Freelander 1 Rear Diff Ratios

Anyone got the definitive answer on the above for the Freelander 1?

I see rear diffs for sale saying basically that one size fits all - 1.8, V6, TD4, L
Haynes suggests that there are different ratios for different models and gearboxes:
Petrol - 4.2:1
L - 3.647:1
TD4 Manual - 3.182:1
TD4 Auto - 2.910:1

I also see 47098 referred to as the 'old version' which caused more transmission wind up and the 51441 being the 'later version'.

Is using a manual TD4 diff on an Auto Td4 going to cause me problems?
Has anyone got the true story on what fits what and perhaps, why they are different (assume it is to match front wheel gearing)?

early FL: rear diff is 4.200 (petrol) 3.647 (diesel)

late FL: 3.182 td4 manual, 2.91 td4 auto, 4.20 K series, 3.66 kv6

The Mad Hat Man said:

early FL: rear diff is 4.200 (petrol) 3.647 (diesel)

late FL: 3.182 td4 manual, 2.91 td4 auto, 4.20 K series, 3.66 kv6

Click to expand...

How can that be true if (the K and TD4 at least) share the same IRD?

Are you not talking about the final drive in the gear box?

Having read some other threads....the search has not worked for a while.....I think GG is right and even Haynes is muddled. The ratios given seem to be the final drive in gearbox. Even Bell state that all diffs are same but later ones had uprated bearings. Anyone confirm this?

andyfreelandy said:

Having read some other threads....the search has not worked for a while.....I think GG is right and even Haynes is muddled. The ratios given seem to be the final drive in gearbox. Even Bell state that all diffs are same but later ones had uprated bearings. Anyone confirm this?

Click to expand...

I'm not sure why they would have uprated the bearings - they are tough as old boots.

Are you not thinking of the F2 rear diff, which was conversely, as soft as cheese!

In 2012 Austen posted 'The rear diff ratio's are all the same from all years and all models, the only differenmce is from around 2000-01 the rear diffs had larger bearings fitted to the carrier. This was done due to diff failures which were infact caused by VCU and tyre issues, so infact was completelypointless. Most people want thelatter type as they are deemedstronger, but what we have seen is that the later diffs that overheat due to tyre or vcu issues usually destroythe casing as its weaker due to the lesser amount of material in the diffcasting due to the larger bearing.

Ther final drive ratio from the gearbox is different depending on engine type. The IRD ratio is the same apart from the V6 which is different to all other models,although the majority of the IRD is the same, just a couple of gears in there which do this.'

GrumpyGel said:

I'm not sure why they would have uprated the bearings - they are tough as old boots.

Click to expand...

There were some early diff failures, early in the FL1s life (probably mismatch tyres and a very different diff to IRD ratio). So LR fitted larger diff carrier bearings to reduce failures. This then lead to the IRD failing instead, even though the IRD ratio was altered at the same time, to bring it closer to that of rear diff. Over all, these changes resulted in reducing failure occurrence until much higher mileage had been covered, as long as tyre maintenance was as per LR's instructions.

Thanks. So are all diffs same ratio?

andyfreelandy said:

Thanks. So are all diffs same ratio?

Click to expand...

Yes. Just use the later ones with the larger carrier bearings.

Not sure that make sense.

What you're saying is to use a component that will shift the weak point to the IRD.

The original diffs are of a perfectly acceptable standard and are a lot cheaper and easier to replace than an IRD in the unlikely event it does fail.

GrumpyGel said:

What you're saying is to use a component that will shift the weak point to the IRD.

Click to expand...

The weakest component always fails first.
Early in the Freelander's life, there were lots of diff and IRD failures. The primary reason was probably down to incorrect tyre maintenance. However LR decided to beef up the rear diff bearings and alter the IRD ratio to reduce VCU slip. This made the drive train less susceptible to damage in normal use, although bad tyre maintenance will still end in eventual transmission failure.