Denso AC compressor tale of woe... (1 Viewer)

[Wasatch Jay]

My wife drives a 2002 LX 470, and it has 134,000 miles. Last September, the air conditioning quit and obviously that needed to be fixed. Of course one option would be to take it to a dealership, but I could just picture them salivating at what they were going to charge me. The problem was the AC compressor’s clutch was no longer working properly. Rockauto.com is generally my go-to source for parts.

Looking at the available options, it wasn’t going to cost much more to replace the 20 year old compressor with a new Denso unit (the OEM supplier to Toyota/Lexus) which included a new clutch, as opposed to just replacing the clutch itself. Due to the location of the compressor, it was going to have to come out anyway to service the clutch, so I went that route and ordered a new Denso compressor and a new condenser dessicant bag...

We removed the compressor, drained and measured the amount of oil in the old compressor, and made sure the new compressor had the exact same amount of oil in it when we installed it. The dessicant bag was replaced and we properly added R134A Freon. The system worked great, and I thought we’d have several years of trouble free service (the key word being “thought”).

This vehicle doesn’t get driven much and this past June my wife went on a trip to Montana and then to Washington state and… the AC system quit before she was even half way. Upon her return home it was determined the new Denso compressor had seized after only nine months and about 6,000 miles.

For compressor warranty purposes, Denso requires a new condenser be installed and the system be flushed. Okay, I can understand that if a compressor had an internal failure, but the old compressor was working fine. The clutch was the problem, and you certainly wouldn’t replace the condenser, or flush the system, due to a failed clutch.

I’ve always thought of Denso as a premium supplier of parts, and decided maybe we were just unlucky and got a bad one. I ordered a new Denso compressor and my friend and I installed it; this time with a new condenser and we flushed the system.

Because there would be no warranty coverage, we decided to disassemble the seized compressor and find out what had failed. Sure enough, one of the two cylindrical thrust bearings was fried. To me, that was very disappointing service from what I had thought was a quality parts manufacturer. I certainly hope the new compressor lasts a lot longer...

Pics:

What the cylindrical thrust bearing should look like (the good one).

The destroyed bearing.

 

[nissanh]

You can replace the clutch while the compressor is mounted to the engine. I installed a new bearing in my 2000 LC.

Let me tell you the difference of a part in a DENSO box and in a Toyota Box: Parts inside a toyota box is about 10 times or more superior to a part inside a denso box. My cousin's Honda pilot 2013 completely failed its denso alternator at 100K miles while Toyota Denso alternators in any of my TOY'S didn't even fail at 220K miles (installe new brush kit at this mileage). I bought a distributor cap for my 92 Prizm in a Denso box (bought denso aftermarket.com) and the distributor was made in west Germany and is a common aftermarket distributor.

 

[excessive]

Iver never been able to tell a difference between a retail boxed Aisin or Denso part vs. the Toyota OEM boxed part. Often they look exactly the same.

 

[IndroCruise]

Iver never been able to tell a difference between a retail boxed Aisin or Denso part vs. the Toyota OEM boxed part. Often they look exactly the same.

My experience with a DENSO Alternator ….

The original DENSO factory-fitted OEM Alternator failed after 193,926 kilometres (120,000 miles) and 13 years -- inconveniently while touring!! Re-charged the batteries (two on LC100 with 1HD-FTE turbodiesel), drove 184 kilometres (~144miles, about 2½ hours) from Coonabarabran to Mudgee. One of the side-benefits of the diesel is no spark required, fuel pump is direct-driven by the engine, just needed enough battery voltage for long enough to run the vehicle electronics, brake pressure accumulator motor, radio, phones, other ancillaries etc, etc, but lights OFF, aircon OFF, no stop and re-start of engine -- probably could have travelled much, much further without stopping.

Local gurus said that at that age I should have changed the Alternator pre-emptively before travels, or, carried a spare diode pack, spare brushes and spare bearings for self-repair -- I don’t have to guess what Mrs IndroCruise would have said about the delays caused by that option – but maybe a local independent mechanic would have got me out of trouble if I had the parts ….

On arrival, a new OEM Alternator had been delivered by Toyota Australia Main Distribution Centre to the Local Dealer in Mudgee, Toyota Part Number 27060-17230 for 1HD-FTE turbodiesel engine. The Toyota package contained a new DENSO unit, replica of the original unit -- and this was fitted to the vehicle. This was not the best negotiating position with Mrs IndroCruise on board and while leading a convoy, no time for better ideas from eBay, Impex or Partsouq -- so I was wiser but A$442.75 poorer for a quick fix, supplied and fitted!!

The realities are that, like every other vehicle-maker in the world, Toyota/Lexus don’t make everything themselves. Instead, they have a vast network of manufacturers and suppliers. These include DENSO and AISIN and multiple others such as KYB. Toyota is a significant shareholder in both DENSO and AISIN -- and DENSO and AISIN are shareholders in Toyota -- no prize for guessing that the cross-shareholdings underpin the relationships and the supply contracts.

What comes out of a Toyota/Lexus OEM parts package is what has been put in the package, as received from the supplier to Toyota/Lexus. “Toyota/Lexus Genuine Parts” on the box does not mean that Toyota/Lexus actually manufactured it in-house.

Original OEM factory-fitted DENSO Alternator for LC100 with 1HD-FTE:

Toyota-supplied package containing replacement DENSO Alternator for LC100 with 1HD-FTE:

 

[Malleus]

Every assembly line produces a range of quality products. Variability is built into mass production. For example, bearings have different grades for the same models, produced on the same grinding machines, due to this variability.

The difference between what you find in the Toyota boxed Aisin/Denso parts and similar looking parts in other boxes is the level of acceptable quality. Toyota requires higher quality than manufacturers accept for their products. That's why Toyota OEM parts last decades and "branded" parts last years. It's also why Toyota parts cost more; the highest quality parts come off the assembly lines in the fewest quantities. If you have to make 100 of something to get 3 acceptable parts, those three are going to cost more than the other 97.

 

[ben322]

When I baselined my 250K 100 last year, I ordered a Denso alternator, starter & AC compressor. Alternator & AC compressor worked out fine but the starter was defective. 2nd time was the charm and luckily I didn't put everything back together before testing it.

Fast forward to this spring, my 2K F350 needed an alternator so I saw rockauto had a Denso reman available for less than the Motorcraft reman. 2nd time was the charm for this Denso as well. At least the 7.3L single alternator is a 5-minute job.

 

[nissanh]

"The realities are that, like every other vehicle-maker in the world, Toyota/Lexus don’t make everything themselves. Instead, they have a vast network of manufacturers and suppliers. These include DENSO and AISIN and multiple others such as KYB. Toyota is a significant shareholder in both DENSO and AISIN -- and DENSO and AISIN are shareholders in Toyota -- no prize for guessing that the cross-shareholdings underpin the relationships and the supply contracts."

I have dealth with OEM parts since 1990 and have experience the difference between the parts in OEM box and denso box. I installed an axle bearing into Hilux (OEM Toyota -Koyo bearing) and out of the box, it had a play. upon installation, the play is no longer observed. A friend bought KOYO bearing and had no play out the box, but after the installation, the bearing was tight.

Take home message: Yes, same manufacturer, but when Toyota asks their part to be made the way they want the supplier has to follow Toyota specifications: The part supplier cannot use Toyota specs to make their own.

BY the way, Denso and Aisin are owned by Toyota, that's why many auto makers (including GM, BMW) are using Denso parts in their vehicles now.