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The Aisin kit has identical parts to what you get at the dealer except the timing belt. If you want the Toyota belt you have to get it from Toyota but I don't see the point Mitsuboshi belts are great.
I was talking with a lexus dealer earlier and he said they source their parts from a variety of manufacturers. Aisin being one. Looking at the pics above, where can I get ahold of one of the green printed Toyota belts? I dont want to order one from a dealer and it turn out to be a Aisin one I could have gotten a lot cheaper online.
Not sure what year you own but the belt changed when VVTi was introduced. Either way, it's a very common belt easily sourced from any Toyota dealer as most full-size Toyota trucks use the same belt. Get the correct part number for your year model, find a Toyota dealer who has one in stock, and look inside the box. Aisin does provide parts to Toy/Lexus but timing belts will typically be made by Mitsuboshi.
I wish I seen this thread a year ago.
Last year I bought an Asin timing belt & water pump kit from a trusted ebay seller.
Came with the idler pulley and tensioner all "oem" for my 2004 RX330.
Dealing with a misfire a couple months later due to something else not related to the timing belt I did a crankshaft vs cam sensor waveform on my oscilloscope and noticed my cam timing was a few degress off on one bank and this bothered me. 1 cam gear tooth off on my car is 15 degrees cam error so at 4-5 degrees cam error this implies something else- never thought about the "oem belt".
Taking the timing bet cover off I noticed the white timing mark lines on the new belt were already gone- I was not happy or impressed.
I carefully measured and compared the new idler pulley diameter to the old one and it was perfect match so this wasn't it.
Next I went ahead and ordered 2 new cam gears thinking I had some minor wear that could throw off the cam timing a couple degrees and there was no change.
I never had any codes or timing problems as I suspect the engine ECM can adjust for minor differences in cam error but now I am wondering if the "oem" belt I bought was off by a couple of cam timing degrees with the intention for future possible stretching built into the design that had me pulling my hair out.
Wild- now I need to do another crank vs cam scoping to see how my cams line up since it's been a few thousand miles since and see if any streching changed the crank vs cam relationship after reading ya'lls posts above.
Link is here if anyone wants to see: https://www.clublexus.com/forums/rx-...e-ckp-cmp.html
New "oem" timing belt with white lines pic below showing error of 5 degrees but bank 2 was on the money- this is for 3.3L 3MZFE engine but ya'll get the idea and now I want to order the Timing belt with Green letters just to see if improvement.
I wish I seen this thread a year ago.
Last year I bought an Asin timing belt & water pump kit from a trusted ebay seller.
Came with the idler pulley and tensioner all "oem" for my 2004 RX330.
Dealing with a misfire a couple months later due to something else not related to the timing belt I did a crankshaft vs cam sensor waveform on my oscilloscope and noticed my cam timing was a few degress off on one bank and this bothered me. 1 cam gear tooth off on my car is 15 degrees cam error so at 4-5 degrees cam error this implies something else- never thought about the "oem belt".
Taking the timing bet cover off I noticed the white timing mark lines on the new belt were already gone- I was not happy or impressed.
I carefully measured and compared the new idler pulley diameter to the old one and it was perfect match so this wasn't it.
Next I went ahead and ordered 2 new cam gears thinking I had some minor wear that could throw off the cam timing a couple degrees and there was no change.
I never had any codes or timing problems as I suspect the engine ECM can adjust for minor differences in cam error but now I am wondering if the "oem" belt I bought was off by a couple of cam timing degrees with the intention for future possible stretching built into the design that had me pulling my hair out.
Wild- now I need to do another crank vs cam scoping to see how my cams line up since it's been a few thousand miles since and see if any streching changed the crank vs cam relationship after reading ya'lls posts above.
Link is here if anyone wants to see: https://www.clublexus.com/forums/rx-...e-ckp-cmp.html
New "oem" timing belt with white lines pic below showing error of 5 degrees but bank 2 was on the money- this is for 3.3L 3MZFE engine but ya'll get the idea and now I want to order the Timing belt with Green letters just to see if improvement.
Timing belt stretch is negligible basically to the point of nonexistence. The internal fiberglass cords are extremely strong and robust. Timing belt standards require the belt size far exceed the horsepower rating of the engine. If a TB were to "stretch" even half a millimeter the tensioner/pulley would compensate. Markings wearing off a belt don't necessarily mean it's a sub-standard belt, BUT it's not uncommon for those markings on aftermarket belts to be somewhat ambiguous. I've seen them in sort of a grey area with a mark on the valley instead of the hill so you have to decide which hill (belt cog) to choose either right or left of the mark. This is why marking the old belt before removal in the interest of comparison is important. I'm not familiar with the TB design on an RX but the odds of one cam being 1 tooth off is more likely than a belt stretching.
Timing belt stretch is negligible basically to the point of nonexistence. The internal fiberglass cords are extremely strong and robust. Timing belt standards require the belt size far exceed the horsepower rating of the engine. If a TB were to "stretch" even half a millimeter the tensioner/pulley would compensate. Markings wearing off a belt don't necessarily mean it's a sub-standard belt, BUT it's not uncommon for those markings on aftermarket belts to be somewhat ambiguous. I've seen them in sort of a grey area with a mark on the valley instead of the hill so you have to decide which hill (belt cog) to choose either right or left of the mark. This is why marking the old belt before removal in the interest of comparison is important. I'm not familiar with the TB design on an RX but the odds of one cam being 1 tooth off is more likely than a belt stretching.
Thank you bradland.
i always wondered how much the belt stretches.
On my car a cam tooth off is 15 degrees so being off 5 degrees is somewhere between the teeth.
I'm guessing the engine ECU adjusts for these small differences of error between the teeth by doing a math caluclation offset but I am not able to prove it.
Just saying I did loose a little confidence in the quality when I saw the white lines disappear and saw minor cam error on the scope.
Mitsuboshi has an Ottawa Illinois plant that produces a timing belt for the 1UZ-FE, 2UZ-FE and 3UZ-FE...
Here's the thing...they say the Toyota branded belt and aftermarket belt are off same production line...yet there appear differences in the spine...
I did a side-by-side comparison of the Aisin kit belt and the dealer purchased belt and found the dealer belt had a different spine material.
Certainly the printing of the dealer belt was superior.
There is also a Japanese made timing belt...
Although it performs the same function,.probably several differences between U.S. made belt.
I put my money on the dealer belt due to shoddy screen printing on the Aisin kit belt
When I find one thing, I wonder what else will appear.
Thank you bradland.
i always wondered how much the belt stretches.
On my car a cam tooth off is 15 degrees so being off 5 degrees is somewhere between the teeth.
I'm guessing the engine ECU adjusts for these small differences of error between the teeth by doing a math caluclation offset but I am not able to prove it.
Just saying I did loose a little confidence in the quality when I saw the white lines disappear and saw minor cam error on the scope.
Thought this might be useful info…
‘This is a cam pulley for an RX.
Thought this might be useful info…
‘This is a cam pulley for an RX.
Good pic bradland, can really see it and pic is correct.
As seen in this pic each cam sprocket tooth is 7.5 cam degrees.
Because the crankshaft spins twice for each cam revolution each cam sprocket tooth is also: (720 crankshaft degrees) / (48 teeth on cam spocket)= 15 crankshaft degrees per cam sprocket tooth.
My total timing belt error is 5 crankshaft degrees or 2.5 camshaft degrees.
So basically if I did this right and looking at pic above I have approx 1/3rd cam sprocket tooth error on the new belt.
To be fair I didn't have a before T-belt waveform to compare to so all I was saying is I was a little leery too when I saw the error and also saw the white lines disappear so fast.
Made me hmmmm lol
Add- incedently and probably just a coincedance this is also the bank that throws a "catalytic efficiency below threshold" code but only once a year when on the highway traveling and usually only throws it once per 1,500 mile trip. Just wierd.
Update 01-12-2022- Just noticed the confusion, yeah my above pic is labeled wrong- the cam error is off by 5 crankshaft degrees or 2.5 cam degrees or 1/3 cam sprocket tooth. The timing belt appears to be off a couple millimeters every so many teeth as seen by the cam error is where I was getting at.
Side by side comparison doesn't mean anything since there are production lot differences. Unless they're WILDLY different, you're not likely going to be able to distinguish them aside from markings/labelling.
Side by side comparison doesn't mean anything since there are production lot differences. Unless they're WILDLY different, you're not likely going to be able to distinguish them aside from markings/labelling.
Not here to deposition.
The aftermarket is not better or equal to the Dealer purchased Timing Belt...whether or not manufactured by the same vendor.
Differences exist - the same as with any aftermarket belt, hose, power steering rack, power steering pump, alternator, oxygen sensor, air filter, oil filter, battery, etc, etc.
One factor to not forget is the risk of getting degraded OEM old stock parts. IF a part made of rubber has been on a shelf for 10+ years it could be degraded. It will depend greatly on materials used and the way it is stored.
Does anyone have any insight on real life situation when it comes to timing belts , rubber bushings and simmilar stuff that probably will need replacement over time.
Some car manufacturers describe that the general policy is that after a certain number of years parts are available "while stock lasts" only. This may or may not apply to service items?.
There will be some superseded common items at the dealer. When it comes to specific parts like suspension, certain formed hard line hoses or plastics those get slim-none as those parts are depleted. The aftermarket may provide the rest like alternators, A/C compressors, etc.
The belt that was included in the Aisin kit I installed was marked on the edge at the crankshaft sprocket. No such edge marking at the camshaft sprockets. Odd that there were additional markings corresponding to other features on the sprocket face.
The belt that was included in the Aisin kit I installed was marked on the edge at the crankshaft sprocket. No such edge marking at the camshaft sprockets. Odd that there were additional markings corresponding to other features on the sprocket face.
I just looked at the belt I have with my Aisin kit for my 93. It has the same 3 marks (normal) on the edge of the belt for the crank sprocket but not the extra 2 that show higher up on your crank sprocket. And, same as yours, no edge mark for the cams. I do have one extra edge mark which I have no idea what it's for. It would be somewhere near the idler bearing.
My Aisin kit came with a square gasket (metal) for the thermostat housing. Weird cuz it calls for FIPG and Toyota doesn't even have a gasket for there.
I did find a video on which WP gets the gasket or FIPG where he explained the newer model WP is made smooth on the back instead of having the grooves and also 1mm thinner which is the size of the metal gasket. Short version is the first 2 minutes, size explanation is at 12 minutes of this;
01-06-22, 10:37 AM
