Delayed Transmission Engagement - Fixed

RabidRdKill · **Posted:** Sat Jun 28, 2008 11:40 am

In the last week or so I've noticed that when I first start out after letting it sit for a while - overnight or while at work - when first starting out there is a delay before it gets going. Like it's not in gear. The RPMs climb but the vehicle doesn't move for a moment. This makes me think something in the trans or TC.

Any thoughts?

After the initial event it drives fine until letting it sit again. There's no DTCs in the TCM and 2 in the PCM P0100 (from the ORM) and P0105 the DRB says 'Boost Pressure vs Atmo Pressure'. That's a new one that I haven't seen before but since the RPMs rise and the Jeep doesn't move I'm not thinking that's part of this problem. :?:

I've also had several of the famous "limp in" moments lately always after coming to a stop after a long highway run.

The F37 and all was done by the previous owner so I don't know what they did there as far as part replacement. It's only got 2200 miles left on the 7-70 so if it's something serious I need to take it in soon. At any rate I'm a sparky not a gearhead so whatever goes on in the that mechanical marvel called a transmission is a mystery to me!

EDIT-Just skimmed the TSB sticky - would the TSBs related to trans filters wait 67,000 miles to show up?

truckbouy2 · **Posted:** Sat Jun 28, 2008 11:55 am

Put it in neutral for a few seconds.
I changed the filters, not a dealership, on "The Princess's" Jeep when it had only 900 miles, because it did the same thing. It had the revised filters already.
I read somewhere that there is a lack of pump circulation in park. I haven't been able to confirm that, BUT putting it in neutral for a few seconds works for this issue.
I guess it's just one of those quirks...."The Princess" drives it like she stole it. If it was a weakness or problem with the transmission I'd already have been layin' on my
piece of cardboard.

Cowcatcher · **Posted:** Sat Jun 28, 2008 1:24 pm

The tranny filters did not affect early '05's if I recall correctly. But, it is likely that had they not been changed and needed to be they would have been during the F37.

jinstall · **Posted:** Sat Jun 28, 2008 2:02 pm

Mine does it all the time. the colder the weather the longer it takes. I give it a full 60 seconds beofre I select any gear and it is fine. If I try to get on it when it is like that it takes a few seconds to fully engage and if I stop about 100 meters later I get the tranny shudder and then the engine is dead. I have learned to live with this so I just kick it into neutral before I slow down too much.

Turbowhine · **Posted:** Sat Jun 28, 2008 11:44 pm

Yes, My 06 CRD just started doing this about 30 days ago. Most anytime it sits for 6 hours or more it takes about 15 - 20 seconds for it to move at all. After it does get moving it operates normal. I just got it back from the dealer yesterday and they say everything is just fine. (yea right)I have 25,000 on mine. I do occasional moderate weight towing. Fluid looks fine. I did have the recall for the torque converter done about 9 months or so ago. It's due to have the trans. serviced I guess. We had some trucks (Ford Diesels) at work doing this same thing some time back. They had to install a check valve on one of the cooler lines if I recall correctly. Good luck with your problem!

gmctd · **Posted:** Sun Jun 29, 2008 6:21 pm

Those symptoms usually indicate the check-valve in the trans cooler-return filter, the small round one, is leaking - a fresh filter should cure that, but involves dropping the pan - too bad the eng'rs didn't place that externally, like on the Allison and others

Turbowhine · **Posted:** Sun Jun 29, 2008 7:36 pm

GMCTD,
Thanks! that make sense. I appreciate the info. I'm going to try out and bet it takes care of it.

Thanks again.
Joe

jinstall · **Posted:** Mon Jun 30, 2008 3:31 pm

I had a tanny service done at the dealer and it was still there afterwards.

Hold up, there was a TC recall on the 2006's? Link or TSB # please?

chrismc · **Posted:** Mon Jun 30, 2008 5:00 pm

Mine's at the dealer right now for this exact issue. Fairly consistently, it also bogs down and dies when I come to a stop shortly after starting up (like when I reach the stop sign at the end of my block each morning). My guess it that there are issues with the transmission pump, and it can't flow enough fluid to engage/disengage the torque converter. This is my first auto tranny, though, so its just a guess. After it throws it's morning fit, its fine (until yesterday). Tranny fluid level is fine, and I'm at 42k miles.

Over the weekend the tranny crapped out and wouldn't go over about 35-40mph no matter how much the engine revved. When I pulled over into a parking lot, it was having a really hard time maintaining idle, as if there was a huge amount of drag against the engine. Once I stopped and restarted it, everything ran ok.

Shifts have been a bit rough and unpredictable lately, as well.

I thought I had a rare "good one" and was going to be exempt from all the CRD issues that people have had, but its looking less likely lately. Good thing for 100k-mile extended warranties! I could do without the hassle, though.

chrismc · **Posted:** Tue Jul 01, 2008 3:15 pm

Lovely- The dealer "cannot duplicate the problem". I find that hard to believe. Even though there is so much documented trouble with the transmission in this thing, what do I have to do to have them fix it?

dgeist · **Posted:** Tue Jul 01, 2008 5:21 pm

Let me rephrase the issue since I've been having something like this, too. I start it in the morning, let it warm for 30 seconds or so, then put it into reverse and let off the brake. It doesn't move unless I press the go pedal. It USED to start out slowly in reverse, but not now.... Same issue? Trans service will fix?

Dan

danoid · **Posted:** Wed Jul 02, 2008 9:45 pm

gmctd wrote:

Those symptoms usually indicate the check-valve in the trans cooler-return filter, the small round one, is leaking - a fresh filter should cure that, but involves dropping the pan - too bad the eng'rs didn't place that externally, like on the Allison and others

Torque converter drainback is the cause for the delayed engagement, but I still don't get the stalling. If there's enough line pressure to fill the t/c and engage clutches to drive away, why does the torque converter sieze on the first stop?

gmctd · **Posted:** Wed Jul 02, 2008 11:58 pm

There's prolly not really enuff initial pressure to handle all the stuff going on from that delayed start, including full TCC release at the first stop - everything returns to normal after all the accumulators'n'pistons'n'stuff are primed - could be a.) sticking line pressure regulator, b.) combined initial leakage past all the seal rings, c.) sticking valving that controls the dual pump - sure need to get that pressure-regulator bypass switch hooked up and start driving the KJ to run some of these tests

Joe Romas · **Posted:** Thu Jul 03, 2008 6:49 am

danoid wrote:

[ but I still don't get the stalling. If there's enough line pressure to fill the t/c and engage clutches to drive away, why does the torque converter sieze on the first stop?

As I recall the static state (no fluid pressure) of the clutch in the torque converter is to be engaged and it takes pressure to release it. I could be wrong but I belive this is how it works.

Also the defective filters after the initial findings and recall were sent back in to the field as spares. So even if yours was not subject to the filter recall and the transmission was serviced it could still be the one without the check valve. They have since released a new part number for the correct filter to avoid that. The filters were good they just didn't have the required check valve.

danoid · **Posted:** Thu Jul 03, 2008 11:32 pm

My transmission hasn't been serviced except to be pulled off for the t/c replacement. Since the dealer didn't even bother to flash the engine and trans, I doubt they bothered to open the pan and put in a new filter.

I think it's odd that the t/c will support slip initially but not after coming to a stop later. Revving the engine to 1500 rpm and no vehicle motion means that there is 1500 rpm slip on that lockup clutch, yet 10 seconds later it can't support 700 idle rpm. The transmission at least thinks (according to it's internal sensor) that the pump is generating pressure, I've measured that during a stall event.

If there is insufficient pressure to support t/c unlock, there should also be insufficient pressure to support the transmission clutches, and they aren't throwing any fault codes.

Like I've said, this one has me stumped. If this was a FWD 41TE, I'd say it's a bad solenoid switch valve. I don't know enough about this trans' valve body/solenoid architecture. I've brought this issue to the attention of 545RFE engineering. It's time to start running it higher up the flagple I guess.

Pablo · **Joined:** Thu Feb 02, 2006 10:06 pm **Posts:** 1201

Mine does not like to go into reverse until the motor has ran 5 seconds or so and never has. I just did a tranny service and no difference with it going into reverse. I await everyones findings. Until then, I just wait 5 seconds before putting it into reverse.

RabidRdKill · **Posted:** Wed Jul 23, 2008 11:04 pm

I finally got around to getting it into the stealership. (It's still under the 7/70.)

I dropped it off last night and they called me an hour after they opened this morning immediately jumping on the cracked filter TSB saying that's all it needed, $200 please. It killed me to say it but I told them to go ahead since I've been meaning to do it and it was already there. I assume at this point they didn't do much but duplicate the problem - no real root cause yet.

Well they called me mid afternoon today to say it would take a few days as they were ordering a valve body. (At least now it would be covered under the 7/70 $100 vs $200) This problem screams TC drainback to me. Comparing the Engine RPM to Turbine Speed on EDT you could see that even in P or N on a cold start the TC wasn't doing anything. Anybody have any thoughts on what the valve body would have to do with this? (Danoid?)

On a positive note after researching this problem I'm starting to understand transmissions...scary

curtis · **Posted:** Wed Jul 23, 2008 11:41 pm

RabidRdKill wrote:

I finally got around to getting it into the stealership. (It's still under the 7/70.)

I dropped it off last night and they called me an hour after they opened this morning immediately jumping on the cracked filter TSB saying that's all it needed, $200 please. It killed me to say it but I told them to go ahead since I've been meaning to do it and it was already there. I assume at this point they didn't do much but duplicate the problem - no real root cause yet.

Well they called me mid afternoon today to say it would take a few days as they were ordering a valve body. (At least now it would be covered under the 7/70 $100 vs $200) This problem screams TC drainback to me. Comparing the Engine RPM to Turbine Speed on EDT you could see that even in P or N on a cold start the TC wasn't doing anything. Anybody have any thoughts on what the valve body would have to do with this? (Danoid?)

On a positive note after researching this problem I'm starting to understand transmissions...scary

I think it is the check valve (one way valve) that is to prevent the fluid from draining from the trans cooler back into the trans pan when the trans pump is not running (motor shut off). If the valve sticks open then when your jeep sits a while the fluid slowly drains from the cooler which sits higher than the trans pan ( gravity ).
I don't think the check valve would be inside the valve body, but I could be wrong.
Anyway that is why the vehical won't move until the cooler gets refilled and circulation re enters the trans.

I would talk to the dealer about that.

RabidRdKill · **Posted:** Wed Jul 30, 2008 8:40 pm

Well the service writer/story teller didn't have a clue, no valve body replacement - no surprise there.

When I picked it up the receipt said they replaced the pump and the 4x4 linkage :?:

along with the fluid/filter change. When I asked why the story suddenly changed so much the service manager brought out the hand written notes from the mechanic.

The notes showed that he did the fluid/filter change which didn't fix the problem. That was followed by a pressure test (anybody know what that involves?) leading to the ordering of a new pump. R&R transmission, broke 4x4 linkage removing transmission, order linkage, replace pump, put it all back together.

So far after 2 days I've had no problems. When the F37 was done the pump wasn't replaced so hopefully this means I now have the new pump.

And instead of $200 for the trans service all I owed was the $100 for the 7/70 deductable.

KJ Ash · **Posted:** Wed Jul 30, 2008 10:23 pm

Mine has had this problem for some time now and I have just come to live with it. The idiots at Jeep can never find the problem and the more i here them talk the less confidence I have on their knowledge and ability. If it wasn't for things getting fixed under warranty I wouldn't even go there. Anyway....

If mine is cold I throw it in neutral for a few seconds with a rev or two and off I go with no probs. I'm not really phased by it.

With that in mind if you guys find a simple fix, let us know.

Delayed Transmission Engagement - Fixed

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