'00 Grand Cherokee Limited I6 -- 3 QUESTIONS

[Bob D.]

Originally Posted by sseguin

Another question would be....

When they state that a car has a 4 speed automatic
overdrive transmission, does it mean that it has 4 gears,
plus an overdrive gear (totaling 5 different gears for
forward)? OR is it 3 gears plus an overdrive gear (totaling 4)
?
Anything else that can be said about this?

Lets take first things first.

1. The 5th gear flash is only for the 45re transmission that
comes with the 4.7 V8.

2. It's not a mod, it's a safe Chrysler TCM flash upgrade.

3. When Chrysler states that a Jeep has a 4 speed
automatic overdrive transmission, it means 4 gears total -
the fourth is considered the overdrive gear.

4. If you have a V8 and don't know if you have 4 or 5 gears,
take it to the dealership to find out if the flash has been
performed.

Caveat- you didn't say what year Grand, I believe the 5th
gear upgrade only applies to the '99 to '04 models

Fancy rotors = waste of money. If you don't have warped
rotors, there is no need to replace them with slotted or
drilled ones.

Fancy rotors,?

Sure your 100%...wrong, even just haveing sloted rotors works better in wet weather then stock.

Your "fancy rotors" will also not heat up like factory Rotors, and less like to warp.

And what makes them even more worth it is they last like 10 times longer then stock.

I stop quicker and feel more when i'm slowing down, more "grab" I had my new set side by side next to my old "un turned" rotors and could see the extra bulk of the newer ones.

You will not have to replace them as often, you will stop better, and have less heat, and less fade, and they just look cool.

The Rotors I have are zinc coated silver, they will only get surface rust on the pad to rotor area, and after going around the block they get wiped clean.

On a reg set of rotors they rust, one recall for the ZJ was rusted rotors, that needed replacement.

You will never look back once you have a set. Even GM has a "slot" on GM A bodys on the 70's.

[Bob D.]

Brake facts vs brake myths:

Sure your 100%...wrong, even just haveing sloted rotors
works better in wet weather then stock.

False.
Better than drum brakes yes. Disk brakes no. When was
the last time you heard of water causing stopping problems
with ANY disk brakes? Slotted or un-slotted, the design nature of
disk brakes makes water a non issue.

Your "fancy rotors" will also not heat up like factory Rotors,
and less like to warp.

Fact:
Chrysler testing has proven that heat does NOT play a role
in warping of rotors.
Misaligned rotors and calipers do.
Modern disk brake pads and rotors, slotted or not, are
designed to heat up and operate at higher temperatures for
maximum efficiency.
Rotors do not just inexplicably warp under normal heat;
If this were the case, every Jeep would have warped rotors.

The disk would have to become red hot to be compromised.
I have heated brakes up enough to destroy the pads, the
rotors wore but did not warp.

And what makes them even more worth it is they last like 10
times longer then stock.

70k miles on my original '01 rotors and still going strong.
Even if they did last 10 times longer, (they won't) a Jeep
would have to last 1,000,000. miles take to advantage of
that life span.
Do the math.
Yep, that's worth it.

I stop quicker and feel more when i'm slowing down, more
"grab" I had my new set side by side next to my old "un
turned" rotors and could see the extra bulk of the newer
ones.

"Bulk" or thickness has absolutely nothing to do with stopping power, surface area does, which your slotted and cross drilled rotors have less of.
(ie, when you slot or drill rotors, you remove surface area,
not a good idea on Jeep rotors which already have minimal
pad surface contact area.)

You will not have to replace them as often, you will stop
better, and have less heat, and less fade, and they just look
cool.

Completely unproven.
If you have problems with premature brake wear or brake fade, that's a serious problem, and it's not because you don't have slotted rotors.
The brakes should be inspected and repaired.

If you drive your Jeep like a Ferrari, the pads "might" last a
little longer with slotted or cross drilled rotors, heat dissipation for racing cars being the concept behind their design.

The Rotors I have are zinc coated silver, they will only get
surface rust on the pad to rotor area, and after going
around the block they get wiped clean.

Ditto for my OEM rotors.
Zinc coated silver? Metallurgic snake oil.

You will never look back once you have a set. Even GM has
a "slot" on GM A bodys on the 70's.

If GM really wanted to address stopping deficiencies, they would have put bigger brakes on the Chevy Suburban.

If I felt slotted rotors were any better than OEM, I'd buy some today.
But the fact is that slotted or cross drilled rotors for street vehicles amounts to nothing more than well crafted snake oil.

If fancy looking rotors make you feel better, by all means
use them. But don't try to justify your expense by making
unproven claims.

Seems just about every auto sport from Rally Truck to Super Stock uses slotted or drill and slotted rotors, I guess they just like the looks?....?


Even the Army uses them, mostly on stuff thats made (by the Military) better then the factory made it.

Water tends to go into the holes on a slotted/drilled rotor and out the ribbed vent, rather then trying to compress (water will not) the water and not stopping. I have gone in and out of water on my jeeps and felt the delayed stopping, with my slotted and drilled I don't even feel anything, it just stops...

Most drilled and or slotted Rotors have thicker beams inside the rotor making a better heatsink and thus better to ward off warping, and with the slot and or holes it is able to shed off the heat as it turns, unlike a non drilled slotted rotor a facory type has no turbulence, and no way or getting rid of the dust.

So your saying that your stock rotors dont have a brown rust color to them?

Heres some news, I worked for 3 years at a major auto parts store, I seen more core returns then I care to talk about, but not one was nice and factory clean, they all were rusted in every place but the pad surface, and for sets that sat around for a while, they had rust.

In 5 years do you care to test your rotors to mine with a simple drop test to see the rust?

With a nice coat of rust on your rotors inside is the big deal, you are not cooling off the rotor as well as a new rotor or a treated rotor.

It seems your claims are baised on your own "feelings", you have not told me why they don't work.

The reason GM "A" body like 442 and GTO didnt put bigger stuff on was cost, but they do have a groove, and used it for many years.

[PMDresurrected]

Hi i'm new, so hello everyone.

Bob is right about the surface area, but I would have to think That Ram is right about most of it.

Sure how long do you need to have rotors, but if you have a classic car that your going to keep for a life time, why not get them?

Looks like Ram got banned, but Bob what you think, is it not worth the extra cooling and long life for a car your going to keep for a very long time?