Transmission started grinding in 1st & Reverse

[hockeyman]

Just started this morning at a traffic signal. As I was coming to a complete stop, the truck started surging and I thought it was going to stall. I put it in N and the idle came back up to normal. I then switched into D and it didn't want to go into gear unless I stepped on the gas pedal (up to about 1,200rpm), then it sorta slammed into 1st.

After that, it's now making a grinding sound only while in 1st and R. Once it changes to 2nd gear or higher, there is no noise at all. It shifts smooth.

I put the gear selector into 2nd, then accelerated from a complete stop. No noises. Again, it changes gear(s) just fine.

I checked the fluid level while the engine was hot and it's right where it says Full. Does not smell burnt, either.

Just as a precaution, I lifted the front up and spun the tires to check the wheel bearings. Nothing abnormal. I also inspected the front axles and U-Joints on the driveshafts, but they seem to be good.

I am almost positive that it's something in the trans, but not sure where to go from here. I read this thread and my problem looks/sounds almost identical to #20.

- Any other suggestions that I can try?
- If it is the Reaction Planetary Gear, has anyone ever replaced one in their trans? Can it be done by someone who has never worked on an auto trans, or should I contact a shop? Roundabout idea of price to have to replaced??

 

[Mooseman]

Sounds a bit like this one, which wound up being a failed forward sprag. A grinding noise is never good. A pan drop may help diagnose if you see bits of metal.

 

[fletch09]

my problem was the planetary gear.
what you described, sounds like the how my problem started.
http://www.gmtnation.com/forums/threads/trans-problem-or-something-else.14399/
my noise went away for about 2 weeks, then all hell broke loose.
def. get it checked sooner than later.

 

[hockeyman]

I made an appointment with AAMCO for early tomorrow. They're not that far from me and I'll drive it easy while driving there in the morning.

Not sure what to do though. The diagnosis and most importantly, the price will be the deciding factors. I was thinking about trading it in about a year from now for something like a new GMC Sierra 1500. That day may come sooner than expected...

I love my Envoy and would very happy to get it repaired, but kinda weary about any other issues that may come up further down the road. I'm right around 138k on the odometer and uncertain about how many more miles are left. Oh well, can't wait to hear how much this is going to cost me.

I'll update this thread as soon as I know for sure.

 

[fletch09]

if you have a local trans. shop other than AAMCO, would check them also.
i would think a local place might be more likely to repair or replace only the parts needed, if your are only going to keep it for a little while longer.

 

[Bow_Tied]

Sounds a bit like this one, which wound up being a failed forward sprag. A grinding noise is never good. A pan drop may help diagnose if you see bits of metal.

That is my trans fail thread and I believe the issue the OP has is very different. I had no unusual noises from the trans at all. I did have no 3rd or 4th from a dead stop - #17 on the referenced list.


My guess is that to repair your issue it will be a full R&R, hopefully I am wrong. I second getting a transmission specialty shop to give you a diagnosis. Good luck.

 

[Sparky]

138k? Young thing, I got 214k and counting on mine

 

[hockeyman]

138k? Young thing, I got 214k and counting on mine

Haha, yeah. Considering I did nothing to promote it's fate...except for coming to a "normal/common" stop at a traffic signal. Only thing different is that it was raining like crazy.

I'm still trying to decide whether I want to keep it or not after the prognosis. Knowing my luck, I can almost guarantee it'll be in the 2k+ area...

 

[hockeyman]

Update:
Most likely that the Planetary Gear is toast. Took it to AAMCO this morning. They dropped the pan and there were metal pieces (gear teeth) all over the bottom of the pan. Left it with them and they're currently in the process of removing and rebuilding it. It should be finished by Saturday afternoon. It'll be $2k for a complete rebuild and come with a 2 year warranty.

The guy at the shop is going to call me once it's removed and torn apart so I can go and physically see the damage. I'll take pics and post them here as soon as they're available.

Also, there weren't any CEL codes that were thrown, but the "grinding metal" sound got louder and louder as I was driving to the shop this morning.

Just happened out of nowhere. No adverse conditions. Not driving hard. No bumps. Nothing. Just decided to break as I was coming up to your average rolling stop at a red light. I guess I shouldn't stop anymore...

 

[fletch09]

well that sucks ! but glad you made it there w/o a tow.
interested in seeing the pics, to compare to mine, to see how bad it was.
is there a mileage stipulation w/ the 2 yr warranty?
are they replacing torque converter & sun shell also?

 

[hockeyman]

well that sucks ! but glad you made it there w/o a tow.
interested in seeing the pics, to compare to mine, to see how bad it was.
is there a mileage stipulation w/ the 2 yr warranty?
are they replacing torque converter & sun shell also?

Actually, they said that they're putting in a different trans and going to rebuild & sell mine another time. I don't know if I'm getting a new or used TC. I forgot to ask, but they did say that the sun shell, disks and planetary gear are all brand new and already installed in the other trans. I think the warranty is for 2 years and/or 26k miles.

Pics coming in a few minutes. I have to upload them from my phone.

 

[hockeyman]

Pics of the carnage.

The Planetary gear had chipped teeth on all 4 gears. I only took a picture of the two of them.

 

[Sparky]

That explains why the transmission still worked but was making noise. Kinda wonder what triggered that.

 

[fletch09]

a little more carnage than mine. i only had 2-3 spots on the bigger outer gear,
but all 4 of the smaller gears had damage as well.

 

[hockeyman]

Kinda wonder what triggered that.

I just don't know. I can only guess that someone (or someThing) was taking my Envoy for joyrides at night while I'm sleeping. Other than that, it's a complete mystery to me.

 

[RedRocketZ28]

When it's time, it's time. My parents 02 TB trans gave up the ghost at 227k. My trans in the Rainier has 116k on it and the 1-2 shift is sloppy at times. I have cleaned it up a bit in the tune though. If the trans ever goes it will be getting replaced with a $400 junkyard unit and I'll be trading it in on a new Silverado as well.

 

[Bow_Tied]

Similarly, without warning or abuse, mine failed just shy of 119k (74k miles).

Between these transmissions, the weak transfer cases, the failing AFM, and other things these vehicles sure seem pretty under designed. :/ I know every brand has its issues but it seems like one have to try to do worse. Maybe I am just smarting from the expenses. FWIW, $2k/2y warranty is amazing price compared to my locale which is 50% more and half the warranty.