Crane High Clearance Extreme Diff Cover

By Bill "BillaVista" Ansell
Photography: Bill Ansell
Copyright 2008 - Bill Ansell
(click any pic to enlarge)

Introduction

There are a lot of diff covers on the market, ranging from re-boxed "thick" stock covers, to welded together products and all the way up to the king of them all - the Crane Extreme Diff Cover. Naturally, in keeping with the theme of building the BV-60 to be the best, I wanted the best diff cover money could buy - and I chose Crane. Here's why:


	The kit comes with diff cover, socket-head style fill plug, button-head mounting bolts, sealant, and instructions. Nothing is second rate - the bolts themselves are top of the line. They are Holo Krome® button-head bolts that are far stronger than a regular SAE Grade 8 bolt. In fact Holo Krome is one of only 2 SAE brands recommended by that perennial godfather of engineering tech and quality - the late Carroll Smith. Even the sealant is not some cheap throw-away generic tube. You get a tube of The Right Stuff™ RTV - one of the best on the market, and my personal favourite next to the factory GM stuff.

	Cast as a single seamless piece of chrom-moly alloy steel, this is unquestionably the strongest diff cover available. There are no seams, no welds, no heat-affected zone stress raisers - juts one piece of bulletproof chrom-moly steel.

	The design is also important . Built to be abused for a lifetime, and specifically for hardcore 4x4 use, the diff cover is lipless - leaving no edges to catch on the rocks. It also has the fill plug in a raised location, allowing for plenty of lubricant in the diff - which is great for raised pinions common in 4x4s. Due to a low chasis height' the Wolf's pinion isn't radically tilted, but the extra capacity offers great cooling and lubrication.

	The steel cover is also fully machineable and weldable. It was designed specifically to accommodate our many different needs - from welding on mounts (like a steering assist cylinder mount) to shaving - it is designed so that you can easily customize it.

	Of course, the real deal is in the beef. A good 1/4" thick at the flange, and thicker throughout the body - you're not going to be punching a hole in this cover. And, if by some freak you do break the cover - it is fully covered by a lifetime guarantee on workmanship and materials. When I spoke personally with Tim at Crane High Clearance, he said "If you break one of these, we will replace it, period. And be sure to post pics, because that carnage we have to see!"

	The cover bolts are nicely recessed and protected in their pockets. Crane offer "stainless steel" bolts on request, but personally i would advise against them. Though I don;t know the specific grade of stainless they use, in general stainless steals are much weaker then non-stainless alloys - usually somewhere between grade 2 and 5 on the scale. I'd stick with the very groovy Holo Krome® bolts.

	The cover comes unfinished - so you have to paint or powder coat or finish it to your liking. I painted mine with a quality zinc self-etching primer first (essential to get proper adherence to the raw steel), and then top coated them with Bowman "Detroit Diesel Silver" Industrial Coating (spray bomb!)

	Here's the mangled beast it is replacing. You can clearly see why I need the strongest cover available. I like to drive by feel! Think about it, your diff cover is way out there in front - first to meet the rocks, and covering the heart of your axle, the diff. It HAS to be strong. Look at all the various pieces of 1/4" steel welded to this Frankenstein creation in an attempt to protect the diff.

	The only trouble is, no matter how much steel I welded on, I was left with the weak, flimsy lip that was never designed for the abuse I dish out. You can see here I have peeled, bent, and ground it into oblivion. It will be so nice to not have to worry about peeled covers and dripping gear oil anymore!

	Of course, my front diff is no longer to "factory spec", the rocks and my 4.5" mini-grinder have both conspired to grind down the housing bottom over the years. Crane anticipated that, and included in the instructions guidelines for trimming the Extreme Diff Cover to match. It's so nice to have products professionally designed and manufactured by folks who 'wheel and understand our needs too.

	I marked the offending overhang with a permanent marker while the cover was installed, then removed the cover.

	And put to work the 4.5" mini-grinder with thin zip-disk cutting wheel attached; to remove the overhang.

	Once that was done, I installed the cover. Unexpectedly I hit a snag. One of the cover bolt holes wouldn't line up with the housing. Uh-oh! It wasn't off by much, just a hair. Damn! I tried several things - made sure all the other bolts were loose, reinstalled the cover twice, and even matched it up back-to-back with a stock cover to make sure my housing wasn't tweaked or warped. The hole was off a touch - but no big deal, I just opened it up with drill, about 1/16" was all it took - not even enough for me to use a washer under the bolt head.
Naturally, I spoke to Crane about the misaligned bolt-hole. I told them it wasn't a really big deal, but a minor frustration, and suggested maybe they might want to check their Quality Control procedure. Their response was quite unexpected. First we shared a laugh at the irony - not one other cover has had a reported problem - why did it have to be the guy with the big mouth and the blazing keyboard?! Then this is what they said: "As a fledgling company we will not compromise on our quality. We are out to set the the standard by which others are measured in this very competitive market. We will send you a replacement cover, that is our policy if anyone is unhappy with our product, this not just special treatment for you. We sincerely apologize for any inconvenience. Our goal of 100% customer satisfaction will be obtained by offering the finest products available with a lifetime guarantee." Chris Crane. I think that's superb customer service, and speaks volumes about the company. It's why I love to deal with the small, independent guys. There's nothing better than a company that truly stands behind what it says and does. They made no excuses, offered no bull, demanded nothing from me - not proof, not the other one back - they simply took me at my word (and photo of course) and made it better than right. I respect that, a LOT! It's far too rare these days, and I ALWAYS want to do business with companies like that. Good on ya' Crane!
	The BillaVista-60 now has some seriously beefy protection up front. Brute strength, no lip to catch and bend, leak free, rounded bolt heads to minimize rock-rash, extra oil capacity, and a lifetime guarantee. Like Crane's company motto says: ABUSER FRIENDLY!!