Transmission not working properly after wrong size tires were installed?

SMCCAIN31

MEMBER
2014 JEEP COMPASS
4WD
AUTOMATIC
115,000 MILES

I recently had two new front tires put on. The tires were the wrong size - different than the back two. After they were put on the 4wd! Light came on and it felt like the vehicle had trouble changing gears. When the tires were replaced with the correct size, the light no longer comes on, but it still feels like it is having trouble changing gears. The 4wd has to be manually put on normally, so I'm not sure if this has affected the transmission or not.

Tuesday, May 11th, 2021 AT 8:25 AM

1 Reply

JACOBANDNICKOLAS

MECHANIC
110,068 POSTS

Hi,

How many miles were driven prior to realizing they were different? The idea that the 4wd light came on was likely due to the vehicle thinking there was a slippage in the tires. One was turning faster than the other. If you drove a short distance, it shouldn't have hurt anything if it was always in 2wd. Extended driving could cause a problem. Damage comes in from the heat build-up from the tire diameter difference. That adds wear on fluids and any clutches involved.

What I would recommend is to start by checking the fluid in the transfer case and both differentials. Make sure they are clean and full.

Pic 1 below shows how to check the transfer case fluid.

Pic 2 shows how to check the fluid in the differential. I highlighted the fill plug. Remove that plug and the fluid should be to the top of the lower threaded part of the bolt hole.

Let me know what you find.

Joe

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