Help!!! 06 lly/lbz Allison 1000 6 speed clunking

[Dirtymaxrandy]

hello, I have a 2006 Chevy Duramax crew cab dually 4x4 Truck intermittently has slight difficulty coming out and going in to gears P,R,N,D, and coming in and out of park With a loud clunk harsh feeling as if it is loaded or parked on a hill once in any gear runs perfect, doesn’t skip a beat and having it in four-wheel-drive low or high makes no difference still clinks and shifts hard Whether transmission is hot or cold, there is no difference I’ve put it in 4hi and Checked for play in the front drive shaft with the front end on and off the ground would say less then a 1/4 inch of play NOT quarter turn 1/4 of an inch all new u-joints and carrier/center bearing prior to issue 1 thing we all agreed on is it had notthing to do with front/rear driveshafts or axles

Backstory
Bought the truck in 2021 in good condition for it age with 166k ran and drove fine drove it 2k miles fixing stuff little by little and decided to rebuild a lot of of it
The only things that have not been replaced repaired or rebuilt our front axle rear axle transfer case and transmission everything else is new including fluids transmission fluid was fairly clean with no particles and no smell
Transfer case fluid was pretty dark not sure it was ever replaced goes in and out of four-wheel-drive with no issue and smoothly

Took it to my mechanic to have a few things done
New exterior trans filter
And a few other unrelated things, the truck was broken into And the truck wouldn’t start Not sure exactly what happened, the mechanic said I was repaired and the truck was ready. I brought it home. And the next day noticed the issue with the transmission. Took it back yes I know stupid idea he inspected it. and couldn’t find anything. Took it to two other transmission shops. One said transfer case fluid was bad. Told me it was good and sent me on my way
Still the same issue Took it back and they said in plain words were just guessing

Took it to another shop and was told it was the shift linkage. They would do a transmission service. Check the linkage and replace if necessary work was done shift linkage was good and did not need replaced was sent on my way. Took it back they said it need to be rebuilt


I’m thinking it’s either electrical something broke in the transfer case or maybe a broken or damaged parking pawl any help would be greatly appreciated

 

[Dirtymaxrandy]

Well after spending thousands and thousands of dollars and taking it to shop after shop after shop and even rebuilding the transmission from the ground up I stumble upon a TSB explaining the exact issue saying it’s a completely normal characteristic of this Transmission f**k my life

thanks to those who didn’t respond or give any input or personal experience was really appreciated hopefully this helps somebody else

At least I have a built Transmission now

 

[PureHybrid]

You're very welcome

If none of those "shops" could tell you it's normal by a test drive, how are we supposed to be able to tell from the keyboard?

 

[Chevy1925]

You're very welcome

If none of those "shops" could tell you it's normal by a test drive, how are we supposed to be able to tell from the keyboard?

Because we have physic powers, duh!

Aint it cool when a new guy shows up, asks a question, goes dormant for a month and half, contributes not a darn thing to the forum, and then gets upset with us because we offered no help in between his absence? I mean, clearly he cant work on the truck and has to have a shop work on it but somehow we would be able to coach him through this.

Best part, posts that a tsb states its normal, puts a post up to “help others with the same issue” and yet cant even post up the tsb. Just brilliant OP. Dont let the door hit ya on the way out!

 

[Dirtymaxrandy]

Sorry for the late response



It was just a joke I thought nobody was gonna see it



but here’s a rundown

how did I figure somebody on this site might have more insight than the shops I’ve taken it to I’m sure there’s more than a few Transmission builders enthusiast and people that know just as much about these trucks as the manufacturer



while I always intended on having the Transmission built I wanted to have it done at Inglewood Trans 3months for now but ended up running into this issue and while my transmission and transfer case was completely taken apart, it occurred to me. I probably could have test drove another truck to see. Maybe it’s something that these trucks just do which it is and that’s when I found the TSB so I ended up having the shop just build it instead of just putting back together the factory parts which were all perfect so now I have the built trans I wanted today instead of three months from now on my trip

and I posted that question on five different site and didn’t get a single response asked a few questions from other write ups about similar problems no response called multiple Transmission shops and nothing post tried to say just rebuild it

But why wouldn’t they I guess most shops are just out for a profit only I guess but

I thought these forms were resource to help

educate people Didn’t get much help on any of them but whatever $h1t happens, I guess it’s not that big of a deal



And the majority of the shops here didn’t know Jack /much of anything about these Allison’s which is pretty crazy if you ask me,

but that was the case with majority of the shops that I went to



Plus most shops here where I live go by nobody leaves without a diagnosis even if you and the shop know

what they’re trying to sell you on is something you both know isn’t going to do anything like oh yeah it’s your tranny fluid or transfer case fluid at every single shop at lmaoo no jk even though both had new fluid

and some just guess literally no diagnostics not even start it test drive it, this was multiple shops



I can work on the truck myself but I have a full life and choose not to everybody spends money on stupid stuff one way or another I choose spending it to having other people work on my truck so I could spend more time with my kids



why didn’t you respond before I posted that if you know so much about them and what would it have mattered if I stayed on here every minute of every day while shaking in my boots and hoping somebody responds lmao

but I guess even your response was better than nothing



I think that letting something hit you on the way out is probably your department, since you’re so butt hurt about it my response
Mr. staff member lol

an here’s that TSB just in case anybody else has that problem maybe you could pull that door that hit you on the way out and save them jk lol hi nice to meet you by the way have a good nite

 

[PureHybrid]

I understand the full life part... usually on here skimming on break at work.

Not sure about others, but when I'm on here I just check the "what's new" tab. If your post wasn't seen once then the next time I'm on it won't show as "new". Like James said, if it was an issue you were having trouble diagnosing your best route would've been to update your post within a week or so.

 

[PureHybrid]

And to be honest, the TSB makes it sound like the clunk would be fairly subtle compared to your description

 

[Dirtymaxrandy]

Yeah, I didn’t even know updating the post was an option.I should’ve done more research.

And I thought the same about the TSB I’m not best at giving description guess lol but after driving three other Duramax‘s similar years I know for sure it’s something they just do and it’s normal

 

[TheBac]

I would've guessed that a clunk coming out of park could've been the common driveshaft yoke lube issue.

 

[Chevy1925]

Sorry for the late response



It was just a joke I thought nobody was gonna see it



but here’s a rundown

how did I figure somebody on this site might have more insight than the shops I’ve taken it to I’m sure there’s more than a few Transmission builders enthusiast and people that know just as much about these trucks as the manufacturer



while I always intended on having the Transmission built I wanted to have it done at Inglewood Trans 3months for now but ended up running into this issue and while my transmission and transfer case was completely taken apart, it occurred to me. I probably could have test drove another truck to see. Maybe it’s something that these trucks just do which it is and that’s when I found the TSB so I ended up having the shop just build it instead of just putting back together the factory parts which were all perfect so now I have the built trans I wanted today instead of three months from now on my trip

and I posted that question on five different site and didn’t get a single response asked a few questions from other write ups about similar problems no response called multiple Transmission shops and nothing post tried to say just rebuild it

But why wouldn’t they I guess most shops are just out for a profit only I guess but

I thought these forms were resource to help

educate people Didn’t get much help on any of them but whatever $h1t happens, I guess it’s not that big of a deal



And the majority of the shops here didn’t know Jack /much of anything about these Allison’s which is pretty crazy if you ask me,

but that was the case with majority of the shops that I went to



Plus most shops here where I live go by nobody leaves without a diagnosis even if you and the shop know

what they’re trying to sell you on is something you both know isn’t going to do anything like oh yeah it’s your tranny fluid or transfer case fluid at every single shop at lmaoo no jk even though both had new fluid

and some just guess literally no diagnostics not even start it test drive it, this was multiple shops



I can work on the truck myself but I have a full life and choose not to everybody spends money on stupid stuff one way or another I choose spending it to having other people work on my truck so I could spend more time with my kids



why didn’t you respond before I posted that if you know so much about them and what would it have mattered if I stayed on here every minute of every day while shaking in my boots and hoping somebody responds lmao

but I guess even your response was better than nothing



I think that letting something hit you on the way out is probably your department, since you’re so butt hurt about it my response
Mr. staff member lol

an here’s that TSB just in case anybody else has that problem maybe you could pull that door that hit you on the way out and save them jk lol hi nice to meet you by the way have a good nite





View attachment 127784

Yeah… joke… sure. Then proceed to write a 30 min novel about how its not a joke, ive upset you, you think this forum was made to have to help people like you, and dont have time to work on it but have time to write this novel.

I do not care for your whining. Knock it off or you’re gone

 

[Dirtymaxrandy]

OK, thank you , Almighty staff member

And TheBac
I would’ve guessed the same thing, but I rebuilt both front and rear drive shafts and had them balanced and tested by two shops so I knew it wasn’t that

I ended up finding that issue while backing up to a camper,I threw the truck in reverse shifted normal backed up about 2 inches and threw it back into park and it shifted hard. Tried it again and did it again. Tried through the other gears and the same thing. But if you waited a while. and then shifted into park it would be not as bad or not at all . But It wasn’t like I was going from P to R super quick imagine backing up to a camper an having to going back an extra 2 inches and then going back into park and that was the first time I experienced that in this truck
but this was also the first time I drove the truck after it got broken into at the mechanic shop It

I also thought it could’ve even been a damaged portion of the parking pawl or something in the transfer case, but none of it ever quite fit what I was experiencing

 

[2004LB7]

OK, thank you , Almighty staff member

And TheBac
I would’ve guessed the same thing, but I rebuilt both front and rear drive shafts and had them balanced and tested by two shops so I knew it wasn’t that

I ended up finding that issue while backing up to a camper,I threw the truck in reverse shifted normal backed up about 2 inches and threw it back into park and it shifted hard. Tried it again and did it again. Tried through the other gears and the same thing. But if you waited a while. and then shifted into park it would be not as bad or not at all . But It wasn’t like I was going from P to R super quick imagine backing up to a camper an having to going back an extra 2 inches and then going back into park and that was the first time I experienced that in this truck
but this was also the first time I drove the truck after it got broken into at the mechanic shop It

I also thought it could’ve even been a damaged portion of the parking pawl or something in the transfer case, but none of it ever quite fit what I was experiencing

You might not realize this being new here but he is the Almighty staff member. Infact, he owns the forum. So, best not poke the bear of you want to stick around. You are pulling on a very short string.

 

[TheBac]

OK, thank you , Almighty staff member

And TheBac
I would’ve guessed the same thing, but I rebuilt both front and rear drive shafts and had them balanced and tested by two shops so I knew it wasn’t that

I ended up finding that issue while backing up to a camper,I threw the truck in reverse shifted normal backed up about 2 inches and threw it back into park and it shifted hard. Tried it again and did it again. Tried through the other gears and the same thing. But if you waited a while. and then shifted into park it would be not as bad or not at all . But It wasn’t like I was going from P to R super quick imagine backing up to a camper an having to going back an extra 2 inches and then going back into park and that was the first time I experienced that in this truck
but this was also the first time I drove the truck after it got broken into at the mechanic shop It

I also thought it could’ve even been a damaged portion of the parking pawl or something in the transfer case, but none of it ever quite fit what I was experiencing

When you rebuilt the D-shafts, did you change out the rear yoke for the newer nickel one or did you lube the splines of the original before reinstall?
If you'd ever seen the parking pawl inside an Allison, its not likely you could've damaged it. There are also built-in protections inside the trans that wont allow pawl to engage in certain circumstances.