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Tire Rubbing issues & speedometer calibration…

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Old 04-07-2009, 08:49 PM
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Default Tire Rubbing issues & speedometer calibration…

Helllo all, new guy to the forum here. Didn't know where to go for answers and I found this forum. I did search for tire rubbing and came up empty .

I have a stock 2008 Ram 2500, 5.7 Hemi and I am wanting to put bigger tires on for the sake of more weight bearing capacity. I believe the stock rims are rated for 3,450 and Nitto Terra Grappler tires, size 285/70/17 E are rated for 3,750 per tire versus the standard 3,195/tire for 265/70/17. The truck came stock with 245/70/17. I’m wanting to compensate for the weight of a heavy camper. I’m planning on adding a leaf, sway bar, and possibly helper springs (Super Springs, maybe Hellwigs).

Will the 285’s rub at all? If I go with 285s (or 265s for that matter) will I need to have my speedometer recalibrated?

Also, I haven’t done all the math on what my GAWR is/will be. Right now I know I won't be overweight with my current camper, but I haven’t had it on yet (new truck, camper is still snowed in), and I do plan on buying a bigger/heavier camper.

Any ideas whether these tires will rub and if I'll have to recalibrate the speedometer?

Thanks,
Tim
 
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Old 04-07-2009, 09:32 PM
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i think any tire size change from factory would require a speedo calibration.
get yourself a superchips!
i run 285/70 r17's with no problem all i have done is a t-bar crank im wanting bigger tires think im gunna go with 33x12.50's which is said not to rub with a level.
so on size you should be good, as for the weight, i failed math class so cant help there.
 
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Old 04-07-2009, 09:46 PM
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I have 33 inch tires on my 2500 and they do not rub at all and that is without a leveling kit. I have a Superchips and I did not have to recalibrate my speedo. The Superchips says that my tire size stored in the ECM is 31.25 but my speedo is dead on...
 
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Old 04-07-2009, 09:54 PM
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Originally Posted by slackjaw71
Helllo all, new guy to the forum here. Didn't know where to go for answers and I found this forum. I did search for tire rubbing and came up empty .

I have a stock 2008 Ram 2500, 5.7 Hemi and I am wanting to put bigger tires on for the sake of more weight bearing capacity. I believe the stock rims are rated for 3,450 and Nitto Terra Grappler tires, size 285/70/17 E are rated for 3,750 per tire versus the standard 3,195/tire for 265/70/17. The truck came stock with 245/70/17. I’m wanting to compensate for the weight of a heavy camper. I’m planning on adding a leaf, sway bar, and possibly helper springs (Super Springs, maybe Hellwigs).

Will the 285’s rub at all? If I go with 285s (or 265s for that matter) will I need to have my speedometer recalibrated?

Also, I haven’t done all the math on what my GAWR is/will be. Right now I know I won't be overweight with my current camper, but I haven’t had it on yet (new truck, camper is still snowed in), and I do plan on buying a bigger/heavier camper.

Any ideas whether these tires will rub and if I'll have to recalibrate the speedometer?

Thanks,
Tim
You should be fine with those tires on your truck. Yes you will have to have your speedo recalibrated or purchase a tuner.

Do yourself a favor and get Air Bags instead of an add-a-leaf, better ride, better capacity, better all around...
 
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Old 04-08-2009, 12:02 AM
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Originally Posted by HammerZ71
You should be fine with those tires on your truck. Yes you will have to have your speedo recalibrated or purchase a tuner.

Do yourself a favor and get Air Bags instead of an add-a-leaf, better ride, better capacity, better all around...
I was worried that the airbags may make the truck a little top heavy and more unstable as the bags go inside the leaf springs. Not sure if air bags will help my capacity problem either.

BTW, anyone got a link so I can read more about superchips?

Tim
 
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Old 04-08-2009, 12:18 AM
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I put 285's on my 2500 with plenty of clearance lock to lock. As far as the speedo, its off by 5 mph @ 70 (speedo says 70 actually doing 75)
 
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Old 04-08-2009, 12:24 PM
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I really don't care about being off on the speedo, I have a gps I toy around with when I drive. Is there another reason to re-cal the speedo? Doesn't the tranny shift based on truck speed? Or is it rpm? If oversize tires aren't going to screw me up somewhere else I don't really see a need to recalibrate.

Tim
 

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Old 04-08-2009, 02:36 PM
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Originally Posted by slackjaw71
I was worried that the airbags may make the truck a little top heavy and more unstable as the bags go inside the leaf springs. Not sure if air bags will help my capacity problem either.

BTW, anyone got a link so I can read more about superchips?

Tim
depends on the bags, there are bags to achieve lift and bags to increase capacity. The ones to increase capacity will not give you any appreciable height increase. The advantage of the bags is that aired down with no weight in the truck, you'll NOT bounce all over the road like you would with helpers.

I've had both and I'll never do helper springs again after having bags.

For a 2500 series truck, there are bags with a 5000 lb. capacity, that's 5000#s of combined bed/tongue weight, not towing capacity. Yet, aired down, it's like they are not even there. I have not seen ANY springs with that type of capacity....
 
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Old 04-08-2009, 04:46 PM
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What's the name of the air bags you're talking about? The only thing I've found locally is Firestone Ride Rite air bags. I didn't know you could get bags to compensate for weight too, I thought they just helped with lift. Give me a brand name if you would, and I'll search 'em.

Thanks,

Tim
 
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Old 04-08-2009, 05:45 PM
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http://www.airliftcompany.com/load_support_index.html

I have the 2000# Ride Control series. With 10# air, the rear of my truck is no higher than before I put on the bags. For sh*ts and giggles one day, I filled them to 100% capacity and the EMPTY bed only rose 3/4"...
 


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