cv joint and wheelbearing grease, with a twist.

[cryptokid]

looking for a good grease for wheel bearings and cv joints on a miata, however my primary concern is not cv/bearing life, but fuel economy. if you ever held a cv joint in your hand and noticed how difficult it is to turn, compared to when it is dry. same goes for a wheelbearing.

so i am looking for a grease to significantly reduce the resistance encountered in there drivetrain devices, that is my primary concern, my secondary convern is life of the joints/bearings.

can anyone recomend a grease to fit my needs?

 

[JohnBrowning]

most CV joints reqire Krytex(sp) grease. I have always used a moly fortified grease and never had any problems!

 

[widman]

I'm using Chevron Black Pearl. I like it's adhesion and mainenance of consistency.

 

[cryptokid]

will any of these greases give me a fuel economy increase?
what about filling up motor oil in the cv joint?

 

[MolaKule]

Try this:

http://www.myoilshop.com/AutoPrds.html

No MO, not enough EP additives nor enough adhesion or tackiness.

 

[geeeman]

cryptokid...

Put your Miata on the slightest slope in neutral.
Your car WILL start rolling.

There is so little rolling resistance in the mentioned components that it seems like a waste of time, effort and money to try and improve on it.

Pump your tires up a few PSI, it will cost nothing and will help MPG ever so slightly.

 

[porterdog]

quote:

---

Originally posted by geeeman:
Put your Miata on the slightest slope in neutral.
Your car WILL start rolling.

---

Excellent real world test! I agree- the Miata is an _easy_ car to push.

 

[cryptokid]

it is not so easy to manually spin the drive wheels by hand. there HAS to be a way to gain some efficency by using a thinner viscosity no?

 

[tdi-rick]

On race cars to enable the CV's to plunge and operate more freely I used to use a flapper wheel on the die grinder to relieve the races, and a grinding wheel to relieve the cage slightly.

This made a huge difference, particularly when new. Sometimes the balls and cages were so tight on new assemblies that lightweight cars like Formula Fords would actually hop on the track in situations where you experienced large amounts of suspension movement, due to the binding of a new CV.

I always used Neo CV joint grease (CV 500, I think)and a Neo synthetic wheel bearing grease.

We sometimes would use 7wt gear oil instead of 75W-90 (less drag), particularly in cold weather. Also we would minimum fill the Hewland 'box, (600ml instead of 1 litre) again less drag (splash lube transaxle).

The thing is, we were after ultimate performance and prepared to rebuild things if they failed, but this is a road car, why risk it ?

[ February 16, 2004, 04:34 PM: Message edited by: tdi-rick ]

 

[cryptokid]

cv joints are $10 a piece. wheel bearings, free.
transmission is $50, the price of a ruined component is of no concern and i have AAA, they will tow me up to 150 miles no charge so being stranded is of little concern as well. everywhere i need to go is within 150 miles from my house, my dads house, my mothers house, or a friends house.

why i want to do this, is basically just to see how much fuel efficency i can eek out of the thing. my curiosity has the better of me and i am willing to trade a bit of component life for some more mpg, in the name of expirementation!

somtime in the future i plan on re packing the wheel bearings, and replacing the cv joint boots as they are starting to crack. i figured this would be a good time to put in some more fuel efficent lubes!

against the owner manual recomendation, i am already running 0w30 mobil 1 long life, (am suppose to be on 40wt or 20w50 because of the hot florida weather.
the trans is filled with the thinnest oil i could find, MTL, which is thinner than the owner manual says to use.

so you think neo grease would be good? ill check them out.

 

[XS650]

quote:

---

Originally posted by cryptokid:
it is not so easy to manually spin the drive wheels by hand. there HAS to be a way to gain some efficency by using a thinner viscosity no?

---

Crypto, are you spinning both rear wheels together? If you aren't you are feeling losses in the differential spider gears which aren't very efficient and don't come into play unless you are turning.

A lot of real heavy duy applications use oil instead of grease for tapered roller wheel bearings. If you want to experiment, that might be the way to go. You would obviously need seals that are in good shape and you would need to determine how much oil to use. You need enough oil that both bearings get oil when the centripidal force has evenly distributed the oil around the outside of the bearing cavity. If you don't use enough oil you will toast the smaller diameter bearing. You shouldn't need more than a 30 weight. You could probably get by with a 20 weight, maybe less.

You would also need to add a fill plug to the bearing hub cap.

It looks like you could do it to Miata front wheel bearings (i think they are like these RX-7 bearings), don't know about the rear.
http://www.mazdatrix.com/faq/frontbrg.htm


I think you are chasing after differences that are too small to notice, but more power to you and experimentation.

[ February 16, 2004, 06:53 PM: Message edited by: XS650 ]

 

[Kestas]

Keep in mind it's not so much the grease as it is the seals that cause drag.

Our testing facility has just developed a new rig to test drag in a bearing. The issue of drag from seals often comes up, but not so much drag from the grease.

There is so much more the grease has to resist than friction... it has to resist water, temperature, oil bleed. Life under adverse conditions is the number one concern for a bearing.