Engine Under Panel removal

Once before I lifted the front end and took out the fasteners of the maintenance door, but today I thought I'd try removing the whole panel. Comparing to just removing the fasteners at the door, It took maybe an additional 10 minutes, say 5 minutes vs 15 minutes.

There's a row of 4 10mm (socket size) galvanized bolts at the front, which capture both the leading edge of the engine underpanel and the trailing edge of the plastic "spoiler" ahead of it. Then a couple more 10mm bolts back a bit, interspaced with 2 push-in fasteners.

There's about 4 push-in fasteners down each side, and about 3 at the back. 2 of the back ones have grey heads, and are the only disimilar push-in fasteners. Per someone's suggestion, I daubed their heads, and directly adjacent, with a dab of quick-dry white out.

When putting it back in, on each side near the wheel well there's pairs of fasteners, quite close together. One of the pair only goes through 2 layers of plastic, the other goes through a backing metal plate as well. Once both are pushed in it feels much more solid. With only the plastic/plastic fastener in it feels like something is wrong, too loose, but once the second fastener goes in it all tightens up, more stable.

Anyway, here's a few pics. I was also looking at transmission and engine oil drain/filter access. And I applied some hockey (friction) tape to both sides of the maintenance door, and a second seam I noticed, that runs the full width, further forward.

All the fasteners:



A full view of the panel, oriented as it would be on the car:



In the above picture, the second hinge point I mentioned is apparent: it runs through the "equator" of the large circular opening at centre front of the cover (the hole exposes the front jacking point). This looks to be a second bend point that could be used, if you undid all the rear fasteners but left the cover connected at the front end. Likely just as fragile, though.

Also, not that practical for a DIY'r using floor jack and safety stands: even if you can raise the car enough to swing down at that second hinge point, it blocks access if you're crawling under from the front of the vehicle.

Close up of the maintenance door:



Better view of the maintenance door hinge, on a bench (the underside):




And the inside (top side) of the same hinge area, with friction tape applied (cleaned the area first):



Another view of the underside of hinge, this time with tape applied:



The view to the right, when you crawl under, showing oil filter and drain bolt (14mm socket):



A close up of the same area, with (Honda) oil filter socket in place:



And view to the left, the transmission housing, with right side drive shaft going in. Just to left of drive shaft is the fill bolt, and down and slightly right is the drain bolt:



Close up of the tran. fill bolt with 10mm hex socket on it. A 6" extension on torque wrench is needed. Not quite so much for the drain bolt, but it doesn't hurt:



Torque wrench on the tran. drain bolt:

 

There might be some strong points on the sub-frame you can also use, but so far I've just used the usual: the points just fore and aft of rear and front wheel wells, on the rocker panel seams. They're shown in the Owners Manual: basically the same points where you would put the scissors jack, the one included for changing a flat.

If you look on that bottom of rocker panel seam there's a pair of notches: put the jack stand in between them. The usual disclaimers apply: apply parking brake and use wheel chocks on the rear wheels, give the raised vehicle a nudge or two to ensure it's stable.

Also a good idea when getting under: take something with you that's thicker than you, and sturdy, say a tool box.

 

Last weekend I replaced both the engine oil and filter, and the transaxle fluid. It was at 11 mo and 15022 km, which was 8000 km more than the last oil change service, so km's governed (it's still 8000 km per, in Canada). I know this is way ahead of Toyota's recommendation for transaxle fluid change (never?, nearly never??), but it cost me about $40, so...

Anticipating the transaxle drain might be messy, I took the engine bay undercover off completely. If you can manage it, this is really the way to go. It takes at most an extra 10 minutes, makes access much easier, and saves wear-and-tear on the infamous maintenance flap. It also affords you a much better view of CV joints and steering linkages, frame members and bolts, which are mentioned in the schedule (at least the Canadian one) as items to check.

There are about 10 plastic push-in fasteners (2 are different, worth marking), and 6 10mm hex head bolts. Whenever I have the plastic fasteners off I thoroughly rinse them off. I believe it's accumlating grit that leads to a lot of the breakage. I also lightly oil the bolts.

Anyway, raised the entire car about 10~11 inches, level, onto 6 ton safety stands. Removed the fill plug on the transaxle first, then the drain plug. For the engine oil drains I've been using a bottle and big funnel setup. Here it is under a previous vehicle:



But for transaxle I elected to use a big, galvanized sheet metail drain pan I have. Turned out to be a good idea. Maybe in part because I had the fill plug removed (next time I'll just break it loose, but leave it on for the drain) the fluid came out in a real rush, splashing a bit on a strut. Mostly it ended up in the pan.

For refill of the transaxle I used the funnel and tube method, worked like a charm. My wife poured, I kept an eye on it, watching for the start of overflow. Ended up overshooting a bit, let it drain well, to a slow drip, then buttoned everything up and dropped the car.

Since it was the first change, and because the repair manual stipulates: the next day, after a decent drive, I raised it up again, level, cover off, pan under, removed the fill plug only, to verify level was ok. It was basically the same, a slow drip.

So it looks like when you do the fill it doesn't change, with a bit of running time. Anyway, this time I made a point of checking the level with a finger, and made a point of splashing a bit out, and letting it sit till it completely quit dripping. Then buttoned up once again and dropped.

FYI, fill and drain plugs on the transaxle require a 10mm hex drive bit. And the torque is 29 ft/lb. It's recommended to change the washer (I didn't rechange on the second check). The fluid is Toyota ATF-WS, which set me back around $9 per liter. I got 4 liters, you'll need around 3.5.

 

It would seem like the faster the fluid whips out, the more completely it's going pull out sediment. All the Hondas we had over the years had a magnetic drain plug on the auto transmission, but not Toyota. Can't hurt I think. They would invariably have a good crop of sludgy filings.

This was the second oil change, and this time around I put in 4 liters, and said that's it. Actually that's all I had, anyways, so...

Anyway: I find when I check it after a change, and that's after running for a minute, to circulate into the fresh oil filter, it looks fairly low, close to mid-way between the marks. But give it a day, check it again, and it was less than 1/4" below the top mark (4 US quarts would a bit lower though, maybe still ok). And with our Prius at least: that level seems to bairly budge, between changes.

 

Just an update, I've started placing the front jackstands at the front end of the structural "rails" on the underbody. They're about a foot in from the rocker panel edges, about 1.5~2" wide. They curve down slightly at the front, slightly, which means when you've just got the front end raised they're not that far off horizontal.

They're a much broader contact surface, and a lot more confidence inspiring. The knife edge of the rocker panel does not feel good when used with jack stands, especially if raised fairly high: they feel like they're on the verge of kicking out.

Once I've got the front jackstands under those rail ends, if I raise the rear (which is needed for transmission fluid change), I do put the rear jackstands on the usual rear rocker panel support points. The back is lighter, and coming back to horizontal it feels more solid.