Transmission service?

[2003ChevyTahoeZ71]

Hi everyone, I have a 2003 Z71 Tahoe with 284k on it and just had to replace the factory trans with a used one that had 160k on it. Shop put fresh fluid in and new filter and I put a can of BG in it.

My question is should I have the trans services and flushed with fresh fluid, filter, and bg put into it after a certain amount of miles? Or just leave it as is?

 

[Tonyrodz]

Hi everyone, I have a 2003 Z71 Tahoe with 284k on it and just had to replace the factory trans with a used one that had 160k on it. Shop put fresh fluid in and new filter and I put a can of BG in it.

My question is should I have the trans services and flushed with fresh fluid, filter, and bg put into it after a certain amount of miles? Or just leave it as is?

Me personally, with a used trans with that many miles, I'd put fresh fluid in and a filter and leave it. These transmissions aren't known for longevity. Did they even check it out internally? While it was out. Just to make sure it wasn't gonna take a dump on you in a week.

 

[Chubbs]

I don't think it's a good idea to use any cleaning solvents or flushing exercise with a high mileage trans, period. Flushing and/or stripping contaminants usually ends up in failure of the unit, especially if the regular maintenance intervals were never met. I have to assume that you do not know the service history of the newly acquired trans so I suggest draining the the contents and refilling with straight dex6 only to clear out the BG cleaner or whatever it is. You can either dump the pan or pull the return pipe and pump the contents out under engine power but kill the engine BEFORE complete evacuation so that you don't run the pump dry. Maybe read up on that procedure; not something you want to do blindly. If dumping the pan only, over half of the original fill is retained in the system, including a high concentration of whatever additives that were used.

Or you could just go with you got & don't look back but def no machine or solvent flush where pressure and additional chemicals are used. I'm no consumer of commercial transmission flush but I have read up on it.

 

[UrbanSuburban]

I am really impressed that you were able to get that many miles on the original tranny without a rebuild. You should put that one into the Smithsonian. While it would run counter to commonsense, putting fresh oil into the second tranny is really only hastening the removal of varnish and all the material that keeps the tranny working. As was said above, these trannies do not have a long life, Your first one notwithstanding. Did they replace the Torque Converter as well? I hope it lasts for you. Cheers

 

[Rocket Man]

By "BG" are you referring to their Conditioner? If so, and considering that at 160k on the replacement trans it's already at the end of any expected life, leave it. The new fluid should easily outlive the trans. I'd be looking at getting another trans rebuilt and ready because 150k is about when a 4l60 usually goes out.