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33's or 35's with 3.7L?

Brad

Well-Known Member
Messages
45
Location
New England
Congrats on the new tires!
Thank's!

Haven't driven it much yet but so far the power seems to be about the same honestly. Definitly still faster than my old Explorer. Not sure about MPG. The M/Ts do make some noise going down the road but I think it sounds good. The speedometer is off now though. I will have to get that corrected. Thinking a local performance shop should be able to do that pretty cheap but if not I will do the mail order tune from PCMofNC. Still need to do the two inch lift and get a snorkel and raise my differential vents and stuff, but I think I will be happy with the tires and don't think I will be getting stuck with this Hummer in the places I got the Explorer stuck..........
https://ibb.co/Pw7swVT
 
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rascole

Well-Known Member
Messages
2,848
Location
Bellflower, CA
Looks good. PCMofNC does a great job. They will easily tune it to get the HP back, correct the speedo & eliminate the Passlock nuisance. I raised the front diff and TC vents and zip tied them next to the tranny dip stick makes adding oil easy and clean. Raised the rear diff vent to behind the tail light large void back there to hide it.

Thank's!

Haven't driven it much yet but so far the power seems to be about the same honestly. Definitly still faster than my old Explorer. Not sure about MPG. The M/Ts do make some noise going down the road but I think it sounds good. The speedometer is off now though. I will have to get that corrected. Thinking a local performance shop should be able to do that pretty cheap but if not I will do the mail order tune from PCMofNC. Still need to do the two inch lift and get a snorkel and raise my differential vents and stuff, but I think I will be happy with the tires and don't think I will be getting stuck with this Hummer in the places I got the Explorer stuck..........
https://ibb.co/Pw7swVT
 

Brad

Well-Known Member
Messages
45
Location
New England
So it drives good with the new tires and I haven't noticed any rubbing although they are noisy being a mud terrain. (I'm going to have to check my wheel bearings periodically because I will never hear a bad one now) I got it through the state inspection too. I finally thought I would be able to enjoy the truck a little so I headed up to my friends in NH, didn't even make it close when the rpms suddenly got real high on the highway. I pulled off and it seems I only have 1st and 2nd gear. Fluid was a little over a quart low and I don't know where it went because it was full before and I haven't seen any drips. Topped it off and it's no better though. Luckily I am still within the 30 days of purchase and wasn't too far from the dealer, so I drove it back to the dealer on backroads real slow in 2nd gear and he is supposed to be replacing the transmission for me. On my way there it also developed a creaking that sounds like a bushing or something. I hear it over bumps at parking lot speeds or when I turn the wheel at low speeds or stopped. IDK, I spent all this money on a nice truck (and put myself in some debt for it) thinking I wouldn't have constant problems but I have barely been able to drive it and have had to keep dumping money into it and it has been in the shop longer than I have been able to drive it. Almost thinking I would have had better luck with some sub 1000 dollar crapbox.
 

rascole

Well-Known Member
Messages
2,848
Location
Bellflower, CA
Keep your head up. You have a great 4x4 with a few problems and you are in the right place to help. The 4L60E has had it's issues but fortunately the problems are easily fixed and upgraded. The creaking sound is most likely a suspension bushing, any 15 year old car will start to make noises. Crawl under and look around for cracked rubber and go from there. Post pics of what you find so we can help out.
 

Brad

Well-Known Member
Messages
45
Location
New England
Keep your head up. You have a great 4x4 with a few problems and you are in the right place to help. The 4L60E has had it's issues but fortunately the problems are easily fixed and upgraded. The creaking sound is most likely a suspension bushing, any 15 year old car will start to make noises. Crawl under and look around for cracked rubber and go from there. Post pics of what you find so we can help out.

I have to wait and get it back from the used car dealer with a used transmission. Hopefully this one will last for awhile. Pretty sure GM put the 4L60E in tons of vehicles and before that it's predecessor the 700r4. Although not as strong as the old TH350 and TH400 transmissions, I don't think they usually fail this early so this must have been a fluke. (My father has nearly 300k on his Yukon and I have a coworker with almost 300k on his Suburban too and I'm pretty sure they both have the 4l60E in 4wd flavor. If it fails again in the future maybe I will have money to put a proper built one in then. Already going broke at the moment though so I told the dealer put in a used one since it won't cost me anything. He offered to have a local place rebuild mine for an extra 1k but who knows what exactly they would do or if it would still be messed up after. I'm sure it wouldn't be like a performance remanufactured one. Anyway, I told the dealer to look at the squeaking too. It's probably just a bushing that needs a little silicone spray but it could be one worn out. I did hear something about the steering rack bushings go bad and a kit with a reinforced bracket and stuff but I'm pretty sure if that is bad there is supossed to be a clunk and play in the steering. Hopefully I will get it back soon. I'm dying to get these 35 mud terrains dirty.
 

Brad

Well-Known Member
Messages
45
Location
New England
any 15 year old car will start to make noises.
My 2004 Deville never makes any suspension noise. My old 2004 Monty SS never made any suspension noises either. And the old 1996 Explorer that had well over 300k on it (with a second engine) and very severe rust, entire rear crossmembers rotted to nothing with a new hitch reciever holding the back of the frame together, with no rear sway bar or rear shocks (rotted off), although having some rattles and a bouncy rear end, I never heard any bushings creaking on that. Not once! Even after going swimming with it twice. Lol
https://ibb.co/HpKzf9x
https://ibb.co/VmzRyw9
https://ibb.co/9T0S9X0
Yes, after winching that out with a come along that Explorer fired right up and drove out of the woods just fine.
(I have waders now so I can test the water first if it looks like it could be deep)
 
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SlcHummer

Well-Known Member
Messages
368
Location
Salt Lake City, UT
I always get a lot of creaking after coming back from a Moab trip and a good spray down of my leaf springs seems to do the trick. Not sure this is your issue since you hear these creaks when simply turning your front wheels and lower speeds.
 

Brad

Well-Known Member
Messages
45
Location
New England
Just got home with it. An hour drive home. Everything seems good, it's shifting nice, and the creaking is gone too. After having driven it a decent amount now, I can say it definitely rides nice on these 35s. Glad I went with them. I don't hear any rubbing even at full lock but I bet if I look there are some marks on the sway bar. Power doesn't really seem any different than before and it runs a lower rpm on the highway than with the 33's. You would think that would give it better MPG but I guess more rotational weight and a bigger contact patch. Not really sure how much it reduced my gas mileage but I should know roughly after this weekend if it doesn't have any more problems.
 

Brad

Well-Known Member
Messages
45
Location
New England
Idk how accurate of a calculation this is as who knows if the fuel sender is 100% accurate or linear. I drove gingerly but at the speed limits. I filled the tank and drove 111 miles (by gps) on a roughly 50/50 mix of somewhat hilly highway (55-65mph) and also somewhat hilly country roads (40-55mph) and was down to 74% fuel after. Which would mean (if the sender is accurate and linear) I burned 5.98 gallons over 111 miles for a MPG of 18.56. Does this sound like it could be correct?
 
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rsm688

Well-Known Member
Messages
234
Location
mississippi
My 3.5 with exhaust, PCM of NC tune, and AirDoc did just fine with 35s from 80k miles to 160k miles when I sold it. I had it tuned for premium for more power. Did just fine offroad and highway. Does eat up upper ball joints fairly frequently. I replaced upper control arms every 30k miles or so as I'm OCD about tight suspension/steering. Need an upgraded steering mount with 35s.
 

Brad

Well-Known Member
Messages
45
Location
New England
My 3.5 with exhaust, PCM of NC tune, and AirDoc did just fine with 35s from 80k miles to 160k miles when I sold it. I had it tuned for premium for more power. Did just fine offroad and highway. Does eat up upper ball joints fairly frequently. I replaced upper control arms every 30k miles or so as I'm OCD about tight suspension/steering. Need an upgraded steering mount with 35s.
IDK why no one warned me about this stuff ahead of time lol. From what I have heard these H3's eat upper balljoints regardless of what tire is on there though. But what's the deal with the upgraded steering mount? Is that something I really NEED, and why?
 

Brad

Well-Known Member
Messages
45
Location
New England
I feel a steering rack reinforcement kit is necessary to keep your steering stiff/without play if you plan on taking your rig on more aggressive off road trails. Outfitterdesign has a good video here, https://www.outfitterdesign.com/steering-rack-reinforcement-kit.html
Is that one the only option still available? Wouldn't mind paying the 200 bucks or so they say it costs but that shipping charge is rape. The freight on my brush guard/winch mount wasn't even close to that much. What about putting poly bushings instead?

Edit: If I try to purchase it, it says sold out anyway.
 

JPaul

Well-Known Member
Messages
2,436
Location
Way up north, UT
Is that one the only option still available? Wouldn't mind paying the 200 bucks or so they say it costs but that shipping charge is rape. The freight on my brush guard/winch mount wasn't even close to that much. What about putting poly bushings instead?

Edit: If I try to purchase it, it says sold out anyway.

The drop down you see with the two prices isn't the shipping rate itself, it's the price plus shipping depending on if it's going to an address here in the US or outside of the country. So it's $212 out the door, shipped, total. I think they send it in a flat rate USPS box.

And yes, they are pretty much the only ones these days offering anything like it anymore. The owner, atv4speed, is a member on here and might chime in about availability, or you can message him to see when he expects to have more in. Supply chains are still screwed right now so I am not surprised he's out of stock.

As for the upper ball joints don't believe everything you hear. Yes, they don't last as long as people would like, but unless you are wheeling every weekend you're going to be fine. I've had 2 H3's over the last 7+ years and have only replaced one set with the +100K miles I have driven them. They're pretty inexpensive relatively speaking to buy new ones, and they're easy to replace.



The fuel gauge is nowhere near linear so don't go by the gauge, you either need something like an Ultragauge (highly recommend this) or a ScanGauge (much pricier and not as feature rich as the Ultragauge) that can actually track realtime fuel usage, or just use the old tried and true method of filling the tank back up again to see how many gallons you actually used. I can guarantee you probably used more than 6 gallons, +18mpg with 35's in New England (I'm a NH native btw, live in UT now) is really optimistic unless you filled up at the top of Mt. Washington and then drove down. I couldn't get that with my base 3.7L on 33" Duratrac's on the highway here in UT (where it is much flatter on the highways) unless I had a tailwind the whole way. I think the average is around 15mpg at best.


Going to 35's, with a 3.7 no less, your fuel economy is going to suck, period. Not that it was great in stock form (3.7L is rated at 14mpg city, 18mpg highway, and that was with the stock 31" SUV tires). So without changing gears in the differentials (which you can't in the 5 cylinder models, you already have the tallest gears possible that will fit in the front diff housing) you effectively decreased your gear ratio by going to the larger tires, which as you pointed out are also heavier and wider so the contact patch is greater. Combined with the tread pattern and softer compound for a much higher rolling resistance, you're not going to see the MPG you used to have. That's the trade off for making your rig more capable offroad. If you want good fuel economy in a truck you need to go buy a Ford F150 with the EcoBoost 2.7L.

And yeah, it's going to be a dog in the mountains with the 3.7L and 35" tires. Even having 33" tires my old 3.7L would struggle badly on the steeper grades. Vail pass in Colorado was the worst one I went over. I had my wife and daughters with me and luggage in the back and I struggled to keep it anywhere close to the speedlimit without the thermostat swinging wildly open and shut in the middle of winter. I would watch the temperature gauge needle swing up and down every time the thermostat would cycle, about once every 20-30 seconds. Gave up after a bit and just went 45mph up the pass. My Alpha (5.7L) on 35's on the other hand is a totally different story and will bomb up passes like they're nothing, but I am running a hotter cam and regeared the differentials to restore the stock ratios (Alpha comes with a shorter gear set than the 3.7L to help with fuel economy).

Not to say that you can't enjoy it still. Alrock has had his for years on 35's and still enjoys driving it regularly. Just know that you're going to be slower up the mountain passes than most everyone else, so instead of worrying about when you'll get there, just enjoy the beauty of the White Mountains and take your time. We don't buy these rigs to win races (well, maybe except for Chris, 06 H3, but he's an edge case! :)), so just enjoy the ride in a rig that is far more comfortable to ride in than any Jeep, and just as capable depending on how much money you throw at it (again, see Chris for the edge case!). Only reasons I upgraded to an Alpha was the price was right, it gave me a bunch of other upgrades from my base model H3, and I wanted to be able to better tackle the Rockies while towing a trailer.
 

rsm688

Well-Known Member
Messages
234
Location
mississippi
IDK why no one warned me about this stuff ahead of time lol. From what I have heard these H3's eat upper balljoints regardless of what tire is on there though. But what's the deal with the upgraded steering mount? Is that something I really NEED, and why?

Lol i learned it myself with time. I haven't had a factory H3 more than 2 weeks so I can't attest to it as all mine got leveled or lifted and 35s within a few weeks of getting them. I also drive like a bat out of hell and live in an area with **** roads so I probably burn mine faster than most. MOOG upper control arms are the only ones I use anything else falls apart much faster even the factory arms. The arms are cheap and take no time to install so doesn't really bother me much. I'd take that all day long over a stock ride, gotta pay to play lol.

The factory steering mount sucks so with anything over stock there is some wiggle so your steering suffers especially offroad. Outfitter design is the only company I know of still making it. I used Scorpworks on 2 of mine and Outfitter on 2 of them. No complaints from either. Have to pull the rack off the frame to install it. Replace the rack while you're at it as it doesn't take but maybe 30 more minutes to swap it completely and you will thank me later because your steering will be vastly improved and you'll probably never have to touch it again or at least for a long time. Steering rack isn't super expensive for a rebuilt unit off eBay. Have used two detroit axle ones and both still holding strong with 50k miles on them when I sold the H3s. I bought a brand new one for my Alpha as it is on 37s. That plus the Outfitter design steering kit and zero issues with 37s. Steers better than it did when I got it stock on 33s. Email or call outfitter probably just ran out and should have more coming soon. They have been selling them for as long as I have had an H3.


Get your ECM programmed by PCMofNC.com . Will give you a decent bump in power, they change the transmission shift points, and will calibrate for your tire size so speedo is accurate. I did that (had them tune it for 93 octane for better power) plus Magnaflow exhaust, AirDoc Intake, and BCM air filter and my 06 with 3.5 and 35s never had an issue. Can do all the above mods for like $1k and well worth it in my opinion. Did not seem any worse than factory tires/no upgrades. Gas mileage isn't great period but will drop a little but honestly I didn't notice hardly any change in mileage with the above mods as I feel the extra power kept the RPMs from being as high which helped the mileage and compensated some for the bigger tires. Run some seafoam through your gas tank if you don't every now and then, replace the plugs if you haven't in a while.
 
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Brad

Well-Known Member
Messages
45
Location
New England
Yeah upper control arms are no biggie to me. Will definitely try and get my hands on one of those steering mounts though if they are available. Gonna do the PCMofNC too (Got quoted by 2 local shops 250 bucks just to calibrate the speedo). Already did a tune up (plugs, new maf, cleaned TB, BG44k injector cleaner, seafoam through the intake, replaced VVT solenoid, changed belt). Just installed my grill guard and got my winch mounted up. I still have a snorkel waiting for when I get brave enough to drill the holes in the fender. Pretty much out of funds for a little while now though so the steering mount and pcm will have to wait a bit.
 
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