Pros and cons to transmission fluid and filter change after 150k miles?

[Alan Smith]

Regarding my 2007 Gmc 2500hd 2wd. It has just over 160k. Is it still a good idea to do a trans service? 

[nominion]

If it has been serviced before and it is operating normally, you should be good with a drain, pan drop, filter changed, and refill. I personally would not do any type of flush.

 

If never serviced previously, there is always a chance you will experience some slipping after replacing the fluid once the fluid warms up. You might get away with adding a conditioner to the fluid if that does happen.  

 

I'd probably do it and see what happens, but that is just me. If it does slip after, it's probably time for a rebuild anyway. 

[KARNUT]

You will probably get a few different answers. On the half ton around that time period, the recommendation was 150K normal service. Id check the manual see what the service is recommended. See what the factory fill was. It may have been synthetic. I personally wouldn't do flush. I'd drop the pan. Depending on the color and smell I'd probably do a dipstick exchange from there after some miles.

 

[diyer2]

28 minutes ago, KARNUT said:

You will probably get a few different answers. On the half ton around that time period, the recommendation was 150K normal service. Id check the manual see what the service is recommended. See what the factory fill was. It may have been synthetic. I personally wouldn't do flush. I'd drop the pan. Depending on the color and smell I'd probably do a dipstick exchange from there after some miles.

 

Agree

[jay webb]

issue with the pan drop and filter change is you only change out the amount of fluid that is in the pan. typically 6-8qts. the trans holds 12-16qts. so not all of the fluid is new. 

 

but it shouldnt cause any issues with in the trans. if you already are having issues this is not going to correct them. 

 

as far as the flush that some one else recommended against. not true typically the "flush" aka fluid exchange machines that are used ( that i use at the shop i work at) use the trans pump to exchange the fluid. you connect the machine in series to the trans via cooler lines. and with the truck at normal temp running the pump will pump out the fluid in the trans and suck in the new fluid. this is typically the best way to exchange the fluid. no matter what you do you will never get all of the fluid. but a fluid exchange service will get most of it. 

 

also if this is an Alison trans it has an external filter as well ( looks like a normal oil filter ) replace this as well.  

[mookdoc6]

1 hour ago, jay webb said:

issue with the pan drop and filter change is you only change out the amount of fluid that is in the pan. typically 6-8qts. the trans holds 12-16qts. so not all of the fluid is new. 

 

but it shouldnt cause any issues with in the trans. if you already are having issues this is not going to correct them. 

 

as far as the flush that some one else recommended against. not true typically the "flush" aka fluid exchange machines that are used ( that i use at the shop i work at) use the trans pump to exchange the fluid. you connect the machine in series to the trans via cooler lines. and with the truck at normal temp running the pump will pump out the fluid in the trans and suck in the new fluid. this is typically the best way to exchange the fluid. no matter what you do you will never get all of the fluid. but a fluid exchange service will get most of it. 

 

also if this is an Alison trans it has an external filter as well ( looks like a normal oil filter ) replace this as well.  

Yup!  I have this exact service performed on my 8L90.  Just had it done 1week ago....As always absolutely no issues!  If I had no idea of vehicle service and had High mileage I would pan drop, run it for a week and pan drop again call it good.

[Black02Silverado]

6 hours ago, KARNUT said:

You will probably get a few different answers. On the half ton around that time period, the recommendation was 150K normal service. Id check the manual see what the service is recommended. See what the factory fill was. It may have been synthetic. I personally wouldn't do flush. I'd drop the pan. Depending on the color and smell I'd probably do a dipstick exchange from there after some miles.

 

This