Timing marks for 2004 GX470 non-VVTi (1 Viewer)

[gx470itp]

I've read lots of info about setting up timing marks for VVTi to do a belt replacement but haven't had any luck finding info from people who had success with non-VVTi timing belt replacements. I have the Lexus service manual and Aisin instructions but I need to hear definitive tips from someone who had success, how they set up their timing marks for belt removal, and whether they had the cams jump.

It seems that real-world advice might vary greatly from FSM/Aisin instructions.

Thank you in advance for any advice and thoughts!

 

[Stonefoot72]

My experience...invest time in getting the crank positioned right before removal. The variable cams WILL jump (at least they did on me), but the Asin kit belt has the cam alignment marks as well as the crank tooth mark. There's a tool you can use to turn the cams against the valve spring tension, but I just wedged a #2 flat tip between the one of the bolts and the VVT housing. It is easier with an extra set of hands, but can be done alone with some aptitude and patience. Triple check your marks AFTER you pull the tensioner pin...

My .02...cheers!

 

[Rednexus]

I did this recently on a friend's 2002 4.7 Tundra. The Aisin directions are indeed a bit different than the various YouTube videos and other online advice. We just followed the Aisin directions and it went fine. As mentioned above, the driver's cam can slip really easy so make sure to check everything multiple times before putting it back together.

 

[FrankTorres]

Follow the FSM, I believe it calls for 50*atdc, in that position the cams are at their flat spot and do not rotate easily.

Good luck

 

[jiggletits]

I’ve done 4 belt jobs on 2UZs.

It is the same on both VVTi and non motors. Pretty simple.

Cams might move a hair, it isn’t the end of the world. Just move them back. Marks are on the belt. Don’t overthink it.

These are non-interference motors unless they are in VVT power range which is irrelevant if the motor isn’t running.

More importantly, check all you pulleys for any sings of play or resistance while you have it apart. Replace as necessary.

I used to be a ‘don’t replace the alternator until it breaks’ guy but then i had to replace one. It is a foul whore. If you don’t know alternator history, just replace it. Denso only. WAY easier while doing the t belt.

 

[gx470itp]

Thanks all for the feedback. I thought it could do damage if the cams moved, but perhaps this is pretty common in belt removal. This, and the T-marks vs I-marks, and 50* BTDC vs ATDC vs TDC etc for belt removal have been my biggest hangup in progress as there is so much conflicting info out there.

I was planning on replacing the alternator and when I looked at parts, most everything was re-manufactured so I shelved that idea. Maybe I'll just buy a remanufactured alternator since parts in general might be scarce for a while. Also replacing most everything else that is difficult to get to since I've got 190k miles on it, water pump, pulleys, tensioners, fan brucket, fan clutch, water pump, cam and crank seals (front), thermostat, radiator, hoses...

This forum is invaluable for the amount of info from people who've done this job.

 

[jiggletits]

I think re-man is all that is available. These trucks are old at this point.

I cannot stress this enough; DO NOT REPLACE YOUR CAM/CRANK SEALS. That is a horror story waiting to happen if you do not get the cams back in right, also THEY NEVER LEAK IT'S A WASTE OF TIME. Plenty of things need replaced on these engines, those are not typically one of them. They do leak on the 5.7, never on the 4.7.

Cam cover seal? Sure, those leak. Those are easy. Do spark plugs while you are at it. If you have the ticking sound (very tiny exhaust leak on manifold) use the Doug Thorley short tube kit. The OE replacements even new from Lexus still have the same issue as the old ones. Tiny cracks and a small leak that makes it sound like a crappy old Ford v8. Without those leaks, the 4.7 is QUIET. So quiet it's almost absurd. You should hardly hear anything.

 

[Rednexus]

The Aisin instructions are accurate and will get you through the belt job. The FSM should work too, but only if you have a copy printed out .

There is nothing wrong with remanufactured parts. A Denso reman alternator should be just as good as a new one. Name brand reman parts are better than no-name new parts IMO. Most of the part will still be OEM Toyota, with the wear items replaced.

 

[gx470itp]

For model/year, FSM/Aisin instructions said to set crank at 50* before TDC. Instead, I set up the cam marks to the T's, crank to the dowel on the timing cover/4square marking on the oil pump. Cams did not jump. Hope this helps someone else.

 

[5280 Lexus]

When I did the timing belt on my 2003 I followed the FSM which I believe was 50° BTDC. My cams did end up jumping a bit, but I was able to reposition them after and verify that everything lined up correctly.

I don’t believe any damage occurred. I’ve done 5000 miles now and no issues. My understanding from the FSM is setting them like that minimizes risk of damage but I’m not sure it’s necessary

 

[Rednexus]

I think that as long as consistent instructions from an authoritative/official source are followed, whether FSM or Aisin, it should be fine. Where it could be problematic is "mixing and matching" different sets of instructions and/or Youtube/forum posts.

2UZ's are non-interference unless VVTI is activated, per the above posts. So there is very little chance of damaging anything if the cams slip and is moved back.

 

[Bigtime]

I think re-man is all that is available. These trucks are old at this point.

I cannot stress this enough; DO NOT REPLACE YOUR CAM/CRANK SEALS. That is a horror story waiting to happen if you do not get the cams back in right, also THEY NEVER LEAK IT'S A WASTE OF TIME. Plenty of things need replaced on these engines, those are not typically one of them. They do leak on the 5.7, never on the 4.7.

Cam cover seal? Sure, those leak. Those are easy. Do spark plugs while you are at it. If you have the ticking sound (very tiny exhaust leak on manifold) use the Doug Thorley short tube kit. The OE replacements even new from Lexus still have the same issue as the old ones. Tiny cracks and a small leak that makes it sound like a crappy old Ford v8. Without those leaks, the 4.7 is QUIET. So quiet it's almost absurd. You should hardly hear anything.

Yeah, I've heard several people say cam seals never leak. I guess I must have been the unlucky one because mine were no doubt leaking. BUT I would not consider it a DIY if you are hesitant with a standard timing belt job. The VVTI 2UZ requires removal of the cam shaft AND cam disassembly. The non VVTI is more a conventional procedure that is fairly simple. No way was I going through all that trouble of the timing belt to not do the leaking cam seal though.

 

[jiggletits]

Leaking and seeping are two different things. They will seep for 500k miles and never be an issue. If they are leaking, like really leaking then someone probably messed with them, replacing them for no reason and caused problems that weren't there in the first place.

 

[Rednexus]

If you have leaking/seeping seals, try a bottle of this stuff before you replace the seal:
Amazon product ASIN B000NVW1LM
Seriously, it's not a snake oil. My rear main had started leaking/seeping, which is pretty common on the 2UZ. I used on bottle of this stuff and it dried up completely. Rubber/viton seals lose some of their plasticity with age and start to leak, this stuff is a polymer conditions them and makes them more flexible (and therefore seal better). $20 is worth a shot compared to pulling the cams.

 

[gx470itp]

Yeah, I've heard several people say cam seals never leak. I guess I must have been the unlucky one because mine were no doubt leaking. BUT I would not consider it a DIY if you are hesitant with a standard timing belt job. The VVTI 2UZ requires removal of the cam shaft AND cam disassembly. The non VVTI is more a conventional procedure that is fairly simple. No way was I going through all that trouble of the timing belt to not do the leaking cam seal though.

I'm curious how many miles were on your gx when this was noticed?

 

[gx470itp]

If you have leaking/seeping seals, try a bottle of this stuff before you replace the seal:
Amazon product ASIN B000NVW1LM
Seriously, it's not a snake oil. My rear main had started leaking/seeping, which is pretty common on the 2UZ. I used on bottle of this stuff and it dried up completely. Rubber/viton seals lose some of their plasticity with age and start to leak, this stuff is a polymer conditions them and makes them more flexible (and therefore seal better). $20 is worth a shot compared to pulling the cams.

Yeah, I've heard several people say cam seals never leak. I guess I must have been the unlucky one because mine were no doubt leaking. BUT I would not consider it a DIY if you are hesitant with a standard timing belt job. The VVTI 2UZ requires removal of the cam shaft AND cam disassembly. The non VVTI is more a conventional procedure that is fairly simple. No way was I going through all that trouble of the timing belt to not do the leaking cam seal though.

How many miles on your gx when you noticed the leak?