changing wheels need suggestion

[Sunny]

Hi guys I have 2012 Tahoe few months back I changed stock 17" wheels to 20" wheels .I got these from craigslist 2 tires wr like new so I replaced other 2 with new .so the story is last month in snow I switch to 4*4 and truck started making grinding noise and wont run freely, as soon as I get feet off from gas pedal it will come to stop so switch back to 2 wheels took the truck to dealer. they diagnosed and said your transfercase is burnt , well I argued with them I never drove in 4*4 so how it can damaged .reason he gave was my wheels 20 inch with different size in front and back .I was not aware of tht as tire guys did the job.
I had feeling dealer wants to make money , so I changed my stock wheels as it was before and bingo the nise slowly went away in 4*4 truck running without any issues.but now its time to change my tire on stock 17 iam confused I still have 20" wheel which I like iam scared to run on them ,reading online do we have to calibrate ecm after changing wheel size or what shld I do to run on 20" plzz help thanks.

 

[PG01]

1- when was last time( before this one) that u used 4wd
2- size diff on tires(20's)? What was the diff
3-i think it's coincidence, if the noise 'slowly went away with 17's' i would put 20's back on and pit it in 4wd and see of it does it again( on grass or dirt or gravel or snow)
Maybe you havent used 4wd in while and shit had to 'loosen up' a bit.
My 2 cents

 

[NeverSatisfied]

I have no clue why but I was always told you have to run the same size tires on all four corners of a 4x4 or AWD.

Edit: just did as little google search and first thing that came up was that with different sizes on the front a rear they will be spinning at different speeds which will cause everything to be out of sync.

 

[PG01]

I complete suscribe to that theory but, how much of a diff size tire could they gave put on the 20" tread depth? Width? They had to be close, why but they put complete diff sizes on the 20's(tire shop) i dont know just my thoughts, a 1/2 inch to inch gonna make a diff?

 

[Sunny]

1- when was last time( before this one) that u used 4wd
2- size diff on tires(20's)? What was the diff
3-i think it's coincidence, if the noise 'slowly went away with 17's' i would put 20's back on and pit it in 4wd and see of it does it again( on grass or dirt or gravel or snow)
Maybe you havent used 4wd in while and shit had to 'loosen up' a bit.
My 2 cents

yes I used 4*4 after almost a year but last time used with 17s there was no problem ,I changed the wheels in june 2016 to 20s in jan snow time this was the 1st time I tried 4*4 and issue started , well It looks like is tire size problem front and back . will install again and try with 20s with same thread thanks.

 

[Sunny]

I have no clue why but I was always told you have to run the same size tires on all four corners of a 4x4 or AWD.

Edit: just did as little google search and first thing that came up was that with different sizes on the front a rear they will be spinning at different speeds which will cause everything to be out of sync.

yes ur right 2 different size effected the transfercase so putting back same fixed the noise , I will try again with 20s same thread .
now question is do I require any calibration ??

 

[Sunny]

I complete suscribe to that theory but, how much of a diff size tire could they gave put on the 20" tread depth? Width? They had to be close, why but they put complete diff sizes on the 20's(tire shop) i dont know just my thoughts, a 1/2 inch to inch gonna make a diff?

let me post pics of both different size

 

[PG01]

yes ur right 2 different size effected the transfercase so putting back same fixed the noise , I will try again with 20s same thread .
now question is do I require any calibration ??

Yes, if u go with the 20 s i believe so

 

[HiHoeSilver]

The rim size is irrelevant here. What are the TIRE sizes we are talking about?

 

[PG01]

The rim size is irrelevant here. What are the TIRE sizes we are talking about?

Thats what im asking.....dont think anybody is saying thing about diff rim sizes, op asked about calibration if he swaps to his 20s....."with same tread"