Club Lexus

T0ked · 08-14-05, 04:22 PM

Since I decided to do this and I haven't seen a write up on it here, I thought I'd give it a shot. This is a fairly quick project anyone can do on their own taking about 45 minutes IF you don't drop a screw and take 3+ hours trying to find it. I wound up taking off the underbody panels and searching for that thing. Eventually found it sitting on the front sway bar mount. How it bounced in there, I will never know. Anyway, here goes.

I wanted to give myself some room so I removed the intake piping, MAF and airbox. I was going to mod the airbox anyway, but it is not necessary. Unplug all the plug wires and the wiring harness. No real need to keep track of wires since they are all marked on the wire and the cap. You just need to know that plug 1 is at the top. Then undo the 3 screws and remove the cap. Leave the rotor on. Change it after you have everything back together.

You'll need to mark the position of both the main bolt and the rotor as this will be paramount in keeping your timing.

Once removed, you can see the oil thats been leaking through the seal.

The original seal was done after 95k miles of heat. It had shrunk and become brittle. It ripped as I was trying to remove it.

You can see the nice plump new O-ring.

When putting everything back, just go in reverse order. Since the disrtibutor has a helical gear, when reinserting the body, the rotor will turn clockwise. To get the rotor to realign, insert it turned slightly counterclockwise. Tighten the bolt back on and hopefully everything will mate up. While youre at it, replace the rotor and cap now. There was a quick writeup on that, but it is very simple which entails just removing a couple of screws and replacing the parts. The rotor can only be reinstalled 2 ways, the original position and 180 degrees. So unless you impulsively took off the rotor without noting its original position, it is almost fool-proof. And like I said, make sure plug 1 is positioned at the top of the cap.

This is a fairly quick and easy maintenance procedure anyone with an SC near 100k miles should do. And try not to drop any screws.

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Din · 08-15-05, 06:50 PM

great im gonna do this when i do my valve cover gaskets. I need to find a write up for that. How much was teh oring? did u get it from lexus or can you get it from local autoparts store?

got_trd · 08-15-05, 07:02 PM

hmmm...... for some reason it took someone I know more than 45 mins to do this....

T0ked · 08-16-05, 01:32 AM

The O-ring is a $3 part most dealers carry. I just stopped my mine on the way home from work. I'm also going to do the valve cover gaskets in a week or so along with the exhaust manifold gasket. I'll put up a write up of that too.

Din · 08-16-05, 09:06 AM

cool ill be waiting for the write up on the valve cover gasket.

dejacky · 01-31-06, 01:25 PM

Thank you for this write up. I'm about to try it, but am afraid of skewing timing. How many of you had success replacing the distributor o'ring with this method without messing up the timing at all when everything was reassembled?

deruvian · 01-31-06, 11:17 PM

Quote:

Originally Posted by dejacky

Thank you for this write up. I'm about to try it, but am afraid of skewing timing. How many of you had success replacing the distributor o'ring with this method without messing up the timing at all when everything was reassembled?

I didn't use this exact method when changing the dizzy O-ring, but definitely used one similar. As far as I'm concerned, there are only two things you need to watch out for:
- The placement of the dizzy bracket/housing, and
- The rotation of the helical gears.

Before you touch anything, make a little mark, as shown in the first picture, next to the one-and-only bracket/housing bolt. That thing rotates (obviously), and, given that your timing was correct in the first place, you want to reinstall it just like it was before to keep the timing the correct.

I don't recall needing to worry about the rotor, since it can really only go on in one particular way.

Secondly, when you remove the housing, mark the helical gear that drives the dizzy. Don't rotate it at all, after removing it, until you've marked the gear... However, the important part is that, as you're removing it, be sure to watch the rotation of the rotor. Since the gear is helical, it will rotate upon removal. Before reinstallation, rotate the gear slightly past your marking, in the opposite direction in which it spun during removal.

I wish I could remember the direction to spin it, but I can't (and I don't want to guess).

Sounds funky in explanation, but it's hella easy in practice. You'll see, and you'll be fine... The car won't start unless you install it w/ the appropriate timing advance, and since you marked the bracket all you have to do is pull out the dizzy and rotate the gear just a bit to fix the problem.

T0ked · 02-01-06, 07:01 AM

The direction of the rotation of the cap while removing and replacing the distributor is mentioned in the last paragraph of my writeup. It's pretty straight forward. As you pull out the whole unit, the rotor will twist due to the gears. Just note where the rotor was in the first place. When reinserting the distributor, compensate for this twist by turning it the other way. Unless you jacked up the gearing, the rotor should return to its last position. This is very important you don't remove the rotor until you've replaced the 0-ring. GL. I whipped up this drawing. Hope it explains it a bit more. Also shows why its important to leave the rotor on until you finish this job.

dejacky · 02-01-06, 08:33 AM

Quote:

Originally Posted by T0ked

The direction of the rotation of the cap while removing and replacing the distributor is mentioned in the last paragraph of my writeup. It's pretty straight forward. As you pull out the whole unit, the rotor will twist due to the gears. Just note where the rotor was in the first place. When reinserting the distributor, compensate for this twist by turning it the other way. Unless you jacked up the gearing, the rotor should return to its last position. This is very important you don't remove the rotor until you've replaced the 0-ring. GL. I whipped up this drawing. Hope it explains it a bit more. Also shows why its important to leave the rotor on until you finish this job.

That helps TREMENDOUSLY. Thanks!

Since I already replaced the rotor and distributor cap, I'm just going to replace the o'ring and leave those parts untouched

.

rscott · 02-01-06, 11:08 AM

ive been meaning to get around to doing this for about a year and a half. The o-ring is sitting on my desk =)

nice write up.

Project300 · 02-01-06, 11:41 AM

Thanks for the write-up T0ked.

Your 2nd photo is a good shot of the absolutely crucial steps of this procedure. You must mark very clearly where the distributor mounts and where the distributor shaft (or rotor) are.

I used a similar procedure when I did mine. Before I loosened the single mounting bolt, I marked the position of the bolt by scratching the aluminum with a knife outlining it. This bolt is to the left in the 2nd picture. It will likely be really oily, so only scratching the outline will mark it well enough.

To mark the postion of the distributor shaft I took off the rotor and used a white pen (really usesful in the toobox) to mark where one of the teeth in the toothed "gear" met with the base. I put a mark on a tooth and a mark on the base next to it. You can see this "gear" in the 2nd photo too. This gave me a small and exact mark of the position of the shaft and rotor.

When I reassembled everything it took me a few tries before the rotor lined up due to the helical gears, but it wasn't difficult. Just be sure to mark everything precisely before taking it off.

No more oily engine!

Project300 · 02-01-06, 11:56 AM

Quote:

Originally Posted by deruvian

Secondly, when you remove the housing, mark the helical gear that drives the dizzy. Don't rotate it at all, after removing it, until you've marked the gear... However, the important part is that, as you're removing it, be sure to watch the rotation of the rotor. Since the gear is helical, it will rotate upon removal. Before reinstallation, rotate the gear slightly past your marking, in the opposite direction in which it spun during removal.

Holy crap! DO NOT use this procedure! No offense, deruvian.

If you remove the distributor before marking the postion of the shaft (or rotor) you will very likely throw your timing off and have a hard time finding it again. Just mark the positon of the rotor BEFORE removing the distributor. Dont mark the helical gear, mark the shaft, or rotor in relation to the housing. Then make sure your marks line up in the same postition when everything is reassembled.

deruvian · 02-05-06, 11:08 PM

Quote:

Originally Posted by Project300

Holy crap! DO NOT use this procedure! No offense, deruvian.

If you remove the distributor before marking the postion of the shaft (or rotor) you will very likely throw your timing off and have a hard time finding it again. Just mark the positon of the rotor BEFORE removing the distributor. Dont mark the helical gear, mark the shaft, or rotor in relation to the housing. Then make sure your marks line up in the same postition when everything is reassembled.

That's alright mate. To each his own... This worked fantastically for me.

97-SC300 · 07-19-06, 08:39 PM

do you have to first set the number one cylinder to TDC compression?

T0ked · 07-19-06, 09:11 PM

Nope. Just follow the instructions above.