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View Full Version : Am I hurting my VX transmission?



Lease-V-cross
08/02/2005, 04:42 PM
Sometimes when I am cruising along and I am coming down a steep hill, I downshift to 3, then 2 and possibly 1st gear.
Therefore saving my brakes.
This is a good thing, correct?
I never sit at a red light in 1st gear and race anyone, taking my VX up thru all the gears. I don't think that's a wise thing to do anyway.
Also, does anyone else's VX make a "clunk" when changing gears? I think it happens mostly when I go from Drive to Park... or Park to Reverse.
What is that noise? Is my transmission going?

thanks!

WyrreJ
08/02/2005, 06:24 PM
No. compression braking was a good thing like 20 years ago. Modern brakes are a lot longer-lived than they used to be, so now compression braking does more harm than it does good.

As for sitting in 1st at a red light, that's where you ought to be anytime you are stopped unless you've got unusual conditions like a really icy road. If you leave it on automatic that's where the AT will go on its own.

The VX is my first and only automatic, but I really see no reason to manually shift during normal operation.

thebear54
08/02/2005, 07:14 PM
I have always used 3rd and 2nd downshifts when I cruise down a steep hill in every imaginable vehicle and have never had any tranny problems. Like you said it saves on the brakes.
The clunking you are hearing when you shift from park could be weak U-joints. When was the last time you greased them? Grease them up and you might hear a big difference. There are three fittings on the VX drive line so it doesn't take very long.
John

Lease-V-cross
08/02/2005, 07:18 PM
I'm not much of a mechanic....where are these "U joints" you speak of ? (sounding like a cave-man )

Moncha
08/02/2005, 07:34 PM
Looking under your VX, the long tubular thing that runs the length of the vehicle is the drive shaft. The U-Joints are at the points like where the driveshaft meets the transmission, the rear axle and in the middle.

MZ-N10
08/02/2005, 08:23 PM
well...if u look in the vx manual they acutally tell u to down shift down hill, i think it was called engine braking.

transio
08/02/2005, 09:08 PM
I know for a fact that engine braking is not suggested in a high performance manual car (clutches are way more expensive than brake pads). Not sure about an automatic, though...

SGT.BATGUANO
08/03/2005, 12:01 AM
Engine braking does just that, it reduces your speed by tranferring energy in reverse order through the driveline . It also causes extra wear on those components, especially the timing belt/chain. Use the brakes unless you're in exceptionally steep, hilly terrain.

MachineVX
08/03/2005, 05:00 AM
Brakes are a lot cheaper than transmission . . .

VehiGAZ
08/03/2005, 05:59 AM
Amen to that, MachineVX! Yes, everyone is correct that engine-compression braking saves wear on the brakes, but you all have to go the rest of the way with that thought... "engine-compression braking saves wear on the brakes ...at the expense of your clutch and drive-train. Brake pads are cheap compared to a new clutch, friends.

That said, it is perfectly ok and highly recommended to use gears 2 and 3 for keeping your car from accelerating while descending a steep hill, especially on wet or snowy roads. But that assumes you are at the speed you want to be at before you downshift. Downshifting to slow the car down is a lousy idea.

V-Twin hiCROSS
08/03/2005, 10:02 AM
Does anyone have a list of all of the grease fittings on the VX, and with maybe a brief description of where they are located? I could not find many.
Thanks

thebear54
08/03/2005, 06:00 PM
There are only three you have to worry about.
All three are on the driveshaft, one at each end(U-Joints) and one in the center. All you have to do is crawl under there with a grease gun (loaded of course :p ) .
Grease the U-Joints until just a little grease filters out. The center one reqires a little more that a few cranks. Just look for the tiny nipples (sorry),those are called fittings or zirx, thats where the grease goes.
That "should" take care of the clunking sound when you shift.
Good luck!!
John

VehiX
08/04/2005, 01:27 PM
What type of grease should be used for this process for those not in the know :confused:

Moncha
08/04/2005, 01:55 PM
Hi temp grease made for universal joints or an equiv.

V-Twin hiCROSS
08/05/2005, 05:37 AM
Moncha,
Is that different form the regular grease that I have always used to grease our vehicles?

Moncha
08/05/2005, 07:20 AM
There are some all purpose greases that can meet the requirements, but mostly standard chassis grease is not made for u-joints. You want to make sure. Read the lables. Last thing you want is for the driveline to break down due to the break down of your grease..

Jolly Roger VX'er
08/05/2005, 01:16 PM
I personally have always did both...dropped her into 3rd on the VX Auto as well as periodically braking which when in combination keeps both the rpms down and allows the pads a chance to cool. I've always driven this way even with a manual trannie and have never observed any ill effects...my Fiero clutch lasted 209,000 miles before she expired..by then it was time to junk the car...lol.

Actually when John and I descended Mt. Equinox during the VX-Plore 1 meet I also made use of the Emergency brake as they are separate pads....so I was engine braking....while braking....while occassionally pulling up on the E-brake to let the main brakes cool...I did this whenever the descent leveled off so as not to put a strain on the e-brakes either.

thebear54
08/05/2005, 07:16 PM
Man did we put the brakes and trannies to a good test up there on that mountain. That 7,000+ drop down the mountain really showed that the VX was up to the challenge. I did it again about two weeks after the meet...2nd and 1st all the way down using the E-Brake once in a while...what a rush!!! and hairpins like you would not beleive. Blew out my little flexible exhaust pipe on the second run because of compression but the brakes never got warm.
John

Jolly Roger VX'er
08/06/2005, 06:17 PM
Hey John, if you ever put together another meet, (fall colors would be good! hint..hint!),
count me in! I'd love another crack at ole Equinox...especially the ascent part with hopefully cooler conditions...lol. That 90's crap made me a little nervous the last time even though all turned out well.

thebear54
08/06/2005, 06:31 PM
Sounds like it might be a possiblity Greg....I'll let you know :)
John

iownvx
08/06/2005, 09:41 PM
The reason to use engine breaking is so that breaks do not overheat and stop working. It is really for safety.

SGT.BATGUANO
08/07/2005, 02:40 AM
The reason to use engine breaking is so that breaks do not overheat and stop working. It is really for safety.

Maybe in a racing situation where the brakes get red hot, or could fade ; where the engine is made to handle the stresses of downshifting.

Regular driving and wheeling shouldn't overheat our brakes. Save the engine unless your driving on a grade.

The brakes are designed to be safe under normal conditions.

pbkid
08/09/2005, 04:45 PM
well if it makes you feel any better about your clunking my car does it too, when i shift from park to drive. especially on a hill. im gonna try to grease my ujoints hopefully that will help the problem. it has been worrying me too.
pbkid