Advice needed on Quaife LSD self-install

[ionofchios]

Tried searching, but can’t seem to find anything on this.

I’m thinking about getting a Quaife LSD for my e86 3.0si, manufactured December 2006. From Bird’s site, I gather that in order to have a chance of doing this myself, my current diff ought to have a ‘bolted crown wheel’. Apparently, they stopped making those in 2007, so I might be lucky, or perhaps not. How do I tell if mine is bolted or permanently attached (to whatever it is attached to)? What am I looking for and can I see it without taking the diff unit off the car?

Anything else I should know if I am planning on doing the install myself? Anything that’s really tricky or needs special tools?

Cheers!

[Cirstu]

Birds are fitting a LSD to my 2008 E86 on 26-09-18, took the easy option......

[MACK]

IIRC I think all the I6 engined E85/86 diffs are the bolted type, known as type 188. The welded ones started on later E models with different diffs entirely.

[ionofchios]

IIRC I think all the I6 engined E85/86 diffs are the bolted type, known as type 188. The welded ones started on later E models with different diffs entirely.

Ah, OK, hope that is the case.

[Yorkie Z]

It will look like this, it's not a bad job if you're handy with the spanners

[ionofchios]

It will look like this, it's not a bad job if you're handy with the spanners

Good pic! Are those bolts on the back of the large gear the ones I should be looking for?

[GuidoK]

Looks like this if you're handy with the spanners:


(yes this is mine after I was done giving it a complete refurb/overhaul)

You need some special tools though. (large snap ring pliers, micrometer dial with magnetic stand (those are cheaper (on ebay) than that it sounds) large/strong knife edge puller and potentially a press)

@Yorkie Z: does the diff casing still have to be split in half in order to get it to fit/making 'turn' at the bearing holes (and bolted back toghether back in the casing), or have they already adapted the core housing to a slightly more slender design to be able to put it in as a whole unit?


The thing to look out for with the install is that the boltholes that have to be loctited must be cleaned really really meticulously (with acetone, ovencleaner, soap etc) to give maximum adhesion to the loctite.
Otherwise bolts can come loose and seriously damage the donordiff (dont ask how I know...)
Or at least thats what I suspect happened, I had bolts snapping completely in half.

BTW 188 diff doesn't mean if its bolted or not, its the diameter of the crown wheel.
But all e85/86 cars have bolted crown wheels

[wspohn]

If you are talking about installing the existing ring and pinion on a Quaife diff it is not a job for an amateur. If you want to save some money you could remove the diff unit from the car and take it to a specialist with the Quaife unit.

Be aware that technically, a Quaife is an automatic torque biasing (ATB) diff not a true limited slip, in that if you lift one wheel off the ground, you will get no drive, vs. a Posi which will still drive. They work very well on the street and quite well on the track, depending on what car they are fitted to (I run one in my live axe race car)

[GuidoK]

. a Posi which will still drive.

Actually thats not true. A ramp style plate diff also needs an internal pretention to generate the force required to actuate the ramps and engage the clutchpack. But I guess most available units will have that function. Sometimes you can specify the amount of pretention on the clutchpack.

But a Quaife ATB (and also wavetrac) also have a build in function to generate some pretention. A percentage of that pretention is the drive force to the other wheel (but thats generally not enough to really make a difference lots of examples on video that both quaife and wavetrac dont do well in icy patches, but thats in the first place not a good place to drive a z4).
In my picture you can see the stack of belleville washers that gives that pretention (in case of the quaife).
But either way, quaife has a very good reputation on track: radical cars (like the radical rxc turbo 500 that is faster around tracks than a mclaren P1 to give an idea) are standard equipped with a quaife atb. You can optionally get a clutch style LSD (probably also made by quaife because the do those too). But the performance standard those cars are set to are so far beyond what a z4 could ever achieve, that I think that from a performance pov the decision to go for either is a bit far fetched. Things like usability, maintenance or service life, cost and drive feel (there is a big difference!) are much much more important. Whatever a z4 could ever achive on a track, either diff type can handle it.

I was not talking about the install of the existing ring/pinion on the quaife. I'm talking about the 11 m8 hex bolts that hold the 2 halves of the quaife core toghether. I had 3 of them broken and the rest loose (backed out). This happened after 7 years. I dont know the exact cause; it was either that the 3 bolts broke resulting in loosing tension between the 2 halves and thus the other bolts could back out, or all other bolts first backed out and the last 3 were not strong enough to hold the 2 halves togheter and thus they broke.
Really meticulously cleaning the boltholes and bolts before loctiting only is a potential fix to the last of the 2 scenarios, for the first scenario stronger bolts are required (to try and solve that I didnt use the same make of bolts quaife used, but chose my own brand; but it comes down to that all bolts made in that size are made outside europe, so either in india or in china....)

I had my pinion/ringgear completely destroyed, but the quaife diff completely survived, so thats a testimony to the quality of materials used; the quaife case and gears are insanely strong. The forces applied on my exploding diff where so strong that the outer cast casing deformed.

[Yorkie Z]

It will look like this, it's not a bad job if you're handy with the spanners

Good pic! Are those bolts on the back of the large gear the ones I should be looking for?

Yeah that's the ones

[Yorkie Z]

Looks like this if you're handy with the spanners:


(yes this is mine after I was done giving it a complete refurb/overhaul)

You need some special tools though. (large snap ring pliers, micrometer dial with magnetic stand (those are cheaper (on ebay) than that it sounds) large/strong knife edge puller and potentially a press)

@Yorkie Z: does the diff casing still have to be split in half in order to get it to fit/making 'turn' at the bearing holes (and bolted back toghether back in the casing), or have they already adapted the core housing to a slightly more slender design to be able to put it in as a whole unit?


The thing to look out for with the install is that the boltholes that have to be loctited must be cleaned really really meticulously (with acetone, ovencleaner, soap etc) to give maximum adhesion to the loctite.
Otherwise bolts can come loose and seriously damage the donordiff (dont ask how I know...)
Or at least thats what I suspect happened, I had bolts snapping completely in half.

BTW 188 diff doesn't mean if its bolted or not, its the diameter of the crown wheel.
But all e85/86 cars have bolted crown wheels

No just the open diff out and bolt the new one in then check the measurements.

Amazing strip down on your diff

[firebobby]

Looks like this if you're handy with the spanners:



No. You mean VERY VERY handy with the spanners

[PerryGunn]

Looks like this if you're handy with the spanners:

No. You mean VERY VERY handy with the spanners

Nah, it's pretty easy to get most things into that state - it's the putting back together that's the difficult bit

[firebobby]

Looks like this if you're handy with the spanners:

No. You mean VERY VERY handy with the spanners

Nah, it's pretty easy to get most things into that state - it's the putting back together that's the difficult bit