Re: 1956 Merc 2dht. Tried to mount a 15x7 Crager s/s with a 215/70 R15 Douglas tire on the rear of this car. Casing is too wide to go between wheel opening and brake drum. Don't want have to drop the shock . Would be difficult on the road. Didn't try letting the air out. I like the appearance of this combo. Could try a 75 series but the tire spec sheet stated not much difference. Could use a 6 inch wide rim. I think the 7 inch is the problem. I dropped the shock to try it and this combo fits ok without rubbing the opening. Could use a 205/75 on the 7 inch and see. Would still have the same height. Has anyone ran into this situation? Thanks. Ned
Mine had a 235/70R15 stuffed in it with 2" lowering blocks. Swore my *** off trying to get those off the rear. Going with 205 all around and lost the lowering blocks.
Thanks. 205/75 on the 7 inch rim is my next step. Have access to used tires so no $ invested yet. Will be using 3 inch lowering springs rather than blocks to help this situation. I wonder if there is a longer extended shock available. Last option, get 15x6 rims. Don't think it would be noticeable with the 7 inch on the front. Thanks again for your input. Ned
I run a 235/75-15 on the rear of my '59 on 7" wheels. If I jack it up and let the axle hang, I have a minor struggle to get them on/off. It was on jack stands for the 1st install, I had to let the air out the tires. Try jacking it up from the side. I carry a floor jack in my trunk.
That black and white Merc the one you pulled a 400 out of? Yours have the same spring snubbers mounted on frame toward front of leaf that mine has? (Pic 1) I have 205 70R 15 on 7" wheels on the back of my 56 Merc. No issues putting those on, but I never use a bumper jack for fear of damaging bumpers and too tippy besides. Floor jack only and another small one or bottle jack for axle if it drops too much. IDK what offset my wheels are, but there is about an inch of tire clearance outside, but a good 4" on the inside. So, a bigger tire would appear to fit easily as long as the backspacing was correct for the wheelwell and axle. Axle could probably be shorter too with less wheel backspace for ease of tire changes, but then there is the oddball (to me anyway) 5" bolt pattern.. My wheels were just cast-offs from somebody's Chev street rod cuz they changed wheel styles also. I prefer Cragars or Keystones. But the wheels had 4.75 and 5.0 bolt patterns, so they fit and the tires on the car were so ancient it was a good $200 investment to keep the Merc a roller.
From page 3 of the "Sticky FAQ" https://www.racingjunk.com/news/how-to-get-perfect-rear-wheel-and-tire-fitment/
Member cka7 posted his tire sizes awhile back. He has 1" drop blocks on the rear and he trimmed the wheelwell lip 1/4". He's able to run 255/45ZR17s on the rear. Wheels are AR Torq-Thrust 17x8"/5x114.3mm with a 4.81 offset. It's necessary to disconnect the shocks and let the rear hang to shove 'em up in there. I think it looks great!
4.81 offset or backspace? There's a big difference. I have 235-75-15s on the back of my '57. No issue getting on or off. Shortened differential case 3/4 per side longer shocks ('56) disc brakes 7" wheel, can't remember the backspace, I think 4.5" NO mods to fender well, have 1" plus clearance, may go to 245s if I ever wear these out....49k miles and not 1/2 worn.
Yes, same car. And, Have those snubbers/bumpers. My tire problem was the sidewalls were too wide to go between brake drum and wheel opening. The photo with the wheel/tire mounted on the rear I had to remove lower shock mount. There is good clearance between tire and wheel opening lip. Thanks for your input.
Photo of the 400 next to the 292 I put in. Car didn't have engine or trans when I got it. Sold the 400 to a guy whose putting it in a 78 F-150. Your rims look good.
Well guys,,, I got the wheel mounted as-is. It fits with about an inch of clearance to wheel opening. The distance between top of brake drum to wheel opening is 8 1/4 ". The tire sidewall 8 7/8". Was trying to push the tire top first. Tried it like the drawing I made. Shock in place. Learn something everyday.
Didn't realize Cragar unilug went to 5 on 5. Thought it was just 4.5 and 4.75. You have about 4" spare room in back as I do? That available rear space in mine tells me a 57 Ford axle would be just right to put wider tires on with the backspacing on my 15 x 7 wheels. 60" Merc - 57.25 Ford = 2.75 ÷ 2 = 1 3/8" inboard per side. 1" existing outside + 1 3/8" = 2 3/8" new outside space. 4" existing inside - 1 3/8" = 2 5/8" new inside space. Darn near perfect... Of course, then my wheels would not fit anyway and the bolt patterns would be different. So, have to put disk brakes on with Ford 4.5 pattern... IDK, seems like a lot of work.
Hey Eventho.. The first pic of my car that you shared is when I had 17's on the back and I didnt have to trim the fenders at all for them. Plenty of room, but I did have to drop the shock. (no big deal to me) The rim details were acurate that you shared. However, I wanted more tire under the car and the second pic you showed is after I went to 18's and I did trim a 1/4 just to be clear of any chance of rubbing. Here is the 18 inch set up with "11.45" of tire on the ground. 18 INCH TORQUE THRUST 18 x 10 American Racing VN5158165 - American Racing VN515 Polished Torq-Thrust II One-Piece Wheels - 18 in. x 10.0 in. 5 x 4.50 in. Bolt Circle, backspace is 5.74 plus 6mm (.23) so basically 5.74 + .23 5.97 inch backspace leaving 4 inches to the front. TIRES - Nitto 285/40-18
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