gm52594

Hello all,

I have a 1998 LS400 with the 1UZ. I am currently replacing the timing belt, water pump, and all seals. I've read the VVTI pulley O-ring leak is becoming somewhat common so I decided to disassemble and rebuild those with new O-rings while I have everything apart.

Upon disassembly I noticed Lexus used a quad ring instead of an O-ring for this application. I bought two O-rings from eBay that stated they were for 1UZ, 1JZ, 2JZ etc. VVTI cam pulleys. They appear to be number 041 - 3" x 3 1/8" x 1/16" Viton O-rings. They are noticeably smaller than the groove for the quad ring. They take up about half of the groove, maybe a bit more. They DO stand proud from the groove so there is some O-ring contact before the two halves are bolted together but it doesn't feel like a lot to me. Maybe 1/32" of "crush" on the O-ring but this is just a guess.

This size O-ring was mentioned in another post on here that was a write-up of the rebuild. It was a very old post and there was no follow up as to whether it was leaking or ok after some time. Also, in one other post a user claimed that he used this size O-ring and he had a slow seeping leak from the pulleys afterward.

Does anyone have any more information or have done this themselves? I was thinking a number 151 O-ring would be better since it is another 1/32" thicker of an O-ring. Any help on this would be appreciated.

Thanks,
Greg.

gm52594

I'm not talking about the camshaft seals. I'm talking about the O-ring in the VVTI timing tube. Here is the new (too small) O-ring on mine. Thanks.

bradland

I completely forgot there's an O-ring inside the assembly and when I watched the vid provided in the ebay listing I remembered why. You are a brave soul taking it apart! Obviously it's been done successfully so I tip my hat to you.

In the vid at 8:50 he talks about stretching the O-ring as it will not fit properly unless you do.
Also I think the original started as an O-ring but became compressed into a quad shape over time...?

Hopefully this helps and good luck !

dicer

Get the correct one from Lexus.

gm52594

I'm glad I took the old ones apart since the quad rings were toast. They weren't leaking *yet* but the right side came out in pieces and it was hard as a rock. The originals were definitely quad rings since the groove is square.

After measuring all the dimensions on my VVTI pulley with a caliper, it seems the O-ring supplied by a few different sources for this repair is wrong. For one, you shouldn't have to manipulate and stretch it into the groove. Also, the groove is .056" deep and O-ring supplied has a cross section of .070". Having .014" of crush is not even 1/64" of material standing proud. One previous poster on an old thread commented his leaked after using this O-ring (3" x 3 1/8" x 1/16") and I can see why. There is barely any clamping force on the O-ring and it isn't held tight by the groove at all. If it were forced to the OD of the groove by oil pressure when running, it would stretch even more and become thinner, thus reducing the cross section even more....

The factory groove dimensions are 3.017" x 3.268" x .056". The 3" x 3 1/8" x 1/16" O-ring is a size 041. The nominal size of a 041 O-ring is actually 2.989" x 3.129" x .070". So the OD of this O-ring roughly comes to the middle of the groove. But a 042 O-ring is much too big for the groove. So on to metric....

The best fit I could find is going to be a M2.5x77 O-ring. The dimensions for that are 3.031" x 3.228" x .098". It will fit in the groove without needing to either stretch it or compress it without much excess space on either side. Also with a cross section of .098" there will be about 3/64" or right at 1mm standing proud for more O-ring compression. I hope this information helps someone in the future but I wouldn't use the 3" x 3 1/8" x 1/16" that some people sell for this.

You can't get the part from Lexus because the VVTI pulley is supposed to be non-serviceable.

YODAONE

Purchase replacement Viton o-rings for VVti assembly from Jeff Tsai.

They worked well...

Be sure you matchmark your VVti cover to its base, otherwise serious problems...DO NOT use a Sharpie but make three cut (I used Dremel tool) marks on the companion halves before dissembling...the factory uses a laser for indexxing.

Also, understand how to insert (and remove) service bolt into scissors gear assembly to properly hold preload of spring washer before dissembling...otherwise you will have cam gear lash noise on reassembly.

Jeff does not discuss this in his video and was unfamiliar with this element of our 1UZ-FE and 3UZ-FE engines cam phasers.

This little oversite required that I disassemble the timing belt assembly and temove intake camshaft 3 times to sort this out.

I set the engine for TDC...but first removed valve covers and locked the cams in place with crescent wrenches to prevent movement of cams from scissor gears tension washer...

Stressful job because you can damage engine if not careful and valves hit pistons.



McMaster-Carr o-rings size code selection chart.



McMaster-Carr o-ring materials properties by temperature range..this is not complete in that it does not discuss compression set, abrasion resistance and elongation...other properies to consder....but Viton is correct material..but with lower temperature variant...

The question to ask Jeff is which Viton o-ring compound he is using...lower temperature range..

YODAONE

Are quad rings the same as x-profile o-rings or akin to square-profile o-rings??

gm52594

The factory quad rings are square profile, not X-rings. The problem with trying to source a new quad ring is that they all seem to come in English O-ring sizes; 001, 002, 003, etc. I have not found any quad or X-ring seals in metric sizing. So that means I would have the same issue of a ring that needs to stretch to fit in to the groove and won't take up the groove space anyway. The best fit at this point seems to be either a M2.0x77 or M2.5x77 O-ring. This will give me a seal that will fit in the groove without having to manipulate it while giving more O-ring squeeze.

As far as the O-rings from Jeff, I believe they are the same 3" x 3 1/8" x 1/16" (041) that were supplied to me. I believe they are too thin, they take up only 50% of the groove space, and you need to stretch them to fit initially. Another poster used these and claimed they leaked for him. Not that you could see it externally, but he pulled the cam covers off after running it for a while and there were oil deposits slung from the pulley. So there may be a lot of people that have used these and have a slow seeping leak and don't even know it because you wouldn't notice it externally.

YODAONE

So, o-rings can stretch somewhat...certain materials endure elongatation better than others...

Now we have Square O-rings...

Part number and recommend source Stateside?

Any disagreement Viton is correct material.?

If anyone has a piece of old o-ring, then easy enough to have a rubber manufacturer perform material test.

There are different grades of Viton..the lower
temperature range is an issue and as you go lower, other desireable properties are (sightly) co 16mm promised...

I have an extra VVti cam phaser so if you can provide P.N. and source information.

BiGEZ

iTrader: (24)

I too need to replace my VVTi cam gears O Rings due to them slinging oil. I talked to Jeff about getting them rebuilt, and still have to get them off and sent in for service. Now seeing this not sure if the O Rings he has will work, time for more research.
OP or anyone with info please share.

YODAONE

Anyone have a 1" or larger piece of o-ring that has a profile relatively intact willing to package and send to me or manufacturer for profile identification and material test...

Also..I have a VVti assembly and know someone who can produce the correct size o-rings.

BiGEZ

iTrader: (24)

I have a spare VVTI gear in my storage unit I will take it a part to see what the condition of the O Rings is in.

gm52594

As far as the O-ring sizing goes, I do not know if Jeff has a different size for the 1UZ vs 1JZ/2JZ. I was under the impression that people were selling the same size O-ring for all these VVTI applications. That was the issue with the one I was supplied through eBay - the listing stated that it was for all 1UZ, 3UZ, 1JZ, 2JZ engines, but it was clearly inadequate.

I would NOT use the number 041 (3" x 3 1/8" x 1/16") O-ring. If you look at the pictures you can see it only fills half the groove. It also doesn't have much squeeze on the O-ring with a .070" cross section in a .056" deep groove. Even if it didn't leak heavily, I would be worried that it was seeping inside the cam covers without me knowing it like a previous person experienced. I should be receiving a size 151 and M2x77 O-ring today so I will see how either of these fit tonight or tomorrow.

I believe Viton would be the correct or acceptable material. It is oil/chemical resistant and has a wide temperature range. I wouldn't use a standard nitrile rubber O-ring.

BiGEZ

iTrader: (24)

I finally got around to taking the cam gear apart, however the O Ring is as brittle as a chip and I cannot get it out in big enough pieces. As such I cannot get you good sample of the O Ring.
So hopefully someone can locate the correct material and size O Ring needed.
What I found out though is as long as you mark the 2 halves and align them correctly upon reassembly the O Ring is easy to replace, no need to take the actual VVTI internal gears.
I have to get these O Rings replaced soon to fix the leaks on my car.

gm52594