2nd Gen Non-Engine/Transmission Bigger tires for my dually

[AC]

It's time for some new tires and I'm considering going bigger. A 235/85/16 is what I'm thinking. I am worried about three things,



1) Rubbing. I have a heavy cab over and tow horses. It's hard enough backing under the camper, don't want to put spacers on.



2) Bigger tires will change my speedometer. Can this be fixed on a 98?



3) It's a long way between 3rd and 4th gear as it is. How much of an difference will be felt?



I'm thinking of going with Les Schwab's Open Country A/T if that makes a difference. Should I stick with the 215's or go bigger



Thanks, AC

 

[BillGotthelf]

I have seen larger tires than stock come off the duals with severe tire rub between the tires from heavy loads and very little space between the tires. AS the tires turn the come together and rub. It wore off all the rubber (sidewalls are thin anyway) and the 4 tires were shot.

 

[SOOT]

I went to a 235/85/16 on my 97 without a tire rub problem even when loaded. As long as you keep the tire pressure above about 60 psi when loaded you won't have a problem.

 

[AC]

What about the speedometer calibration? Is that fixable on a 98? Any noticeable difference with my 3. 54's and a five speed towing a grade? AC

 

[SEmerson]

What am I missing here????? Both my 3500's came with 235/85/16 tires. So that is stock size... ... ... ... . I am looking at getting 245/75/16 now. I have been told that 255 will fit.

 

[ToolManTimTaylor]

255's will fit on anything 2001 on up as they came with oem 235's.



The 1994-2000 rigs came with 215's and could go as high as a 235.

 

[barbwire]

tire brands different widths

I have a set of 235s in a Cooper line, they do not rub together. I also have a generic set of 235s (do not know the brand right off) , but had to put a spacer in between and they still rub.

MORAL> not all tire brands of the same size are the same width. IMO

 

[RustyJC]

The wheel offset was increased when Dodge went to the LT235/85R-16's as the standard dually tire. Reportedly, 255's can be used on the later trucks and 235's on the earlier trucks (the ones like my 1996 that had LT215/85R-16's as standard).



Don't discount this tire sidewall rub under load. If you're going to carry or tow heavy loads, sidewall rub can cause tire failures that will ruin your whole day!



Trucks with PCM's can have the speedometer recalibrated by the dealer and some aftermarket OBDII scanners/programmers. You just have to know the number of tire revolutions per mile - data available on Michelin's (and other tire manufacturers') websites for any given tire.



Rusty

 

[Cowboy Medic]

I went to the 235's on my 99. Then when I went to the aftermarket rims I noticed I had more space between tires. So I am considering going a little bit larger this next time. However I just put on some BFG AT's about a year ago and have put 35,000 on them and can hardly tell any wear, so it might be a while before I have to buy again and at that point I may just jump to the 19. 5's

 

[willyslover]

use a tire like a Mich. XPS and you'll not have a problem... VERY TUFF SIDE WALLS and don't crush down like others.

Thay are a commercial rated tire. . will handle what your doing with a cushion of safety



note available in both traction tread and hwy tread

 

[DPelletier]

My buddy put 235 85 16's (XPS Tractions) on his '97 dually and he has to keep them aired up quite high to avoid the rubbing issue. When we were in Baja, the rest of us aired down to prevent our campers from being beaten to death, but he couldn't. He broke spot welds in his bed.

I think the XPS Michelins are the strongest tire available in 16".

Its a tough call, because the 215's look a little small, but having to worry about rub is a PITA.



Dave

 

[Partyat33]

I went from 235/75/16's to 265/75/16's without rubbing. Its pretty close though. A 1/4" spacer would make me feel a little better.



Dennis

 

[willyslover]

something don't sound right there DP... not saying your wrong. . but my expierence and others I know of don't agree with what your saying.

On my old rig [now wrecked, 98. 5] with stock 215's went to 235 XPS tractions and have had many 2500 lb loads in the bed... never even bothered to go over my normal 55 lb airing. . I'm on my 5th set of them now between 2 rigs.

 

[DPelletier]

Willyslover,

Its OK, I didn't look myself and my buddies the nervous sort. I think he said he didn't think he could go below 60psi with his camper on (approx 4000 lbs) without rubbing issues. When we were in Baja, Mark and I aired down to 40-50 psi and our trucks rode the washboard smoother. this is, of course, not enough air pressure to run on the highway with, but the road was BAD!

I totally agree the XPS's are a great tire (arguably in a class by themselves, due to thier construction), I just hope they make them in 17" by the time I need tires!

Cheers

Dave

 

[y-knot]

You should have no problems with 235-85-16's, they are not that much larger and should still give you the clearance between tires that you need. Also don't be so afraid of spacers. There is nothing wrong with using them, just buy a quality set from a reputable dealer.

Your speedometer will be off, by about 5% so 60 now becomes 63 mph. There are products to correct this, or you can just do the mental correction as needed. If you have a GPS you can use it to get an accurate mph reading.

 

[rrl989]

AC, If you have a cabover and tow, I would not go to the 235's,

I have carried 4000+ lb. loads on my truck w/ my Slide-On & the same wish for going to 235's. Since I went for the 3500, I used it for what it was designed for, carrying heavy loads. I bought 6 new Mich XPS Tractions 215/85/16's / No regrets - Great tire! Good Luck .



Ron

 

[AC]

Thanks for the replies. I have decided to leave well enough alone. Like FF1063, I use my dually for hauling heavy. I will not compromise the safety of my family for looks. I could change the rims and re flash the computer and be safe but that's more money than It's worth to me.



AC

 

[HEMI®Dart]

#ad

 

[cropdust]

There are some company's out there that make a spacer for the rear duals so that the tires don't rub.





2003 ram dually,ez,gearvendors,x-monitor.

 

[barbwire]

Contact a TDR member NO Neck

He has just picked up a set of spacers that I believe a friend made for him. I saw them, and they are a very professional , and functional looking set. I believe that the fellow that made them for him would make more sets.