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FAQ part 8/10
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Subject: FAQ part 8/10
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From: "Rick Kjeldsen" <fcmk@domain.elided>
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Date: Thu, 01 Dec 1994 12:46:42 -0500
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Section 17.6: Why should tires be rotated?
A: (by Roger M. Stenerson: stealth@domain.elided)
I have always rotated my tires front <> back at 6000 miles on rwd cars.
(3000 miles between rotations on fwd cars.) I've had very good luck with
even tire wear. Don't forget to use a torque wrench for proper torque and
tighten the nuts in the proper order. (1-3-5-2-4 or 1-3-2-4) Or you will
end up with warped brake rotors.
<<<<< (by Mustafizur Rahman: rahman@domain.elided)
I got my stock GS-N's were rotated about 10k miles. The dealer recommends
every 7.5k miles - basically during every inspection.
==============================
Section 17.7: Snow tire recommendation
A: (by Richard Welty: welty@domain.elided)
Nokia makes 3 tires worth considering:
Hakkapolitta NR09 -- a older tire, excellent in snow but noisy
Hakkapolitta NR10 (or just Hakkapolitta 10)
-- newer design, excellent in snow, slightly quieter
not available in certain sizes (but the NR09 generally
is available in these sizes, which are usually narrower
tires for older european cars.)
Nokia NRW -- "all season"; not as agressive as the NR09 or 10,
and reportedly more pleasant on dry pavement. far
better than most tires labeled "all season" from what
i hear.
by mail order:
Greer Enterprises in WI 414-747-0996
Pat Greer seems like a very nice guy and his prices are quite good. i
paid $77/tire including shipping for a pair of 185/65R14s and $73/tire
including shipping for a set of 185/65R15s back in December.
==============================
+ Section 17.8: Inflation pressures
A: (by Tom Childers:tchilder@domain.elided)
> Hmmm... how does the tire pressure change the size of the contact area?
> Wouldn't become long snd thin vice more square?
This used to be true, but the rules are a little different for radial tires. In
the days of bias-ply tires, an over-inflated tire would have a smaller contact
patch, and would wear excessively in the center of the tread design. These
days, an over-inflated radial simply gives a harsh ride and the "footprint"
doesn't seem to distort too much.
Under-inflated tires used to wear too much on the shoulders...however my
(apparently) under-inflated Pirelli radials (at 36 psi) wore excessively in the
center. I say under-inflated, because the handling and steering of the car
dramatically improved when I popped the pressure up to 39 psi. I still don't
fully understand this.
==============================
+ Section 17.9: Tire rolling direction
A: (by John Dempsey:johnde@domain.elided)
> I had a well-known national tire store install some Michelin XM+S 130
> snow tires on my 318i. I just noticed today, that the left and right
> front tires were installed backwards, so that the rotation arrows
> stamped on the tires travel tail first.
Unless your car is four wheel drive, then they probably did it right.
Anyone familiar with racing tires has experience with this. The idea
with the arrows is to align the tire for the maximum torque it will re-
cieve. Obviously (without four wheel drive), the front tires on your
car can not transfer much torque when accelerating. But they can when
they are braking. So the arrows point in the opposite direction.
In the rear the situation is reversed. These wheels are being driven, so
the arrows point in the direction of the maximum torque. I would guess if
you had a car that was designed to roll down mondo hills (like a 2500 lb.,
luxury laden soap box racer), then the arrows for the rear tires would be
pointed backwards also.
All this means, is that when you rotate the tires, they will have to move
in the following pattern:
LF -> RR
RF -> LR
LR -> RF
RR -> LF
in order to keep the arrows going in the correct directions.
==============================
+ Section 17.10: Tire sizes and related issues
A: (by Fillipo Morelli:bilge@domain.elided)
> Actually +1 and +2 indicate rim diameter from stock.
>
Not really.
> +1 on a car that had 14" rims originally would be 15".
> It has nothing to do with the width.
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
This is correct. It has NOTHING to do with rim width. Furthermore,
I did not mention anything about rim width. +1 and +2 are commonly
used to represent the fact that you can go one or two tire sizes
over stock size and not effect the final drive ratio. It is common
for sport-oriented folks to buy +1 tires which provide a slighty
wider / lower profile tire without any effect to final drive ratios
and speedometer readings.
Wheel diameters are critical only with respect to brake clearance.
<<<<< (by Rick Kjeldsen:kjeldsen@domain.elided)
For a little subjective feel of the difference:
My car has stock 195/65-14 tires. Changing to 195/65-15 (1" larger
diameter) gave quite a noticable decrease in accel. Changing to
195/60-14 (.75" smaller diameter) gave a noticable
(and quite nice ;-) increase, especially off the line, but the tires
look small in the wheel wells. There was no noticable difference in
highway noise due to rpm changes (but then my car only turns 2k rpm on
the highway!) There was only a very slight difference in ride (could
easily have been different makes of tire), the gear ratios still felt
just fine.
rick
'87 325es
<<<<< (by Richard Welty:welty@domain.elided)
the following C program was originally written by netter Mark Sirota
some years back; it is quite useful for comparing various and
sundry tire/wheel setups. mark is no longer at the rochester.edu
address listed in the program, but is now at greenwich.com (and i
don't recall his username there.) i thought i'd pass it on:
< send mail to Mark or Richard for a listing of the program.>
- - ---------------------------------------------------------------------------
Chapter 18.0: Body Work and miscellaneous
Section 18.1: Fixing squeaking doors
A: (by John Coffin:JCOFFIN@domain.elided)
Generally in all striker plates a impact driver is needed. An impact
driver is like thick phillips screwdriver with a twist action in the shaft
so as the hammer strikes the top of the driver, a twisting action also
happens to loosen (or tighten) without stripping the head.
Adjusting the door is much more than moving the striker plate. While this
may fix the squeaking the door may require more effort to close. The give
in the door is actually in the pivot of the hinge. Door placement is a
system of the door frame, hinge spacing, and striker alignent.
==============================
Section 18.2: Long-term car storage
A: (by Rick Kjeldsen: kjeldsen@domain.elided)
Based on my experience on storing bikes and cars for winter, I would:
- Change the oil.
- Change the brake fluid.
- If it is old, change the antifreeze.
- If you want be fanatical, change the transmission fluid and rear
end oil, but I think this is less important.
- Empty the gas tank, and run the engine dry of gas; Or put
stabilizing compound in the gas and run the car till you are sure it
is in the injectors.
- Remove the plugs and squirt a little medium weight oil into each
cylinder. Turn over the engine over a few times without starting
it to spread the oil. Re-install the plugs.
- Put the car on jack stands to get the weight off the tires, so they
won't get flat spots.
- Take the battery completely out.
- Put mothballs in key points in the car (under the hood, inside,
behind the heater grills, etc) to help keep out mice.
- Plug the tail pipe suffeciently to keep out mice and moisture.
- Keep the car in a dry place, out of the sun. At the very least,
cover it with a thick, breathable cover. Best is to keep it in a dry
garage. Either way, make sure the car can breath, so condensation
doesn't build up. You may want to keep the windows open a little.
==============================
Section 18.3: Shifter feel improvement
A: (by Dale Beuning)
@
/
/ Shift Lever
(D)/
\===================================== @ ================= Floor Pan ====
|- - -Shifter Plate- - - -|--/
- - ------------]=[]@----------------------@
Trans- ] ]](A) (B) (C) Rear Connection
mission ]]]]]]]]]]]]Driveshaft]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]
] ]]
- - ------------] Guibo
Hi Dave,
The above is a profile view of the car I hope it makes sense to you.
1) The short answer is that there are two things you MUST MUST MUST replace
to tighten-up your shifter.
The first is the (Forward Connection) brass fitting at the rear of the
transmission($10), the driveshaft must be removed to replace this. (A)
The second is the rear connection, the shift lever is a two piece
affair, upper and lower. The upper part is the chrome piece that the
shift knob gets pressed onto. The lower part is what MUST be replaced (C)
it has a non-replaceable lower bushing that wears out. Cost $30.
Also! As long as you have the shifter lever torn apart to replace the
lower part, replace the little nylon half cups that the ball of the
lower part rides in. Aprox $0.50 each. (D) The driveshaft does not
need to be removed to replace the lower half of the shift lever nor
do you have to disassemble the console. You will need lots of patience
to reassemble the shifter lever. Maybe I can scan in the exploded
view from Bentley and clarify the drawing to simplify the replacement
of this part.
2) The long answer is that the more pieces your replace the better it
feels. I'll list all of the parts I replaced and try to rate them from
1 to 3 in terms of helping shifter feel. (1 is best!)
Description | Rating | Price
- - ------------------------------------|--------|-------
Forward Brass Connection (A) | 1 | $10
Lower half of shifter lever (C) | 1 | $30
Nylon bushings for shifter lever(D) | 1 | $1
Shifter rod (B) | 2 | $30
Shifter plate bushings(3) | 3 | $35
Leather Shift Knob | ergonomic improvement ! | $60
==============================
+ Section 18.4: Wheel Cleaners
A: (by Ronald Cheeca:CHECCA@domain.elided)
I've been washing aluminum wheels for many years now, and nothing
replaces elbow grease. Spray on/wash off type cleaners just don't
cut it. They would have to be very strong to break the bonds between the
brake dust and the paint without some scrubbing, and strong cleaners
can be caustic resulting in damage to the finish of the wheel.
I personally use a sheepskin car wash mit (from Imparts for about $8)
and the remains of my wash water and gently wash the wheel. I usually
wash my car weekly and with semi-metallic brake pads, the wheels are not
all that dirty, so the majority of the crap comes off easily with the
mit. If I'm going to Concour the car, I'll use Simple Green, P21s or BMW
wheel cleaner (which is really P21s) and a round China bristle parts
cleaning brush to get into all of the nooks and crannies. All of these
cleaners are gentle on the finish and do a great cleaning job. ZYMOL
sells the round China Bristle brush for about $8, but I've seen it for
much less from Eastwood and Harbor Freight. It works really well too.
>PS: I've tried ALL sorts of wheel cleaners - and so far it's a toss-up between
>the special ones and Simple Green right out of the sprayer! (Simple Green clean
>almost anything!)
I agree - Simple Green works very well, it's easier on the environment
and it smells real good too. It can be reduced with water, although I
can't remember exactly how much water I put in, but it still cleaned my
"not so dirty" wheels well. I think I reduced it around 50%. You can
pick up Simple Green on sale at K-Mart for much less than the specialty
cleaners too.
==============================
+ Section 18.5: Rocker panel coating
A: (by Don Eilenberger:dje@domain.elided)
>The "rubberized?" paint coating on the rocker panels of my '87 325 is
>coming off in places and generally looks ratty. Otherwise
>the exterior of this car looks brand new.
>
>Is there a consumer paint product available that I can use to
>fix this with moderate skill levels and equipment?
Yes, but it's actually two products:
#1 is some semigloss paint - look for something made for
automotive purposes
#2 is harder to find - it is a clear rockerpanel spray on
coating - it purposely leaves the dimpled finish that you
see on your rockers now.
To use, first check for compatibility between the two (try on some scrap metal
first), and then test compatibility with the existing finish on your car
(there isn't any need to removeit if the finished are compatible). Spray some
of the black onto your rockers and make sure it doesn't have a bad reaction
with what is there. (Masking carefully with masking tape and newspaper first
of course!). When the black dries - overcoat it with the rockerpanel spray
(which purposely stays somewhat flexible).
<<<<< (by Sandeep Pathak:uunet!etnibsd!sandeep)
I used Wurth's Underbody Seal Black. I just had to spray it on. Its about
$13 for i can. Its seems ok so far.
=============================
Section 18.6: Water Leaks
A: (by Rick Kjeldsen: kjeldsen@domain.elided)
Water on the (usually passenger side) floor in an E30 is often caused by
a clogged air plenenum drain hose. There is a large air plenun at the
base of the windshield that takes air from the air vents to the heater
core in the center. There is a drain on the passenger side that drains
water that comes in the vents out into the engine compartement before it
can soak in past the gaskets where the heater core punches through the
firewall.
The easiest way to find it is from the engine compt. If you have a
325 (6 cyl) follow the plastic "tube" that holds the plug wires back
toward the firewall. If it were long enough to touch the firewall,
the place it would touch you will see a 3" by 1" by 1/2" rubber hose
comming out of the firewall and pointing down. That is the drain that
gets clogged. You can usually clean it by squeezing it on the sides,
but if it's badly clogged, you can take it off and clean it out.
If you have a 318 or M3, find it by looking at the very inside edge of
the battery tray on the firewall.
=============================
Section 18.7: Plastic Panel Repair
A: (by idickers@domain.elided (Ian Dickerson))
While at the auto paint store this weekend, I learned a neat trick to repair
cracks in non-load bearing plastic, like the bottom of air dams that have
prematurely met the local parking bumpers (and who has NOT ever scraped over
one of these suckers?). Anyway, an unmounted airdam came with my 2002, and
I wanted to repair several cracks before putting it on the car. One of the
cracks is at the top, close to the mounting holes, so I thought I'd epoxy
a plastic brace behind it, but the guy at the counter suggested a much
neater trick.
First, sand the area surounding the crack about 3-4" on each side, clean up
the dust, and use superglue to tack the broken pieces together. Next, use
flexible epoxy to make a bead and cover the crack (on the back, of course).
Finally, use more flexible epoxy to cover a wide area (the area you sanded),
and press nylon material onto the epoxy. This dries as a single skin which
will flex, yet has surprising strength. The counter guy claimed any nylon
fabric would work, but I used ripstop (used in tents and camping gear). I did
this last night, and the results look impressive. This isn't a do-all fix,
but it does look like a good repair for minor cracks and dings.
=============================
Section 18.8: E24 Steering Bolt
A: (by Robert Baron <baron@domain.elided>)
The following is copied from the Sunbelt Chapter BMWCCA July Newsletter,
which quotes John Watts of the Buckeye Chapter as follows:
"Owners of the following BMWs take notice of a potential
problem: all E24 bodies (6 series), all E28 bodies (5 series), early
E32 bodies (new 7 series, 1988 & 1989 models), and early E34 bodies (new
5 series, 1989 model). There is evidence of a design flaw in a bolt
that holds the steering box in place. Out of three vehicles we checked
we discovered one catastrophic failure, one significant deformation, and
only one appearing normal. What I am saying is this: I believe a
questionable bolt may be holding most of your steering boxes in place.
The old bolt part number is 32 13 1 123 865. The new bolt part number
is 32 12 1 136 051 and retails for about $12.00."
I'm just passing this along for what its worth....I'm a lawyer, not a
mechanic...but it seemed of a least some possible passing (!)
significance.
==============================
Section 18.9: Wheel paint
A: (by John Dempsey: johnde@domain.elided)
> * polished would look very nice with the Bristol, but I am concerned
> * about long term effects (if any) on the wheels with leaving them
> * unprotected.
>
> this advice is from a racer's point of view, but may be of interest
> in this context anyway:
>
> you should have the wheels bead blasted to clean/strip them, and then
> have them dye checked for cracks while they're in this state. then
I know where Richard is going with this one. You can probably do a good
job of removing the paint with a good automotive stripper and a high pres-
sure, car wash, type sprayer. Be very, very careful with this stuff-
even wear eye protection. It is *nasty*. But it will get everything off.
Don't get the cheap hardware store type strippers- unless you like being
frustrated and applying several coats. And don't do it in the cold- it
does not work.
You can then buy a dye kit if you like, and easily check the wheels your-
self. There are several sources.
> paint them with a suitable paint; if you are engaged in high performance
> (track) driving, then use a cheap laquer like Krylon. if you are
The idea with the laquer is that it is brittle in comparison to enamels and
polyurethanes. So, if a crack developes, it will be echoed in the paint.
So (hopefully) you will catch it in time before it becomes a problem.
> more interested in having them look nice on the street, there are a
> couple of decent wheel paints from companies like Wurth and VHT.
Wurth is indeed good. With good results. I'd say there is not really a
problem with leaving them unprotected- I guess that corrosion could be a
problem, but I don't think that much. Besides, when aluminum oxidizes, it
radically changes composition. Luckily this also keeps it from oxidizing
farther- kinda like what anodizing is all about.
I will say that looks suffer. And upkeep is higher. So even if my wheels
were completely polished, I'd still clearcoat them. Heck, it even gives
them a deeper shine.
For a gray car, I'd go with a silver/platinum center color, with polished
lips. Although I don't know the style of wheel you're dealing with (either
it was not mentioned, or I did not catch it).
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