hesitation/bucking in my 99 Tahoe

[Tex99Tahoe]

Ever seen a cutaway pic of a torque converter with TCC? There's a clutch in there, like the old-school clutch, engages the front face. With that thing engaging/disengaging, and the possibility that the flexplate bolts are loosening up, I'm not surprized you're hearing that clunk.

For sure, the entire torque converter has to be replaced. Question now is if it's shedding material that's getting into the oil. Probably oughta keep an eye on it.

The other disturbing thing is that as this progresses, it'll damage more stuff, throwing off the post-mortem diagnostics. I think it's time to go back to the tranny shop, give them your notes and this thread, and tell them you fear for your life (seriously)!

 

[lesterl]

The clunk is Torque lock of the slip yoke in the rear of the transmision, you need to lubricate the splines with a special waxy grease to prevent it... Been there done that.

Mine would clunk most when taking off....

 

[Tex99Tahoe]

So soon after a transmission overhaul? If so, you're dealing with an incompetent shop...

 

[lesterl]

I have delt with so many incompetent "professionals", it happens.....

 

[Stripermike]

From all of the research I've been able to do and the feedback from this site it seems like any engine code info is a "symptom" of the problem, and not likely to lead to a solution. At this point I'm feeling like if I continue to drive the vehicle I'm risking damage to an otherwise healthy engine and other components.
My dilemma - do I bring this truck back to my tranny shop and say "I don't want it back until it's really fixed"? In my mind, if the truck had a transmission issue when I brought it in and it still has the same symptoms then I spent $2500 to accomplish nothing, and if there's still an issue causing the transmission to act up that's part and parcel of the overhaul. Am I right in this line of thought?

 

[lesterl]

If the issue is indeed a transmission issue, then they do owe your a repair still after taking $2500 off your hands. If it isnt the transmission, I can see where they wouldnt need to cover those repairs due to having been in for a transmission rebuild.

 

[rockenthebowtie]

If you have a p1534 crankshaft camshaft correlation you may not have the distributor set right the camshaft position sensor is located in the distributor and if its not set right the vehicle will still start and run you need a scan tool so that you may see ckp cmp sensor angle degrees to set it... then after that you may need to run the ckp cmp varistion relearn...again you will need a GM tech 2 scan tool for that

 

[rockenthebowtie]

Oops sorry meant p1345

 

[Slammed]

Hey what are the codes again I'll run them through identifix at work

 

[Stripermike]

p1345 and p0340.

 

[Slammed]

install scanner look at the cam retard value with the engine at 1200 p.m. In park to factory specifications 0 degrees plus or minus 2 degrees The confirmed fixes are cam retard offset and everything else points to the distributor assembly

 

[Stripermike]

Don't have a scanner. The distributor assembly is brand new - WPI all metal distributor. I'm thinking the codes are being thrown because of the TCC lockup issue.

 

[Slammed]

No it never showed any thing else so basically your timing is off

 

[rockenthebowtie]

Striper I agree with slammed thats exactly what I posted its either the distributor isnt clocked right or defective the tcc will have absolutely nothing to do with the p1345 seting a camshaft dtc also like I said it may also need a crankshaft camshaft variation relearn .. however you do need a scan tool to clock it right by looking at the data display then loosing the hold down bolt on the distributor and like slammed said having no more then plus or minus 2 degrees variation between the camshaft and crankshaft.. also don't put all your in new parts thats why they have warranty some new parts can be defective

 

[rockenthebowtie]

Another thing the shift points in the transmission can be affected by the crankshaft camshaft variation being off because the pcm is having trouble calculating the crankshaft camshaft data input

 

[Stripermike]

This is actually the 2nd distributor I've put in the truck. Been fighting this problem since June - originally had the truck at a shop that found broken dist. - tabs snapped off and cap held on with wood screws. They put a reman. in, but when the tranny got done and there was still an issue the tranny shop put in a new one, said they heard of possible issues with the remanufactured distributors.
Would a Snap-On scanner like we pulled the codes with at the tranny shop do what I need?

 

[rockenthebowtie]

Yes a snap on scanner does have the data you need to view to set the crankshaft camshaft correlation. Between me and you im a GM certified technician been so for 22 years just here to help out. . Hope this info does.. good luck

 

[Stripermike]

Thanks rock - I appreciate the help and input everyone's been sharing. I'm going to talk to my tranny guy and see if I can get him to play around with this info - he wants the truck to be right almost as much as I do at this point. It was at their shop for 3 months....

 

[Stripermike]

Once we can determine the distributor is clocked right how is the relearn accomplished?

 

[rockenthebowtie]

I'm not sure if the snap on scan tool can do the variation relearn but you can clock it with that scan tool by looking at ckp and cmp sensor data but have them look in the functional test menu of the scan to see if crankshaft camshaft variation relearn is present again it may or may not need that clock it right first and go from there