PDA

View Full Version : Dodge Vacuum Shift Motor



paweldor
12-03-2008, 06:37 AM
My neighbor has a 98 Dodge Ram 4x4. Told me he was having problems with the thing going in 4x4. I told him my former Dodge had the same problem. Was the Vacuum Shift Motor located on the axle tube. I looked under his truck and discovered the 2 vacuum lines were off the module. I reinstalled them, and still no 4x4. I then did a vacuum check on the lines to insure there wasn't something wrong back at the transfer. Good vacuum.
Sprayed WD 40 in the hose connections, and 4x4 started to work, but no indicator light working on dash. I pulled the connection at the switch, jumped it, and the light worked.

This indicated that the vacuum shift motor (I have no idea why they named this thing that, it's simply a vacuum diaphragm module with a metal rod that operates the shift fork and closes the switch.

Then we got to wondering how the hoses got disconnected in the first place. He does no off roading. However, he recently had suspension work done. We assumed that the truck was put on a lift and while the axles were hanging, the drop on the front axle was so great that the hoses were disconnected.

Anyway, moisture had entered the vacuum chamber and corroded the inside. I pulled the whole gizzmo off yesterday and attempted to clean it up. No dice. It would only partially engage the 4x4 slide. I suggested that even though he HAS 4 wheel drive, it's not fully engaged, and under severe conditions it's possible to tear something up in the slider, or one of the axle tubes. He opted to buy a new "vacuum shift motor". When I changed mine I paid $179 for it. When he returned with his, the price was $297. Here's what he got for those big bucks (naturally this is the old one). What a rip off.

mrmikey
12-03-2008, 06:59 AM
$300 bucks for that, hope he got kissed because he certaintly got screwed. Worst thing is they got 'ya, pretty near impossable to jury rig something up for that.
Buddy of mine a few years back priced a multifunction switch for a Geo Metro as his lights were screwin' up, according to him almost a grand, for a fancy switch....Mike

David R
12-03-2008, 08:05 AM
I have patched a few of them with Epoxy because the body had rusted through. I started patching them once I found how much they cost. Same thing in a jeep.

Chebys are Lectric.

David :)

mla2ofus
12-03-2008, 09:06 AM
I still see nothing wrong w/ locking hubs and manual shift transfer case. Maybe a majority of truck buyers have gotten so dumbed down they can't figure out how to do that.
JMHO,
Mike

farmersamm
12-03-2008, 10:01 AM
I still see nothing wrong w/ locking hubs and manual shift transfer case. Maybe a majority of truck buyers have gotten so dumbed down they can't figure out how to do that.
JMHO,
Mike

I think you're right. Plus you can't even buy a truck nowdays without power everything. I think it's a mistake on the part of the auto makers. A good cheaper truck without all the bells and whistles would sell better.

mrmikey
12-03-2008, 12:02 PM
I still see nothing wrong w/ locking hubs and manual shift transfer case.
Agree 100%, why go thru different process to accomplish something simple. You've got a push button signalling a computer which in turn electrically opens a valve which in turn causes a vacuum on a diaphram to move a rod which in turn moves a linkage. Damn, just move the linkage manually....Mike

Mondo
12-03-2008, 12:59 PM
[QUOTE=paweldor;231843]...This indicated that the vacuum shift motor (I have no idea why they named this thing that, it's simply a vacuum diaphragm module with a metal rod that operates the shift fork and closes the switch. ...[QUOTE]

Definition of "motor" - Something, such as a machine or an engine, that produces or imparts motion. (http://dictionary.reference.com/browse/motor )

So it is a linear motor actuated by application of vacuum (suction).

as to all the fancy automation and power conveniences....
1) People are basically lazy. why walk when you can ride? Why muscle a bug ugly lever when you can just push a pretty little button?

2) The manufaturers (and the dealers) make a greater profit with more "features" installed. Power windows and locks, air conditioning, power steering, power brakes... (well, it might be argued that the latter two are safety items making it easier to steer and stop) all have become almost standard equipment, or at least the norm for vehicles ordered as dealer stock.

Remember when a manual transmission was called "standard"? That was because a manual transmission was standard equipment while the automatic transmission was optional for more money. Today it is difficult to find a vehicle on a dealer's lot that has a manual transmission, even 1/2 and 3/4 ton trucks. Many vehicles today are not available with a manual transmission. Automatic slush boxes are today's standard. The same for all these newfangled power trains. Convenience sells and makes more profit for the manufacturers.

Besides, aren't we all clamoring for more high-tech???? Why think or make decisions when we can have a computer do it for us!!!! If something goes wrong we can avoid culpability - blame it on the computer!

BTW: I once had an '87 Jimmy 4x4 with automatic locking hubs. When one broke I took it back to the dealer and had them install manual hubs. Much better!! :)

-Mondo

Tractapac
12-03-2008, 04:43 PM
I think it's a mistake on the part of the auto makers. A good cheaper truck without all the bells and whistles would sell better.

Maybe when they get their bailout, that's what they'll make??

I see this time though that the three car chiefs are traveling to DC in Hybrids instead of corporate jets. Still 3 x hybrids, why not a regular airline plane? (in economy!) :laugh::laugh:

JTMcC
12-03-2008, 05:07 PM
You can replace the whole thing with a manually (from the cab) operated cable.
I use 4wd in my truck almost every day, way more than the average 4X4 owner, usually several times a day going from off-to-on-to-off road again repeatedly, I'm glad to not have manual hubs to get out and lock in/out. I do have a old school lever on the floor tho.
My vacume is working fine after a ton of use, but when it does go south, it'll be a cable replacement for me. An added side benefit of the cable operated system is 2 wheel drive low range, for backing trailers on hard surfaces.

If you think the price is a rip off, then price what it would cost you to make it yourself, transport it and stock it, in the small numbers that are bought every year.
Our schools really need to do a better job of educating young minds on the (somewhat)free enterprise system and how the cost of goods/services are determined.

JTMcC

farmersamm
12-03-2008, 08:31 PM
Half, or most, of the aftermarket parts are made in sweatshops in China, Mexico, other South American countries. The markup is huge.

OEM parts are, at least from what I understand, production over runs in order to have the parts on the shelf when needed. The same cost/item saving realized in the production run ought to be passed to the consumer.

Also, I've noticed in the past 5yrs. or so, that the price of auto parts from, let's say Checker, are escalating pretty fast. I think someone figured out that the segment of the public that does their own repairs is pretty down on their bucks, relatively speaking. So the retailers figure, Hell it costs so much (x amount of money) to get it done in a shop, so why should we sell the parts for much less than the cost of a commercial repair. They gotta fix the car one way or another.

Then the high cost of parts affects the professional mechanic too, he has to pass it along, making it harder for his customers to stay with him because they reach the point where they can't afford it.

Billdacat
12-03-2008, 08:38 PM
That is robbery! I think this is the same part for almost half the price.
http://quad4x4.com/Dodge%20Frt%20Axle&Steering.htm
PN# QK4904.
A cable shifter is the better option or if you have locking hubs; install a fixed axle.
The Jeep's TJ Wranglers have done away with the axle shifter and hubs. 4WD is disabled at the transfer case; go figure.:drinkup:

JTMcC
12-03-2008, 08:55 PM
Half, or most, of the aftermarket parts are made in sweatshops in China, Mexico, other South American countries. The markup is huge.

OEM parts are, at least from what I understand, production over runs in order to have the parts on the shelf when needed. The same cost/item saving realized in the production run ought to be passed to the consumer.

Also, I've noticed in the past 5yrs. or so, that the price of auto parts from, let's say Checker, are escalating pretty fast. I think someone figured out that the segment of the public that does their own repairs is pretty down on their bucks, relatively speaking. So the retailers figure, Hell it costs so much (x amount of money) to get it done in a shop, so why should we sell the parts for much less than the cost of a commercial repair. They gotta fix the car one way or another.

Then the high cost of parts affects the professional mechanic too, he has to pass it along, making it harder for his customers to stay with him because they reach the point where they can't afford it.



Again, this is a fundamental misunderstanding of the market, as it exists today in the U.S.

There isn't an opportunity for an entire segment of the parts industry to "figure out" something and greatly increase their margins. Because there will be somebody willing to produce the product at the normal margin. This would put everyone charging those incredible rates out of business in about one month or less.
There is a certain amount (on a average over a period of time) that can be made with an investment of X number of dollars. When people take the risk of starting a business, they have a realistic expectation of a certain return on their investment. The market will put them out of business if they make substantially less than that amount, and the market will provide willing and able competitors to undercut their price if they price their service/product at too high of a margin. It's a self governing system for the most part.
When people talk about "being robbed", "incredible profit margins", ect., they are just showing that they really don't understand the costs of doing business and producing a product/service, or they just don't understand the fundamentals of the American free market.
When they talk about "huge markups", they decidedly don't know what they are talking about. Huge, or higher than normal markups are only possible, in our competitive system, when there are very few people capable of doing the work, or when the risk in the work is great.
Otherwise, you have venture capitalists lined up willing to fund companies doing the work at a "normal" markup ten miles long. Again I have to blame this on public schools not teaching the fundamentals of the American markets.

JTMcC.

Magnetic Mechanic
12-03-2008, 09:29 PM
Agree 100%, why go thru different process to accomplish something simple. You've got a push button signalling a computer which in turn electrically opens a valve which in turn causes a vacuum on a diaphram to move a rod which in turn moves a linkage. Damn, just move the linkage manually....Mike

Here is how we do it in AR

<embed width="448" height="361" type="application/x-shockwave-flash" wmode="transparent" src="http://i459.photobucket.com/player.swf?file=http://vid459.photobucket.com/albums/qq318/magmek/Power_Wi.flv">

Magnetic Mechanic
12-03-2008, 09:39 PM
OEM parts are, at least from what I understand, production over runs in order to have the parts on the shelf when needed. The same cost/item saving realized in the production run ought to be passed to the consumer.

I May be Wrong, BUT- It is my understanding that Parts on the shelf (better known as inventory) Are no longer deductible, and since they require investment, they're history. Thats how JIT production came about. Then again I may be wrong.

farmersamm
12-03-2008, 09:50 PM
OEM parts are, at least from what I understand, production over runs in order to have the parts on the shelf when needed. The same cost/item saving realized in the production run ought to be passed to the consumer.

I May be Wrong, BUT- It is my understanding that Parts on the shelf (better known as inventory) Are no longer deductible, and since they require investment, they're history. Thats how JIT production came about. Then again I may be wrong.

I'm all screwed up again(not the first time:D). I guess it's hearsay, but I thought there was a regulation, or industry standard, that applied to making parts available for cars x no. of yrs. after manufacture. I think it applied to the automakers, but I'm not sure. If that was the case, the overrun is expected part of doing business. I'm probably way off.

Magnetic Mechanic
12-03-2008, 10:05 PM
I'm all screwed up again(not the first time:D). I guess it's hearsay, but I thought there was a regulation, or industry standard, that applied to making parts available for cars x no. of yrs. after manufacture. I think it applied to the automakers, but I'm not sure. If that was the case, the overrun is expected part of doing business. I'm probably way off.

Well you can make parts available without front loading them - theoreticaly you dont need parts til lthe vehicle ages

Yes i am dislexic - but my wife said the spell checker don't work, and i'm tired of opening it.

farmersamm
12-04-2008, 06:45 AM
Well you can make parts available without front loading them - theoreticaly you dont need parts til lthe vehicle ages

Yes i am dislexic - but my wife said the spell checker don't work, and i'm tired of opening it.

Ok, by the light of day, I see what you're sayin':laugh:. Besides how are they going to know what the high failure, or high wear parts are going to be?

MarkBall2
12-04-2008, 09:32 PM
Go here for Posi-lock (http://www.4x4posi-lok.com/app_dodge.html)

On Flea-Bay (http://cgi.ebay.com/ebaymotors/85-93-DODGE-RAM-TRUCK-RAMCHARGER-POSI-LOK-4X4-ACTUATOR_W0QQitemZ300271786725QQcmdZViewItemQQimsx Z20081108?IMSfp=TL0811081010009r16730)

I agree things have been "dumbed down". My girlfriend won't drive the mini-van, calls it a "mommy van". Only wants to drive the truck. I tell her the van gets twice the mileage the truck does, she doesn't mind........................ :mad: