highway speed in full time 4X4?

With a vehicle as short as a Jeep, locking the rear wheels will cause it to go snaky like a bike does, but you can't lean out of it. A bike also has the gyroscope effect big time with at least the front wheel still.

A longer vehicle will also act the same, but it is a bit more forgiving so you can maybe hold it straight with the steering wheel.

Once it breaks free, not many people can hold the vehicle straight.

Locked up the rear tires slide way faster than the free turning front ones.

We used to do this on purpose when racing on ice roads or frozen lakes to help get around corners faster.

In part time 4x4 when you lock up the brakes, all 4 wheels lock for the reasons you think.

This just up and slides you sideways into the ditch or straight off the corner.

This action is a fast 'low side finder' like a locker on ice and is one reason I think you see so many SUV's calmly sitting sideways in the ditches during snow storms.

I always highly recommend folks new to 4x4 hit an empty parking lot and try it out come first snow. The braking action in 4x4 is like nothing else you have ever driven.

Mike

86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00 88 Cherokee 235 BFG AT's

Tim Hayes wrote:

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Mike Romain
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On 08 Jan 2004 06:13 AM, Mike Romain posted the following:

You could call it a proportioning valve. 8^)

---------------------------------------------------- Del Rawlins- del@_kills_spammers_rawlinsbrothers.org Remove _kills_spammers_ to reply via email. Unofficial Bearhawk FAQ website:

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Del Rawlins

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L.W.(ßill)

Or on a combination disc/drum brake system or pure drum/drum or anywhere that weight transfer unloads the rears so they tend to lock up if fed the same hydraulic pressure as the fronts.

Actually I've been wondering why this topic is relevant for Jeeps? Is the addition of a brake proportioning valve some sort of recent ["recent" in terms of someone other than Bill H.] mod or something?

I can remember drum/drum brake systems that had a proportioning valve to send more to the front brakes to avoid rear lockup due to weight transfer waaayyyyy back on sports cars and in the 60's on 'merkin ones.

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L0nD0t.$t0we11

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L.W.(ßill)

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Will Honea

I know... you can call it "Brake System that Anti-locks" or BSA

(this is starting to read like the debate CRWLR and myself had about gear ratios... terminology differences)

-- JimG

80' CJ-7 258 CID 35" BFG MT on 15x10 Centerlines D44 Rear, Dana 30 Front. SOA 4.56 Gears, LockRight F&R Dana 300 w/4:1 & Currie twin sticks Warn X8000i w/ dual batteries

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JimG

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L.W.(ßill)

That's interesting to know. Next time we get a little snow, I'm going to have someone watch me in an empty parking lot, and test this out. I had always thought I was locking up all four wheels when I hit the brakes pretty good in slippery conditions.

...One of these days I'll know enough to be knowledgeable and not just enough to be dangerous ;-) ...

Reply to
Bob

Agreed.

I guess I will call it a combination valve like it is with a proportioning part in it.

It is a dynamic proportioning valve too though.

And it's only design or purpose is to provide rear anti lock brakes, 'Not' 'ABS' as folks today think of it, but 'to prevent rear brake lockup'....

Damn I wish I could find those old advertisements, then I would call it exactly like it was sold as.

Mike

Del Rawl>

Reply to
Mike Romain

Jeeps got the combination valve in 74 according to one of my manuals to prevent rear wheel lockup under hard braking.

Mike

"L0nD0t.$t0we11" wrote:

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Mike Romain

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