Vs Calais l67 diff

[_R_J_K_]

Unless it's been rebuilt a stock original LSD will just be made of dust pretty much. That LSD would be nigh on 20 years old.

If you get a 3.07, it's a bees dick of difference, to the point where I probably wouldn't get it corrected.

 

[Flyl67Boy]

Okay thanks guys look like either a rebuilt 3.08 LSD or 3.07

 

[Flyl67Boy]

Okay guys back again... Couldn't find much info that I needed. I've found a 3.08 LSD rebuilt 12 months ago. And a 3.07 in good condition. Now I've read the standard 3.08 doesn't need any modification to fit which is a good thing but isn't as good as the 3.07.. ? The 3.07 is a newer diff but need so modification and also maybe a speedo recalibration but some say it's not even worth it. So I'm at a cross road and kinda stuck on what diff would be better. And also better take off would be the 3.07

 

[_R_J_K_]

The 3.07 is a newer diff but need so modification and also maybe a speedo recalibration but some say it's not even worth it. So I'm at a cross road and kinda stuck on what diff would be better. And also better take off would be the 3.07

Like I said before, there would be a bees dick of difference in the speedo and acceleration would be a bees dick worse. .01 of a rotation to be exact. The only modification that you need is to swap the front flange over.

I suggest you google for some guides on the M80 to early model diff swap to work out what you want to do.

 

[Immortality]

No need to recalibrate for a 3.07 ratio diff, you will get a greater difference in the speedo in tyre wear from a new tyre to a totally worn tyre.

if you do get the 3.07 diff you need the entire diff not just the diff centre as you can't put M80 bits in a M75 housing.

The M80 diff is only better if you intend to upgrade to a true-trac type diff centre because they can be had a lot cheaper than a true-trac to suit the M75 diff. If you just want a standard factory style LSD centre it is probably better to stick with what you have as the M75 centre is easier to rebuild.

Also, a M80 from a VT should still have the flange type coupling like the earlier diffs, it was from VX onwards that they started using the dougnut type couplings/drive shafts.

 

[TI3VOM]

The M80 I bought had a 3.07:1 ratio & was the LSD version.
My original M78 had a 3.08:1 ratio and was not.

I was under the impression that the diffs with 3.07:1 were LSD's & the ones with 3.08:1 were open diffs.

You might want to confirm that you are getting an actual LSD and not a high performance diff.

 

[Immortality]

M75/78 and M80 come in both open and LSD versions.

 

[TI3VOM]

M75/78 and M80 come in both open and LSD versions.

I understand that, but I was under the impression that the 3.07:1 was the LSD and the 3.08:1 was the open diff, or the high performance on rare occasions (with tag to suit).

 

[Immortality]

3.08 is M75/78 3.07 is M80. The difference in ratio is because the M80 obviously has a larger diameter ring gear so the ratio of teeth on the ring gear to pinion are slightly different.

 

[Pollushon]

Cause yours is an IRS setup changing the centre over is pretty easy, but an extra pair of hands is recommended, the diff is plenty heavy enough to crush your melon. You can find a reco 3.08 LSD for around $500-$600 but noting the standard LSD is pretty crap and if you're hard on it, it'll become a single pegger in no time.

If you do change ratio as others said you have two options;
Speedo corrector (I prefer the Yellr box over the JayCar, they are hit and miss, bit jerky as well)
Retune, which consists of a change to the PPK value to suit the ratio - then a full shift point retune as PPK changes will screw it up.

The corrector is a better option as it's cheaper and means you can swap diff ratios regularly with ease