fourby to highlight their importance.

While live front axles remain the king for most hardcore four wheel drivers, independant front suspension has become the flavour of choice for most modern vehicle manufacturers, due to their great road handling manners and increased passenger car comfort.

However, install any aftermarket suspension into an IFS vehicle (even as little as 30mm over standard in some cases) the diff centre is moved away from the chassis, which causes the driveshafts to operate on an increased angle, significantly increasing wear as they are working outside of their design capabilities.  This creates a range of issues to consider:

• Driveshaft strength – the increased angles reduce the immediate strength of the CV (attached to each end of the driveshaft)

• Durability – whilst you may not do any extreme 4WD’ing – this poor angle will accelerate wear on the CV’s, creating both short and long term issues.

• Clearance issues with CV boots rubbing against themselves and other components causing premature wear and water/dust ingress resulting in component failure. CV wear is accelerated on lifted vehicles further if larger (wider) wheels and tyres are fitted.

Different vehicles have different diff drop system requirements. Some require an engineered spacer kit, others a replacement heavy duty cross member. In most Diff Drop Kit scenarios hardware required to space down the factory bash plates are supplied as standard, providing a complete solution.

A number of people are concerned about the loss of ground clearance once they have fitted a Diff Drop Kit.  The reality is many IFS vehicles fitted with a Diff Drop Kit will maintain more ground clearance with its legally fitted aftermarket tyres and lift height than a Nissan Patrol or Land Cruiser with its large diff centres on 35” rubber. 

So while you have lowered the diff by 20mm to gain reliability and durability of the front drivetrain, you still have more than adequate clearance in comparison to heavily modified Patrols and Cruisers on big tyres.  Just because most IFS vehicles are smaller doesn’t mean they can’t keep up with the big boys, especially once you’ve made a few adjustment to the front suspension to get it working to better suit 4WD’ing requirements.

Roadsafe have a great range of Diff Drop Kits in the Roadsafe 4WD brand.  Roadsafe 4WD IFS Diff Drop kits are application specific and supplied complete to get the job done.  The bolt on kits correct the geometry of the front driveshaft and CV’s, lowering the front diff by between 20 to 25mm, reducing the angles the CV joints need to operate on and avoiding the expensive replacements of CV’s and boots.  Roadsafe 4WD kits allow for the bash plate to be refitted.

The Roadsafe 4WD DDCOL02 kit to suit RG Colorado, DMax and MUX (2012-on) lifted between 2 to 4 inches, is supplied complete with a solid flame cut 15mm steel replacement crossmember and alloy spacers, that all work together to drop the inner CV joint by approximately 30mm. 

The Roadsafe 4WD range includes kits available to suit key IFS models including PX Ranger/BT50, RG Colorado/DMax/MUX, D22 Navara, KUN Hilux, Landcruiser 100 & 200 series plus Volkswagen Amarok.  

For further information chat to your local Roadsafe 4WD stockist. To find your nearest stockist visit