Chevy and GMC Duramax Diesel Forum banner
  • Hey Everyone! Enter your ride HERE to be a part of this months Ride of the Month Challenge!
1 - 8 of 8 Posts

·
Registered
Joined
·
33 Posts
Discussion Starter · #1 ·
First of all, the link in the sticky for the Allison transmission fluid intervals is broken. I own a 2017 2500HD L5P.

I talked to a diesel mechanic shop owner that told me "at 70,000 miles I wouldn't change the transmission fluid because it will do more harm than good". He then said "If you dont change it around 50k, then its not worth changing because of the risk." Basically saying that the mileage was too high and it would hurt the trans / cause it to slip. Didn't make a whole lot of sense to me as 70k is basically nothing for these diesel trucks but I wanted to ask anyway before I did something to harm my transmission and cost myself a lot of money.

I'm wanting to change the fluid because I bought the truck with 58k on it and don't know if its ever been changed. I want to do the double drain and fill method with TranSynd fluid and change the internal filter while I'm at it.

The transmission shifts fine aside from a the 4th or 5th gear (cant remember which) which shifts noticeably harder than the others but not like slam your head back harder, just a quick jerk.

Any thoughts on this?
 

·
Premium Member
Joined
·
3,601 Posts
Makes no sense to me either, unless he is referring to a transmission "flush", which can do more harm than good by stirring up dirt & debris in the trans.
 

·
Registered
2019 LTZ
Joined
·
94 Posts
First of all, the link in the sticky for the Allison transmission fluid intervals is broken. I own a 2017 2500HD L5P.

I talked to a diesel mechanic shop owner that told me "at 70,000 miles I wouldn't change the transmission fluid because it will do more harm than good". He then said "If you dont change it around 50k, then its not worth changing because of the risk." Basically saying that the mileage was too high and it would hurt the trans / cause it to slip. Didn't make a whole lot of sense to me as 70k is basically nothing for these diesel trucks but I wanted to ask anyway before I did something to harm my transmission and cost myself a lot of money.

I'm wanting to change the fluid because I bought the truck with 58k on it and don't know if its ever been changed. I want to do the double drain and fill method with TranSynd fluid and change the internal filter while I'm at it.

The transmission shifts fine aside from a the 4th or 5th gear (cant remember which) which shifts noticeably harder than the others but not like slam your head back harder, just a quick jerk.

Any thoughts on this?
I would dump it and change it with fresh along with a new external filter
 

·
Registered
2019 LTZ
Joined
·
94 Posts
The external trans filter is changed every other oil change along with the fuel filter.
I agree and follow that same schedule… I guess I just as just mentioning that at the time you dump your fluid it “might” be ok to screw in a new filter as well. Thank you for helping me with my advice 👍
 

·
Registered
Joined
·
33 Posts
Discussion Starter · #6 ·
I agree and follow that same schedule… I guess I just as just mentioning that at the time you dump your fluid it “might” be ok to screw in a new filter as well. Thank you for helping me with my advice 👍
Oh yeah of course. I will change everything when I change the fluid. Shoulda said it more clear.
 

·
Registered
Joined
·
1,882 Posts
I would use transynd as well.

Sent from my SM-N975U using Tapatalk
 
  • Like
Reactions: 2019LTZ
1 - 8 of 8 Posts
Top