My transmission is working perfectly. I’ve not done a transmission service in a long time or maybe never since I bought it ten years ago. I’ve reached the 200k miles with about 70k of those miles with me. Any thoughts on doing a service? I’ve heard, if you haven’t done it in such a long time/miles and it’s working fine, don’t mess with it…. Looking forward to your advice

 

Have you checked the condition of the fluid? The main concern with servicing a transmission that has not been messed with is stirring up the clutch material sitting in the bottom of the pan, and having it clog up some of the small passages or valves. You can always drain and fill the ZF. The filter is just a screen mesh so replacement is possible, but not necessary. Let me know if you have questions. I can walk you through a few scenarios.

 

The issue with replacing the transmission fluid at advanced mileage is that fresh fluid has lots of detergents in it and may dislodge the clutch lining material from the substrate. D2 transmissions rarely give trouble, I would not mess with it. I have three well over 230k with no issues.

 

I serviced mine . No harm has happened . But.....I did have one friend scorn me for doing it . He said it was hurtful to the transmission to drain all of the fluid out . Don't remember much else .

 

Extinct,
What do you mean when you say it may dislodge the clutch lining from the substrate? Are you saying the clutches will peel away from the steel plates they are bonded to? Most of the ones I have seen that peel off are due to heat. The main concern I have heard is material being dislodged from one location and either blocking orfices, passages, or valves. Although not impossible, I am not certain the detergents would have that much of a cleaning effect to dislodge much. Short story, I don't see any harm in a simple drain and fill. This only changes less that half the fluid anyway. Any thoughts?

 

Yes, long history of complete change dislodging whatever remaining material on clutch plates off of them, GM trans are particularly prone to this. Simple drain and fill will likely not do this but complete change there is some risk. The ZFHP2X is extremely durable however not prone to either mileage related failure nor fluid change related failure.

 

My understanding is that a piece of this is also that old fluid in a particularly worn transmission also still has the worn off clutch material floating around in it. Does not do bushings any favors, but does help older more worn clutches continue to grab leading to slipping when the fluid is changed.

 

Wow, all the replies were awesome. I think I am going to stay put, "If it ain't broke, don't fix it" kind of thing.... Thanks again everyone.....

 

Me, l'd pull the fill plug while not running, you will lose around three quarts. Start it up and refill, following manufacturers guidelines. Drive it for about 200/300 miles, then drop all of the fluid and filter and clean pan. It's kind of becoming the normal procedure for changing trans fluids on vehicles that have been neglected, and yes, 200K is neglected. The additive packages start breaking down, and that's why new fluid has to be introduced. But, if you do it in a two-step process...it does not "shock" the system. It introduces a little new fluid that mingles with the older fluid and slowly refreshen o-rings and seals in clutch hubs. Then, once the trans has adjusted to that...you change it all. There will always be some trans fluid in the torque convertor...unless you are having a flush done.