No ABS with Dana44?

I recall reading that if you opted for a 44 in your XJ you could not get ABS, is this true or are there a few ABS models floating around? Hitting the bone yard soon and going to see if there are any worthy parts for Xnowyte. Thanks

XJguy

As far as I know,the ABS option was only available with the Dana 35 rear. I *could* be wrong,but that's what I've always thought/heard.

A guy I knew was replacing his D35 w/abs with an 8.8. As it turns out, the 8.8 has exactly twice as many 'nubs' on the tone ring. His plan was to remove every other one on the 8.8. I don't know if it ever worked, but I have always wondered. Don't even know how to contact him anymore. His name is Mike Meyers, he knows Glenn Baker but probably hasn't been in touch with him in a while either. He was on JU to as MMeyers, I believe, so if you are curious, he'd be the guy to ask.

YEA Y?????? ABS is shuch a waste of time and money for off roading! when i put my 8.8 in i just cut the abs lines!!!!! who NEEDS EM!!!!!!!!!!

stoney

I realize that for offroading its not a good idea, I even have an article on this floaring around the web, but since my Jeep spends 99.9% on the asphalt I might as well use what I have.

XJguy

What size tires are you running on Xnowyte? If they are bigger than stock, I seriously doubt that you will be able to lock the brakes up on dry roads anyways. Are you trying to keep abs for winter driving?

35" x 12.5 are on the way..and youre right I have yet to lock up the tires even with the 33"

XJguy

yea my jeep is a daily driver too and abs wouldn't help in any sitution i have been in yet!! so i wouldn't even waste my time trying to figure it out!

stoney

87 - 89 had the D44 - ABS started in 89

I have never seen ABS on the early D44's - and almost never seen ABS prior to 90 altho it supposedly was available in 89?
The early ABS is nothing but trouble - just delete it.

You're better off removing the ABS, ESPECIALLY for winter driving. The only situations where ABS might give you an edge is either in the rain, or on glare ice (in both cases, hydroplaning is the issue). In slush or snow, you will have shorter stopping distances if you are able to lock up the tires and dig in.

I removed the ABS when I swapped in the 8.8. Glad that I did because I would rather do the driving instead of the jeep doing it for me.

Hydroplaning on ice? I've never heard of this phenomenon before! I've always felt that locking up the wheels on any surface will increase stopping distances. Locking up the wheels is breaking traction and traction is the only thing stopping you.

On ice at or near the freezing point, the friction from the tires travelling over the surface of the ice will be just enough to create a very thin layer of water between the ice and your tires. This layer is what causes the hydroplaning. In regions where the temperature is far below zero, traction on bare ice is noticably better. You can experience the same thing on a hockey rink right after the Zamboni has resurfaced the ice, and there is still a film of water on the ice. Go out and walk across the ice in a pair of sneakers (carefully...!), then wait a while until the surface has frozen hard, and do it again.

As far as being able to lock up your tires = shorter stopping distances in the snow, ask any ice racer or rally driver and they will confirm that under certain snowy conditions, you can improve stopping distances by locking up your tires. This allows the tires to dig into the snow, increasing contact area and producing a mild snowplow effect. I also recall reading several test articles in car magazines that confirm this (as well as my own personal experience driving in the snow and ice racing here in the Northeast). Skidding on dry or wet asphalt obviously does not produce the same result. Keep in mind that when you lock up your front tires, you aren't going to have steering control....

What about leaving the front ABS hooked up? Just curious, I'm in the same D35ABS boat.

This is just a guess, but if you disconnected one end (the rear) of your vehicle's ABS system, wouldn't the computer think that the rear wheels were skidding (since there would be no signal from the rear, same as when the wheel was not rotating) and therefore reduce line pressure to those wheels?

Or are you talking about physically re-routing the brake lines from the master cylinder itself? (bypassing the ABS pump)

no when u cut the rear the computer jsut kinda shuts the computer down so the abs jsut doesn't work anymore and it defaults to standard operstaion conditons!

my fronts are still hooked up! but i know the abs doesn't work!

i am still one day going to change over to non abs system cuz mine sux!!!! but the ABS is not a problem!!

take it from me i know!!!!!!! i idid it!!!!!!!

stoney!

trying to keep abs would be the biggest waste of time and money. you can stop quicker w/o abs than you can with, and thats no bs. i learned all about why abs is like richard simons from behind the wheel situations at summit point raceway.

Hunter

jalehman said:

I've always felt that locking up the wheels on any surface will increase stopping distances. Locking up the wheels is breaking traction and traction is the only thing stopping you.

Click to expand...

I've always thought, from a physics perspective, that this is 100%theoretically correct . . . but not accurate for the real world.

The reason being that when locked up (despite the loss of some traction when this happens), there is still significant friction to the roadway (on pavement - the tires leave a trail of rubber that has ground off and melted to the asphalt - this is pretty significant friction!).

The traction IS slightly better just before locking the tires up, but it is not physically possible for a human being to modulate the brakes (due to reaction time of the driver and delays in the braking system) to keep the braking system just short of locking up - sometimes you press too hard and the brakes lock, sometimes you press too lightly and you get almost no braking effect. The net effect is that a human driver (that includes most of us ) will almost always stop shorter "locking her up," over trying to modulate the brakes. No steering control, but shorter overall stopping distances.

A properly set-up ABS is designed to overcome the human's shortcoming to balance on the edge of locking up, while maintaining steering control - although, it still won't stop as quickly as the theoretical limit says is possible.

I hope someone can tell me if my understanding is correct.

Well the theory (and practice) behind not locking up your tires on the pavement revoves around that layer of rubber you grind off your tires. The rubber that grinds off your tires will form small balls of rubber that act like small ball bearings between the tire and the road surface. This really reduces the coefficient of friction of the tire on the pavement. (ever see a race car on a track when the driver moves out of the groove, up into the "marbles"? These marbles are the small balls of rubber that have been shed by the tires during the race, and if a driver drifts into this area, he will almost always slide right up into the wall from lack of traction.) This issue never shows up in the snow/ice since the surface is not abrasive enough to remove rubber from the tires.

Traction on ice is 99% due to the tire compound, and ice tires have soft compounds with high silica content which makes them hydrophillic, or attracted to moisture. There are also some tricks with the rubber such as incorporating microbubbles into the rubber itself. When the tire wears, it exposes these small bubbles and the result is increased surface area, as well as a mild "suction cup" effect on bare ice conditions.

Traction in snow revolves mostly around tread pattern. True modern snow (not ice) tires try to compress the snow and form it into whatever pattern the tread happens to be. And, it's been found that the most effective traction pattern for the contact patch is many many small lugs, or sipes, on snow tires. The days of big ol' diggers for snow tires are gone. Big heavy lugs will dig through the layer of snow, rather than use the snow's cohesive qualities to their advantage. Check out a set of Blizzax's, or Michelin Alpin snows, or my personal favourites, a set of Hakkapeliitta snows. They all have relatively tame looking tread patterns, but are designed to compress the snow into the many hundreds of sipes and voids in the tire, and use the snow's tendancy to stick to itself for traction.

With our Jeeps, we all run A/T or M/T style tires, and we use them year-round. This type of tyre will behave the same in snow and slush the same way that older generation snow tires did - they will be most effective when they are allowed to dig into the snow, rather than just float across the top. This is why ABS increases stopping distances with these types of tires: the ABS prevents the tire from locking up, which keeps it from being able to dig in. This is the braking equivalent action of spinning a tire in the mud to clear it in order to gain maximum forward traction.

And once again, always keep in mind that when you lock up your front tires, you have lost your ability to steer.....locking up your tires is only effective when trying to stop in a straight line.

This thread has seemed to digress from the original subject a wee bit!!