Jump to content
SAU Community

Post Track Day Q's: Rotor Wear, Gearbox Oil, Ps Pump, Manifold Nuts


V28VX37
 Share

Recommended Posts

Gearbox oil, I would personally stay away from Redline shock proof, even the light weight stuff. I learnt the hard way and screwed up my synchros in my box. It happily grinds 3rd 4th 5th now.

Do you mean to say that Redline did not work in your gearbox, or are you saying it damaged your synchos?

Link to comment
Share on other sites

Damaged them, box was fine till I used redline

What did the damage look like? Normal wear? Plz post photos if you have them. I've been using it for ~8 years/75,000kms and about 30 track days and no problems so far.

  • Like 1
Link to comment
Share on other sites

Haven't pulled the box out yet, but pretty much was running VMX80 felt fine. Then decided "hey, I'm feeling a little rich let's get redline" so yeah did that and was good for about a year then it started grinding and harder to get into gears.

Flushed it all out, even had the car in 1st gear moving on idle on jack stands and sprayed degreaser to get all the crap out. Now running Nulon Smooth Shift, less grinding but I believe the damage has been done. I will wait till the box grenades and I'll take photos

Link to comment
Share on other sites

That's right nizmo, the clinginess of shockproof means it stays trapped between the syncro ring and the taper on the gear. The sticky, high film strength oil helps the worn syncro get the gear up to shaft speed for a smoother shift. jonilicite, it's hard to imagine shockproof causing good syncros to prematurely wear. Maybe fast shifting of a gearbox with very good syncros using shockproof could cause a problem, the tight syncro clearance would have to force out the sticky shockproof quickly causing possible mechanical stress to the ring.

Link to comment
Share on other sites

On the packaging of shockproof I recently purchased it does warn of a slight increase of wear on synchros. I guess most people who use it give no fu*#s as their gearboxes where already crunching. Ive only been using it for a couple of months, so I can't really comment on its long term effect. It has stopped a crunchy 4th gear but I believe it was only crunchy as some idiot mechanic only put 2.5 litres of oil in a rb25 box. Its shifting pretty slick ATM but time will tell in the long run.

Link to comment
Share on other sites

yeah redline themselves say don't use lightweight in a synchro box because it is too slippery. I think people generally use it in old boxes to mask synchro problems (I sure have, and it worked great), but if you have a new or rebuilt box I would definitely not use it.

Link to comment
Share on other sites

Haven't pulled the box out yet, but pretty much was running VMX80 felt fine. Then decided "hey, I'm feeling a little rich let's get redline" so yeah did that and was good for about a year then it started grinding and harder to get into gears.

Flushed it all out, even had the car in 1st gear moving on idle on jack stands and sprayed degreaser to get all the crap out. Now running Nulon Smooth Shift, less grinding but I believe the damage has been done. I will wait till the box grenades and I'll take photos

One of my mates who works at a gearbox/diff shop said specifically not to use degreaser to clean gearbox internals, and only to use brake cleaner. Apparently the degreaser is know for eating away the synchro whereas brake cleaner does not. So i would say you might have done more harm than good there.

Link to comment
Share on other sites

Whoa given the conversation above I think I'll just stick with my Shockproof Light. It seems to work and I don't like mixing oils & not keen to have to clean the box.

Also with the 'clinginess' I think there'd be a big difference between Light and Heavy. I also just learned that there's superlight too: http://www.redlineoil.com/Products.aspx?pcid=8

They also seem to warn about synchros with the Heavy variant only. I remember reading somewhere that that's the one to use with a crunchy/worn gearbox.

Link to comment
Share on other sites

  • 3 weeks later...

...

With the brakes, BrakesDirect reckon that wear is fine and to be expected since I didn't machine the rotors. I'll keep an eye on it for the next little while until the pads wear in a bit more. I hear what you're saying about cleaning under the rotors - I did all of that when I put the new DBA rotors in in late 2014 and they haven't been off the car since. Also since the disc wear looks the same on both sides I don't think it's an anomaly.

...

Ok so I just pulled the pads out to check them, not looking good (these are the RH pads, outer on the left):

25983317625_b6d42ebdd1.jpg

I measured each pad and found the following difference between the inner (centre of disc) and outer (rim of disc) thickness:

  • LH inner pad: 0.26mm
  • LH outer pad: 0.67mm
  • RH inner pad: 0.12mm
  • RH outer pad: 1.01mm !!

The RH outer pad is the worst by far but the LH outer one doesn't look that flash either :(

I'm keen to check against my previous set just to see if there's any similarities in the wear.

What could be the cause? Have a damaged the pistons during installation or something?

Also do you guys normally machine your rotors when changing pads? Could that be the cause?

Link to comment
Share on other sites

25983317625_b6d42ebdd1.jpg&&0){for(var>

I measured each pad and found the following difference between the inner (centre of disc) and outer (rim of disc) thickness:

  • LH inner pad: 0.26mm
  • LH outer pad: 0.67mm
  • RH inner pad: 0.12mm
  • RH outer pad: 1.01mm !!

...

Just measured my old pads, here's the difference in pad material thickness:

  • Side 1 inner pad 0.33 mm
  • Side 1 outer pad 1.05 mm
  • Side 2 inner pad 0.46 mm
  • Side 2 outer pad 1.1 mm

So the good news is that I don't think it's my installation, however the bad news is that the car is chewing the outer pads pretty badly.

I'm pretty sure it's the half shims, the anti-squeal ones:

25169920520_1e3752faa7.jpg

I think I could either ditch all half shims, or just the outer ones – what do you guys think?

I think I'm up for another new set of pads too + possibly machining the rotors :/

Link to comment
Share on other sites

very unlikely to be shim related, most likely you have seized pistons in both calipers, or potentially a wheel bearing issue (although less likely to happen on both sides).

Bummer. All pistons did move back fully when compressed during pad change but I'm not sure if that proves anything.

Is there any way to check for seized pistons? What's the remedy, a caliper rebuild?

Probably little point in rebuilding stock calipers unless it's very cheap (unlikely).

Link to comment
Share on other sites

Any suggestions on how to check for seized brake pistons?

Also is there anything else to check for wheel bearings except for the classic 12 o'clock + 6 o'clock shake?

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share




×
×
  • Create New...