A cautionary tale for DIYer's

[WNDSRFR]

So
After 180,000 miles, I figured, maybe it's time to change the transmission and diff oil. So I ordered a hundred bucks worth of Motul Gear 300 from Amazon. Got it the next day. This is going to be a quick easy job, I figured. I'll do the transmission first.
So I drove the front end onto ramps on my angled driveway just like I do to change the oil. The angle of the driveway vs. the angle of the ramps causes the car to be almost perfectly level. ALMOST level but not quite.
So first I remove the fiber undercover to get access to the transmission. Then remove the fill plug, then the drain plug and drain the oil. Replace the drain plug, fill the transmission with oil, replace the fill plug. Easy.
It's supposed to take 2.2 liters of oil but it took about 2.5 liters. No big deal I think.
So I go for a test drive. 1st, 2nd, 3rd, 4th gear everything is fine. I get to 5th gear and it starts making a horrible noise. Oh No. I slow down and the noise goes away. Let's try it again. Same thing. 5th gear horrible noise. Slow down and it goes away. SHIT!!! It's getting late I'll invesitigate tomorrow.
So this morning I put the car up on ramps again. This time insuring it's level. I remove the fill plug and oil starts draining out. Quite a bit actually. I replace the fill plug and go for a test drive. Same thing as before. 5th gear, horrible noise.
So I go back home, back on the ramps, remove the fill plug and more oil drains out. Must be because it heated up. Now it's got to be good.
So I go for a test drive, Same thing!! 5th gear horrible noise. I shift into neutral, still makes noise until I slow down to 45 mph. Try it again. this time I'll just stay in 4th and get up to 55 mph. Same thing. The noise is related to speed not what gear I'm in. The noise occurs at 55 mph regardless of what gear I'm in or even in neutral. I think I know what the problem is.
Oh, did I forget to mention? This whole time the fiber undercover has been off.
So I replace the undercover, go for a test drive and the noise is gone.
The noise was caused by another undercover vibrating at 55 mph.

I think I'll wait until tomorrow to do the differential. And have a beer instead.

[Darkrune]

I have had this sort of thing happen to me on other cars. "Oh crap, a noise!!" Oh its just this piece of plastic I was too lazy to secure. Lessons learned.

[SuperTom]

good lesson glad it wasn't something serious. My boss is lady with a Mercedes. She comes into work freaking out her motor is making some crazy noise coming down the highway. Naturally she comes to me because I know cars. Found some piece of plastic undercarriage loose and rattling. Too easy to save the day.

[malubawla]

it may be the undercover on the driver side for the hard brake lines flapping around

[BFIFE22]

I am thinking about changing my trans and diff fluid soon so the first half of this post scared the shit out of me

Glad to hear it was all good in the end

[DarkSunrise]

I've had that same flapping noise at speed when driving without the underbody panels. As stated, just needed to put in a bolt on the driver side to secure the loose panel near the brake lines.

[Teseo]

Damn, 180k miles. Any problems at all?

[humfrz]

Originally Posted by WNDSRFR

So
After 180,000 miles, I figured, maybe it's time to change the transmission and diff oil............... I think I'll wait until tomorrow to do the differential...... And have a beer instead.

Why so soon ......??

No hurry .....

So, I see you're following ol @Tcoat s transmission and differential oil change schedule. ........


humfrz

[radroach]

> After 180,000 miles, I figured, maybe it's time to change the transmission and diff oil.

[why?]

isn't the diff and transmission fluid suppose to be changed every other year?

[humfrz]

Originally Posted by why?

isn't the diff and transmission fluid suppose to be changed every other year?

The manual for my MT, 2013 FR-S (which only goes up to 90,000 miles or 90 months) says it only has to be "inspected" ....... about yours.

Personally, unless my pinky finger comes out of the filler hole, covered with a baby puke, frothy, look and smell ...... I figure I'm good till the next inspection.




humfrz

[redlined600]

Funny, this happened to me as well(different circumstances). There is another cover/flap that the air forces down at a certain speed. Look at where in shares a clip or bolt with the fiber cover and I bet money you'll see scrape marks on the leading edge.

[allowe]

Has it made any difference in shifting? I'm about to change my tranny and diff fluids


Sent from my iPhone using Tapatalk

[strat61caster]

DIY mistake storytime?

I decided my Nissan pickup truck has a bad timing chain, it was rattling (KA24 life for those ex-Nissan owners out there) so I tear it all apart, a week later it goes back together and I go to test drive it and... fuck, there's no power. Did I screw up the distributor/oil pump alignment? Shit fuck damn. A year goes by, I intermittently try to fix it, I uninstall and reinstall that damn oil pump at least half a dozen times, I've probably had that thing on a timing light for at least half an hour futzing with the distributor cap.

On a whim we check the intake, filter, etc. Upon re-assembly I realize I never plugged in the vacuum hose to the intake. Good as new by sliding a little rubber hose back into place.



So far my only screwup on the 86 is not torquing the toe arm eccentric bolts enough, I am a wimpy boy so 'tight enough' isn't something I can manage on those suckers. Let's just say dynamic toe is something best left to the manufacturers and not the shadetree mechanics.

Because stories of other people screwing up makes us all feel better right? Good on you OP for figuring it out and having almost zero repercussions other than a few gray hairs.

Originally Posted by DarkSunrise

I've had that same flapping noise at speed when driving without the underbody panels. As stated, just needed to put in a bolt on the driver side to secure the loose panel near the brake lines.

Hmm maybe this phantom noise I'm hearing is this... I'll have to keep an eye out next week.