GI: Affordable Helical LSD's for the G-series!!

[wheresthericego]

I'm going to contact Mazdaspeed Motorsports tomorrow. I don't plan on using a MSP diff again, but it would be nice to have a functional one I can sell.

Thats what I was getting at.

[Inspector 24]

The washers are more for noise-control than pre-load

What if I wanted the noise, what would it sound like, is it tuneable?


Just kidding

So other than noise reduction they don't perform any other tasks? I'm not really worried as the car seems to prefer staying low on the curbing, rather than get upset by going over it, and potentially lifting a wheel off the ground. I'm just curious.

[MFactory]

They help with slop when you go on/off the throttle

[Dan [Sac]]

I had another track session today.

Had a late night last night and put the LSD-box back on after having the shop go through it again - they found something wrong with the 5th gear synchros, changed those, and the tranny was shifting fine in every gear after that. I bought a brand new axle, put that on, and put in a spare clutch disc to make the car road worthy again. I figured I should give it one more shot before the down time while the PAR-geared box gets made.



Thus far the only unsatisfactory thing is the driver side axle not going in all the way. It's about 3/16" from full engagement against the gearbox and its seal. Not only that, but it moves a further 1/8" out pretty much at will.

The problem with the first 3/16" is that it allows fluid to leak out. Not gushing, but within a 1/2 mile of driving the bottom of the diff. housing is wet from the fluid seeping from the gap between the seal and the shaft. Also, while driving and coming off the throttle, you can hear the rattle of the axle moving in and out for that 1/8".

The axle is brand new, and it did the same thing with the previous axle, and Jon had the same experience when test fitting.

I made 2 passes, and the 60ft times were consistent with previous outings - 1.70 and 1.78. I had some full boost electrical issues (had electrical power cut out over 20 psi for some reason), so I didn't really get full passes, but did enough to put the diff to work through a few gears. I would say the launches were mildly aggressive, with a 'soft' clutch drop at 4800 rpm off the line. I'd say there is another .05 to a full tenth left in there if going all out.

Burnouts were where I saw the biggest advantage - no more single spinners, very consistent on both tires.

I was getting the axle chatter on the return road both times, and it's that 1/8" of travel (see the video).

I'll tear down this transmission in about 2 weeks and remove the LSD for inspection for now, before reusing it with the PAR gears. I have a show to make in L.A. next weekend that's been in the works for almost 8 months, which is why I'm leaving the transmission in there for now.

This outing only cost me about $275...


Click here for YouTube video of what I'm talking about.

The view is from the driver side straight down (from just next to the brake master cyl).

[Mellowness65]

good to see it survived
keep up the good work

[ragnarock01]

Hmm, so it sounds like the problem is that the axle just can't push in far enough to stick, and/or there is no space to let it lock in place inside the LSD.

[Inspector 24]

Dan, does the axle click into place? Is the c-clip still holding it in?

MFactory, can this axle play be addressed?

[MFactory]

Yes, this is something that we will look into and try to address for the production units

[chief tool]

Maybe a Left side driveshaft cup should have been supplied to MFactory along with the sample diff.

I have heard rumours that Mazdas with factory viscous LSDs have some variation in the driveshafts (not sure exactly what the difference is)

[Dan [Sac]]

Dan, does the axle click into place? Is the c-clip still holding it in?

At the 'forward' most position (closest to the transmission), the axle is clicked into place and the c-clip is holding it (it won't slide out any more than the video shows unless you pry it out). It also won't go in any further, so I think that's part of the issue - when the internal gears get remachined/redimensioned they'll probably provide for this discrepancy and should fit like OEM.

[MFactory]

One thing of note is that Jon said the same thing happened with his stock diff as well (the play). Could you try your axles with your stock diff also to see if this play is present for you.

[therieldeal]

I noticed some play with the stock open diff but there was more play with the MFactory unit. to me it didnt seem like it would be a problem, but i obviously didnt have it running in a car. if its leaking and making noise, the additional play must be too much.

I'm sure we could easily come up with some inner axle stubs to send over if needed.

[1992tracerlts]

I have some extra axles. off my parts car 26 spline.

[Inspector 24]

Agreed, I've got plenty of spare axles around, would happily supply a grease free example.

And I certainly don't have any problem with the play as long as it can't possibly affect performance or reliability to the tune of 30+ autocrosses a year, 5-6 track days and all the traveling in between.

I've got three G-Series tran's sitting in cars at my house, I'll take a look at them to see if any have similar play.

Ryan

[qikslvr2006]

not selling my spot. ima keep this bad boy. lol