2001 Grand Prix (4T65E) Valv. Dex VI UOA

[WishIhadatruck]

2001 4 Door Grand Prix GT, 3800 V6 with 4T65E trans.

Trans History:
May 2001: Purchased new
12/06/2003, 30,026 miles: Dropped the pan, changed the filter, refilled with 7.5 qts of Mobil 1 ATF
3/25/2006 60,800 miles: Added a ATF cooler
3/26/2006 60,820 miles: Dropped the pan, changed the filter, refilled with 7.5 qts of Mobil 1 ATF
8/23/2008 90,690 miles: Dropped the pan, changed the filter, flushed with 2.5 qts of leftover Mobil 1 ATF (DexIIIh) and 12+ qts of GM Vehicle Care Dex VI.
1/4/2010 121,108 miles: Dropped the pan, changed the filter, installed ZZPerformance shift kit, refilled with 8 qts of Valv. Dex VI.
3/24/11 150,009 miles: Dropped the pan, changed the filter, refilled with 8 qts of Valv. Dex. VI.

Sometime around 110k I started to have issues with the car slamming from gear to gear. It would mostly do this when running in hotter weather doing stop and go driving. It apparently is a common problem where the trans. thinks it isn't shifting fast enough (solenoid issue?) and defaults into a fail safe mode where it max.'s out the pump pressure. You hear lots of pump whine and the shifting gets incredibly hard. I installed a shift kit at the 120k mile pan drop and that seemed to pretty much fix the issue. Much cheaper than dropping the trans. to replace some valves. It will occasionally shift a little more firmly when hot but never like before. More recently (last summer) it was often kicking in and out of torque converter lock-up. Another not so uncommon problem with this trans apparently. By playing with the throttle you could minimize it but it was annoying and I was concerned with the additional wear. Researching it, I found there were multiple causes. To me it felt like the computer could just not make up its mind. I disconnected the battery for an afternoon last fall and it never really did it again. Maybe slightly during the next week or so but that was many months ago and so far so good, zero issues since. Due to those two issues I was wondering how valuable a UOA would be since I expected some extra wear metals and debris due to those two issues. I never saw anything unusual in my pan drops, even pulling the filter apart. This recent pan drop was no different. The pan looked very clean and the inside of the filter was very clean also.


Blackstone Coments: The universal average column along the right side of this page shows typical wear for a GM 4T65E transmission after about 40,000 miles on the oil. You ran this oil 30,000 miles, and wear accumulation was well below average across the board, which is a very good indication that your transmission's internal parts are all functioning properly at 179,999 miles. The viscosity was correct for ATF and no moisture or insolubles were found. The TAN came back at 1.4, showing only a normal amount of acidity present. Keep doing what you are doing. Your transmission looks good.

Comments welcome. I've got Redline D4 in it now. I did a pan drop with a filter change (8 qts) and flushed another 4 qts thru it for a total of 12 qts used. If I still have the car in another 90k miles I'll test it again.

I guess used Dex VI is still thinner than used M1 Dex IIIh. I can't complain about the wear however, especially considering the issues I had during this 90k mile period.

Code:


OIL Valv Dex VI M1 DexIIIh

MILES IN USE 30k 30k Uni Avg

MILES 180k 90.5k

SAMPLE TAKEN 07/21/12 08/23/08



ALUMINUM 2 4 8

CHROMIUM 0 0 0

IRON 25 79 81

COPPER 54 113 112

LEAD 10 58 54

TIN 1 4 3

MOLYBDENUM 0 0 1

NICKEL 0 1 1

MANGANESE 0 1 1

SILVER 0 0 0

TITANIUM 0 0 0

POTASSIUM 1 2 2

BORON 72 83 86

SILICON 4 5 8

SODIUM 3 9 5

CALCIUM 69 132 142

MAGNESIUM 1 3 2

PHOSPHORUS 193 382 294

ZINC 11 11 45

BARIUM 0 0 0





INSOLUBLES 0 TR

WATER 0 0

FLASHPOINT ºF 390 405

SUS VIS 210ºF 44.0 45.0

cSt @ 212ºF 5.41 5.72

TAN 1.4 1.4

 

[yonyon]

So it's finally broken in then, is it?

 

[simple_gifts]

Why no Redline D6?

 

[WishIhadatruck]

Originally Posted By: yonyon
So it's finally broken in then, is it?


I think so!

Originally Posted By: simple_gifts
Why no Redline D6?


I was curious if the lower viscosity of Dex VI was part of the shifting issues. On hot days with lots of stop and go driving it still shifts a bit firm and kind of odd. I guess the thicker D4 didn't make a difference. It acts exactly the same. The D4 was kind of an test since it is fairly thick, even for a Dex III type fluid.

 

[Jim Allen]

Those really are some pretty nice UOAs... but then they are short intervals. I suspect your shifting issues are less with the oil than they are with something mechanical/electrical. That the behavior improves when you let the PCM readapt is telling... but I don't know enough about the particular car to tell you where to look. Sensors, inputs, outputs solenoids.. sumthin.'

 

[WishIhadatruck]

Originally Posted By: Jim Allen
Those really are some pretty nice UOAs... but then they are short intervals. I suspect your shifting issues are less with the oil than they are with something mechanical/electrical. That the behavior improves when you let the PCM readapt is telling... but I don't know enough about the particular car to tell you where to look. Sensors, inputs, outputs solenoids.. sumthin.'


The solenoids are buried on the side and require the trans. to get dropped to get to. It works pretty well right now and only slightly mis-behaves when the temp.'s are hot. I'll just let it go and keep driving it. It probably shifts as well as some new cars on the market.

 

[INDYMAC]

After trying several different fluid flushes in my 2000 Tundra, I was only able to fix firm/hard shifts by treating the tranny with Auto-Rx. I suspect that the valves needed some cleaning. You might give it a try if the shifting gets worse or too annoying.

 

[WishIhadatruck]

Originally Posted By: INDYMAC
After trying several different fluid flushes in my 2000 Tundra, I was only able to fix firm/hard shifts by treating the tranny with Auto-Rx. I suspect that the valves needed some cleaning. You might give it a try if the shifting gets worse or too annoying.


Thanks for the suggestion. I'd forgotten I had considered that a while back. I should look I might still have a partial bottle sitting around, does the stuff go bad after a while or would it still be good after a few years?

 

[INDYMAC]

I don't think it can go bad unless you left the cap off of the bottle. You will need 6 ozs. Drive 1-3K miles and then flush. If you have a real filter, you'll need to replace it also after the treatment. Good luck!

 

[dnewton3]

I find it interesting that the DEX VI essentially made for less wear, over the same exposure duration of 30k miles. With the M1 UOA at 90k and the DEX VI at 180k, it is not like break-in wasn't overwith.

And yet people will often deride DEXVI becaues it's "thinner".