So I have done some research already and I know that the clunking has to do with the driveshaft or the slipyoke. However, I am having another odd problem. I first really noticed it driving the through the mountains of East TN and NC last weekend. Basically when driving I was noticing that the transmission was shifting extremely quickly into OD even and low speeds and then didn't want to downshift until I got on it a bit and then there was the clunk.

98k miles
Havent done any transmission work or maintenance

It is tuned...could that have something to do with it?

 

The FIRST thing you do to troubleshoot ANY issue like this if you are tuned is remove the tune.

At 98k you really should get the trans fluid completely exchanged.

 

I will do that tonite. Detune the truck that is. I guess my question is Ive had the tune on there for a while now I wonder why if it is the tune would it be doing something now.

 

It's possible the tune has become corrupted.

 

Its detuned. Ill drive it tomorrow to see if its still doing it.

 

Detuned it and it seems to be misfiring a bit on idle and at around 60 but the trans issue isnt happen or not that I can tell. The thing is that it isnt throwing any codes.

 

How many miles on the plugs and cops?

 

Hi.

Apart from the fundamental maintenance aspects that need to be addressed (as no tuning will operate correctly if there are pre-existing issues, and may exacerbate same), MPT offers free tuning corrections within the first 6 months.

If you feel yer shifting isn't kosher, or you simply wanted some modifications to same ( or any other driveability preferences) for personal reasons, it behooves you contact them ASAP. They will take care of you.

May require you to provide datalogs, but they will walk you through that as well.

My tow tunes do indeed drop me into OD quickly - and hold it. That is by design to preserve the TC, and reduce slip-induced fluid heating. The tune adds so much extra grunt that this works very effectively. Note that it is throttle dependent - if going WFO, behaviour is more perf-oriented, going to high rpm's before shifting, as you'd expect. Progressively firmer shift as well (I chose 'Street').

Get the maint squared away and them call MPT - they won't bite

EDIT - the 'clunck' may be a separate issue altogether - driveline - slip yolk dry, universal, that sort of thing. You sayin' the 'clunk' is completely gone running stock, under the same conditions?

good luck

 

Spark Plugs were replaced at 80k and the COPS are original. Yeah I know about the six months thing but yeah im outside of that. The thing is it just started doing the shifting thing lately as in the last few weeks and then I really noticed it last weekend.

Update: I noticed yesterday that at Idle while in Drive is when I feel it the most even with it detuned. In park there is a bit of roughness but nothing like when its in gear.

 

Did you replace the cop boots when you changed the plugs?

You MIGHT be having the leaky fuel injector issue.

 

No I didnt change the COP boots. Can you buy those separately or do you need to buy the entire COP?

 

Well when I drive it it seems as though it isnt clunk when downshifting or it could be the fact that Im driving on straight flat roads for the most part and dont have to dip in the throttle too much.

 

You can buy just the boots. $6.37 each for OEM at rockauto.com, aftermarket cheaper. Have been told you can get Belden at NAPA for about $4 each and they are good.

 

Could that be what it is?

 

It could be, especially if you didn't use dielectric grease properly.