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New Vs. Used - A Guideline For Buying Off-Road Parts

Posted in Product Reviews on October 31, 2014
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Photographers: Christian Hazel

Are you looking for your next big off-road part purchase but can’t stomach paying retail prices? Or maybe your natural instinct is to always buy new to avoid potential pitfalls and problems, no matter what the cost? Either way, why waste money when you don’t have to? If you’re paying retail prices for stuff that can be had just as good used, you’re tossing money out the window. Likewise, “scoring” used garbage that will need rebuilding or replacing can often cost as much or more than just buying it new in the first place. We pooled our collective experience to come up with a loose guideline of what’s normally OK to buy used and when you should bite the bullet and go new.

Mechanical and automatic lockers, limited slips, and open diffs are a mixed bag. For mechanical lockers (full case and automatic), inspect the teeth for damage and the case (if applicable) for wear. For limited slips, clutch-type units may be rebuilt with new friction packs. Just expect this will need to be done and factor the cost into the price. A mechanical limited slip (like this Eaton Truetrac) shouldn’t lose performance over years as long as the gears and case are in good shape. Take note that it’s recommended you reassemble the case and gears exactly in the same orientation as they came apart, so unless you’re the one who blew it apart for inspection, don’t buy a disassembled mechanical unit.

Axle assemblies, whether OEM or aftermarket, can usually represent a screaming deal as long as you know what you’re doing. Check the ring-and-pinion and lockers for damage, wear, and other bad juju. Pull the axleshafts and make sure the splines aren’t twisted. Also, take note that the bearings aren’t hashed or races/spindles scored and burned. If all that checks out and the axles are the correct width and bolt pattern you’re after, it’s often an easy job of cutting off and rewelding brackets to fit your application. Many aftermarket companies offer universal and vehicle-specific bracket kits for a number of applications.

Used ring-and-pinion gearsets can be OK, but overall, they’re too much of a crapshoot to count on. Microscopic cracks, bad wear patterns that aren’t overtly obvious to the naked eye, and even major trauma can all bite you in the rear. Not to mention, some used gearsets can increase the pattern setup, costing more to install than a new gearset. Some shops won’t even deal with used gearsets. Just do yourself a favor and plan on buying new gears.

Companies like Spidertrax make good quality wheel spacers that are designed to hold up to the rigors of larger-than-stock tires in an off-road environment. However, there are several Chinese knock-offs made of inferior materials that can crack or catastrophically fail even when maintained correctly. Unless the units you’re looking at are stamped with “USA” and are the familiar Spidertrax anodized blue finish, we’d skip the used spacers and just order some new ones from a reputable manufacturer for peace of mind.

When it comes to T-cases and aftermarket gearboxes (overdrives, underdrives, and so on), the same deal goes here as with manual transmissions. As long as parts spin freely, there are no chipped or broken teeth, and the internals are free of syncro debris and rust, anything goes. On chain-drive T-cases, inspect the chain for excessive slop. Different T-cases have varying amounts of acceptable chain stretch, so check the Internet before you head out the door with your wad of $20s.

When it comes to automatic transmissions, new is often the best course of action. Unless you know the seller or have the opportunity to spend a lot of seat time in the vehicle before a used auto transmission is pulled for sale, assume any automatic transmission you’re buying will need a full rebuild. We’ve rarely been blessed with a used auto that was completely trouble free. Most wind up on the rebuilder’s bench.

For manual truck transmissions, almost any used unit will be workable, and in many cases these days, unless you’re talking about a fully rebuilt unit from a place like Novak Conversions or Advance Adapters, it’s your only choice. Check the pilot tip and splines on the input gear for damage and the throwout bearing retainer for wear. Pop the top off and inspect the shift rails and forks and look for rusted or broken gears and syncro material in the bottom of the case. In almost every case, replacement parts are available, so it really comes down to just figuring out what your used tranny needs and haggling the price down accordingly.

When it comes to carburetors like Q-Jets or Motorcraft 2100s, pop the top off and make sure the interior isn’t all crudded up and all the needles and small parts are there. Plan on a parts store rebuild kit to refresh the gaskets and rubber parts. If you’re shopping for a used aftermarket injection system, obviously scoring a deal like this Edelbrock system still in the plastic is ideal. If not, make sure the instructions are there or available online so you can check the itemized parts list against what the seller has. You’ll also want to verify when the unit you’re buying was manufactured to ensure parts are still available. As long as the system is all there, you can usually get a killer deal with a used injection system as compared with buying brand new.

Used engines are a mixed bag. More modern engines like Gen III and Gen IV GM units and modern Hemi engines are incredibly durable. We’d be more inclined to take a seller’s word on one of these than an older V-6 or V-8. Many older engines designed prior to the late ‘90s will almost always require new gaskets. Often, plan on a timing chain set at best and a full valve job or rebuild at worst. Plan on doing a compression check to make sure all the cylinders are within 10-15 percent of each other. If you get a chance to, listen to the engine run before you pay money. In most cases you can get a good rebuilt crate engine from GM for about the same cost as a rebuild on a tired unit like this 1973 350 shown.

Springs sag, and custom springs are made for custom applications. Unfortunately, the only true way to know what you’re really buying when it comes to coil or leaf springs is to install them and try them out -- or at least drive the vehicle they came off of beforehand. That said, as long as you’re not the type who obsesses over 1⁄4-inch of lift height one way or the other, used springs (providing they’re in good shape) can often be had for a fraction of the cost of new units. Inspect the bushings and friction pads on leaf springs. Also, make sure none of the main or secondary leafs are bent or twisted. On coils, ensure the windings are the same and the measured free height (spring placed on floor) are identical.

You’d think it’d be a no-brainer when it comes to replacing your dented or rotted sheetmetal. New, right? Not always. Many body panels available through catalogs and parts wholesalers are imported reproductions that are ill-fitting at best and paper-thin at worst. If you can find it, some aftermarket suppliers bought up stocks of OE-spec sheetmetal when dealerships stopped stocking parts for much older models. Or, consider good, used panels from a junkyard. You may need to have them blasted and painted, but they’ll often give you a better fit and more durable longevity than less expensive imported junk.

Anytime you’re buying anything with a compressed gas cylinder, whether it’s for welding, onboard air, or even a paintball gun, you want to buy it already pressurized. That not only tells you there are no leaks, it tells you gas warehouses will still service the tank. On the whole, tanks must have a hydroscopic test every five years.

The date of the last test will be stamped with the month and year somewhere on the tank. In rare instances, a star after the date will be present, which indicates a 10-year retest period, not the usual five. In the case of this Powertank, the original manufacture date (02A03) was February 2003. We had it hydro tested again in April of 2010. Having a tank hydro’d is only about $20, so as long as the tank is fine, don’t let an out-of-date hydro stamp deter you from an otherwise great deal.

If you’ve priced new suspension seats lately, you could have a heart attack. Used seats are a lot friendlier on the ol’ wallet. As long as the frame isn’t broken or bent, the foam is intact and not rotted, and the suspension portion of the seats are in good shape, don’t shy away from faded, scuzzy, or oddly colored seats that would otherwise be a great addition to your 4x4. Most manufacturers offer replacement fabrics for their seats. We obtained new covers directly from the manufacturer to refresh these otherwise perfect Corbeau suspension seats. You’d never know they weren’t brand new when we were finished with them.

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