Tranny acting and sounding weird. kinda long but need help.

[NYEXPLOR1]

Hello to all. I am new to these trucks and to 4wds in general. I have a 97 XLT SOHC V6. I had it for 3 months now without any major problems. I got it with 95K miles and it now has 100K.
The first thing I noticed is that every once in a while when I would put it in reverse and then start to back up, there would be a large clunking sound in the rear. Again, it was every once in a while.
Well, yesterday, as my girl and I was driving it on the highway, we heard a loud, high pitched grinding noise. We stopped and looked the car over and found no visible problem.
I continued to drive and noticed that when the car got up to highway speed or anything above 40mph it would run fine until i let my foot off the gas pedal to slow down or ease up. the high pitch grinding would begin. To stop it, I would have to give the truck gas and then it would catch and be normal again. As long as the rpm stayed above 2K at highway speeds, it was ok.
driving around town, their were no problems whatsoever. the tranny shifted fine even under hard acceleration. but as soon as the speed got up in the 40's and i let off the throttle, i can hear the high pitch griniding of something under the car but in the middle. the sound of it was related to the mph but the tach would go down as it normally would. apply some gas, and the tranny would catch and the grinding disappears.
Does anyone know what might be the problem before i head over to the mechanic?
thanks in advance.

 

[NYEXPLOR1]

electrical maybe...

i was out driving tonight and had to make a u-turn. i put it in reverse and it would not go into reverse gear. it just make that loud grinding noise again and it got louder as i pressed on the gas pedal. i turned the car off and then back on and it went into reverse with no problem.
Does anyone have any ideas???

 

[Hartman]

Grinding noises are certainly not related to the electrical system. Sounds like your tranny is on its deathbed.

 

[cherrybomb]

Initially, my guess would be that it's a problem with your rear end. It sounds as though when you are decelerating, or running on the back side of the ring gear, you're having problems.

Of course, that doesn't explain why you have trouble shifting into reverse.

It's a shame our differentials don't really have drain plugs, I'd encourage you to take a look in there for any metal shavings etc.

 

[TPLYNCH]

The grinding (does it sound like a ratcheting noise) @ speed while decellerating is a sign of a shot Transfercase.

 

[NYEXPLOR1]

yes it does sound like what you described. the higher the speed, the higher the sound. it also stops once the speed gets to about 20mph. i will have my mechanic take a look at it in the morning.
thanks

 

[cherrybomb]

The grinding (does it sound like a ratcheting noise) @ speed while decellerating is a sign of a shot Transfercase.

Ohh yeah, that. I drive a 2wd, so I forget about that additional drivetrain component.

Sounds like a much more likely candidate.

 

[pj8847]

Sounds like the T-Case for sure. I don't remeber the name of the company, and I can't find the link, but there is a company that makes new case halves that solve the problem/defects these factory cases have. Maybe someone can post that info again?

P.S. Good to see someone local...Queens that is

 

[freakaftr8]

Take note also, I had this prob once, Check the U-Joints for excessive wear , but still doesnt explain the not going into reverse, hmmmm Mine doesnt go into reverse, I learned to live with it.. Do you have any excessive vibrations?

 

[trod]

i have the same thing on my 97 xlt but mine dose it anytime or any speed even when i put it natural it will still make the grinding noise and the grinding stops when i give it some gas

 

[NYEXPLOR1]

It'll be going to the grave yard soon like mine did.