"Stiff" new Cusco RS 1.5 Way

[lmx5B]

Just fitted Cusco RS 1.5 Way to my NC. Specialist transmission garage that fitted it and set diff readings advised that it is very stiff, so added light LSD oil - Penrite Limslip 90. So far I have only dríven a short way but noticed lots of slip and juddering. Does LSD need "bedding in"? Any advice?

[philz]

you should bed it in, by doing figure 8's in one direction and the other direction

read this thread: http://www.forum.jdmstyletuning.com/sho ... php?t=8959

find a suitable car park or open area at night

do the figure 8s.

Replace oil

done.

[mx52nv]

When you have a new LSD and new oil, it is recommended to do figure eights to work the oil in.

Without hearing and viewing your problem, it sounds like LSD chatter. This was the same for Ian when he too went to a Cusco LSD and it was a little too irritating for him.

We prepared Redling Shockproof gear oil and Redline Differential Friction Modifiers/Break-In Additive (to reduce LSD chatter and aid break-in of any new differential. Can be added to any gear oil to reduce temperature during break-in and prevent gear softening).

However, after the oil change to Redline Shockproof, the chatter was reduced sufficiently that he decided not to use the friction modifier. However, if you so choose, you can put it in at any time in the future if you like (a few millilitres).

I hope this helps but I should also mention the for mechanical LSDs (i.e. with plates like a clutch), I have only ever used Redline Shockproof when I still had the workshop.

I hope this helps.

Les @ MX5 Shop

[lmx5B]

Fortunately we live at the top of a quiet cul-de-sac with a turning area that is perfect for doing slow figure of eights, which I have been doing for the last half hour or so (to the amusement of neighbours who are at home). When on full lock, as soon as any power is applied, the inside wheel slips and screeches as if the diff is completely locked and the inside wheel is trying to rotate at the same speed as the outside wheel.

[Okibi]

I don't mind spending a few hours to do some circle work in your car for you.

Might make for some good video footage too.

[rascal]

When my mazdaspeed diff went in, it was very tight too, almost convinced me it was a locker..

I also did nearly 20 mins of figure 8s in a deserted street before getting dizzy and deciding I'd had enough. After this the diff was still just as stiff as before.

A few days later was the next trackday, and it got progressively smoother after each session.
After the track day I changed the oil again (Penrite Sin 80 (80w-140) and its been smooth and whisper quiet ever since..

[marcusus]

When I put mine in not long ago, Steve Lee from KYP suggested the figure 8 trick as well, along with 500km of driving on it, and then also an oil change after that.

I haven't had a chance to do the figure 8's (not really anywhere good/convenient for me to do it), but I've done the k's and got the oil changed. Although the inside wheel still chatters, the clunking has definitely gone way down since the oil change. I'm not fussed about the chatter because it tells me the diff is working, but having the clunking gone is good.

[hamx5ter]

When my mazdaspeed diff went in, it was very tight too, almost convinced me it was a locker..

I also did nearly 20 mins of figure 8s in a deserted street before getting dizzy and deciding I'd had enough. After this the diff was still just as stiff as before.

A few days later was the next trackday, and it got progressively smoother after each session.
After the track day I changed the oil again (Penrite Sin 80 (80w-140) and its been smooth and whisper quiet ever since..

I just put in the Cusco RS LSD and having a bit of strife with how it locks/unlocks on sweeping turns. It's only done about 200kms so I know it will settle down over time, but at the moment, the car is very twitchy and very sensitive to any change in throttle position. SO far at least, a royal pain on the street and semi-spirited driving.. I can see how good it is if you keep the pedal down.

Do you think it will be fine to put the LSD to work on a track day next week (it will have less than 500 clicks on it then)?

and the other thing I was wondering about the track-day, was how did you handle the locking/unlocking it does on part-throttle on the turns? I can see how much of a pain it might be on turns 2 and 10 for a start at wakie... and also the kink, where I always seem to hesitate with the throttle (will make my nose swing around with my LSD).

Maybe I'm over-analysing... just need to head out there and find out for myself...

[rascal]

Do you think it will be fine to put the LSD to work on a track day next week (it will have less than 500 clicks on it then)?

I wouldnt drive a brand new 0km lsd on the track, but you have done a couple of hundred kms which is plenty of initial run in and the track day will finish off the run in. Just make sure you change the oil after the track day and then you will be fine..

and the other thing I was wondering about the track-day, was how did you handle the locking/unlocking it does on part-throttle on the turns? I can see how much of a pain it might be on turns 2 and 10 for a start at wakie... and also the kink, where I always seem to hesitate with the throttle (will make my nose swing around with my LSD).

To be honest, you dont really notice it. Mine kicks in with the slightest bit of throttle, and at that point prob only has about 10kw underfoot so isnt going to wrench the car sideways...
And its not like it locks up with a bang.. It just gives much better drive out of corners where before the inside wheel would spin up and kill all your momentum.

[hamx5ter]

Yeah, i've taken it out a a couple of runs since then (still going easy) and learning to manage the judicious use of throttle.

The car seems to have loads and loads of grip now, and power on in the turns just makes it go go go.

Glad to know it should be fine for the track day. I'll change the oil right after.

Deen.

[lmx5B]

Thanks for all the assistance. Final solution has been lots of Figure 8's (see attachment) and changing oil to Red Line Gear Oil with Red Line LSD Friction Modifier/Break-In Additive. Now done about 400km plus an Autotest. Still have some low speed "parking lot" chattering which I am told I just have to get used to. Extra rear traction introduced more understeer during the Autotest so will try harder rear swaybar setting and adjusting tyre pressures for better balance.