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Confused? Email your questions about trucks, 4x4s, and off-roading tech using "Nuts, I'm confused" as the subject and include a picture (if it's applicable). Digital photos must measure no less than 1600 x 1200 pixels (or two megapixels) and be saved as a TIFF, an EPS, or a maximum-quality JPEG file. Also, I'll be checking the forums on our website (www.4wheeloffroad.com), and if I see a question that I think more of you might want to have answered, I'll print that as well. Otherwise drop it old-school style with the envelope addressed to the address below. Letters published in this magazine reflect the opinions of the writers, and we reserve the right to edit letters for clarity, brevity, or other purposes.
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Nuts & Bolts
4-Wheel & Off-Road
6420 Wilshire Blvd
Los Angeles, CA 90048-5515
fax 323.782.2704.
Email to:
nuts@4wheeloffroad.com
Chilled Slush-Box
Question: I have a fullsize '89 Blazer 5.7L V-8 and 700R4 transmission. I bought a TorqFlo Super Cool transmission cooler (PN 911679) to install on it, and I am unsure which way I should install it. The directions show two ways of doing it. One is to install it in series with the radiator so that the transmission fluid still travels through the radiator as well as through the new cooler. The other way is to disconnect the lines from the radiator altogether and only have the fluid passing through the cooler. I am unsure which way would be the best for my truck.
I have heard of radiators going bad internally and allowing water and coolant to enter the transmission, turning the fluid into Pepto Bismol. I don't do any towing with my truck at this time, I am only putting on this cooler for a little extra protection for my tranny since I already replaced one, and, frankly, as expensive as it was to buy and find one, I don't want to have to do it again anytime soon. Any advice you can give me in this matter will be greatly appreciated.
Lou F.
via 4wheeloffroad.com
Answer: If protecting your transmission is the goal, I'd say use both coolers. If your are nervous about the coolant leaking from the radiator to the transmission cooler that is built in the radiator, then have your radiator serviced or replaced. Many times the in-radiator trans fluid cooler is nothing more than a tube running through the tank of the radiator, so bypassing it won't make too much difference, but I say two coolers are better than one.
Run, Jimmy, Run
Question: I have an '85 GMC S-15 Jimmy that I have been working to turn into a decent wheeler. The original plan was to build it to run in a local fire department's Tough Truck event. The truck has been completely gutted except for the driver seat. The only real additions made to it are a hoop-style rollbar and a front stinger as well as a nice rattle-can paint job. Now that I've spent some time in, on, under, and around my truck, I'd like to try and beef it up a little and try to make it into a decent trail rig. Not something huge and extreme, just something capable of making its way through without breaking.
I've searched high and low and can't seem to find any aftermarket support for this style Jimmy/ Blazer. Am I condemned to fabricating all my own parts, or is help out there? Any ideas on the types of improvements would be great. I'm new to wheeling, and I'm not sure where to start.
David F.
via 4wheeloffroad.com
Answer: There are actually many options for your S-15, also known as a Chevy S-10. If I could only have a few off-road performance parts I'd vote for a locking rear differential and better tires. Randy's Ring & Pinion (888.905.5021, www.ringpinion.com) offers quite a few different locking and limited-slip differentials for your GM 71/2-inch rearend, for between $400 and $600. But if you are really budget minded you could just weld up the spider gears, even though that's harder on axles and tires in the long run.
As for tires, your axles and front differential will not take excessively large tires for long, so I'd go up an inch or two from what you have, trim the fenders if they hit, and go have fun. Find the most aggressive tread you can if your trails have mud holes in them. Eventually you may want 1-ton axles, lower gears, and more power, but for now get some traction and go wheeling. Go with friends, and as parts break you'll figure out what to upgrade next.
Axle Answers
Question: I have a '90 Cherokee 4.0L, 4.10s, 33s, 8.8 out back, Dana 30 up front, and EZ lockers all around. I would love to upgrade front axleshafts. I know '98 and newer Cherokees have larger U-joints, but it's still a weak shaft. Chromoly would give me more strength, but the cost is high enough that if I go that route and still break a shaft my wife may just kill me.
My question is: If I get a set of donor shafts from, say, a full-width Dana 60, could I then have them cut and resplined to fit my 30? I know there would be a fairly high cost with this option (assuming it is doable), but in theory this would be the last set of shafts I would ever need. Does this make any sense, or am I looking at this all wrong?
Kevin T.
via 4wheeloffroad.com
Answer: Resplining and stuffing a Dana 60 axle shaft in a Dana 30 housing and differential is like trying to tighten that little screw on your sunglasses with an impact gun. No only is it the wrong tool for the job, but it's also not going to fit and will likely break other parts. The Dana 30 is a small 1.16-inch 27-spline axleshaft, and the Dana 60 inner shafts are 11/2-inch 35-spline, meaning you'll need to cut the shafts down just to get them into the carrier-and then you'll likely have machined through the hardening of the axleshaft. Plus you're not going to be able to fit the Dana 60 joints and yokes inside the knuckle. Basically it's not a good idea.
Either swap in a 30-spline carrier like an ARB Air Locker and go to the bigger 30-spline chromoly axleshafts, or swap in a complete bigger axle like a Dana 44 or Dana 60. Either way, you'll need to hide it from your wife.