Calgary Jeep Association

4x4 Related Groups => Tech Talk => Topic started by: w squared on December 03, 2009, 10:27:59 PM

Title: ZJ diff question
Post by: w squared on December 03, 2009, 10:27:59 PM
I've got an acquaintance (I'd don't know him well enough to really call him a friend) that's considering picking up an older ZJ (Either a 97 or 98, I can't remember which he said) as a trail rig. He likes the idea of having a V-8, and likes the asking price.

The thing is that I'm not too sure that the guy trying to sell it to him is on the straight and level. He's told my acquaintance that because he didn't put the friction modifier (for the Trac-Loc LSD) into the rear diff, it's just as good as having a locker.  ???

I'm not a mechanic (and I didn't even stay at a Holiday Inn express last night), but my gut tells me that there's a difference between a real locker (or a spool, or Lincoln Lockers) and some beat-up clutch packs that are being run without a friction modifier. I'm not even sure that this idea would work as well as something like an Aussie locker...

Am I out to lunch, or is this guy trying to pull a fast one? Or maybe he just doesn't know what he's talking about. Any thoughts?
Title: Re: ZJ diff question
Post by: JackstandJohnny on December 03, 2009, 10:36:12 PM
what does it have for an engine in it Todd? if its a 6, it'll have the D35 and a trashloc in it. if its a V8 its a D44a, and its completely open. so if the jeep has an V8 he's full of it. 

Title: Re: ZJ diff question
Post by: w squared on December 03, 2009, 11:08:17 PM
what does it have for an engine in it Todd? if its a 6, it'll have the D35 and a trashloc in it. if its a V8 its a D44a, and its completely open. so if the jeep has an V8 he's full of it. 



I'm not 100% on the V-8...but I do remember talking with him about the trac-loc. The guy trying to sell it apparently talked at length about how good it was.
Title: Re: ZJ diff question
Post by: WhiteOut on December 03, 2009, 11:10:48 PM
Is the ZJ lifted or stock? The amount of wear and tear plays a huge factor
Title: Re: ZJ diff question
Post by: w squared on December 03, 2009, 11:18:51 PM
I think it's lifted. I've never seen this rig, just trying to make sure that I've got a good bead on what makes sense and what's a load of over-ripe sheep manure.
Title: Re: ZJ diff question
Post by: JackstandJohnny on December 03, 2009, 11:22:58 PM
I'm not 100% on the V-8...but I do remember talking with him about the trac-loc. The guy trying to sell it apparently talked at length about how good it was.

Todd. don't let your buddy buy it then... my 95 with the V8 (D35)has a trashlock in it. i can't even tell its there. its completely open diff. they lose any real usefullness in the first 40k  only an idiot would bragg about how great a tracloc is to sell a ZJ.  as to the additive thing, i don't know how that works.  
Title: Re: ZJ diff question
Post by: tubby on December 03, 2009, 11:30:35 PM
NO! NO!NO!and NO!

Are you kidding me Todd? Tell this "guy" that leaving that little bottle of friction-modifier out of his Dana-35 with Trac-Loc DOES NOT make it a true locker. The Trac-Lock needs that additive to help it "be a poor excuse for a limited slip" Pffft!

I'm going to say this once. A factory optioned LSD(Dodge,Ford,GM) is not a true locker. An ARB is also not a locker. It's a freakin spool when engaged! Detroit True-Trac - also not a locker. GM Gov-Loc...still a limited slip with those little weights.

Grrr! Must be a tuesday...

Tell your pal to do his homework please. Trac Loc in whatever(D-35,8.25,whatever) will never be a locker. You can't even Lincoln that puppy in LSD form. Trac-Loc minus friction modifier being a locker ranks up there with "blinker light fluid or a body lift on an XJ"
Title: Re: ZJ diff question
Post by: LEMON-AID JAY on December 04, 2009, 12:25:22 AM
He's told my acquaintance that because he didn't put the friction modifier (for the Trac-Loc LSD) into the rear diff, it's just as good as having a locker.  ???


I call BS on this one (its funny what some people think)
Title: Re: ZJ diff question
Post by: The Machinist on December 04, 2009, 06:21:45 AM
I threw a banana in my trac-loc, when the potasium mixes with gear oil it forms an epoxy and locks up the rear end.  Works better than a spool!
Title: Re: ZJ diff question
Post by: w squared on December 04, 2009, 06:25:23 AM
Thanks guys!

I'll tell my buddy that he can just add a banana and get better results that way.  ;D

I kinda thought that the dude with the ZJ was either a complete idiot or was trying to pull a fast one...but I don't know that much about the ZJ platform, and I wanted to be sure. Now we all know.
Title: Re: ZJ diff question
Post by: The Machinist on December 04, 2009, 07:34:39 AM
I believe this will work better than a banana!  Didn't realize they made a lunch box locker for a 29 spline 8.25" trac-loc.  MUST GET ONE NOW!

Powertrax 92-0382-2925
Title: Re: ZJ diff question
Post by: cLAY on December 04, 2009, 08:38:47 AM
Actually the guy isn't totally out to lunch, leaving the friction modifier out makes a LSD work WAY more aggressively. Unfortunately it also shortens its life span. The friction modifier makes the oil more slippery and thus also the clutches in the LSD in slip easier. Common complaint on a new vehicle was that it chirped going around corners, the fix was simply to add more friction modifier.

Leaving out the modifier was a trick I used to do when I had a posi in front D44 on my XJ. It worked much more aggressively that way and when I was in Moab the people I met there thought I had a front locker. With the right application of the brake pedal it almost was a locker. However it was very tricky trying to do some of the obstacles while pushing on the brake and twice the LSD opened up and  slipped causing me to lurch to one side on a obstacle and almost roll.

Its no where near as good as an actual locker but it can make a night and day difference to an older LSD with some wear on it. Now your going to ask who much extra wear? Well I ran mine about 4 years with no friction modifier and it wasn't doing much when I pulled it. Now that was in the front, on a diff with locking hubs and I only wheeled it, not a DD. In the rear on a DD you would probably get a year or so I'm guessing. However if your LSD isn't doing anything anyway you have nothing to lose and may get a year of it actually doing something. If you try it don't expect to see immediate results, after changing the oil it may take awhile to work the friction modifier out of the clutches. Also some oils come with friction modifier in them.
Title: Re: ZJ diff question
Post by: rws on December 04, 2009, 08:41:41 AM
I have rebuilt several trac-locks.  The clutch pack is usually gone after 10K and and you are left with an open dif.  They are garbage but are better than nothing once new clutches are installed.  
Title: Re: ZJ diff question
Post by: JackstandJohnny on December 04, 2009, 08:59:12 AM
i call my tracloc a trashlock for a reason. it doesn't do anything.   wait, not true, it does work when the ebrake is applied. its not a 50/50 split though. might have been 30/70.  same when the bakes are applied.  maybe some people (clay) are smart enough to brake,clutch,drive,etc to utilize an LSD.  i' m not. so i push the easy buttons labelled ARB ;)


wanna make a trashlock a spool, weld it.  ;)  its still got side gears, side gears can be welded to a carrier;)
Title: Re: ZJ diff question
Post by: Bnine on December 04, 2009, 11:22:44 PM
What Clay said. I left the fluid out of a tracloc before (comanche 44 btw), and it was pretty grabby. Im sure it wouldnt have last long being daily driven, but never the less, it was "grabbier" for a while. Even provided the odd detroit like clunk once in a while.
Title: Re: ZJ diff question
Post by: XJHERO on December 05, 2009, 12:11:59 AM
LOL



BURN



ROFL

Thanx Clay and Bill you made my day
Title: Re: ZJ diff question
Post by: tubby on December 06, 2009, 04:43:36 AM
What Clay said. I left the fluid out of a tracloc before (comanche 44 btw), and it was pretty grabby. Im sure it wouldnt have last long being daily driven, but never the less, it was "grabbier" for a while. Even provided the odd detroit like clunk once in a while.

Still not a locker Billy ;)
I don't want some poor saps to leave the friction modifier/LSD addititive out of their Trac-Loc equipped vehicles; thinking it will be a TRUE locker. I accidentally forgot to add the little bottle to my 12bolt Posi in my 69Chevelle when I was 18. It smoked both rear tires for a few weeks and then turned to one-wheel peel. I took the diff cover off and found that my clutches were burned up.

My advice remains the same Todd. If your buddy buys the Jeep thinking he has something special in the rear; he will be dissapointed when the "grabbiness" goes away. Jeepers are cheap but Sheesh!  Find an open carrier diff with the same gear ratio, shake the couch for change and buy a lunchbox. Pop on over to Bills and get it installed ;)
Title: Re: ZJ diff question
Post by: w squared on December 06, 2009, 05:23:46 AM
Mmmmm....problem is, my friend is a cheap bugger. Can I tell him that you'll do the install  ;D
Title: Re: ZJ diff question
Post by: tubby on December 07, 2009, 05:44:31 AM
Just to hijack slightly... Tubby said that the "lockers" being sold are "just a spool".  Ummm when a locker is locked, isn't that the point you are after?  Locked carrier == spool


I don't know where I said that the "wannabe locker" being sold is a spool Pat. Spool is 100% locked at all times. A true locker can un-lock.
I've run full spools,mini-spools,Detroit Lockers, 1st and 2nd Gen. ARb's, various lunchboxes and even a Lenco Locker. Pay to get the real thing if you want the traction. Get an open carrier and Lincoln/Hobart /Redneck if need be.

Some people have had success with the Trac-Loc trick mentioned in past posts. I'll stick to the real thing thank you.