What happened to my rear diff in Moab... OUCH!!!

Well as I told most of the guys in Moab, my rear locker was broken in Moab, not sure why but its possible it broke doing Double Whammy... who knows... regardless, it wouldn't disengage and was making awful noises... anyways, took it in today and heres the list of everything that was destroyed...
Both spider gears (one was missing two teeth, the other was missing three teeth... not sure how that happened)
Clutch Gear
Differential Case
Cross shaft
Piston
All bearings within the ARB
Cylinder Cap
Splined Side Gear
A few other little miscellaneous parts - now that was teh ARB...
it seemes that when the ARB blew it also took out three teeth from the main ring of the 4.56 ring and pinion, so thats basically bad...
all pinion bearings
pinion seal
rear wheel seal
housing gasket
new differential cover (this wasn't bad but I figured better replace it anyway)

So in conclusion, I'll be replacing the entire ARB locker unit (hopefully under warranty) as well as the entire rear ring and pinion (unfortanetly this won't be under warranty since the blown out ARB caused the chips)... I took some pictures of the gears, etc. so hopefully i'll have them in a few days.

Lucky me!

------------------
Matt Adams
94 Explorer 4-door nick-named "Tippy"
http://bart.is-s.com/~explorers/explorer/explorer.html

Do you think that the ARB was deffective or were you beating it hard? The 8.8 is normally pretty sturdy. Now is ARB going to except some responsibility or are they going to put it off on the installer? Either way, it cost a lot of $$$. Good luck

Matt,
Call ARB yourself and tell them what happened, I called them today and told him we took out 3 or 4 ARB 8.8 lockers this weekend and I don't think he believed me. He didn't argue with me but he sounded doubtful. He made the comment on how strong they were and that I must have done something wrong. He also told me that I was the only one to call with a complaint. He said he would like to hear what else we broke as far as ARBs go.
ARB is going to cover my rear one last time even though they said that last time was it. It works out good for me because they are fixing both the front and rear, and my warrenty is up on MAY 11!
The number for the Tech at ARB is (206) 264-1669.

JAY

Jay - We're in the process of speaking to them... he didn't mention anyone else had called but I didn't think to mention that we had 3 ARB's blow out on this trip... warranty should be no problem HOWEVER the guys that looked at it did say whoever installed it (Dick Cepek, now Chapter 7) did quite a poor job on installation of both the locker and the ring and pinion, but they wouldn't tell ARB that. That will help offset the cost of a new locker (about $650) but still leaves the cost of the gears, the bearings, and install of the gears/lockers as well as the cost of diagnosing the locker... about $1200. Either way it'l probably be a while before I go wheeling again.

------------------
Matt Adams
94 Explorer 4-door nick-named "Tippy"
http://bart.is-s.com/~explorers/explorer/explorer.html

I spoke to Tim at ARB this morning. He said that the 8.8" is very prone to case flex. I told him about the T/A rear cover that I run with the pre-load bolts and he said that can help increase the life of the Airlocker.

He also said that the Airlockers are only rated for 31-10.50s! Now that is something I had never heard before.

I asked him about the possibility of poor heat treating of the spider gears and he said that was a possibility, but it couldn't be confirmed until he got to see the broken units.

What it came down to was his belief that the 8.8" is a marginal axle when used in extreme conditions under an Explorer. He said the same axle under a TJ, CJ etc would hold up great due to less weight.

I wish I had heard that before I dumped all those $$$ into my new 8.8" and Airlocker. I'm sure the rest of you feel the same way.

------------------
Rick Horwitz
Editor
explorer@4x4central.com
www.4x4central.com
Ricks Explorer

Rick - I agree... Though there is no real way for them to know you are running something OTHER then 31"s unless you tell them... so far gotta say that I am not extremely impressed witht he locker... not just ofr myself but Jay breaking four of them, T.C. breaking his and me breaking one, none of us were doing anything I would call EXTREME, some of the obstacles were a bit tricky and put a lot of strain on the lockers but not any thing I can see shearing off spider gears. And to me, if three people break spider gears, I guess that means the spider gears are the weakest point of the locker, maybe they oughtta make me stronger...

------------------
Matt Adams
94 Explorer 4-door nick-named "Tippy"
http://bart.is-s.com/~explorers/madams/

Rick, sounds to me like a bunch of excuses to try to get out of warranty work. The 8.8 suffers from pinion deflection (flexing), but the preloaded cover solves that problem. Other than that it is a very strong axle.

If the ARB's are only good for 31x10.50's, then what are all the rock crawlers doing. They certainly are not running 31's. Most of them will run a hard locker in the rear (Detroit) and the ARB in the front. They do have some problems with the ARB's, but are willing to put up with it to be able switch off the locker. In the rear, it really isn't a big deal to have a Detroit, unless you live where there is alot of snow and ice.

Also, if the 8.8's are soooo weak, and have case deflection soooo bad that it will blow up any diff with tires larger than 31's, then why do the Detroits have NO PROBLEMS.

Frankly, I see people with 44's, 10-bolts, and 60's blowing them also. I wonder what their excuse would be on those?

I dealt with a company once that handled customer service very much like it sounds like ARB is handling it...... it is always someone elses fault. This is why I no longer have my Vortech Supercharger.

JMHO

Gloria
93 EB Explorer (highly modified)
94 F150 Lightning

Matt, I didn't tell them what size tires anyone was running. Also, I have video of Jays ARB breaking. In that situation it could have just as easily been an axle shaft that snapped. He had his tire up on the ledge of Double Whammy, it was spinning fast and it fell off the ledge and came to a dead stop on the rock below.

Even those of us that made it up shocked the heck out of the drivetrain. I mean it can't be easy on it when you back up and drive into a knee high (for most of us ;-)) ledge with momentum.

That's exactly why Dan said that out of every ten vehicles you take through Golden Spike 2 will have problems. And if your lucky enough to get through once with no problems 4 will have problems next time. That may be a bit overly simplistic, but it's pretty close to being right on.

Gloria, as far as them getting out of warranty work, I guess we should have read their warranty in the first place (I'm including myself).

ARB Corporation Limited does not warrant or make any representations concerning it's ARB Airlocker Differentials when:

(iii) The products are installed in vehicles fitted with aftermarket non-standard tyres with diameters in excess of OEM specifications.

(iv) The products are installed in vehicles with engines that have been modified to increase performance beyond that reccomended by the original manufacturere or ARB.

(v) The products are installed in vehicles fitted with non original engines of greater performance than the engines orignally fitted.

I have no idea what the Detroit Lockers warranty is. I got the above info from the instruction sheet that came with my Dana 44 Airlocker.

Tim came right out and said that the spider gears are the weakest link in the 8.8" locker. I think they need to look into using better materials or a better heat treating process.

Gloria, ARB has warranted many of our lockers in the past without a problem. Mine and Jay's included. Jay said that they are going to warranty his for the fourth time. I don't think Matt has recieved confirmation yet, but I don't expect him to have a problem.

As far as breaking front ARBs. Tim said that they are almost impossible to break because you'll break an axle, U-joint or hub first. he said that after you break multiple axles U-joints or hubs you may then grenade a front ARB due to it finally weakening.

------------------
Rick Horwitz
Editor
explorer@4x4central.com
www.4x4central.com
Ricks Explorer

Rick is right, ARB had told my shop last time that they were not going to warrenty my rear anymore, but when I called them personally and explained to them that we broke multiple ARB lockers, they said it would be no problem. They didn't try to blame the shop that installed it, they did ask where I was at, and they are very familiar with Moab, but they didn't use that as an excuse to not fix my rear again.

Personally I liked talking to the tech at ARB, he asked alot of questions, told me what he though, didn't treat me like I was ignorant and answered every question I had. I broke both the rear AND the front this weekend. When I told ARB he just chuckled and said to send the front in with the rear.

ARB is right about the front being stronger, I have broken other parts of my axle already. I believe that it was just time for the front because when it broke I was just decending a very small grade, not even under power.

JAY

How could the ARB only be rated for 31's? When the rock crawlers are running larger tires like you guys/gals said. But more than that arent alot of those rock crawlers sporting at least a 350ci engine that is farely modified? Then that wouldnt matter if you have 31's, because of the torque at hand. Wouldnt the torque just rip the ARB apart if they say you can only run 31's with it?
Just my .02 cents


------------------
Brian
94 2wd
4" Fabtech Lift
265/75/16
Flowmaster 2 chamber 2.25"
KKM intake
Clears all the way around
4.11 gears w/Auburn posi

You can add one more to that list of broken ARB's. When mine broke last year it was 5 years old, so I think I got my moneys worth out of it. But instead of replacing it with another ARB I went with the Detroit in the rear and kept the ARB in the front.

Hmmmm, warranty for the Detroit Locker....... hmmmmm, I haven't the foggiest idea. Never occured to me to look. The only one I have ever heard of breaking was a 24 year old unit in a rockcrawling Scout. He was able to fix that unit himself by getting the side gears and a pin.

Hint, the person who did this was one of the McClullen brothers. They are harder on an off-road vehicle than a pack of teenagers (one rolled his on the freeway, turned it over, and drove it home...... was out wheeling 2 days later).

I stopped using Lock-rights because they kept failing. That the company will warranty the unit does not keep your vehicle from being down. If I blow a front locker, I can unlock the hubs. I imagine it is probably kinda difficult to drive home with a blown rear diff.

Like I said, I will get one for the front of the Beast (if my 4wd ever works), but I sure am happy with my indestructible rear locker.

I sure am happy that ARB will still warranty the units. But it makes me wonder that they know about the weakness, but don't fix it. Of course they have to warranty it, because if they didn't, the word would get out to the off-road community....... and no more business.

Actually it is kinda funny. I bet you could poll 100 off-roaders who run ARB's and that 1 person, or less would know about the silly conditions of warranty. For a company that markets their product to the off-road world, that is the silliest thing I have ever read. They must have had a real good lawyer write that one up. Covered about anything possible. I can see it already "Sorry, we can't warranty your ARB because you are running a K&N Filter and 235's instead of the stock 215's"


Anyway, enough of my sarcasm..... hehe

Gloria
93 EB Explorer, 1000 RTI
94 F150 Lightning

[This message has been edited by Extreme4x4 (edited 05-10-2000).]

"Sorry, we can't warranty your ARB because you are running a K&N Filter and 235's
instead of the stock 215's"


Gloria, I was thinking the same thing myself...

Matt,

I think that explains the banging sound I heard when you went up Lion's Back. (I think it was you that had that banging noise). That would be a symptom of missing teeth on the ring and/or pinion. It is possible that the broken teeth from the spider gears got scooped up into the ring and caused further breakage (I'm assuming that the ARB has big enough openings to allow the broken parts to get into the bottom of the diffy case).

It sounded pretty scary to me. I'd hate to have to back down that hill!!

I agree with Rick in regards to the weakest link idea. I think that in this case, the ARB spiders may be the weakest link in the rear drive train, as opposed to other parts in the Dana 35 front end. Hopefully, there will be some design changes to the ARB to make it a bit stronger in this application.

------------------
Tom
99 Sport 4x4
SOHC
Auburn Rear & Gerald's old Shackles
265/75-R16 BFG AT's that weren't supposed to fit

Well, a few thoughts...

first of all it was Jay's vehicle that was banging going up Lions Back, of course he broke both lockers also, tough to say.

I actually knew the limitations of the warranty when i purchased it, just didn't really care too much... still haven't heard on whether or not they'll warranty mine... hopefully mine will be out of the shop tomorrow or Monday, better then new (literally)

------------------
Matt Adams
94 Explorer 4-door nick-named "Tippy"
http://bart.is-s.com/~explorers/madams/

Got my baby back today, not bad, thanks to High Country, they made quick work of overnight the parts (at my expense of course) and the installation was speedy, they forgot to put on a new diff cover but we'll worry about that later, I'm just about broke as it is now! heh heh. Final cost of repairs/parts (new locker, new ring and pinion, all pinion parts, bearings, etc)/labor, etc. came out to about $1625, a bit less then I expected but more then I wanted Dead Link Removed. They overnighted the ARB to us but sent the damaged ARB back by ground so we are unsure yet if it will be covered under warranty, if it is they'll just refund me back $650, said they shouldn't have a problem with it, that would bring total to around $1000.

On a side note, I'm going to stay away from Moab for a while, I consider it to be cursed, ha ha ha. Just kidding.

------------------
Matt Adams
94 Explorer 4-door nick-named "Tippy"
http://bart.is-s.com/~explorers/madams/

After MOAB and several people breaking ARB's, I'm rethinking my choice of rear lockers. Would any of you purchased a Detroit instead of ARB for the rear if you knew this would happen? Or maybe better stated, What would you put in the back if you were to do it all over?

I'm leaning towards a Detroit now. Not sure if drivability will be that affected since it's in the rear and not up front. I still lean towards an ARB up front when the EZ-Locker goes ( I think? )

Ideas? Suggestions?

------------------
Rob Robertson
94 XLT 4X4 4 door
5.5" Superlift,RS9000s,Warn manual hubs,33 X 12.5's ProComp MTs
"What's Potato Salad Hill?"

not necesarily, I'd just learn to disconnect my rear driveshaft if anything goofy is going on with the locker like it not disengaging Dead Link Removed. Mainly because it is my daily driver and I drive it in town through ice and snow where I don't WANT a locker. I still like the ability to go from 100% engaged to 100% disengaged though.

------------------
Matt Adams
94 Explorer 4-door nick-named "Tippy"
http://bart.is-s.com/~explorers/madams/

Rob -

I'd definately throw a Detroit in the rear diff if I had to do it again (or if I have to do it in the future).

A Detroit in the rear will more than likely get you off the trail if you're knee deep in obstacles and your ARB compressor decides to quit...

Matt's right about the driving conditions on snow and ice, but that should not be a major issue if you remain in Texas.

Paul

Rob, I agree 100% with Paul S. When my rear ARB went out last year, I had Darien put in a Detroit instead of another ARB. Since it doesn't snow here (except in the local Mts.)in sunny So. CA. I do not worry about it. Just watch those street corners, but since you like to go fast, you might like the tire noise.