73-87chevytrucks.com
73-87 Chevy _ GMC Trucks => Wheels & Tires => Topic started by: Fairlane514 on June 01, 2012, 09:37:45 am
-
1984 C10..........I installed the 2 inch aluminum spacers which included the correct lugs and torqued then to 95 ft lbs, then I installed the tires/wheels.
When I dropped the truck back on the ground the wheel looks to be "in" at the top and "out" at the bottom. I can raise the truck back up and the wheel looks square to the body and turns without runout. Drop it back down and it appears to be off, or not square. I don't believe the axle bearings are bad, I'm sure they are original. No noise comes from the rear end while driving and there is no leakage from the axle tubes.
I did notice the lugs from the axle flange are a little short and are recessed into the spacer lug nuts even when tight.
-
I installed a 2" spacer on both my 87 K5 (33" tires) and 86 K10 (31" tires). Both with 10 bolt rear ends and they both do the same thing as yours. I have about a 1000 miles on the K10 and 50 on the blazer and haven't seem any issues with them. I believe it is because of the extra leverage the wheels put on those little axles. I hope to hear more from people who have run these spacers on a more long term as I too am curious.
-
Yeah, I agree on the extra leverage theory, I guess a 1 inch spacer would show less "tilt."
Also seems like the tire would wear wrong.
-
I would sure hope that what your describing isn't happening (bowing the axle in some way). If so, it would be in your best interest to remove the spacers before you create a mess & someone gets hurt. Lorne
-
If the rear axle is bowing like that, take them off immediately! You'll break an axle shaft quickly like that!
If the front is bowing but NOT the rear, go have an alignment done, you changed the geometry so the old alignment is invalid now.
-
Its on the rear, and I did take them off............I did not drive the truck with them on, I noticed the tilt when I dropped it after the install.
I don't know if its worse with the 15x7 rally or 15x8. The 15x7 has about a 3 1/2 inch back space and the 15x8 has a 4 inch. Mine are the 15x7........
-
I am just trying to figure why spacers (that is if the spacer itself is machined right) would cause the axle to "bow" as described.
I have never used spacers for this, how do they go on and where (between what pieces) of the rear end ? If the are mounted on the backside of the rim up against the drum/disk brake and mounted and torqued properly, then why would these spacers make the axle bow and not the tire and rim combo by itself ?
-
I question this myself...That's why my post said "If". This should be no different than putting on the same wheel with 2" less backspace...Wheel/tire combo moved out 2" from the "normal" distance from the axle bearing, carrying the load. With all of the foolish things I've seen people do with wheels & tires from big 4x4 trucks to the 20" hydraulic guys on normal 10 bolt axles, I would think it would be more "well known".
I have fixed several small axle (28 spline) 9" rears from broken axleshafts &/or repeated axle bearing failure by going to the bigger 31 spline shafts. These were all with big Pro Street type tires & deep dish (little backspace) wheels...same theory, so I won't say "Can't be". None of these vehicles had any real power or were abused, just poser driver type vehicles so that didn't figure into it. In 2 of the 3 I'm referring to, the bearing centerline was not 100% true to the center carrier bearings when the housing was shortened so I blamed it on the whip effect that 78Silverado was thinking about. Lorne
-
The spacers are billet aluminum and bolt to the brake drum surface with supplied lug nuts and they in turn have studs pressed into them. The wheel then bolts to the "new" studs.
All I can say is, there is a noticeable tilt to the wheel after installing the spacers.
-
That would be something that would drive me crazy, I would end up tearing it apart 10 time probably until I figure out why.
-
What rear end do you have? It may just be the OE axles. These trucks had the wheel's tucked pretty good. even 4x4s stock had tucked wheels. It may be the stock light axles can't handle it.
I've had a 77 1/2 ton with a 12 bolt and an 87 1/2 ton with a 10 bolt, both i had oversized wheels, but on the STOCK RIM.
Only one of these trucks I've changes the offset on was my 78 3/4 ton. The axles don't support my truck, the hubs do, on my 14 bolt the axles only make them spin, but don't support any weight.
I can't help on this past theory cuz I aint done it on one of these trucks except a 3/4 ton-up truck.
Maybe some OE-TYPE stiffer axles? I'm guessing here. But I do know that as solid axle, essentially, if the rear bows on any 1/2 ton and 88-up 3/4 tons, you are bending the axle shafts themselves which can break them. I do know on the stock axles, from outer bearing to flange face is less than 4" approx 3" that much bending in a 3" span is bad, really bad, considering the entire length of the axle shaft.
Like above though, I do wonder why you are having this problem, as I've see big ol mud tires that stuck way out with no problem, and wide rims that stuck out on lowered trucks with no problem.
Maybe, install it and have the alignment shop check them for you. they may just look off but may not actually be. illusions can screw you up. install all four spacers and have the alignment shop check you out. they will tell you if it won't work, or should, if they are reputable.
-
The rear end is stock 10 bolt single track. I placed a level against the tire (stock 7 inch rally wheels) vertically and in order to get it "level" or square I had to pull the top of the level away from the tire about 5/8 to 3/4 inch. Without the spacer I had to pull the level out about 1/8 to 3/16 inch. This was done with the tires on the ground.
I only used the spacers on the rear tires, I took them off and never drove the truck with them on.
-
The rear end is stock 10 bolt single track. I placed a level against the tire (stock 7 inch rally wheels) vertically and in order to get it "level" or square I had to pull the top of the level away from the tire about 5/8 to 3/4 inch. Without the spacer I had to pull the level out about 1/8 to 3/16 inch. This was done with the tires on the ground.
I only used the spacers on the rear tires, I took them off and never drove the truck with them on.
Are you sure your rear axle is not bent already ?
-
When I lift the truck up and spin the tires they have no runout, so I don't think they are bent. The truck drives fine, no noise or wobble or odd feeling from the rear end.
-
When I lift the truck up and spin the tires they have no runout, so I don't think they are bent. The truck drives fine, no noise or wobble or odd feeling from the rear end.
That is still perplexing to me that 2" spacers can cause that much difference.
-
Any updates on this 'bowing' issue of the rear axels?
I'd like to get some spacers for my rear. I installed a suburban rear end/axle, and it's noticeably shorter length wise. I'd like the wheels to stick out a little bit. But this issue sounds terrible.
-
im going to add this, im not a expert on this but theres a such thing as hub centric wheels and lug centric wheels. most oem wheels will fit snugly over the hub of the axle and the lugs just hold the wheel on vertically while the hub holds most of the weight. if you install a spacer you are essentially turning your hub centric wheels into lug centric and putting all the weight on the lugs. i dont know if the problem but to me it makes sense to me and if you turn the spacers into hub centric spacers then it should fix the problem