Starter rebuild kit - asking for trouble?

Yes, that is correct

If the old starter works 4 out of 5 days in the car, you might get the same results when bench testing. Are you going to bench test a starter for a week? Or test it while in the car?

I’ve been “testing” it in the car when you put it that way. And it occasionally fails. A little different point of view with a good insight.

Even the best of new parts can be defective from time to time, and when you do enough volume you run across those bad parts… I tell the tech to do a quick bench test, takes 30 seconds, if they don’t and install it anyway and it is bad out of the box, well that is on them and I am not paying them twice unless it tested good and then failed in the vehicle… I tested most of them before given to the installer or doing it myself if possible… And I bought from all the top parts houses and never the cheap line, had to send back many over the years, better to be safe then sorry… And no it is not a everyday thing, but it never happens at a great time… lol

I’ll never forget the time I bought a new (not rebuilt) starter from a local parts store, installed it and went to start the engine. One click and then a loud humming sound as I saw the battery cables smoking and melting off the insulation. Thank goodness I still had the wrenches there and managed to get one off the battery…

2 Likes

Do cars have toothed flywheels like my old boat engine did? If so I’d check the teeth on the flywheel too. I had a boat engine with a few bad teeth on the flywheel, and if the bad gears lined up with the starter, it would not turn over. My mechanic replaced both starter and flywheel gear ring. It was an old Evinrude, made in the 1960s.

Yes, the teeth on the starter engage with the ring gear (teeth) on the flywheel/flexplate or in older Mopar’s torque converter…

Yeah even lawn mowers have a ring gear. We had a fork lift once that was dead in the water with a stripped flywheel. Gotta fix it where it sits. I was able to tow my mower into the garage at least. Starter not ring gear. I learned to fear shutting stuff off over the years which is one reason I don’t like that new feature shutting the engine down at every stop light.

Not sure if this applies universally to all cars, but the toothed part of a car’s flywheel is often replaceable, just a large toothed ring that is pressed on to the existing flywheel.

That might be how it was made for a manual transmission. I’ve not seen one replaced. Have you? For automatic transmissions the ring is welded on.

1 Like

Given that every rule has an exception… Both a flywheel and a flexplate have ring gears (for a starter to engage)…

The flywheel is found primarily in vehicles that have a manual transmission and has a machined surface for a clutch/pressure plate assembly, whereas the flex plate is found in automatic transmission vehicles and is normally much thinner and the torque converter bolt/mounts to it…

The flexplate has the ring gears welded to the outside of the flexplate in most cases, older Mopar’s had the ring gear welded to the torque converter…

The flywheel ring gear is usually fixed to the flywheel through use of an interference fit, which is achieved by heating the ring gear and so that thermal expansion allows it to be placed around the flywheel, therefor being replaceable with the right tools…

1 Like

Here is a 1970 F-100 5.0L flywheel ring gear at rock auto… (unknown flywheel above in video)

https://www.rockauto.com/en/moreinfo.php?pk=65882&cc=1119833&pt=5360&jsn=471

$18 ring gear vs $113+ new flywheel… (if nothing else wrong with it… lol_)

2 Likes

Learn something new every day. Anyone here replaced a ring gear?

I have watched it being done many times, but I don’t remember ever doing it myself, of course there are a few years I don’t remember much about either… lol

3 Likes

No need b/c I’ve never had a ring gear that failed. But Ray and Tom discussed this topic on their radio program as I recall, so I presume they’ve done it. I do, what? 4 or 5 car repairs a year. Pro mechanics like Ray probably do 20-30 every day.

Interesting discussion, especially the difference between ring gear location on automatics vs manuals but on a practical level …

Since on startup the starter is doing all the work, it’s a safe assumption that it’s the starter that’s worn out and needs to be replaced

As others have mentioned, especially for the DIY w/o the benefit of a lift it’s a PITA job, especially on an older car with 18 years of accumulated rust, corrosion and road grease so if the replacement doesn’t work, how often do you want to repeat the job?

For myself it’s an easy decision, instead of spending hours doing a DIY rebuild or saving $30 by buying a used/reman, spend the extra money for the new part and you’re done for probably the remaining life of the car.

Nope. Only a few flywheels in my life but usually the face is in questionable enough shape to warrant just replacing it anyway. Flywheels were relatively inexpensive parts to replace for me- maybe $120? Only way I would mess around with replacing just the gear would be if installed a new flywheel and it got damaged shortly afterward. Even then, kind of a lot of messing around for $100 savings…

Although not as common as it used to be, ring gears could still be replaced on more expensive flywheels (if even available) where a starter Bendix fails and doesn’t engage the flywheel and chews the teeth up… Or aluminum flywheels for racing engines or even heavy equipment…

But then again, you used to have parts houses like Carquest etc that had small machine shops in them and used to turn flywheels, now it is almost impossible to find anyplace that does that anymore… I’m sure these new fancy flywheels like the dual mass and maybe others didn’t help either…

Some of these DMF’s are very expensive, like the cheap 2007 Focus with the $395 to $563 dual mass flywheel would be a great candidate for a ring gear replacement if one was available…

That’s my thought. If I’ve gone to all the work of removing the transmission, clutch, and flywheel, I’m very likely to replace the pressure plate, clutch, and flywheel unless I’d save a LOT of money just replacing the ring gear.

Seems like the time it would take to replace a ring gear probably isn’t worth the $ savings in most cases. I suppose there are situations where it makes sense though. Here’s a vdo showing how it is done.

1 Like