DIY Network

	AUTOS & BOATS Index
	Auto Restoration & Kit Cars Air Conditioning Automotive Body Work Automotive Cooling System Electrical Systems Exhaust System Fuel Systems Boats Brakes Buying Detailing Engine Exterior Interior Parts & Accessories Safety Security Small Engines Stereo Suspension Tires Tools Trailers Transmission Vehicle Types Windows

Best of Autos Boats

Classic Car Restoration
Preventive Maintenance
Ultimate Car-Care Guide

SPONSOR LINKS

Replace Headlights
Replace Door Panel

Merkur XR4ti: Limited Slip Differential

Andrew Totolos installs a limited slip differential on an American car with German roots — the turbo-charged Merkur XR4ti.

From "Tricked Out"
episode DTRK-405

(Continued from page 3)

The heavy-duty axles, greased and ready for installation.

Install Limited Slip Differential and New Axles

The differential has been prepped, so now it's time to get it into the housing and then back into the car. The housing must be ground down so the new differential will fit inside. The differential will then fit into the housing, and the entire unit will be installed in the car. Andrew also installs a new set of axles.

Andrew and the owner of the Merkur, Chris McKinney

Materials and tools:

standard mechanic's tools
masking tape
permanent marker
carbide burr with grinding bit and sanding drum
air gun
silicone sealant
transmission jack
axle grease
transmission fluid formulated for limited slip differential
set of heavy-duty axles

Steps:

The new differential doesn't fit into the old housing. Andrew grinds out the housing to make it fit.

Clean out the housing and tape up the inside to catch any shavings that might fall inside. Use regular masking tape to protect the housing and make cleanup much easier.
Use a permanent marker to mark the sections of the housing that need to be ground away.
Make steady strokes using a carbide burr to wear down the inside corner of the housing until the permanent marker is almost completely removed.
When the first side is ground down and smoothed out, flip the case over and grind down the other side.
Swap out the grinding bit for a sanding drum to smooth out the fresh cuts.
To rid of all the shavings, remove all the masking tape, wipe it down, and use an air gun to blow away any stray shavings.
Clean up the work area to avoid getting any debris into the differential as you begin assembly. With a little patience, the differential goes in the housing.

Figure G

Figure H

Figure I
And now the remainder of the install: the castle rings go back in to secure the differential on both sides.
Once they're seated, tighten them up (figure G) until the gears have only a little bit of play in them.
Slide in the axle stubs, and tighten them down (figure H).
Apply a fresh bead of silicone to the differential cover, and seal the new limited slip differential.
At the car, use the transmission jack to lift the differential back into position until it's close enough to push the long bolt back in and get the nut on the back side to hold it in place.
Replace the original mounting bolts.
Lift the jack more to raise the differential in order to install the rear mount.
Once everything is tightened down, pour in a couple quarts of limited-slip gear oil to lubricate the new differential.
Pop the plug in to complete the installation.
At the workbench, apply an entire package of axle grease to each of the CV joints.
Once they're lubricated, push the bolts through the washer plates and wipe off the excess lubricant.
The new axles go in just like the old ones came out. Slide them into place (figure I) and tighten down the six bolts at each end.
Pop in the driveshaft, and bolt it into place.
Complete the project by strapping the tailpipe back into position.

Test Drive

The new differential has been installed, we test out its effect on performance at the track. Taking the car to a local drag strip is the best way to test the modifications in a safe environment.

1 | 2 | 3 | 4