1. This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.

2 different tire sizes on the 80

Discussion in '80-Series Tech' started by Land Schmoozer, Aug 16, 2006.

  1. Land Schmoozer

    Land Schmoozer

    Messages:
    248
    Likes Received:
    0
    Joined:
    Nov 20, 2002
    Location:
    Des Moines, IA
    not a good thing...

    picked up a '94 with 276K miles and lockers, planning on parting it out because it steers hard and all four tires scrub when turning more than 1/2 way either direction. then notice that one of the tires is 265-70-16 the other three are 275-70-16... all are shot... the rims are in great shape so I have new 285 BFG's mounted to use on one of the others... drive it home from the shop and the scrubbing is gone and it turns lock to lock much easier...

    guessing the smaller tire was causing the diffs problems throwing the steering off and causing the scrubbing...

    despite the high miles this rig runs, stops and just works better than the '93 with 160k been better maintained too (except for the tire)... am now think of making this the wheeling rig instead of the '93...

    what other issues might have been caused by running this smaller tire for who knows how long? as always, any words of wisdom would be appreciated... :flamingo:
     
  2. SOCALFJ

    SOCALFJ

    Messages:
    5,657
    Likes Received:
    4
    Joined:
    Aug 17, 2005
    Location:
    Forest Falls, CA
    i doubt anything else is screwed up.. it's not like it was running around with a 31" and 35" tires.... just ate them up fast thats all.. The axle angle wasn't severe enough for diff fluid to run down a tube or anything... the rest is prolly fine. For the heck of it i would prolly change the diff fluid and inspect the birfs/bearings etc.
     
  3. -Spike-

    -Spike-

    Messages:
    6,457
    Likes Received:
    254
    Joined:
    May 26, 2005
    Location:
    Phoenix
  4. stevek

    stevek

    Messages:
    479
    Likes Received:
    0
    Joined:
    Sep 20, 2003
    Location:
    Suffolk, VA
    I thought the VC would/could get damaged from different sized tires?
     
  5. -Spike-

    -Spike-

    Messages:
    6,457
    Likes Received:
    254
    Joined:
    May 26, 2005
    Location:
    Phoenix
    This is just my opinion, no facts to back it up: The VC is designed to allow for some differential in driveshaft speeds, so a slightly smaller tire shouldn't hurt it, especially if it's not run too long. I'd avoid running a much different tire size, or two moderately smaller tires on one axle.

    I wonder what running one 35" and one 31" tire on each axle would do, besides look incredibly stupid? Probably nothing, unless you locked them..

    -Spike
     
  6. SOCALFJ

    SOCALFJ

    Messages:
    5,657
    Likes Received:
    4
    Joined:
    Aug 17, 2005
    Location:
    Forest Falls, CA
    Exactly..I agree, the minute you lock it up.. you've got major daddy issues..
     
  7. firetruck41

    firetruck41

    Messages:
    5,732
    Likes Received:
    24
    Joined:
    Mar 27, 2003
    Location:
    Camas, WA USA
    Problem is, it sounds like it was locking up with the minor difference in tire size, he said the tires would srub around corners, and steering was hard, that is what happens when you have the center diff locked (or VC in this case). So it sounds like the VC was locking, but if it is working now, all is good, the question is, will it cause early failure or just keep on tickin'? Hopefully the latter!
     
  8. -Spike-

    -Spike-

    Messages:
    6,457
    Likes Received:
    254
    Joined:
    May 26, 2005
    Location:
    Phoenix
    Well, your options are to tear into it or leave it alone and hope it goes away. I'd be hoping, myself. :D

    -Spike
     
  9. Rusty Phillips

    Rusty Phillips

    Messages:
    496
    Likes Received:
    1
    Joined:
    Jan 13, 2004
    another thought - was the smaller tire on the front or on the rear of the truck?

    if all tires are same dia - the front tires / axle have to turn faster when going around a corner than the rear tires / axle -

    it seems to me that if you had to put a smaller dia tire on, it would have less impact on the rear of the truck
     
  10. SUMOTOY

    SUMOTOY

    Messages:
    1,836
    Likes Received:
    3
    Joined:
    Jun 1, 2005
    Location:
    Chicago
    275/70 16 = 31.16in diam
    265/70 16 = 30.61 in diam

    Measured difference = .55in diam

    Get the tire model and brand, go to tirerack.com under specification, find out the *actual* rolling diameter, add in the tire wear variances. I suspect this really hasn't caused any undue stress on the drivetrain. I haven't done the math, but I suspect if you did axle angle calculations, you probably aren't even close to fully locked up on the VC.

    Scott Justusson
     
  11. firetruck41

    firetruck41

    Messages:
    5,732
    Likes Received:
    24
    Joined:
    Mar 27, 2003
    Location:
    Camas, WA USA
    That is a fairly minor difference, but I can't think of another reason it would scrub tires and have "hard" steering (same as if you drive with locked center diff), and then works fine with new tires?
     
  12. Land Schmoozer

    Land Schmoozer

    Messages:
    248
    Likes Received:
    0
    Joined:
    Nov 20, 2002
    Location:
    Des Moines, IA
    replaced all the tires with new, same size. Much better but still minor scrubbing at full turn... going to tear into the knuckles and see what happening in there!
     
  13. DanKunz

    DanKunz SILVER Star

    Messages:
    9,598
    Media:
    2
    Albums:
    1
    Likes Received:
    956
    Joined:
    Feb 7, 2002
    Location:
    Woodstock, GA
    buy a part time kit and lose the VC...problem solved :)
     
  14. SUMOTOY

    SUMOTOY

    Messages:
    1,836
    Likes Received:
    3
    Joined:
    Jun 1, 2005
    Location:
    Chicago
    I doubt that's the problem. If you still have scrubbing, you might have overheated the VC and have partial lockup all the time. Not sure the definition of scrubbing at full turn, but my truck will scrub at full turn, and the VC is fine.

    Scott Justusson
     
data-matched-content-rows-num="2,1" data-matched-content-columns-num="1,4" data-matched-content-ui-type="image_stacked" data-ad-format="autorelaxed">