My 33" Tire Thread (Sorry its late ...) - Part I - Chevy TrailBlazer, TrailBlazer SS and GMC Envoy Forum

Welcome Enthusiast! If you already own a Chevy TrailBlazer or GMC Envoy or perhaps thinking of purchasing such a vehicle, then you have come to the best TrailBlazer and Envoy site on the net! Rainier, Bravada, Ascender, and 9-7x owners welcome too!

You are currently viewing our site as a guest which gives you limited access to view most discussions and access our other features. By joining our free community you will have access to search and post topics, communicate privately with other members, respond to polls, upload content, and access many other special features. Registration is fast, simple and absolutely free so please, join our community today!

If you have any problems with the registration process or your account login, please contact contact us.
Join Today!
Go Back   Chevy TrailBlazer, TrailBlazer SS and GMC Envoy Forum > 2002 - 2009 TrailBlazer/Envoy Tech > 02-09 Brakes, Suspension, Wheels and Tires > Tires

Tires Tires is the premier GMC Envoy Forum on the internet. Registered Users do not see the above ads.
Thread Tools
Old 10-21-2006, 10:13 PM
AlekG's Avatar
AlekG AlekG is offline
TrailVoy Alumni
2006 Chevy TrailBlazer LT
Expedition White 4.2L I6 4X4
Join Date: Sep 2006
Location: Toronto, Ontario, Canada
Posts: 1,055
My 33" Tire Thread (Sorry its late ...) - Part I

The Hows and Whys Of Going Up To 33 Inch Tires

I bought my Trailblazer back in 2002 and did not have a clear plan for modifications at the get-go. Two reasons: I always lease my vehicles, and back then there WERE NO modifications for our rides. It took me about 5 minutes to forget about the lease thing as I knew right away that I was going to buy the Trailblazer out at the end of the lease. Then, in the summer of 02 some mods started to appear. Air filter kits, JET chips, etc.

The BIG problem was the wheel (and suspension set up). As most everyone knows by now, GM for some reason decided to put a front wheel drive type set up on our trucks. This means a VERY HIGH offset for our wheels. Even more strange, they decided to use a practically non-existant bolt pattern of 6x5 for the wheels. And to top it all off, the front suspension set up has a protruding "knuckle" which limits even upping the tire size on the stock wheels! Almost makes me believe they did all this on purpose to stop us from improving the somewhat lame stock tire set up.

My specs were 16x7 wheels with a +50 offset. Tires were 245/70R16 with an approximate diameter of 29.5 inches. Needless to say there was nothing out there in terms of aftemarket wheels. As a small batch of aluminum wheels started to appear in early 03, I started to think about how I was going to outfit the Trailblazer in my usual summer/winter fashion. Note: up here in Toronto, SALT is used heavily in the winter so keeping any kind of aluminum or chrome wheels on all winter is basically not a good idea.

So in 2003, I was looking for tires I wanted to use on my stock wheels for winter driving and larger size polished or chrome wheels and performance tires for summer driving. My summer set is listed in my profile for anybody that is interested. The winter tires posed a problem as I really wanted to go with a wider tire than stock but that suspension hardware puts a big restriction on that.

This is when I started to look into spacers and adapters. I read many articles and opinions, talked to local people, and ended up deciding that I was comfortable with PROPER adapters. Specifically, NOT the kind that use the stock lug bolts and only push the wheel out, but this kind. They bolt up to the stock lug bolts on our axles and provide new and stronger bolts for the wheels to bolt up to. The reason I ordered from Sam's Offroad was that they were the only shop back then (that I could find) that would get adapters made in our bolt pattern and would ship to Canada. There is much more selection these days ...

My original spacers were 1.5 inches thick, had 6x5 bolt patterns, and a center bore of 3 inches. With that extra 1.5 inches, I could get the tires I wanted for winter: Dayton Timberline 265/75R16. These would fit onto the stock 16x7 wheels. They are listed as 32" in diameter so I was a bit worried at the time about clearance.

However, after three winters, I can say that I have had no significant clearance problems. No left/right wheel well contact, only some rubbing on the top of the wheel well on major compressions.

So when I started to get into modifications again this past summer, I started to look for a third set of wheels/tires that would be more suited to offroad adventures. This wheel and tire combination really cought my eye:

Of all the wheels I looked at, I liked the simulated bead lock on this one the best. Its an Eagle Alloy Series 1378, 16x8.0 with a +5 offset. I also like that its black painted with only polished accents. Problem was that it only came in a 6 x 5.5 bolt pattern. As for the tire, I wanted to go very aggressive and of course, there was no reason to stick to a size I already had so I set my sights on a 33" tire as I knew I was also going to get a 2" lift. Still, front clearance was definitely going to be a problem.

Continued ...
Reply With Quote Quick reply to this message
Sponsored Links
Old 10-21-2006, 10:16 PM
AlekG's Avatar
AlekG AlekG is offline
TrailVoy Alumni
2006 Chevy TrailBlazer LT
Expedition White 4.2L I6 4X4
Join Date: Sep 2006
Location: Toronto, Ontario, Canada
Posts: 1,055
My 33" Tire Thread (Sorry its late ...) - Part II

Continued ...

The first step was to call up Sam's Offroad and see if they could get custom adapters made that bolt up to the stock 6x5 bolt patern but provide a 6x5.5 bolt pattern for the wheels. They said absolutely so I went for it. Note for anyone getting adapters: anything less than 1.5 inches thick (which I was considering as the wheels would also give me some clearance) will require grinding down the stock lug bolts. I didn't really want to do that so I stuck with the 1.5 thickness. Here's a picture of the adapters after being powder coated yellow. So that takes care of the suspension clearance.

The next step was to get the BDS 2" strut and coil mount lift kit. I believe that this is essential for 33" tires as I am sure there would be significant rubbing on the upper part of the wheel well on larger size bumps or dips.

I then got the tires mounted and balanced. At the same time I did a test fit on the truck. The rear was fine, however, the front had issues as I suspected so I drew some guides for cutting. The yellow lines are approximately where I ended up cutting at the end. The reason for this was that with the first cuts, the tires would still hit the bottom of both linings when turning in forward and reverse. Notice the partially removed bolt at the rear. This holds the side molding into place and was completely in the way of the tires when turning.

My first attempt to avoid that rear bolt was to remove it, cut the molding at the bottom so that the top part can be bent backwards somewhat, and hammer the metal tab as far back as it can go. I then put the bolt back to hold the molding in place but with the whole thing bent back on an angle. Ultimately this was not enough and I had to cut the metal tab (and a bit more) away completely. The yellow lines are where the cutting had to be done, both on the horizontal and vertical sheet metal.

On the front side, I noticed that the plastic inside the yellow circle was rubbing quite often. Problem is that this piece has a plastic fastener that holds three pieces of plastic together: the front bumper, the under-bumper valence, and an attachment that comes down from the sheet metal that makes that whole corner a lot more stiff. So what I did is remove the fastener, cut the end of the bumper and valence off, drill a new whole through both, and attach all three pieces back together with the fastener. In effect moving the fastener back about an inch. Doing this keeps the whole corner as stiff as it was before.

Continued ...
Reply With Quote Quick reply to this message
Old 10-21-2006, 10:18 PM
AlekG's Avatar
AlekG AlekG is offline
TrailVoy Alumni
2006 Chevy TrailBlazer LT
Expedition White 4.2L I6 4X4
Join Date: Sep 2006
Location: Toronto, Ontario, Canada
Posts: 1,055
My 33" Tire Thread (Sorry its late ...) - Part III

Continued ...

And finally, you can see the results of the metal cutting. The whole area was sprayed with undercoating to avoid rust. One thing to notice is the soft vertical meterial behind the cut area. This is some type of insulation which is well protected when the wheel well is not modified. Therefore to try and recover some of that protection, I cut some mud flaps to shape and attached them to the remaining wheel well material. The rear is wedged on a angle into the space. I did this on the front as well to protect the fog light area where I installed some PIAA lights.

So here is what the whole thing looks like now. I am VERY pleased with the outcome. I have had no vertical rubbing yet, even with some offroad (albeit fairly tame) testing. I do get rubbing in two areas still (refer to the yellow circles), usually in parking lots when doing sharper turns. The front is plastic but so far nothing has prompted me to do any more cutting. The rear is metal and visible, so I wouldn't be doing any work on it myself. I have some other body work to fix in the spring so I may ask the body shop what they could do at the corners to get rid of some material.

There are some more pictures in my gallery.

The End
Reply With Quote Quick reply to this message
Old 10-21-2006, 10:37 PM
blktbon20s blktbon20s is offline
No longer with us
Join Date: Jan 2006
Posts: 6,583
That tire/rim set-up is really nice!
I like it alot.
Reply With Quote Quick reply to this message
Old 10-21-2006, 10:40 PM
jauto98's Avatar
jauto98 jauto98 is offline
TrailVoy Alumni
2004 Chevy TrailBlazer LS
Dark Gray Metallic 4.2L I6 2WD
Join Date: Sep 2004
Location: Georgia
Posts: 1,786
Nice setup. Congrats that it worked out !
Reply With Quote Quick reply to this message
Old 10-21-2006, 10:42 PM
lilchoke's Avatar
lilchoke lilchoke is offline
2003 GMC Envoy SLT XL
Monterey Maroon Metallic 4.2L I6 2WD
Join Date: Mar 2006
Location: Savannah, GA
Posts: 158
what was the total cost. i am liking that set up. may have to adopt it a bit.
Reply With Quote Quick reply to this message
Old 10-21-2006, 11:28 PM
ieatglue's Avatar
ieatglue ieatglue is offline
TrailVoy Guru
2003 Chevy TrailBlazer LT EXT
Onyx Black 4.2L I6 4X4
Join Date: Aug 2005
Location: Toronto, Ontario
Posts: 8,770
Awesome write-up! I'm trying to get a meet going next week. Maybe you can stop by and show us in person
Horsepower is how fast you hit a wall, Torque is how far you take the wall with you

Reply With Quote Quick reply to this message
Old 10-21-2006, 11:56 PM
ScarabEpic22 ScarabEpic22 is offline
Northwest Chapter
not here not here not here
not here Other AWD
Join Date: Apr 2005
Location: not on this site
Posts: 11,824
Schweet man!

Im going the opposite way, but if I get an SS and keep my 02, I think if I dont turbo it that I will make it an offroad truck like your and the roadie's!
Reply With Quote Quick reply to this message
Old 10-22-2006, 12:02 AM
ghoster ghoster is offline
No longer with us
2011 Chevy Tahoe
Mocha Steel Metallic 5.3L V8 4X4
Join Date: Dec 2005
Location: Baltimore
Posts: 12,260
NIcely done! Love the color too!
Reply With Quote Quick reply to this message
Old 10-22-2006, 12:25 AM
Trailblazin's Avatar
Trailblazin Trailblazin is offline
TrailVoy Alumni
2007 GMC Yukon Denali
Black Other AWD
Join Date: Jun 2005
Location: Jabriya, Kuwait
Posts: 1,244
Very good write up! Damn, I'm surprised it takes that much to fit in 33"s.. and there I was thinking it would only be the inner fender wall liner ah well, im sure after another 10,000miles you'll be able to turn full lock with no problems what so ever

Do you guys think that even with the 2" body lift, there will be this much hacking and dicing to get 33s to fit??? I mean, by the looks of things, the centre of the wheel when suspension is compressed fits right next to the bottom of the rear wheel well..

meaning if there was an extra 2" body lift, the tires should meet almost 5/8th way up to where the end of the wheel well meets??

Just a question...

Cheers again for the write-up AlekG! You've helped me see the light lol

***MODS any chance you could resize the image?? I don't wanna ruin the shape of the page***
'07 GMC Yukon Denali
220/234 .570/.588, ARH 1 3/4" with 3" ORY, PRC Doubles, LC1, TVS1900 w/ 2.8 pulley
Reply With Quote Quick reply to this message
Sponsored Links

Quick Reply

Register Now

In order to be able to post messages on the Chevy TrailBlazer, TrailBlazer SS and GMC Envoy Forum forums, you must first register.

Please enter your desired user name, your email address and other required details in the form below.
(Only letters, numbers, dashes and underscores are permitted for user names)
The user name that you choose is permanent and can never be changed.
User Name:
Please enter a password for your user account. Note that passwords are case-sensitive.
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
Thread Tools

Posting Rules
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Rear spare tire carrier AlekG Off-Road 13 05-20-2017 03:48 PM
Spare Tire Secondary Latch? and Tire Rotation Puzzler Coach Steve Tires 18 02-26-2009 04:07 PM
TBSS Multiple Spring Part Numbers TBSSLoweringPro TrailBlazer SS Chat 0 03-07-2008 02:53 AM
Tire pressure monitor system part numbers, any one have? blueblazer5_3 Tires 2 04-10-2007 10:42 AM
Sticky with common part numbers and descriptions EnvoyXL Community Help 18 03-06-2006 12:29 PM

» Sponsors

Advertising Info

All times are GMT -4. The time now is 05:43 PM.

Chevy TrailBlazer and GMC Envoy Enthusiasts - Copyright 2004 - 2009 All Rights Reserved.
All trademarks referenced herein are property of their respective owners.
RSS Feed