99 Suburban 4x4 ?

cc1999 · January 20, 2008

We just bought a 99 suburban 4x4 LT with push button 4x4, it has 58,000 miles on it. It makes a groaning sound in the front end when its cold, it seems to go away after a few miles. I was wondering how oftern the front diff should be serviced. I was thinking that maybe 8-9 year old gear oil might be getting thick when its cold and casuing that sound, that maybe some fresh fluids might help. Anyone have any thoughts to the sound I am describing. The owners manual does not seem to have a time table for diff service intervals.

Thank you

Deichler · January 20, 2008

My 02 Silverado makes a groaning sound when it gets into OD lately. It has been very cold here lately and the noise is a little louder than it usually is. I was wondering if this is normal due to the extreme cold we have been having or if it is something different? Any comments or suggestions are welcome. I was just wondering as it has me a little concerned at this point. The trans was serviced at 69,000 with a full flush and fluid change and a change of the trans filter at the same time, it has 74400 on it now. If someone could tell me if they have had this problem or if it is a cause for concern. Sorry to rob the post, but I too have a groaning noise, but not until it gets into OD and @45MPH when you accelerate a little bit it groans a little. Please help!

gmtech4 · January 21, 2008

My 02 Silverado makes a groaning sound when it gets into OD lately. It has been very cold here lately and the noise is a little louder than it usually is. I was wondering if this is normal due to the extreme cold we have been having or if it is something different? Any comments or suggestions are welcome. I was just wondering as it has me a little concerned at this point. The trans was serviced at 69,000 with a full flush and fluid change and a change of the trans filter at the same time, it has 74400 on it now. If someone could tell me if they have had this problem or if it is a cause for concern. Sorry to rob the post, but I too have a groaning noise, but not until it gets into OD and @45MPH when you accelerate a little bit it groans a little. Please help!

synthetic gear oil is the recommended lubricant for the frt diff,these can groan while turning in 4wd on the hard pack,and is not recommended in the first place,intervals for service should be listed somewhere.

cc1999 · January 21, 2008

It was about 30 degrees outside when we bought it, and the graoning sound was in 2wd mode from 0 mph changing in tone and volume all the way up to highway speeds in the 70mph range. When turning it did not feel like it was stuck in 4wd, I thought at fitrst that it might have been hung up in 4wd and causing that sound.

We made about a 150 mile raod trip to get the truck, fuel mileage was almost identical on the 99 as my 07, that also lead me to believe that if it were stuck in 4wd that it would have gotten bad mileage. Both suburbans got about 16mpg on the trip home. We topped them both off before we headed home and did so again as soon as we got home. On the trip home we stopped for about a hour to eat at a resturant that was about half way home. When we left the restuarant after the truck had set for an hour the groaning started over again for several mile and then quit groaning again.

Deichler · January 21, 2008

My 02 Silverado makes a groaning sound when it gets into OD lately. It has been very cold here lately and the noise is a little louder than it usually is. I was wondering if this is normal due to the extreme cold we have been having or if it is something different? Any comments or suggestions are welcome. I was just wondering as it has me a little concerned at this point. The trans was serviced at 69,000 with a full flush and fluid change and a change of the trans filter at the same time, it has 74400 on it now. If someone could tell me if they have had this problem or if it is a cause for concern. Sorry to rob the post, but I too have a groaning noise, but not until it gets into OD and @45MPH when you accelerate a little bit it groans a little. Please help!

synthetic gear oil is the recommended lubricant for the frt diff,these can groan while turning in 4wd on the hard pack,and is not recommended in the first place,intervals for service should be listed somewhere.

I had bth the front and rea diffs serviced by the local GM dealer and they used synthetic fluid. My issue i when it gets into OD @ 45MPH hear a groaning noise up to 60MPH. It has been VERY cold here and I think that may have something to do with it. Please give your opinion on the situation. I think the diffs were servied @ 65,000 miles. Thanks for the help so far!

Deichler · January 21, 2008

Also, my truck is in 2wd while it is groaning. Just thought I would put that out there too. I am just hoping that my issue is due to the cold, but gmtech4, if you have heard of anything like this before, can you tell me how it was cured if you have ever had a issue like this.