Another Quadra Drive Vari-Lok thread.... - 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 > WJ Grand Cherokee Forum > Another Quadra Drive Vari-Lok thread....

*VOTE NOW Help Metalcloak Giveaway an XJ Suspension*Stainless Steel Door Hinge PinsPoly Door Hinge Bushings

Reply
Unread 02-06-2013, 01:46 PM   #1
lazyWJ
Registered User
2002 WJ 
 
Join Date: Feb 2013
Location: halifax, ns
Posts: 813
Wj Another Quadra Drive Vari-Lok thread....

Hi all. This is my first thread here, I hope it's not redundant. I have been scouring the net for a while reading up on QD and the vari-lok axles. There seems to be a wide range of opinions on this setup. I've read a lot of negative reviews even from when they were new, and some positive ones even on older used ones (which they pretty well all are now).
Either there is a wide variance in performance, or a wide variance in expectations. I've only had my WJ QD a few months and I can say that my impressions are mostly positive, but I'm also not sure the system works as Jeep claimed it should (to be fair, I'm not sure it doesn't either, I am going to do some measurable tests).
I'm going to run some tests to measure the performance as it is, with 145k kms on it, and whatever fluid is in the axles as a baseline. For all I know it might be the factory fill lube. If I'm lucky I'll round up some other local QD's and put them through the same test. What I'm curious to find out is if there's a correlation between "locking" performance and the amount of FM used. The general consensus is that the more FM, the less chatter and more slippage. What I want to find out is if the "locking" performance of the diffs improve with diminishing levels of FM, or if it just makes them horrible to live with.
Obviously a certain amount of FM is required to make the system work properly, but is it as much as is specified? I wonder how consistent Chrysler was in metering out the FM, and whether or not they may have factory filled with more than required, possibly accounting for reported poor performance of the systems even when new. Clearly they would get more complaints from customers about chatter than poor off road performance, so it's not hard to imagine why that might happen.

I've been looking to find if anyone has ever tried to "tune" a vari lok by adjusting the FM content, but haven't come up with anything conclusive. Why bother? Well from what I can tell, QDI is a bit of a dark horse of 4wd systems, or at least it could be if it works as it should. Locking diffs are a big deal off road, and QD Jeeps are relatively inexpensive and plentiful these days. If there's a way to tweak or diagnose the system, I'd be curious to find it. Of course these will never equal a selectable locker in most situations, but if you've already got them sitting under your Jeep it would be nice to get them working as well as they possibly can.
What's my point? Just throwing the idea out to see if anyone has already sorted this out, and if not, I welcome any suggestions on how to proceed with testing. Or perhaps nobody cares? It seems that QD has bit of a bad rap outside the Jeep community, and I'd like to see if it's justified.

lazyWJ is offline   Reply With Quote
Unread 02-06-2013, 02:04 PM   #2
jeep04
Registered User
2004 WJ 
 
Join Date: Dec 2010
Location: South park, pa
Posts: 934
After the last thread on transfer cases i am not making any statements on how they work or suggesting the use of wjjeeps for that info since according to some that is bad info. But i can say that i do not have anything bad to say and am happy with my QD and it has only left me stuck once which was a few weeks ago in the snow but it was more a drivers error then vehicle malfunction. Let us know what you find out, as i think i have to much FM in now do to using royal purple fluid and adding what chrysler calls for in FM on top of whats in the purple.
__________________
04 Jeep wj Limited 4.7 <> 6.5" Iron Rock long arms front & Adjustable lowers on rear <> Bilstein 5100's <> 285/70r17 Goodyear Duratracs <> M/T black classic lock wheels <> Addco swaybars <> Superchips 3875 <> Magnaflow Stainless exhaust <> 2 Kicker comp 12's <> Kenwood head unit.
jeep04 is offline   Reply With Quote
Unread 02-06-2013, 02:12 PM   #3
Planetcat
Registered User
2004 WJ 
 
Join Date: Jan 2010
Location: West of the Mississippi
Posts: 1,410
Wj

Quote:
Originally Posted by lazyWJ View Post
... It seems that QD has bit of a bad rap outside the Jeep community, and I'd like to see if it's justified.
I'm gonna try not to sound inflamatory, but that there makes no sense. That's like saying I read that a steak tastes terrible from the vegan community. I read a lot of internet BS on jeeps, and have never read a bad "review" on quadradrive or vari-lok if it was used for it's designed purpose and under it's designed loads and conditions. I have a detroit true trac in front and a vari-lok in the rear, and I can tell you that they perform very similar to each other. Maybe the true trac engages a little faster and tighter, but almost unnoticeably so. And the true trac is arguably the best limited slip in the industry. The vari lok clutches are not preloaded, so they don't wear out like other clutch LS's. If you're talking about the entire quadradrive system, that's another topic altogether. I find that it all works as designed, works well, and is sufficiently durable if maintained properly. It's all limited slip, nothing like a locker, so don't expect to go on a race through the rubicon with it. Mud, snow, loose dirt/gravel, it's a good system.
__________________
2004 WJ 4.7L, 1959 CJ-5, 1990 XJ Limited, 1996 XJ (sold), 1989 YJ Wrangler 4.2L (Sold)
Planetcat is offline   Reply With Quote
Unread 02-06-2013, 02:46 PM   #4
1AAdam
Registered User
2000 WJ 
 
Join Date: Jun 2010
Location: Massachusetts
Posts: 1,572
i had a wj with the quadra drive system and i loved it. amazing in the snow!
__________________
Adam
1aauto.com
888-844-3393
1AAdam is offline   Reply With Quote
Unread 02-06-2013, 03:02 PM   #5
alfaitalia
CRD Pilot!
 
alfaitalia's Avatar
2004 WJ 
 
Join Date: Feb 2011
Location: Bognor, West Sussex. England. Great Britain
Posts: 2,725
Wish my Quadratrac was Quadradrive...but I think I would need to sell my son into the slave trade to make that fundable! Dont think CRDs ever where supplied with QD, at least I have never seen one...pity.
__________________
If at first you don't succeed, skydiving is not for you.
alfaitalia is offline   Reply With Quote
Unread 02-06-2013, 03:05 PM   #6
PowderHound
Registered User
2003 WJ 
 
Join Date: Mar 2009
Location: Broomfield, CO
Posts: 294
I bought this mopar additive and paired it with some synthetic 75W140. 2 oz front axle and 4 oz rear axle. Next time I will try some synthetic Royal Purple 75W140 or some Redline because it's pre mixed. Quite a few people on this forum are using it with good results. Quadradrive does great here in Colorado winters.
__________________
2003 WJ♦Inferno Red Limited(4.7 H.O., Vari-Lok axles)♦OME HD/BILLY 5100S♦IRO t-case skid, adj. tb, sway links♦Moog SS♦Factory tow package w/harness & tow hooks♦ Amp/12 sub box♦new bad b**ch passenger♦1993 XJ country♦lift/muds/winchbumper-sold♦build thread instead of long A$$ sig soon...
PowderHound is offline   Reply With Quote
Unread 02-06-2013, 03:14 PM   #7
bradywgn71
Senior Member
 
bradywgn71's Avatar
2002 WJ 
 
Join Date: Apr 2011
Location: Tucson, Arizona
Posts: 924
You apparently have a lot of spare time to fill. I'm sure there were many engineers at Dana that figured out how much Friction Modifier was the right amount for both performance and NVH goals in these axles. Is it possible that there was a careless assembly line worker that messed up on the fluid fill at the factory? Sure. Most of the complaints you see are of the chattering complaint; then again, most of these WJs didn't see anything resembling "off road" when they were new. Most of the "tuning" to the Vari-Locks has been of the "does it chatter? add a little more FM" variety. I'm not sure if you're conducting a science experiment or college research, but I think you're really over thinking this. 4oz. rear 2.5oz. front of Friction Modifier. Good luck with your experiment. I'm not sure how much more precise of a measurement you're looking for...
__________________
2002 WJ Overland - 4.7HO - 231tc - 6" Clayton - Bilstein shocks - 285/75-16 Cooper STT - JK Steelies - Kevin's Offroad Belly Skid and Rock Sliders - JKS Track Bar and Disconnects
bradywgn71 is offline   Reply With Quote
Unread 02-06-2013, 04:44 PM   #8
jeep04
Registered User
2004 WJ 
 
Join Date: Dec 2010
Location: South park, pa
Posts: 934
Not to sound like a complete a-s but what does this "chatter" sound or feel like or is this the jumpy feel you get while turning to sharp, not saying mine does this but just asking cause i do have a noise in that area.
__________________
04 Jeep wj Limited 4.7 <> 6.5" Iron Rock long arms front & Adjustable lowers on rear <> Bilstein 5100's <> 285/70r17 Goodyear Duratracs <> M/T black classic lock wheels <> Addco swaybars <> Superchips 3875 <> Magnaflow Stainless exhaust <> 2 Kicker comp 12's <> Kenwood head unit.
jeep04 is offline   Reply With Quote
Unread 02-06-2013, 04:49 PM   #9
bradywgn71
Senior Member
 
bradywgn71's Avatar
2002 WJ 
 
Join Date: Apr 2011
Location: Tucson, Arizona
Posts: 924
It's like a resistance to rolling while turning at full lock, but not a hard resistance or binding. Kind of like a tire rubbing a fenderwell resistance, it's also been described as a shudder. I could hear mine through the vehicle too, like a groaning sound.
__________________
2002 WJ Overland - 4.7HO - 231tc - 6" Clayton - Bilstein shocks - 285/75-16 Cooper STT - JK Steelies - Kevin's Offroad Belly Skid and Rock Sliders - JKS Track Bar and Disconnects
bradywgn71 is offline   Reply With Quote
Unread 02-06-2013, 05:35 PM   #10
jeep04
Registered User
2004 WJ 
 
Join Date: Dec 2010
Location: South park, pa
Posts: 934
Thanks bradywgn71, not the noise i hear then as it sounds more like a wheel bearing thats going bad but under the pedals.
__________________
04 Jeep wj Limited 4.7 <> 6.5" Iron Rock long arms front & Adjustable lowers on rear <> Bilstein 5100's <> 285/70r17 Goodyear Duratracs <> M/T black classic lock wheels <> Addco swaybars <> Superchips 3875 <> Magnaflow Stainless exhaust <> 2 Kicker comp 12's <> Kenwood head unit.
jeep04 is offline   Reply With Quote
Unread 02-06-2013, 06:31 PM   #11
lazyWJ
Registered User
2002 WJ 
 
Join Date: Feb 2013
Location: halifax, ns
Posts: 813
If you've never read anything disparaging about QD, then I'm not really sure what to say? There are volumes on it, and at one point there was a group trying to organize a class action lawsuit. I have read (albeit unverified) accounts of buybacks because the system failed to meet manufacturer claims. Personally I am quite happy with the performance of the system, as many (probably the majority even?); although I didn't pay $53k for my Jeep new either. I also come from "outside" the jeep community, and generally I've found something will get respect if it's warranted, no matter what the name on it.

Yes, I have lots of time on my hands. I like to wile away hours reading compressor maps, dyno sheets, adjusting fuel and timing curves, staring at EGT and WBO2 gauges and other tedious pastimes. A hydra lok differential is just another one of those boring things that attracts my attention. I guess you could call it a... hobby. Even though the factory specs are universally known to without exception provide optimum performance in every scenario (such as ride height, gear ratios, engine compression ratio, tire size, ignition timing, and so on ad nauseam), I still enjoy pissing away hours of my life trying to second guess them in an attempt to make things work a little better. I'll never learn.
Although even I have my limits... I had to laugh when some of my off-highway cohorts tried to convince me that running lower than specified air pressures in my tires would give me better performance off road. Imagine! I smugly pointed to the placard on my door and assured them that many engineers had already determined the best pressures to have in my tires. I'm not sure if they were "airing down" or "smoking up". Crazy.

At any rate, Jeep unambiguously states that "virtually" 100% of developed engine torque can be distributed to the wheel that has the least traction. It's either true, or it isn't. I would tend to believe the theory is sound (otherwise it would be a rather bold lie), but perhaps the execution requires a bit of finessing. I think it's a really nifty system and is worth investing some time in trying to optimize it. The magic may not be in the FM at all, rather it could be in the valving, design of the clutches or whatever combination. Unfortunately most of these other variables are not so easily adjusted, so the FM additive seems to be the simplest place to start. I'm going to wait for things to warm up a bit before I proceed so I can have more consistent viscosity baselines (I suspect viscosity is a player), but I'll post any progress I make for the utility of those interested and the entertainment of those not.
__________________
1993 FZR600RR
2002 Subaru WRX Sedan WRB (314k miles and counting)
2002 GC Overland (90k miles and fingers crossed)
"Bought, Not Built"
lazyWJ is offline   Reply With Quote
Unread 02-06-2013, 06:59 PM   #12
jeep04
Registered User
2004 WJ 
 
Join Date: Dec 2010
Location: South park, pa
Posts: 934
__________________
04 Jeep wj Limited 4.7 <> 6.5" Iron Rock long arms front & Adjustable lowers on rear <> Bilstein 5100's <> 285/70r17 Goodyear Duratracs <> M/T black classic lock wheels <> Addco swaybars <> Superchips 3875 <> Magnaflow Stainless exhaust <> 2 Kicker comp 12's <> Kenwood head unit.
jeep04 is offline   Reply With Quote
Unread 02-06-2013, 07:02 PM   #13
mickey85
Registered User
2004 WJ 
 
Join Date: Apr 2011
Location: Culver, IN
Posts: 189
Well, if 100% of the power is going to the wheel with the least traction, wouldn't that just operate like an open differential? I certainly know when I plant it in the snow in my WJ that both tires on the passenger side spins...ostensibly all the power is going to them, while none (or very little) goes to the left side...
__________________
It's true, you never forget your first Jeep. - 1999 Cherokee - 188,000 miles. DOA.

The Albatross - 2004 WJ Laredo 4.7, clackety lash adjusters, 3 gallons of antifreeze on the floorboard, 109,000 mile daily driver.
mickey85 is offline   Reply With Quote
Unread 02-06-2013, 07:07 PM   #14
lazyWJ
Registered User
2002 WJ 
 
Join Date: Feb 2013
Location: halifax, ns
Posts: 813
Quote:
Originally Posted by mickey85 View Post
Well, if 100% of the power is going to the wheel with the least traction, wouldn't that just operate like an open differential? I certainly know when I plant it in the snow in my WJ that both tires on the passenger side spins...ostensibly all the power is going to them, while none (or very little) goes to the left side...
Sorry, that was a misquote on my part, should have read "most" not least. Been a long day.
Yeah, otherwise it's open diff performance. Depending on the exact source you lift the quote from, it should look something like:
... the Quadra-Drive system can send nearly 100 percent of engine torque to a single wheel when necessary ..."
__________________
1993 FZR600RR
2002 Subaru WRX Sedan WRB (314k miles and counting)
2002 GC Overland (90k miles and fingers crossed)
"Bought, Not Built"
lazyWJ is offline   Reply With Quote
Unread 02-06-2013, 09:42 PM   #15
rm2001wj
Web Wheeler
 
rm2001wj's Avatar
2001 WJ 
 
Join Date: Aug 2005
Location: Memphis, TN
Posts: 3,079
Quote:
Originally Posted by lazyWJ View Post
.................

... the Quadra-Drive system can send nearly 100 percent of engine torque to a single wheel when necessary ..."
To have it make more sense, it probably would be better to say "to a single wheel that has traction." However, there is indeed some finessing in all of this. By design, the gerotor pump is limited as to the amount of pressure it can apply to the clutch pack. That limit can be reached when the torque is well below the maximum torque produced by the engine. Under operating conditions where the engine is not making maximum torque, it is possible that nearly 100% of engine torque can be sent to the single wheel that has traction.
__________________
2001 WJ Limited with Quadra-Drive, Kenne Bell Supercharger, 3-inch Kolak exhaust, Stillen rotors (F/R) and MM pads, Addco sway bars (F/R).
rm2001wj 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.