2tall2slow

After approximately 15 miles of driving I begin to experience what feels like brake drag. ( After replacing my RIGHT FRONT passenger tire 245 75 15 with my spare 235 75 15 is when the issue began.) The drag was initially felt after I put on the spare tire, so I figured old caliper. I replaced the caliper and the drag began to happen on the LEFT FRONT driver side, so I replaced this caliper as well. Afterwards my brake drag issue reappeared on the RIGHT FRONT passenger wheel, causing the jeep to pull hard to the right. Again, this problem only seems to happen after roughly 15 miles of driving. My question is am I dealing with a Master Cylinder issue? Could this be wheel bearing? While replacing both front calipers my brake lines appeared to be in good condition showing no signs of blockage or any compromise. Thoughts? Insight would be greatly appreciated, thanks in advance!

dave1123

I think it has more to do with tire diameter than anything else. The 245 is slightly taller than the 235 so the diff is working hard and creating drag.

EEVEE

yikes sounds like youre really straining the diff

IJM

You've verified that the brakes are dragging by feeling for abnormally hot brakes after driving at speed for a bit without touching the brakes, right? Alternatively, you can feel them grab when you try to roll very slowly to a stop. Just trying to verify that they're actually dragging rather than just feeling like it.

2tall2slow

Thank you all for the quick responses! So while the "drag" seems to be happening I will let off of the throttle completely and will begin to decline in speed at an unusual rate. (Decrease in speed is Not comparable to pushing the brakes to the floor BUT enough decrease in speed to make it obvious that something is impeding my travel) After turning the jeep off I am quick to the front right wheel to do a "abnormal heat test." I do not feel much, if any difference in the heat from this tire compared to any of the others. Is it normal for the calipers to slowly release from the rotors after shutting the vehicle off? I have visually seen this if it matters. I had no idea that a tire of slightly different size could play such a role in the overall operation! (With a single income family of 5 it may be another week or two before I end up with a new tire) Thank you again for any insight!

dave1123

Now, do it again and put your hand on the differential, just for jollies. Those little carrier spider gears are just buzzing to make up the difference in shaft speeds.

firebane

Correct me if I'm not reading this correctly... but are you really running two different sized tires on the front?

tinytrax78

more info would help, heck he never even said if it was 4x4 or not he might not even have a front diff lol!

2tall2slow

dave1123, mucho Caliente! Is the differential normally this hot?

​​​​​​​I wouldn't own a Jeep if it wasn't 4×4. May as well drive a Civic..

dave1123

It shouldn't be unless you've been in 4wd. Check it against the rear diff that's been under power the same distance.

This story may help you understand. My 67 SS Camaro got a flat in the pouring rain on the highway so I threw on the "compact spare" on the left rear. I drove it about 15 miles just to get it off the highway and in the process the speedometer wasn't reading right and I burnt up the clutches in the Positraction! I should have put it on the front and switched that tire to the rear, but I was soaked to the skin just changing the one tire! Expensive shortcut!

EEVEE

I was desperate and had to get new tires before so to get by i had a slightly larger tire on front as well and was the most painful 5 miles ever driven lol. Pulled and everything. Makes me wonder tho wouldnt putting a factory donut on it ruin it as well?

dave1123

D'oh! Crossing threads!