I called a dealer yesterday and they ran my vin and told me its an optional HD plow pkg rear end with "anti slip" diff. Yeah ok .....bunch of crap to make it sound special.
Anyways...he says it IS supposed to have LSD additive but couldnt tell me how much......?? WTF...glad im not getting work done there!

Hammer I tend to believe you over the friggin dealer. So when I have my tires balanced should I just have the fluid changed? that way he can look at the gears and re fill without Additive?

***I can also finally say with confidence that it only does it after a few minutes of driving so the fluid is warm/hot ect....

@dirtydog..... Theres no way this issue was there before the gear change. I hammered the **** out of this thing when I test drove it and paid very close attention to it for the 3 weeks I drove it before taking it for gears just to see if there were any other issues before my dealer warranty ran out.
I also have a 1yr guardian warranty which my buddy who owns the garage I go to says they actually cover things without a huge hassle. So I'm going to try and get anything replaced from here on out covered. They dont need to know about the gear change.
Im definatley going to have the carrier bearing checked though too.
I wouldnt think with 83k on it and never seeing a winter with salted roads that it would be fine but I guess ya never know.

 

Fluid MUST be changed at end of break-in period AND that's the time the gear pattern is supposed to be checked.

The reason it is IMPERATIVE to have the fluid changed after break-in is because A) boxed ring & pinions are shipped with a protective manganese phosphate coating which wears off during break-in. This chemical breaks down the gear lube RAPIDLY. B) it's normal for small shavings to be produced during break-in and you want them out of there. Any large shavings means they set the ring & pinion up wrong.

IMO get someone who knows axles who is NOT the installer to take a look at the fluid and wear pattern to make sure everything is as it should be.

Your dealer probably puts LS slip additive in EVERY vehicle they touch with an LSD, Lockers or Spools. Hell I'd bet they'd put it in an axle with the spiders welded, LOL. The simple truth is ONLY LSDs with clutch packs need a friction modifier. Having it in an open diff or a diff with a non-clutch type unit will make the gear oil slightly less "slippery", but not enough to hurt anything - it's just simply not needed...

 

Thank you for the info hammer! This pisses me off!!

My truck is in the shop now as Im reading this. I just called my buddy and told him to drain the front and rear diff and switch to synthetic which the installer jerk off told me not to use. I also told him to get a visual on the gear wear and shavings and save me anything abnormal. Break in was supposed to be 250 miles (which i was very nice to it for 300 miles) its at 520 now. I still havnt beat on it other than the occasional foot on the gas a little around a corner or two.
Told him NO additive. According to hid snap-on database the 9.25" rear was the only rear that would have needed additive. Obviously mine is a 10.5" . I'm super unimpressed with this ******* I had change the gears....

ALSO.....my tires were off balance...my drivers side E brake was stuck too.
My damn pass side ball joints are whipped along with the stabilizer arm. But those are covered under warranty.

 

Yep, sounds to me like you just had a sh*t installer. This mod is ALL about the install.

A little late now, but I've got a "break-in guide for new gears" in the FAQ section, sorry I didn't mention it sooner.

Hoping the guy who has it now gets you straight...

 

If his contact pattern is set OK and he's not done too many miles over the 500 without the fluid drop.....this might if the above is correct, turn out ok. Especially if his current wrencher is clued up, about these rear ends.
Good luck.
Al

 

The mechanic is a close friend of mine and he knows his ****. But if he doesnt he wont blow smoke up your ***. He'll either get you an answer or send you where you can get one.
The only thing they really dont get into is actually Diffs as far as setups ect..

Anyways....he dropped the fluid front and rear yesterday. It was all very clean. Normal tiny shavings, absolutely nothing large or out of the ordinary.
No ****ed up wear or score marks or anything like that on the gear pattern. He refilled with synthetic and NO additive.

Re balanced all the tires. Took alot of weight. abnormal amount he said. He said the tires didnt even look like they were spinning right on the machine. The tires only have like under 1500 miles on them, i dunno...maybe 2000 if im wrong but they are likely ****. They are Goodyear wrangler Dura Trac tires. Commercial type off road type tire.
When I can afford 4 new tires this fall or next spring I will be going with an aggressive non lugged A/T type tire.
Now that they are balanced differently than before I can feel different little vibrations here and there at different speeds so I know that part is the tires.
The rear end LSD type problem I described hasnt happened again yet but i have only driven it about 20 minutes so far. Hopefully it was the E brake being hung up.
I still plan on having someone who is a pro look at the rear end. The problem in my area is finding someone. No one really messes with rear diffs at all. Except maybe the dealers and Im not into getting raped in labor.

 

NEVER run a Duratrac on a 3/4 or 1 ton truck. Do a Google search and you will find TONS of recorded issues due to poor sidewall construction. If you search this forum you will find I try to even talk 1500 owners out of thus tire.
True, the Duratac is a Jeepers staple tire, but Jeeps barely weigh 3000 lbs.!
Don't let even a manufacturers "E" load rating on this tire fool you. There are numerous reports of sidewall failure on full size trucks.
I hate to say it, but you have the wrong tire for your truck...

 

Man....once again Hammer you are the man! I dunno wtf i would be doing if I hadnt joined this site!!! This really pisses me off now.... The tires were actually on the truck when I bought it so at least I didnt go out of my pocket and waste $1000+ on them.

I was looking at tires literally 10 minutes ago too. Can anyone suggest a tire that isnt going to cost $1500+ for 4? Staying with 35" obviously. Not over 12.5 wide. Preferably 11" or 11.5" . Have 17" wheels.

I was looking at something more like the toyo a/t. That style tire. I dont need a lugged tire. I do need good winter traction and wouldnt mind longer tread wear. I dont off road other than hunting or a few field donuts here or there.

 

Personally, and this is just my experience from almost 30 years of driving and owning 4x4 pickups, but I have NEVER had good luck with ANY tire that said either Goodyear or BFG on the side. I know this always starts a debate, because a lot of guys swear by BFGs.

Honestly, you can look at it two ways. You can save $$$ initially on so-so tires, but as a rule they won't perform as well or last as long. You can spend more right off the bat on a top-tier tire, but they will outperform and in many cases last twice as long as a cheaper tire.

I've had tremendous luck with both Mickey Thompson and Dick Cepek tires (actually sister companies that were recently bought by Cooper Tire). I've had a set of Mickeys last 68k and still have good tread when I traded the truck. My current Cepek FCIIs have about 35k on them and haven't worn 10% yet (as many on this forum have seen personally and can attest to). BUT, they are top tier tires as far as cost goes.

Good brands in 35x17 (or metric equivalent) that I've personally had or have close friends who have them would be Toyo, Nitto (again these are sister brands owned by the same company), Mickey Thompson, Dick Cepek as well as Cooper AT3 and STT.
If you are leaning more toward road use with occasional off-road but no crazy deep mud then look Toyo AT, Nitto Terra Grappler, Mickey ATZ or even the General Grabber. For a good hybrid (combo A/T and M/T) then the Nitto Trail Grappler, Mickey Thompson MTZ or Cepek FCII are good choices.

Tires are hugely personal opinion, so take my opinion for what it's worth...

 

I agree. I wouldnt buy anything that says BFG or Goodyear either. I did put a set of BFG a/t on our last grand cherokee before my wife switched to Denali's and Yukon's. Those BFG's performed awsome in the winter and lasted forever. But they were only 245's too. But they are so overrated/overpriced nowadays.

I was seriously considering the TOYO A/T. They look great too. I see them alot.
I wouldnt be so opposed to a non A/T oriented tire like the cooper SST if I thought they would last as long as an A/T ??? How much do you suspect it would change gas mileage between something like the Toyo A/T and the Cooper SST?? Thats the big thing really. I'll get a M/T if its not going to kill my mpg's. But I also dont want a soft rubber compound either.
My buddy has the toyo M/T (35")and he loves it. Seems to be wearing pretty fast though. I doubt he rotates them though.
In looking at the Mickey MTZ and ATZ I like them both also.
Generals are fine too. I was looking at them because they make a 34" tire too.

I have to say I really like the FCII though. That looks like it would ba a baddass all around tire.

The Kumho Road venture M/T also caught my eye but I cant seem to find any quality opinions of Kumho??

Looks like i should be able to get set up with any of these tires you mentioned for about $1300 - $1500 all 4 mounted and balanced.
We pretty much have the same taste in tires.