New luk torcon converter

[Chris2144]

So I bought this 2007 Yukon Denali with a shuddering converter. It has 161k miles. Has the 6.2 awd 6l80
I replaced the converter with the new luk converter. Tc0017
Was recommended by a shop that it’s the only one they will use for stock replacements now.
The install is straightforward no change really comes with new bolts and out of the box everything looks good.
I’ve got about 900 miles on it now and the shudder is gone, shifts nice and trans temps stay under 180.

I will say that before I did this I pulled the pan. The fluid was a little dark but not terrible and didn’t smell burnt.there was a little metal on the magnet and a slight film coating the pan. I’ve definitely seen way worse so I decided to just go ahead and replace the converter. There were no other symptoms or any codes and lime ramp up pressure looked good so I was fairly confident the overall health of the trans was at least decent.i have not tuned the trans but I will soon.

Overall it seems that this converter is very good and it’ll anyone is running into converter problems and needs a stock replacement I would def recommend it.

Picked it up at AutoZone for 427.00 no core charge.

 

[West 1]

Thanks for the feedback, my 08 Denali at 145,000 miles has just started a small oil leak at the rear main seal. Only about a large drop every night but I hate oil leaks. I will pull the trans and replace the rear main seal but I am thinking this is a great time to install a new converter.

This tranny had a new factory TECHM installed at 65,000 so maybe a new converter will keep it healthy.
Only complaint is sometimes this tranny can clunk on an acceleration downshift, not terrible but not a smooth shift. Is that just the Torque converter unlocking?

 

[SpareParts]

Mine had that weird clunk sometimes when going around a corner with the stock tc. After i tuned it, it took a couple of days to relearn i think, but it no longer has that clunk.
I would like a little more engine breaking going down hill in 1st and 2nd going down hill.
Can that be tuned into it?

 

[West 1]

I have been happy with the factory tranny so far staying locked in 1st and 2nd. We tow our boat into a canyon to launch. I lock it in 1st and let the tranny hold our speed all the way down to the launch. It is maybe 3 miles pretty steep downhill on a narrow twisting road. So far the tranny has worked just fine for that use. Mine is a 2008 6L80 behind a 6.2L., previously towed with our 03 and 4L60 trans, both did this job fine.

We went to visit Pikes Peak but were driving a rented Ford Fusion. On the downhill coming down from Pikes peak, 14,000 ft or so. The Tranny would not hold at all in 1st gear kept upshifting. We were forced to use the brakes and they overheated. Had to stop for a half hour to let them cool enough to continue. I do not understand how a factory could sell a car with that tranny feature. It was flat out dangerous. Does your tranny upshift like that Sparparts?

 

[SpareParts]

No, it works great everyplace honestly. Maybe what im looking for is in the engine tune?
In the wife's 2013 Avalanche going down a steep hill in M1 it feels like when the engine speeds gets up to say 2.5K rpm it feels like it starts breaking harder. My 07 Yukon XL does not do that. Maybe my imagination?
Both stay in whatever gear i manually tell it to.

 

[mikez71]

Thought I heard they added grade braking in the '13-'14 models?
AFAIK there is no way to tune that feature.. idk

I do notice that in our 5.3 tunes, the tcc apply ramp has some big values for negative slip...
(but small for positive slip.. ?)

And if you look at 6.2 tunes, it's opposite.
Although they added a little bump for negative slip in the later years.

'08 6.2

'13 6.2

But also, the 5.3 does not lock TCC in 1st, while the 6.2 does not lock in 1st & 2nd.

 

[Geotrash]

Only complaint is sometimes this tranny can clunk on an acceleration downshift, not terrible but not a smooth shift. Is that just the Torque converter unlocking?

On an ‘08 Denali, clunking on a downshift is most likely to be (in order of probability):

1/ Driver’s side motor mount
2/ Front differential mount bracket bushings
3/ Transfer case chain slop

This has been the case for other folks here, and it was the case on my ‘07. I addressed 1&2 a few years ago which took care of my clunk on downshift problem. Now I have a clunk when coasting and I hit the gas to accelerate, but no downshift needs to be happening. It’s pure driveline slack, and chassis ears tell me it’s the transfer case, which has a ton of slop in the input shaft, and indicates significant chain/sprocket wear internally at 253K.

I’ll eventually address it but just haven’t yet.

 

[West 1]

Food for thought. Driver Motor mount is new. I have had the front differential out and re installed after rebuild, did not even consider wear in the mounts, that may be an issue. At only 145K or so I think the transfer case should be fine, fluid is new and old fluid was pretty clean. Thanks for the tips.

 

[Chris2144]

Unfortunately I cannot attest to any kind hard shift or clunking as this trans was working fine other than the tc in lockup would shudder. Judging from others that have had the tc problem I think I caught this one early which is why I didn’t see any other symptoms