Grinding sound

[Gregory w Bender]

I get a grinding sound when I go up hills or when it down shifts. I came to find out that every time I go up hill or down shifts it going into 4 wheel drive and sound coming from the transfer case. One why would I need 4wd when down shifting or going up hills? I could see if the road was slippy and back tire started spinning. I don't get the sound going down hill. I don't get it on flat only if it down shift to pass someone.

 

[J_C]

What makes you determine that it is going into 4WD in those situations?

Are you assuming you then get sound from the transfer case or is there more evidence suggesting it?

Do you have all 4 tires from same make and model (and size) so you are reasonably confident they are the same diameter?

Is it possible your tranny is just going out and the rest of the info isn't relevant?

Full disclosure: I know less about transmissions than anything else.

 

[Gregory w Bender]

I get the same sound when i put it in 4wd. The front tires are brand new and the back tires are not but the tire place told me it won't bother the 4WD system. before i put had the new tires on front had no tread and the back tires have half tread on it. I know it goes into 4WD just fine.

 

[J_C]

The tire place was wrong, you need equal diameter tires.

 

[Gregory w Bender]

well my friend pulled the fuse out for the 4WD so it won't go into 4WD now. I getting back tires in the spring when i get money for it.

 

[Mbrooks420]

Your tire place is stupid. Bad advice, and not upselling two tires.

 

[J_C]

I hate RWD during snowy winters so if pulling the fuse resolves this temporarily, I'd do the "brown wire mod" which allows disabling 4WD with the flick of a switch, then put the fuse back in so you retain use of 4WD in snow.

 

[Mbrooks420]

Sounds like maybe the clutch is damaged. I think it’d be less detrimental with worn tires on the front.

 

[J_C]

I'd also want the worn tires on the front so the new were on the rear for snow, if stuck with RWD.

 

[XLTrunner]

Agree...sounds like you have some internal clutch band damage. Been there with mine.

As far as tires, the dirty little secret many people don't pay attention to when buying AWD and Control Trac vehicles is that you MUST run with tires of equal make/style/tread diameter and tire pressure to help prevent damage to your transfer case. No more replacing just two at a time like on FWD vehicles. Ideally, a person would be well advised to buy a fifth tire as the spare and rotate all of them on the vehicle according to recommendations so your spare would be the same size as the other four in case you have a flat or blow-out a long distance from home. However, I'm willing to bet virtually nobody does that (including myself).

 

[J_C]

^ Yeah not just fifth tire but also fifth rim to match since my factory spare was stamped steel and wouldn't match in a tire rotation.

 

[XLTrunner]

Good point!

 

[whitebread]

the 4wd kicks in automatically if computer sees a certain load requirement, such as passing, going up steep hills, start from dead stop, etc.... hence the 4x4 "auto" on the selector switch...

 

[Mbrooks420]

The auto setting is supposed to activate when it detects speed differences between the front and rear axles. I don’t believe it duty cycles based on load.

It would actually lose power in such situations, so it’d be counter productive.

 

[Gregory w Bender]

I have new sensors put on the front and on the back axle.

 

[XLTrunner]

Those are your ABS sensors and have nothing to do with engagement of the transfer case. You have two sensors on the transfer case itself that do the monitoring of both drive axles. I seriously doubt those are your problem, however.

 

[CDW6212R]

The auto setting is supposed to activate when it detects speed differences between the front and rear axles. I don’t believe it duty cycles based on load.

It would actually lose power in such situations, so it’d be counter productive.

Placing the most worn tires up front is better than having them in back, because the fronts speed up in all turning.

Placing new tires in front just makes the problem worse with the A4WD sensing the greater speed difference.

I wish the electronics would engage the front axles under high loads, and the steering wheel not turned much. That would be better for high powered applications, and to avoid spinning the right rear tire when it's on slick surfaces. How to make that happen ...

 

[Gregory w Bender]

this friday i am going to take it to walmart have them put the front tire on the back and the back on the front.

 

[Mr. Alligator]

Great idea! Get four matching tires and rims,

Good luck.

 

[Mbrooks420]

Placing the most worn tires up front is better than having them in back, because the fronts speed up in all turning.

Placing new tires in front just makes the problem worse with the A4WD sensing the greater speed difference.

I wish the electronics would engage the front axles under high loads, and the steering wheel not turned much. That would be better for high powered applications, and to avoid spinning the right rear tire when it's on slick surfaces. How to make that happen ...

You could do it with a relay, and two proximity switches. Mount on on the front steering with a flag that moves out of range on anything more than the slightest turn, and mount a prox near the pedal assembly that’s active when you are 3/4 throttle or more. Run these to a relay coil, and send power to the brown clutch wire under the seat.

I’d bite the bullet and buy two more brand new tires, and put the slightly used tires on the back. These trucks really need tires bought in sets of 4.