Why is speed proportional steering a bad thing - JeepForum.com
Search  
Sign Up   Today's Posts
User: Pass: Remember?
Advertise Here
Jeep Home Jeep Forum Jeep Classifieds Jeep Registry JeepSpace Jeep Reviews Jeep Gallery Jeep Clubs Jeep Groups Jeep Videos Jeep Events Jeep Articles
Go Back JeepForum.com > Models > Jeep Grand Cherokee & Commander Forums > ZJ Grand Cherokee Forum > Why is speed proportional steering a bad thing

Poison spyder items @ oconee off road 706 534 9955Ruffstuff Axle Simple Swap Kit!The Ruffstuff NOT Universal 4 Link Kit!

Reply
Unread 01-24-2014, 04:02 PM   #1
RoldGold
Registered User
1996 ZJ 
 
Join Date: Jun 2013
Location: Philadelphia, PA
Posts: 284
Why is speed proportional steering a bad thing

Over the past couple weeks I've noticed quite a few forum posts that say to avoid the 96 PS pumps that have the proportional steering. I've got it, and this being my first car, I don't know what's bad about it. Why should I avoid it/should've avoided it?

__________________
1996 Grand Cherokee Limited 4.0L
PSC Steering Gear; NP249 w/ new VC; Moog TRE's, Track Bar, Stabilizer bar bushings and endlinks, control arm bushings
Still no lift, and almost no paint on the hood
RoldGold is offline   Reply With Quote
Unread 01-24-2014, 05:01 PM   #2
shaban
Registered User
1996 ZJ 
 
Join Date: May 2012
Location: Yarraville, VIC, AU
Posts: 413
Nothing's wrong with it. Speed proportional steering uses a different spool valve in the steering box and a different pump, so they are not not interchangeable with regular pumps/boxes, only as a set.

So if you've got a speed proportional steering, you can only swap in SP pump and SP steering box.
If you've got a regular steering, you can only swap in regular pump and regular box.

I've put a non-SP box from an XJ into my ZJ when mine blew (it was a SP box) and it worked fine, however there's something in the FSM that says "steering response may be affected if doing so".
shaban is offline   Reply With Quote
Unread 01-24-2014, 06:20 PM   #3
KJK
Registered User
1998 ZJ 
 
Join Date: Jan 2007
Location: Dallas, Texas
Posts: 891
The "bad" part is the components are more expensive when it comes time to replace them. Other than that, it's fine.
__________________
5.9 ZJ SCT tuned PCM/ KJK CAI/ Thorley headers with 3" Magnaflow cat and muffler/ Modded kegger/ TransGo shift kit/ Vanco brake kit/ Braided steel brake lines/ Mopar cupholder insert!
KJK is offline   Reply With Quote
Unread 01-24-2014, 06:36 PM   #4
Purcell69
Registered User
1993 ZJ 
 
Join Date: Apr 2010
Location: Oklahoma
Posts: 242
When combined with a five speed MT, it can be annoying. There is nothing worse than turning to pull in to a parking space in a crowded lot, pushing in the clutch to coast in and having the engine drop to idle and at the same time, the PS feels like a manual steering box all of the sudden. Usually I "blip" the throttle while holding the clutch. After 21 years with this Jeep, I am used to it, but it still surprises me from time to time.

-Joe
Purcell69 is offline   Reply With Quote
Unread 01-24-2014, 11:24 PM   #5
KJK
Registered User
1998 ZJ 
 
Join Date: Jan 2007
Location: Dallas, Texas
Posts: 891
Quote:
Originally Posted by Purcell69
When combined with a five speed MT, it can be annoying. There is nothing worse than turning to pull in to a parking space in a crowded lot, pushing in the clutch to coast in and having the engine drop to idle and at the same time, the PS feels like a manual steering box all of the sudden. Usually I "blip" the throttle while holding the clutch. After 21 years with this Jeep, I am used to it, but it still surprises me from time to time. -Joe
It should have the most assist at idle and less as the rpm increases.
__________________
5.9 ZJ SCT tuned PCM/ KJK CAI/ Thorley headers with 3" Magnaflow cat and muffler/ Modded kegger/ TransGo shift kit/ Vanco brake kit/ Braided steel brake lines/ Mopar cupholder insert!
KJK is offline   Reply With Quote
Unread 01-25-2014, 01:32 AM   #6
5-90
Registered User
1988 XJ Cherokee 
 
Join Date: Sep 2006
Location: San Jose, CA, Hammerspace
Posts: 5,344
I don't like it because I expect consistent behaviour from my vehicle's systems, I don't like it when they change for whatever reason.

I don't like ABS for the same reason - and it gets all screwy when I "feather" the brakes to slow down, as I was trained to do.

I definitely don't like any system that I can function without, don't want to pay for, but am forced to have anyhow (ABS, for starters.) I don't like "safety devices" that allow a driver to abdicate responsibility - since I was trained to take responsibility for anything that happens as a result of my maintenance or operation of a vehicle. I don't like the trend toward "smart" cars that allow stupid drivers.

"Feature creep" in creature features is bad enough - but when it's mandated as a "safety push," I draw the line. Your #1 safety device is that mushy 1800cc or so between your ears - if you can't use that properly, then nothing else will be of any help to you (if you can use it properly, you don't need anything else.)
__________________
"recon" (sic - reckon)(tm) "hihgly"(tm) "seceed"(tm)
"Outback AIDS - Alcohol-Induced Dizzy Spells"
5-90 is offline   Reply With Quote
Unread 01-25-2014, 09:58 AM   #7
Technohead
Old School
 
Technohead's Avatar
1998 ZJ 
 
Join Date: Dec 2008
Location: Exeter, RI
Posts: 6,586
Exactly, the more complicated it is the more that can go wrong.
Technohead is offline   Reply With Quote
Unread 01-25-2014, 10:15 AM   #8
dusterdude
Registered User
1996 ZJ 
 
Join Date: Jan 2012
Location: hopewell, va
Posts: 2,044
Not sure about stupid drivers,but lazy sure fits the bill
dusterdude is offline   Reply With Quote
Unread 01-25-2014, 02:53 PM   #9
Purcell69
Registered User
1993 ZJ 
 
Join Date: Apr 2010
Location: Oklahoma
Posts: 242
Quote:
Originally Posted by KJK View Post
It should have the most assist at idle and less as the rpm increases.
That's funny. At idle the PS has a 50/50 chance at being normal or sluggish and has always been that way since day 1 (new). Above idle, the PS feels normal. I just figured it was proportional steering, as was told by the dealer about 20 years ago. It's been annoying, but if it ain't broke....

Now you've given me a reason to try and fix it. Damn.

-Joe
Purcell69 is offline   Reply With Quote
Unread 01-25-2014, 04:13 PM   #10
shaban
Registered User
1996 ZJ 
 
Join Date: May 2012
Location: Yarraville, VIC, AU
Posts: 413
As far as I know, PS just reduces the amount of assist at 40+ speeds, full assist at idle or slow speeds.
Mine's working fine at idle by the way, and I've got a speed proportional.
shaban is offline   Reply With Quote




Jeep, Wrangler, Cherokee, Grand Cherokee, and other models are copyrighted and trademarked to Jeep/Chrysler Corporation. JeepForum.com is not in any way associated with Jeep or the Chrysler Corp.