Tranny issue, need some help figuring it out

[08grey]

Stabilizer bar link bent. Takes allot to do that. Investigate more at that area.

 

[992dr]

Its the lower link of the 4-links. Not quite sure how it happened, troopers drive everywhere. New ones are on the way. I'm going to box the new ones to stiffen them up.

 

[08grey]

I can't remember but didn't you just recently do a wheel alignment? Whoever did it should have mentioned that your lower control arm is bent. If they did not its a good indication that this might have just happened at the dealer. Looks like it fell off a jack stand or was placed wrong on a lift. For ***** and giggles check that quarter panel for bondo. Truck may have been hit before also.

 

[992dr]

Sorry, wrong guy, hah.
I have known about it since my purchase. I just put it off because of being so busy.
A new one is going on Tuesday. It being a retired state police vehicle, I'm sure it was when crossing the median or something. They aren't gentle with them, hah.
Oh, its clean to, no accidents. Dents a dings, yes.

I brought it to a local rear-end shop to check out the noise. Its a pinion bearing. That and a Detroit Tru Trac are going in on Tuesday as well.

 

[08grey]

Yep my bad.

 

[KMeloney]

Watching this thread. I've had trans issues from day one. Get a bucking/shudder coasting down to @ 35 mph, like it doesn't know which gear to be in. And, I get a vibration at highway speeds just north of 70 mph. Could be unrelated, but the shudder issue is just absurd.

 

[992dr]

My best advise would be to find a reputable trans shop and go over it with them. Explain your symptoms in great detail. If you know the sweet spot, you drive and point it out to them.

Also, check your rear-end.

I will be back tomorrow with the results from the rear-end shop after I get it rebuilt and have a Detroit truetrac installed. I'm praying this will resolve my issue. Oh, they're also throwing on a new link to.
After all of this, I should've left it alone and just dealt with the slight shudder.

 

[Chev454ss]

It's a D.I.C. aka Driver Information Center. You can look it up in your owners manual.

 

[992dr]

Well, I got the rear rebuilt and had a truetrac installed. He also threw on a new link for me. It feels great, it took all the slop out of the rear. Its tighter and no clunking at all. I'm happy with it.

Unfortunately, I'm still having that noise/shudder/vibration at 30/35mph up until 40mph. Its got to be either the converter, tune or the valve body. That is all that's left.
I'll be making an appointment at the trans shop sooner than later.

 

[992dr]

Brought it to a shop today. He was very informative, hooked up his tech II and we went for an hour drive. Long story short. Its a drive line vibration.
What's od is how it only happens when my converter locks up at 35mph and slowly dissipates as you go faster. Kind of feels like its out of balance.

Finally found someone willing and capable of fixing it. BUT, he wants to figure it out before we start replacing parts. He's doing some research and I'm getting in contact with FTI for any warranty info on the converter. I'm hoping something gets resolved, otherwise that converter is getting pulled.

 

[992dr]

Got in touch with FTI, great people to deal with. He was very helpful.
I'm going to get it flashed back to the stock tune and see where we go from there. If it still has the same symptoms, FTI will go through it for me at no cost. That's some pretty awesome service.

 

[KMeloney]

Please keep us posted. I'm watching this thread.

 

[992dr]

Will do
I'm planning on swinging by the dealer for them to flash it back to stock sometime this week.

 

[992dr]

Just got back from the dealer.
I did not have a tune for them to re-flash.
POS f**kers lied.

 

[mattluttrell]

Is this a bad ujoint causing a vibration? I've had out of balance driveshafts or bad ujoints cause this.

 

[992dr]

It only happens when the converter locks up at 35mph and stops at roughly 45mph.

I'd think if it were a u-joint it would be more consistent.
I'll check them out though, just to be sure.
Thanks

 

[992dr]

matt,
went under and checked the u-joints. They felt tight. One thing I noticed was a little slop in the yoke.

Here's a couple of quick clips

Well, I had spoken with the owner of the converter company. Cool guy, very helpful.

From the explanation I had given him. He said that it is going to be one of two things, either the converter or a misfire. I just changed my plugs and wires.
It has a slight hiccup at idle and the tuner at RPM picked up several misfires while we were doing a road tune. Its pretty much been like that since I bought it. And since it doesn't throw any codes, not one tech has even attempted to try to resolve this. All I hear is, if it doesn't throw a code, we cant see anything.

Now, how the hell do I figure out exactly where this misfire is coming from?

This was something I had brought up with the original shop, his answer was "its old".
Misdiagnosis and a ton of money down the drain.

 

[mattluttrell]

I don't have any answers.
I will say that my Esky will have a slight misfire at a stoplight once every couple weeks. It won't happen at speed. I also have new plugs and cables. It is never bad enough to be stored in the computer.

The u-joint problem I speculated happened to me when one had needle bearings completely corroded. It caused driveline vibrations at 50mph+ when you were coasting or slowing. They weren't there on acceleration because the torque was keeping it close. It loosened on coast. My u-joint issue was obvious.

A little slop in your yoke is healthy. Lack of slop is actually a problem.

I don't have any Tahoe related advice or guesses. Good luck.

 

[moineau]

By DIY I meant the screen on the dash. I think it's called that. I have a 6.2 so I don't have Afm. Maybe somebody can chime in and tell if it shows on the cluster when it's in 4 mode or even if it's available on a Ppv

I believe you mean DIC (Driver Information Center), not DIY. At least in the Yukon XL Owner's Manual, DIC is used to refer to the cluster panel providing idiot lights for anything wrong (including a small text readout).

DIY is sometimes referring to Do-It-Yourself, so I may be incorrect for GMC trucks but I think the post should have read DIC (yeah, U pronounce it like U want...)

 

[992dr]

Does anyone know what the operating pressure should be on a 4l60e trans?



EDIT Found my answer, I think. Does 190psi sound right? If so, I'm at 80psi. Less than half. Supposedly, this is what's giving me the shudder under lite throttle.