4x4 AnswerMan - Off-Road Truck and SUV Tech Q&A

Dec. 31, 2013 By Jaime Hernandez
Ultra4 Rock Racers at King of Hammers exhibit during Off-Road Expo in Pomona, CA.

Have a truck or SUV question for the 4x4 AnswerMan? Send your questions to [email protected]. Please include your name and location, and be as detailed as possible about your questions.

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4x4 AnswerMan,

I have a Ď94 Toyota truck. My diff is in sad shape vibrating horribly, only vehicle, really need some help.

Joe Nash

Hi Joe,

If youíre feeling vibration from the back end of the truck, it may not be your rear differential that needs servicing, but rather, the rear drive shaft (drive line, propeller). These trucks can go well over 400k miles with little servicing or repairs done to the rear axle, unless you trash on it hard. We have a friend with a similar Toyota that has over 500,000 miles. Itís still rolling strong.

Iíd be willing to go out on a limb and say the vibration you are feeling is coming from the universal joints (u-joints). For giggles, get under your truck, grab a hold of the rear drive shaft and shake it around.  If you notice any excessive play in the front or rear u-joint (where it meets the transmission and the differential), youíve found the problem. The repair shouldnít put you back more than $60 for the pair. 

If you have been driving your truck around for awhile with bad u-joints, you should also have the driveline balanced at a drive shaft shop to make sure itís true.

Good luck.



4x4 AnswerMan,

How good is this motor in the 2005 Tahoe, Vortec with 8 spark plugs? How many miles can you put on it usually?

Hi Rhonda,

The GM Vortec 5.3 engines found in the 2005 Chevy Tahoe are good runners. The Vortec 5300 LM7 was introduced in 1999, and produce 270 hp (201 kW) and 315 lb.-ft. (427 Nēm), 2000-2003 engines made 285 hp (213 kW) and 325 lb.-ft. (441 Nēm). The 2004-2007 engines made 295 hp (220 kW) and 335 lb.-ft. (454 Nēm), and it has a cast iron block and aluminum heads. This engine is found in 2000Ė2006 Chevrolet Tahoe/GMC Yukon.

Just stay up on the engine oil changes and maintenance and it will run a very long time. Weíre seeing them get into the 300k miles with regular maintenance.  These small-block Chevyís are truly workhorses.



4x4 AnswerMan,

Just wanted to get a professional opinion, I have a 97 two-door 4x4 Tahoe with stock suspension and would like to upgrade the tires/wheels. I really like the Rocket Hyper Shot 6 rims and the Nitto Dune Grappler. The Hyper Shots only come in the 20-inch size and I was wondering if I would have to put a lift on my truck if I went with those and the Nitto Dune Grapplers in a 285/50R20 size.


Jay D. Broadus, MSgt, USAF

Hi Jay,

Sounds like youíre getting your Tahoe decked out. For the tire size and wheel diameter you have described, you should be fine since you have a 4x4 model.  There is plenty of room to fit up to 33-inch tires on that SUV. The 285/50 R20 are about 31.2 inches tall, so youíll have plenty of room.

The set of wheels you like should look good on that rig, and the Terra Grapplers are sure to keep you rolling on pavement and dirt. The only thing to be cautious about is the wheel backspacing. Make sure you have at least 4.5 in so you donít have to run spacers or run into rubbing issues.

Send us a photo when you get your rig dialed in.

By the way, if you want to level the front suspension, you can turn up the torsion bars a scosche Ė just make sure to have the front end aligned. To ensure a smooth ride, we recommend you use suspension-leveling keys.




4x4 AnswerMan,

How can I convert my steering wheel on my 2006 Hummer H2 and how much will it cost to me?

Zhan A.

Letter sparked by RHD USA Ford F-150 SVT Raptor

Hello Zhan,

Thanks for resurrecting this awesome Right Hand Drive Conversion off-road truck.  For the H2, there arenít really any off-the-shelf parts to convert it yourself without doing some fabrication and mechanical work. There are a number of outfits out there doing this type of work, but RHD USA does it right. They work hard to engineer all the steering and suspension components so it works correctly and can be serviced in the future with factory OE parts (minus some key proprietary components).  The same goes for the interior, dash, controls, instrument panel, HVAC system, steering wheel and pedal assembly.  On average, RHD conversion are in the $35k-$40k range, though it will vary depending on additional upgrades made, such as engine performance upgrades, off-road wheels and tires, suspension upgrades and such.

RHD USA has done several H2 Hummer conversions in the past, so they should be able to give you a pretty good estimate on cost for their conversion. For more information on Right Hand Drive Conversion, please contact Shawn Rogers directly at:

RHD USA / 4Steer Conversion 619-546-4RHD (4743) USA 61 (03) 9018 7576 Australia  [email protected]


4x4 AnswerMan,
Hoping you can help!!!! I have an 09 Silverado 4x4 1500. At appox. 18,000 miles I had a 2 " leveling kit installed and the truck had all alignment performed. At appox. 35,000 the outer CV boots were showing cracks and leaking grease. Installer & Kit manufacturer informed me this could not be caused by leveling kit because the angle of the CV shafts were not changed enough to cause this to happen. Dealer would not replace under warranty due to modifications made. At 37,900 I had shafts replaced (aftermarket) at my cost. Now at 54,000 both inner and outer boots are starting to shred and leak grease and again Iím being told this shouldn't be happening because of leveling kit. Iím running 285/70R17 Cooper tire on compatible aftermarket rims. Rear shocks were also replaced with Skyjackers.  I just cant get the answers I need to rectify this problem. Everyone just keeps kicking the ball back and forth. Iím very fond of this truck and have dropped many $$$$$ into it. Not wrecked, no serious off-roading, very well maintained. Any ideas ????
Glenn Faircloth

Hello Glenn,
CV Axle boots can be a pain, especially when dealing with a 4x4 truck that cycles the suspension off-road. The reality is that the rubber on the CV Axle boot will get stretched, and will eventually crack and start to leak, even under normal use. Itís one of the design flaws of CV axles Ė they all eventually tear CV boots with regular wear and tear.

When the rubber boot breaks open, it leads to grease oozing out, eventually leaving the inner bearing dryócausing damage. Having the rubber boot open will also lead to dirt and contaminants getting into the bearingówhich will speed up failure. Youíll hear them grinding when they get that bad.

In our experience, the rubber on aftermarket CV boots does not do as well as the factory ones. If your aftermarket ones are already torn, you may be able to get a new set under warranty. Most new OE replacement CV Axles come with a lifetime warranty, or 3yr/36,000 for remanufactured ones.

The truth is, even if you replace them, itís going to happen again sooner or lateróitís just part of owning an IFS truck.


You have a few options to rectify this problem and increase the time between repairs. You can simply replace the CV Axle boots with some heavy duty off-road specific rubber boots and re-pack them with CV Axle grease. The other option is to install a set of Ultimate IFS CV Axles designed to overcome the limitations of stock IFS axle shafts. Both are available from RCV Performance (http://www.rcvperformance.com).


In the recent story by Josh Burns titled Trail-Ready Tundra Upgrades from Fox, Total Chaos, BFG
we ran into a small snag with a little tire rub when the suspension compresses. It was not evident until the Tundra ran down in Baja.

The guys at SoCal Super Trucks (http://www.socalsupertrucks.com/) stepped up and offered us a solution that includes modifying the truck cab mount with some SoCal Super Trucks steel plates that create more clearance for the tires. This modification allows a clean full cycle of the Fox Racing Shocks and Total Chaos Upper Control Arms (UCAs). 

Look for a future story that shows you how you can clear 35-inch tires on your Toyota Tundra with no rubbing, all while keeping it low and nibble for the dirt.


Fifth Generation Ford F-Series pick up truck made from 1967-72 (Photo Wikimedia).

4x4 AnswerMan,

I have a 1967 Ford F250 4X4 and would like to put disc brakes on the front. Do you know of a kit or what parts from what year would work on my truck?

Marshall Wallmark

Hello Marshall,

Unfortunately there arenít any off-the-shelf disk brake conversion for your 4x4 F250 that we could find. You might be able to Frankenstein something using brackets from RuffStuff. 

Your best bet is to find a 6th Generation Ford F-Series donor truck 1973-1979 with disk brakes. You can swap out the axle(s) and add power steering while youíre at it. There are a number of brackets and suspension parts that need to be used, so itís better if you can get the whole enchilada to grab parts from. If you can find a 1977-1979 high pinion Dana 60 front axle, this is the most desirable. 

Good luck.


My name is Dave from Live Oak, CA and I have a question on my dadís 2002 Duramax 2500 ext. cab 4x4, 6 speed manual. My dad passed away in may at 60 and I inherited his truck and I never want to part with it, but I was in a bad motorcycle wreck where driver ran a stop sign and I hit him with my motorcycle, I was life-flighted to Roseville and seven surgeries and a year and a half later Iím losing my fight to keep my left leg. The Dr. would like me to have an amputation so my question is, is there some bolt-on kit to operate my clutch with my hand instead of my foot. Plus the truck vibrates a lot when I hit the brakes and my mechanic says my front hubs are wore out but they are only a year old both sides, is this a common problem with the Duramax? One day I would like a leveling kit on the front but will that make the problem worse.
David Bruemmer Jr
Hi Dave,

Sorry to hear about your loss and your accident. Your dad left you a very nice rig. Those Duramax diesel trucks run forever. It sounds like you might have a stick shift, with the clutch and all. If you do end up loosing use of your leg, you have a few options. One would be to have accelerator and brake hand controls installed, and use your right leg to engage clutch. The other option is to have the truck converted into an automatic with an Allison transmission from the same vintage truck. It really depends on what works best for you.

Wheelchair Accessible Trucks by Ability Center. More info at http://www.abilitycenter.com/.

By the way, you may be able to get some assistance with the hand control conversion. There are a number of grants out there. Here is a link with more information about vehicle conversions in California.

As for the vibrating front end, it can be a few things: worn brakes, loose steering or worn wheel bearings. You should really get this fixed, we donít want another accident. When you get ready to level the front, all you need is leveling torsion keys and an alignment. It should not affect or add any vibration to the front, just make sure they donít crank them too much, as this will give the truck a very stiff ride.

Best of luck! Wishing you a speedy recovery.

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