Transmission failing at 22k miles?

[GrantP]

I just bought the '06 in my sig a few weeks ago with only 22k miles on it. When the truck is started after sitting for a few hours and placed in gear (drive or reverse) it will not move for a few seconds. Applying throttle only revs up the engine with no response from the transmission, if I wait about 5-10 seconds the transmission will behave normally and drives fine afterwards.



My 97 began to do this with only 77k on it until it got to the point where it would take a minute or so before it would move, at that point I had the transmission rebuilt using DTT parts. Am I heading for a rebuild on the 06 already or is this something that can be fixed? Any/all suggestions are welcome.

 

[B.G. Smith]

The oil pump in the transmission don't circulate oil when in park. Some fluid from cooler and torque converter can drain back to pan while inactive. Try putting shifter in neutral for a few seconds when truck is first started. Mine does about the same if it sets for a while. bg

 

[cerberusiam]

Doing that after only a few hours is usually not a good sign. A few days, yes, but a few hours seems a little to short a time. Try the neutral trick for 30 seconds and see if that helps. If it does then the drain back valve is stuck wide open and possibly o-ring on the inout shaft gone or badly worn.

 

[sag2]

Sonnax makes a manual valve that flows in park. It does not necessarily fix the problem, but at least by the time you start and throw it in gear the cooler and converter are charged again. By the way, other than annoying it does no damage. The pump has full pressure and the clutches and bands are fully applied for the gear you select. The slippage is just because the converter is empty and you do not have the fluid coupling needed to move the truck.

 

[GrantP]

Good to know this isn't causing any further damage! Obviously if the problem is at the input shaft seal then the trans has to come out, but where is the drain back valve located? It's in the cooler line in my '97, is it the same in the '06? Is there a way to test it or just do an R&R and cross my fingers?

 

[cerberusiam]

The drain back valve is under the driver side battery in the rubber\brass portion of one of the lines. Frankly, taking it out and throwing it away is a better solution. That little POS is responsible for more problems than it ever solved, IF it is the problem.

Whether or not it is TC drain back is still undetermined. There are transmisison failures that will mimic the minimal symptoms you described. Like I said, a couple hours and this is happening is not usual. A couple days is normal. It is also incorrect to assume that TC drain back is the problem and the cluthc packs are applying correctly. A failed seal in the forward clutch pack, a leaking front servo, a sticky or failed PR valve will give these same symptoms and be eating the trans the whole time you think it is working. The subtle failures will not show for a number of miles and\or hard use.

To be fairly certain you need some more diagnostics with pressure tests under conditions that the anomaly shows or it is just a SWAG where the real problem lies.

 

[sag2]

The drain back valve is under the driver side battery in the rubber\brass portion of one of the lines. Frankly, taking it out and throwing it away is a better solution. That little POS is responsible for more problems than it ever solved, IF it is the problem.

Whether or not it is TC drain back is still undetermined. There are transmisison failures that will mimic the minimal symptoms you described. Like I said, a couple hours and this is happening is not usual. A couple days is normal. It is also incorrect to assume that TC drain back is the problem and the cluthc packs are applying correctly. A failed seal in the forward clutch pack, a leaking front servo, a sticky or failed PR valve will give these same symptoms and be eating the trans the whole time you think it is working. The subtle failures will not show for a number of miles and\or hard use.

To be fairly certain you need some more diagnostics with pressure tests under conditions that the anomaly shows or it is just a SWAG where the real problem lies.

Based on his symptoms (if I wait 5-10 seconds it works fine) and the fact there are not the same two elements applied in reverse and low it is highly unlikely it is a clutch or band.

 

[cerberusiam]

The problem is the apply circutis are tied together in the front and a leak in one will effect the others and how they apply, especialyl at an idle. In addition a sticky PR valve will cause both pressure to the TC and other elements to not rise fast enough on engagement. This type of drain back in a couple hours indicates the possibility of more than a simple check ball failure, just indicates not defines.

To instill confidence the transmission is reliable it will take some testing and trouble shooting. Plan for the worst, hope for the best and one is usually not disappointed.

 

[GrantP]

Thanks guys, I'll take it in to the shop when I get a chance and get it diagnosed. Thankfully I've still got the '97 sitting around.