What are some car-repair jobs you always wished you could do but have never done?

On 7/11/2017 11:45 AM, RS Wood wrote:
> Scott Dorsey wrote:
>
>> Rotors warp in street use all the time when the kids at the chain store use
>> impact wrenches instead of a proper torque wrench to take tires off and
>> put them back on.
>>
>> And of COURSE the chain store blames the driver, the tires, the phase
>> of the moon, for it. "You must be going over potholes too hard."
>
> We covered that in the car forums about three decades ago, where you have
> to wonder how anyone could say what you just said.
>
> I haven't *looked* at the problem you speak of for more than 30 years, but
> let's take it step by step in really big steps here.
>
> 1. How many footpounds *can* you torque a lug nut to before the bolt snaps?
> 2. Let's put *that* amount of torque on ONE of six bolts, shall we.
> 3. A rotor isn't solid, but let's assume a solid rotor for a moment.
> 4. How much torque would it take to *bend* a solid rotor?

It is the balance of the torques.
>
> QUESTION FOR YOU THAT WE ASKED 30 YEARS AGO OF OTHERS:
> Q: How much torque on one bolt would it take to bend a rotor?
>
Had it happen on a Mazda I owned. I wasn't happy and complained
bitterly. You can put a lot more torque of a wheel nut than is required.

--

Xeno

On 11/6/2017 7:19 PM, RS Wood wrote:
> Xeno wrote:
>
>> I only really started learning *after* I completed my apprenticeship -
>> and I've never stopped learning ever since.
>
> You stop learning only when you're dead.
>
> I learned a LOT in this thread, particularly about WHY engines last
> forever, and why exhausts last forever, and why bearings last forever, and
> why ball joints last forever.
>
> That's all good.
>
> I didn't learn a thing on rings that I didn't already know though.
>
> I'm all prepared to learn how the metallurgy or shape of rings is different
> nowadays versus yesteryear, but I haven't seen any reference that shows
> even the slightest improvement over the years.
>
> It might be there, but saying it's there isn't the same as it being there.
> Proof in logic is always very simple.
>

You have not looked
http://www.enginelabs.com/engine-tec...ble-effective/

http://www.underhoodservice.com/adva...ng-technology/
With so many late-model engines running thinner, low-tension moly-faced
ductile iron and steel rings, one might think cast iron rings are fading
into history. They are at the OEM level, but it looks like cast iron
rings will be around for a long, long time in the aftermarket. According
to several ring suppliers, there is still a very strong demand for plain
cast iron rings. The main reason is that cast iron rings cost less than
more durable materials — and they hold up well enough in light-duty
stock rebuilt engines. Even so, plain cast iron rings can’t provide the
durability of a chrome or moly-faced ring set, or a steel or ductile
iron ring set that is engineered for high output, late-model overhead
cam engines.

On Tue, 7 Nov 2017 00:55:08 -0000 (UTC), Frank >
wrote:

>On Mon, 06 Nov 2017 04:49:21 +0000, RS Wood wrote:
>
>> Frank wrote:
>>
>>> Chains are hardly ideal. Chains wear. The wear changes the pitch
>>> between the links and the links no longer quite fit on the sprockets.
>>> It turns into a self reinforcing cycle. More wear = worse fit, worse
>>> fit = accelerated wear. Eventually the poorly fitting chain will jump
>>> one or more teeth on the crank gear or start breaking the teeth on the
>>> cam gear.
>>
>> What are our choices?
>> 1. Chain 2. Belt 3. Pushrod
>>
>> Anything else?
>>
>>> The other effect of chain wear is retarded cam timing. The more worn
>>> links between the crank and cam, the more the camshaft timing gets
>>> retarded. I changed timing sets on conventional OHV engines and that
>>> usually advanced the ignition timing from 5 to 10 degrees, suggesting
>>> that chain wear had retarded the timing by that amount.
>>
>> From a repair standpoint, how long do each typically last?
>> 1. Chain ?
>
>Depends what you mean by "how long does it typically last?"
>
>Timing sets on OHV engines typically wouldn't totally fail at under
>100,000 miles. Most of those sets were used in the days when cars were
>junked at about that mileage. Alot of those cars were junked because the
>timing set failed.
I replaced a lot of timing chains and spockets on OHV engines
particularly The GMs with the plastic cam sprocket
>
>But I'd guess timing set wear would retard cam timing around 1/2 to 1
>degree every 10,000 miles. If we set an arbitrary failure spec of, say 3
>degrees, then the set would have gone out at 30 to 60,000 miles. Of
>course, the car would run even if the camshaft were retarded more than
>this and the driver usually became acclimated to the poorer performance
>and gas mileage.
>
>> 2. Belt ?
>
>I don't know. My car requires belt replacement every 100,000 miles or
>six years. I replaced the belt at eight years and it looked perfect.
>There's no significant timing change as the belt ages, until it fails.
>An insignificant number fail before the required maintenance time.

Except the little Chevy Optima? where virtuallly NONE made it much
bast the recommended change point and many failed well before. Bad
korean belt.
>
>> 3. Pushrod ?
>
>I don't know what you're getting at. Most US pushrod engines drive the
>cam with sprockets and a chain. A few used gears. A few antique
>motorcycles used tower shafts and bevel gears. Maybe some auto engines?
>dunno.
>
The early Riley, for one.
>
>>
>> I don't hear anyone talking about pushrods, so, all I see here are that
>> chains last a *lot* longer in general than do belts, where if either one
>> broke on an interference engine, expensive things can happen.
>
>Pushrod engines can be interference engines. Not sure what you're
>getting at.


>
>>
>>> But I still prefer belts. Even on a tight package like a Dodge Neon
>>> with the 4 speed auto, the replacement isn't too bad, once you know the
>>> routine.
>>
>> If the replacement isn't bad, then the belt isn't 'as' bad.
>
>Easiest belt replacement I ever did was on an early Fox body Mustang with
>the 2.3 liter 4. Take of the drive belts, take off the timing belt
>cover, swap the belts. With some practice and preperation, it would be a
..>clean, 15 minute job.
>
>Much easier and cleaner than replacing a chain timing set!!
>

I replaced the broken timing belt on the side of the road south of
Sydney NS on my '72 Firenza (Vauxhall HC) in less than half an hour
after getting a friend of a friend to pick up the only belt available
west of montreal - which just happened to be hanging on a nail at the
GM dealer in, of all places, Sydney NS - - -

Sometimes it's better to be lucky than good!!!!
2 days later I was in the USA - where NOBODY would have had the part
because the car was never sold there - - -
>
>>
>> In the general sense though, belts, I posit, are bad news multiplied.
>> I try not to take things from the marketing-bull**** standpoint.
>>
>> My take is always from the *why* standpoint.
>> Why did the automakers go to belts over chains?
>>
>> My supposition is that they did it to save them money.
>> No other reason.
>
>Camshaft timing.
>
>>
>> The tradoffs are legendary where the owner is the one who loses in the
>> end calculation.
>
>Belts became important when Overhead cams became important. A worn chain
>in a cam in block engine has, off the top of my head, 10 links between
>the crank sprocket and the cam sprocket. What about a OHC motor? Say 30
>links? 10 worn links might retard cam timing 5 degrees. What about 30
>worn links?
>
>
>>
>>
>>>> Just like FWD cars and tricked-out cars are, to me, nearly worthless.
>>>
>>> I love front wheel drive, especially in the snow.
>>
>> Lots of cars are FWD that never see snow.
>>
>> In the general sense though, FWD, I posit, is bad news multiplied.
>> I try not to take things from the marketing-bull**** standpoint.
>>
>> My take is always from the *why* standpoint.
>> Why did the automakers go to FWD over RWD?
>>
>> My supposition is that they did it to save them money.
>> No other reason.
>>
>> The tradoffs are legendary where the owner is the one who loses in the
>> end calculation (particularly since deep snow is still on the road for
>> what, maybe 10 days out of 365?)
>>
>> Anyone who mentions snow with FWD is falling directly into marketing
>> hell.
>
>Bull****. Here in Chicago, traffic flows much better in the snow than it
>did 30 years ago. In fact, I haven't seen a car stuck in the snow in at
>least a couple of years.
>
>Stuck RWD cars used to impede rush hour traffic on a routine basis.
>Nowadays, I haven't been late to work because of the snow in those two
>years.
>
>Or, maybe it's the FIRE OF MARKETING HELL that's taking care of the
>snow. Either way, I'll take it.
>
>
>> Just like anyone who mentions belts are "quieter" and "lighter" is
>> doing.
>>
>> The sole reason for belts and FWD is to increase manufacturer's profits.
>> Everything else is marketing bull**** because the tradeoffs are
>> legendary.
>
>I know. The "donut in a snowy parking lot" crowd is almost extinct.

On Tue, 07 Nov 2017 01:10:20 +0000, RS Wood wrote:

> Frank wrote:
>
>> Bull****. Here in Chicago, traffic flows much better in the snow than
>> it did 30 years ago. In fact, I haven't seen a car stuck in the snow
>> in at least a couple of years.
>
> People who believe in marketing bull**** never follow basic logic.

Since you've decided how I'm thinking, what's the logic in responding?

>
> Here's simple logic (which may be too difficult for you to follow).
>
> 1. How many days in a year are you *driving* in *deep* snow?
> 2. Tell us what percentage that turns out to be.
> 3. Now, take that percentage and subtract it from one hundred percent.

OK, let's say it's 1% of the days. I don't want to be needlessly late
on ANY of those days. More than that, the FACT that traffic is now
flowing more smoothly on snowy days makes driving less stressful.

I will say that, last year, I was driving home on a snowy day. Traffic
was light and what traffic there was, was making safe progress. Some
dumbass decided to pass me fast on the right, lost traction on his RWD
vehicle and spun his car across three unoccupied lanes and smacked his
passenger side wheels against the curb on the opposite side of the road.
Pretty uncommon now, but things like that used to happen frequently in
the RWD days. I don't miss it.


>
> That's the percentage you're getting the *other* handling out of FWD.

Fine. It makes driving safer and smoother a few days out of the year.
It is NEVER a detriment to me. For me, there is NO handling downside.

>
> You may not want to answer the question because it's too logical a
> question for someone to ask about handling tradeoffs given your
> extremely carefully cherry-picked hand-crafted situations versus normal
> situations.

For me, there is no trade off. Whatever difference there is, is
positive. I didn't need any marketing bull**** to convince me of the
superiority of FWD. All it took was getting through the winter. And I
like the extra interior room, too.

On Mon, 06 Nov 2017 22:08:55 -0500, clare wrote:

> I replaced a lot of timing chains and spockets on OHV engines
> particularly The GMs with the plastic cam sprocket

Ford used the same sort of cam sprocket and they failed the same, too. I
don't think the timing sets with the cast iron/sintered metal cam
sprockets held up much better. Once timing chain wear starts changing
the pitch, it's setting itself up to jump a tooth on the crank sprocket
even if it can no longer break the teeth on the cam sprocket.

Another problem with timing chains is the metal swarf they'd put in the
oil as they wore.

Xeno wrote:

> It is the balance of the torques.

Remember, we covered this in detail DECADES ago.

Everyone confuses *runout* with *warp*.

They're not the same thing.

One requires *permanent bending* of the rotor.

You have to do that without snapping the lug bolts.

Two logical questions HAVE to be considered:
1. How much torque *can* you apply?
2. How much torque does it take to *bend* a rotor?

Without logic - it's just politics or religion.

>> QUESTION FOR YOU THAT WE ASKED 30 YEARS AGO OF OTHERS:
>> Q: How much torque on one bolt would it take to bend a rotor?
>>
> Had it happen on a Mazda I owned. I wasn't happy and complained
> bitterly. You can put a lot more torque of a wheel nut than is required.

There is a huge difference between runout and warp.

Are you talking warp?
Or runout?

I'm only talking pure logic here.
Not religion.

Frank wrote:

> Coking matters to the extent that it plugs filters and oil passages. The
> coke is hard and can abrade bearing surfaces.

I have seen what amounts to black sand in the outside sleeve of the crazy
BMW dipstick tube which doubles as part of the PCV system but where the
clearance is too small (so people drill holes in it to solve that).

I had to dig out the "black sand" which was pure carbon it seemed but rock
hard and packed in there.

On Sun, 05 Nov 2017 14:42:50 +0000, RS Wood wrote:

> What fails rotors the most (by far) is thickness.

Around here, it's the rust that thins the rotors. The braking surfaces
don't rust significantly, but the rust just flakes out of the vent holes.

Replacing rotors every other brake job is about right in the rustbelt.

On 11/6/2017 7:44 PM, Xeno wrote:
> On 7/11/2017 11:35 AM, RS Wood wrote:
>> Xeno wrote:
>>
>>>> Which is the most reliable?
>>>>
>>> Gear by far, chain next, belt last.
>>
>> Interesting. Makes sense.
>> Are gears prevalent?
>
> Used to be on cars. Noise was the issue. Phenolic resin gears solved
> that issue but then gear longevity was sacrificed to the god of noise.
> Used to change a lot of stripped phenolic resin gears back in the 60s
> and 70s.
>
>> If not, is the main reason the cost?
>>
> On larger diesel engines noise isn't a factor and longevity is. Cost is
> less of an issue when long life is the requirement.
>
> Or performance with reliability as in this BMW F1 engine
>
> http://www.formula1-dictionary.net/I...iminggears.jpg
>
> Gears become an issue with distance, as is the case with OHC. In that
> case you need too many idler gears so a chain or belt is more
> efficacious. From memory, the Toyota KZ engines had both gears and then
> a belt to the OHC.
>
>
http://www.edelbrock.com/automotive/...r-drives.shtml

I don't know how well the retrofits held up. Long life and race engines
don't go together.

On Sun, 05 Nov 2017 05:47:02 +0000, RS Wood wrote:

> Never once in my life have I found a single person who has *measured*
> the warp.

Does eyeballing it count? I bought a used car in which I could see about
1/16" of warp as I rotated the rotor and looked through the top of the
caliper. It was one of those cars with the rotor captured behind the hub
and the shop price for the repair probably contributed to the previous
owners desire to get rid of the car.