OT: GM Truck Tranny ? / Problem
 

Has anyone else had this happen?
I have a 2002 2500 Avalanche with the 8.1L and 4L85-E Transmission 4spd Auto. It has the 4.10 rear end.

My driveway has a bit of a dip to it, about 15 feet infront of the garage. It drive the AV up to the garage door, and leave it overnight, so the vehicle is pointed nose up by about 15 degrees. When I come out the next day, fire up, and stick it in Reverse, the truck merely rolls down the incline, into the dip, and does not provide power to back up the rest of the driveway for about 20-30 seconds. This is a very intermittant problem. Also, sometimes, the transmission has more problems for the first 30 minutes of driving, by slamming into each one of the gears as it automatically shifts. This is a horrible problem to be having with a brand new truck, purpose built, and purpose bought to haul my boat. I have not had the boat behind the truck during any of these problems, but that is irrelevant. I believe the harmonic balancer and/or the torque converter are having major issues with draining fluid into the pan overnight, like something may have a crack or a hole in it, and it drains only when that hole ends up on the bottom when I park it for the night. Does this sound feasable? I really need some help here. The Chevy dealer has had the truck twice, both times NTF. The second time, they replaced the Valve Body. It is still having this intermittant problem.

Pleease no Chevy/Ford/Dodge/Avalanche battles back and forth on this thread. I bought the truck. I love the truck. I do not know much about trannys, and I need this fixed before the warranty expires. You know how hard it can sometimes be dealing with warranty crap. The dealer makes no money on this, and they like to replace as little as possible. I am about to demand a new tranny. Please help me understand what could be the problem with this one, so I can speak the terms when I talk to the Service Manage.

I have posted this on www.PickupTruck.com and www.ChevyAvalancheFanClub.com. I am looking for ANY and ALL knowledgeable tranny inputs, and OSO has a wealth of ALL, well rounded information.

Thanks so much, everyone.

Well, just document that you reported the problem under a warantee period. Because I could show that I had a warantable repair I was sucessful with having repairs covered outside of the milage/time window.

I'm no trans expert, but the hesitation does sound like a pressure problem. I would agree with your idea of the trans bleeding down.

How long are you letting the truck warm up ot operating temps??
Under my search for the last 2 months of trucks I have been informed by several owners and a couple dealers that the most common complaint about the allison tranny is the warm up time.

The computer is programmed to obtain operating temp and/or pressure being it will allow it to shift.
Does not matter if is 'warm' outside.
Cold winters it takes longer.

This is not an Allison Tranny. It is an M32 4spd Auto. Bsag, (Brett Dean) who sold me the truck, just called me and explained this is somewhat common. I am still not sure. At least the initial shift/roll problem. The torque converter is draining depending on where the teeth end up each time I park it. Puzzles me though, as my Tahoe did not do this at all. As far as the continuted slamming shift problem for 30 minutes or more after I start to drive it, that could be a bad pressure sensor/sender in the tranny, or a problem with the TPS on the engine, but the TPS would lead me to believe I would have more problems. I am going to watch it for a while; especially as it gets colder; and maybe find a GM dealer with a sharp tranny specialist to have everything looked at. I have over 30K left on the warranty, but I do not want these slamming and shifting problems to wear the transfer case, u-joints, drive shafts, and differentials to a point they are going to blow right after the warranty expires.

Thanks MFB and Cord for your repsonses. Thank you Brett for the call. I have owned a lot of vehicles, and never had something like this. I am going to keep an eye on it. My brother-in-law has the exact same truck, and parks the exact same way I do, tilted nose up. He has had not problems with over 10k on the truck.
More inputs appreciated.

Sydwayz, I think I had the same problem as you. Does it shift like it has a shift kit, really bang the gears hard. If so, thats what mine did. The dealer said the solenoid in the trans that makes it shift smooth had a broken wire. They didn't even open the trans to fix. Saw the parts replaced, not a trans man but it has worked perfect since. Just a thought hope this helps.
mike

I sorta have the same problem on my Jeep Grand Cherokee......granted the truck has 116K miles on it so i'm sure that plays a big factor in this but in the mornings when i start off, the truck wont move right away when shifted into drive or reverse. I start the truck and shift into neutral for like 30seconds. I guess it builds up pressure through the trans and then i shift no problem. This only happens over night when it stands for a good 8hours. I look at it this way...it keeps me from tearing up the engine when its cold! This way atleast the engine has had some time to circulate oil and trans is lubed good too. :)
This is no excuse for a new truck though...

BE CERTAIN that after each time you brought the vehicle in teh service writer closed out the work order. If not, it will appear that the vehicle was only in once. If you have to lemmon law it this can abe a big stumbling block. Just make certain it is closed out and you get a new workorder for each time you go in. Good luck.

Shane

This is not normal operation. Take it to the dealer and have it repaired.

Thank you everyone that has responded so far. I think I am going to find another service dealer; one with more experience on HD trucks. Thank you especially, Mr. Goodwrench.

I have gotten a few responses from the other two boards, but nothing like the responses, PMs, and calls from here. OSO truly is a huge help.

Brian, which dealer are you using now??

Wally-you have the infamous Chrysler hard seals, it will get owrse eventually but a change with the new Chrysler spec trans fluid might help(or maybe not) so you could just wait till it pukes all the way.

I currently use Pohanka Chevy, in Chantilly VA. I am probably going to try Dudley Martin Chevy, in Manassas next.

Yeah, try that, might be good. It is getting more and more difficult to find a good dealer trans guy since the manufacturers only want to put in units-no more fixing them:(

Brian, I talked to our tranny man today and he thinks there was a TSB about that. He is going to try to find it for me. I'll post it if he can find it, our system was down yesterday

Ted, both GM and Daimler/Chrysler are now requiring us to repair in the least expensive manner. It is becoming more and more rare that we can replace the tranny. I can almost recite the numbers now for 46re and 47re trans repairs on Dodge trucks.

That is a VERY good point about a new RO every visit. A lazy service writer will just keep the same one going forever, the good news is that it looks like your vehicle was there for three months and in some states 30 days overrides the number of visits thing.

We had a new (1800 mile) Trailblazer 90 days ago that the lady kept driving even with the warning light glaring in her face and it got so hot that when she parked it the trans literally welded itself together. Try getting that ***** on a lift, we couldn't even roll it.

But remeber, this is humans on assembly lines building stuff and things are going to happen. Chevrolet will make it right, just squeal soon and squeal often if need be.

Funny you should mention that about the fluid! I read that somewhere that the Chryslers dont like the GM dextron stuff and will screw the trans up! Finding that out and knowing the last owner told me he had the trans done not too long ago i got worried about it and was thinking about changing fluid just for piece of mind.......well i didnt get that far!! Driving on the highway one day the trans line blew and dumped all my fluid on the highway at 70mph!!! :eek: So now i do had the +4 fluid in there! :D :D That was about 3000 miles ago....still does it but it dont bother me...and imsorta putting money aside for when or if it does puke! :D

Thanks Bucky. I want to go in as fully armed as possible!

Thanks again Brett for the second call. I appreciate it very much. I am not so concerned with the tranny 'hesistation' as I am with the hard shiffting. I will do as we spoke, and keep an eye on it, and have it checked. It only does the hard shifting (like a tranny kit) immediately after it has had a hesitation problem; so it might be the fault of the computer, or solenoid. The TSB apparently says the 'tranny hesitation' is normal operation for this unit.
Thanks Brett & everyone.

The AV is back in the shop. The Transmission Fluid Pump was found to have a bad check valve seal. This was allowing the pump to take some time building pressure, and letting fluid drain past the pump, into the back of the pan. A new one was shipped, and it had a cracked housing. The second new one was just installed, and everything appears to be fine. We will see when I pick it up this afternoon, and continue to part it nose up. I guess I will not need new tranny fluid anytime soon!

I needed to get this straighted out before I could put aftermarket parts on! The good news is I just called Outlaw Motorsports and ordered a crap-load of new stuff!

Hey Sydwayz, I seen a black av going down the road this morning and it was way up in the air and it looked sweet. So what all you got ordered for the truck?

ARE Outlaw II Rims to match the boat trailer.
Cooper Discoverer AT 265 75 16 D tires.
Nerf Bars
K&N FIPK
Rear Airbags
HyperTech Power Programmer III
Billet Grill
Billet Bowtie
Rear Roof Spoiler
Custom dual Flowmaster exhaust is next when Mark & Mark are done with the mods.

That sounds awesome. I cant wait to see it.