2007.5 yukon denali high rpm 2nd-3rd late shift

[NickTransmissions]

If that is the case would there be a reason it only does this in 3rd gear and not 5th and reverse?

That's a likely suspect casue, not a diagnosis...You really need to pull the TEHCM and valve body assemblies down and bench test each using a DVOM and Test Block (TEHCM) and Sonnax vac test machine and 6L test plates (Valve body). But generally speaking, 2-3 flaring is the beginnings of 3-5-R clutch failure...If you start to notice flairing from 4-5 or delayed engagements / slipping into Reverse, you'll have your answer.

Keep driving it if you want. Worst case you'll lose reverse, third and fifth and will have to either limp it home or have it towed there or to a shop.

 

[kc8kc]

That's a likely suspect casue, not a diagnosis...You really need to pull the TEHCM and valve body assemblies down and bench test each using a DVOM and Test Block (TEHCM) and Sonnax vac test machine and 6L test plates (Valve body). But generally speaking, 2-3 flaring is the beginnings of 3-5-R clutch failure...If you start to notice flairing from 4-5 or delayed engagements / slipping into Reverse, you'll have your answer.

Keep driving it if you want. Worst case you'll lose reverse, third and fifth and will have to either limp it home or have it towed there or to a shop.

ALl other gears do great im really hoping its somthing valve body related obiously i dont have the proper equipment to test correctly but think i might gamble a lil inspect the valve body maby even get a replacment?

 

[NickTransmissions]

ALl other gears do great im really hoping its somthing valve body related obiously i dont have the proper equipment to test correctly but think i might gamble a lil inspect the valve body maby even get a replacment?

Do what you want but you're taking shots in the dark without the proper diag/testing equipment...I'd take it to a trans shop that's versed in those units and have them do a full diagnostic work-up...If it were my vehicle, I'd drop and bench test the TEHCM and VB so I knew for sure that it was one or both of those things...And here's the kicker - let''s just say your VB is bad....guess what? Doens't mean your 3-5-R clutch isn't...By the time the VB wear progresses to the point where it's obvious to test equipment, the associated applied element (in this case, the 3-5-R clutch pack) is already been compromised.

But like I said, you do what you feel is best for your situation, budget, time constraints, etc.

 

[kc8kc]

Do what you want but you're taking shots in the dark without the proper diag/testing equipment...I'd take it to a trans shop that's versed in those units and have them do a full diagnostic work-up...If it were my vehicle, I'd drop and bench test the TEHCM and VB so I knew for sure that it was one or both of those things...And here's the kicker - let''s just say your VB is bad....guess what? Doens't mean your 3-5-R clutch isn't...By the time the VB wear progresses to the point where it's obvious to test equipment, the associated applied element (in this case, the 3-5-R clutch pack) is already been compromised.

But like I said, you do what you feel is best for your situation, budget, time constraints, etc.

Yeah true almost wondering if i should just dump it for 2k with a bad trans and count my losses

 

[NickTransmissions]

Yeah true almost wondering if i should just dump it for 2k with a bad trans and count my losses

Dump the vehicle for 2k or dump 2k into it to fix the problem?

 

[kc8kc]

Dump the vehicle for 2k or dump 2k into it to fix the problem?

One more question for you i have split the valve body to check the check balls if one of the check balls has srunk could that cause my problem and if so how would i idenify if its that gear?

 

[kc8kc]

Dump the vehicle for 2k or dump 2k into it to fix the problem?

 

[NickTransmissions]

One more question for you i have split the valve body to check the check balls if one of the check balls has shrunk could that cause my problem and if so how would i identify if its that gear?

Still don't know what you were referring to by dumping it for 2k or dumping 2k into it....What did you mean by that?

 

[kc8kc]

Still don't know what you were referring to by dumping it for 2k or dumping 2k into it....What did you mean by that?

Sorry im not use to forums seems i replied to one of my coments rambling on the thought of just selling this with a bad trans for what ever i could get out of it.....some other coments i posted about how i split the valve body looking at the check balls was wondering if you could give me some insite to what check valve the screwdriver is pointed to and if that could potentially cause my problem as that one has shrunk

 

[NickTransmissions]

Sorry im not use to forums seems i replied to one of my coments rambling on the thought of just selling this with a bad trans for what ever i could get out of it.....some other coments i posted about how i split the valve body looking at the check balls was wondering if you could give me some insite to what check valve the screwdriver is pointed to and if that could potentially cause my problem as that one has shrunk

When it comes to those check balls, replace them all with torlon check balls in the Sonnax Zip kit. Also carefully scrutinize your spacer plate for wear and replace it if you see the check ball seating locations becoming enlarged...When the #1 check ball gets stuck, you lose all forward movement. If the #5 check ball sticks, you lose reverse. You'll have to look at the other check ball locations in the ATSG manual or check ball book to determine if the worn one in your VB corresponds to the clutch/gear showing symptoms.

I'd suggest installing either the Sonnax Zip kit or Transgo Reprogramming kit since you have it out and apart. Some parts cannot be installed unless the trans is out and apart but the valve body stuff can be done...Also, air check your apply circuits to confirm/deny the existence of cross leaks or weakness in any of your clutch packs - you can check every single clutch pack once that VB assembly is out of the way.

I made a video showing you how to do the air checks for the front three clutch packs via the orifice feed locations on the pump.