1997 GMC Suburban Transmission Problem?

[kryppler]

It has a automatic transmission, it shifts fine but when ever I have it idling for about 5-10 seconds in D, R,1,2,3 - a grinding noise will come from the transmission, but doesn't make the noise in N or P so at a light i will put it in N with my foot on the break and when the light turns green i put it in D and I don't hear anything as long as I accelerate within 1-5 seconds.
Anyone know what the problem could be?

 

[Molson02536]

It has a automatic transmission, it shifts fine but when ever I have it idling for about 5-10 seconds in D, R,1,2,3 - a grinding noise will come from the transmission, but doesn't make the noise in N or P so at a light i will put it in N with my foot on the break and when the light turns green i put it in D and I don't hear anything as long as I accelerate within 1-5 seconds.
Anyone know what the problem could be?

Trans seems noisy when moving in 1st and Reverse, noise goes away instantly if you shift to N or the trans goes into 3rd gear: Reaction planetary is worn out due to high miles or insufficient lubrication. Not a critical failure, but not a good sign either.

Or Either a torrington bearing or a planetary bearing is on its way out. Trans will eventually die a loud, catastrophic death. Cheaper to rebuild now (saves further damage to hard parts), but requires. Remove & Repair (or Rebuild) sooner rather than later.

Sorry for the bad news and keep us posted.