Leave it to me to f*ck something good up...
 

Man - craziness at Road Atlanta this weekend. So how many of you where hoping to see a mangled miata in flames? Sorry to dissappoint - so far!

1st off, the low mileage 6spd I bought and installed failed to shift into 5th - period. So that was a rough start - I'm at that point where I 'feel' I need to double/triple check everything now less anything bad happens - which it did.

So here I was cruising down the back straight at RA at about 120 when I heard a pop - saw no smoke. I got into the brake zone and suddenly smelled diff fluid so I stayed off line and pitted in, but nothing was feeling different with the car, all felt normal other than hearing the pop - which really wasn't any louder than picking up a large marble and slinging it into the well. So I pulled into paddock, parked and looked under the at the diff and sure enough, fluid seemed to be dripping out the left seal. So I yanked the diff and low and behold - holy sh!t - I just destroyed my OSG and 3.6 R&P!! F*CK!!!

https://www.miataturbo.net/attachmen...1&d=1331554598
https://www.miataturbo.net/attachmen...1&d=1331556030

The ASE mech I used to install the R&P and set the lash forgot to do something very important - seems he didn't torque or threadlock one of the bolts holding a lash retaining clip. I used this guy the 1st time when I put in the OSG with no problems, so didn't have any reason for not guessing his work this time.

https://www.miataturbo.net/attachmen...1&d=1331554598


Honestly, I dodged a hell of a bullet. The bolt did not mangle the R&P, in fact you couldn't see ANY damage to the R&P at all, nor on the OSG - so thankful for soft bolts. Of all the possibilies that could have happened - destroying a $2G diff and spinning out at 120 being the worst, I was the luckiest SOB at the track this weekend.

So, fix in effect - right across the paddock was a race shop, threw the shop guy $40 and he tigged up that hole in fine fashion. Threw the unit back together (after cleaning it well) and called Emilio for his expert advice on what fluid would work without effing up the clutch plates (since I didn't have that special OSG gear oil). Discovery Parts happened to have RedLine GL5 85-250 Shockproof gear oil - that pink looking stuff. Big thanks for the info Emilio!!

https://www.miataturbo.net/attachmen...1&d=1331554598
https://www.miataturbo.net/attachmen...1&d=1331555368


So this all happened on friday - ran saturday flawlessly, without 5th of course, which I really needed - that's like my 4th in a 5spd.

Then this poor soul had a date with the tirewall/concrete barrier out of T3...

https://www.miataturbo.net/attachmen...1&d=1331555591
https://www.miataturbo.net/attachmen...1&d=1331555591


And then the second to last run of the day I noticed drastic boost drop - and as I know of, I'm the 1st and only one to expeirence TSE Inconel stud failure...

https://www.miataturbo.net/attachmen...1&d=1331555732

The only thing I can think of is that the resbond did not hold the stud in, so 3, yes, 3 of the studs backed out through the locking fasteners. 2 of them are gone, somewhere on track, the 3rd was kept from falling out by the DP flange. So, I may yank the manifold off and send to Andrew for measurements and see if it was a failure of the resbond, mounting depth of the studs, or wall clearance between the stud and the threaded manifold - all? At this point, I need to get the 1.8 complete and beg/plead for my vband.

Damn, that sucks. Maybe it's time to use roll-pints in the manifold/stud.

I thought that same exact thing. I'm wondering if there was too much clearance between the stud and the M10 threaded manifold Abe made. They weren't tight to thread in... I coated the stud end with resbond and double nutted to tighten it in. But yeah, roll pins sounding like a good idea right now.

At what EGT temps will resbond deteriorate? Met a miata guy who's an engineer with BW, and he was really insterested in my EGTs - he thinking my effiecency flow map is way out of spec with the motor.

Wow Bryan, ---- was not good for you this weekend. Hope you get things worked out.

WOOO that's not lucky. Other than a partial lap on questionable backlash, everything looks fine? Do you know if the bearing adjusters spun at all?

What were your lap times compared to spec miata times?

Correct, 'playing' with the lash seemed to be very tight yet. Seems I caught it VERY early on, but will remove the diff for inspection and re-setting of lash. I did use threadlocker and re-set the retainers. It felt great saturday and sun morn without anything to cause me concern.

Lars - I was probably turning 1:41s but don't yet have a lap timer - even without having 5th gear. Other than that, still beat up on some vettes and mustangs - gt3s in the corners...

Lots of miss-shifting getting used to the trans

That which doesn't kill us . . . . Could've been a lot worse.

Somebody really needs to figure out how to use drilled, inconel bolts that can be safety wired instead of using studs that back out. Yes, I know there are clearance issues. Sigh.

Wow Bryan! thats absolutely nuts! Good job on dodging those nasty bullets this weekend. Were those inconel bolts not safety wired?

It was a resbonded stud with a nut.

I'm not interested in further debate on the merits of bolts vs. studs.

Bryan, were the studs loose in the threads before you torqued them into the manifold?

I want to say there was there was some play, which would be the cause - this is why I debated sending you the manifold for inspection. I do not think it was a failure of the studs or locking hardware themselves, i think the tolerance between the studs and manifold was too great for the resbond to hold. I'll be ordering another set - I might have to get Abe involved if the stud holes are to large.

Wow. Amazing your diff had no damage other than the puncture to the housing.

I'm impressed that you were able to do all of that work/repair at the track. Your 5th gear issue is the same thing that happened to me with my first six speed. I had to get it replaced.

What a rough day. Great test of endurance and patience.

I can't believe you came to RA and didn't call me. Would have come out for beers.
See if I bother calling you when in town for the Honda 250 in a few weeks to see if you want to meet up for food and drinks :(

I fail to see how any of this would be your screw up. More like s--- happens. Maybe the diff was the installer's fault, but you can't be expected to inspect every last detail.

Looks like the welder did a nice job of it, though.

Yeah, sh!t cetainly happened... but it could have been MUCH worse

Awwweee.... you butt hurt? Hehe :) Beers on me when you come on in :) we got the Mitty too...
btw, Melissa was canned from Jeffery's - dunno why but I miss seeing that ass of hers!

Backstory on the silver Miata?

The guy is from Huntsville and lost it in T3/T4 area - snap oversteer put him into the wall

Im assuming that was the place we ate at? I dont remember the name of the place.

What a trooper! A hole in the diff case would have had me putting it on the trailer.

But then again with that giant new trailer of yours you probably had most of your tools from home with you.

Everything but the tig welder! J/K - I left it at the shop - it's currently gutted awaiting some re-make fundage - Sav took it all. But yeah, this happened on friday, which meant one of the local race shops were open where I could find a competent welder to patch the hole... saved my ass!

The guy posted a video on m.net:
http://forum.miata.net/vb/showthread...96#post5657296

I feel worse for this guy than I do when some newb brings out daddys GT500 or vette and does the same thing... it's a very well built SM, but we all know the risks. ---- - screw the panels, what about the paint!

V-Band's FTW!

Thats a good thread.

Wow what a day. Looks like they did a decent job on the diff