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Got 3750 miles on the c8 going on a year so figured do an oil change. While I was at it I figured do the external dct filter.wouldnt hurt.
Filter did definitely look fairly dirty so peace of mind glad I did it.
I’ll do it again on there dime and I think I’ll be good for awhile and replace fluid.
below are pics if interested
Wise decision. This is your car - you don't have to answer to anyone for how you maintain it.
I changed my DCT filter several times and cut each one of them open. I posted this a couple times - you and others can find it by doing a simple search. I would caution you to have the dealership perform the hydraulic system flush at 7500 miles on a NEW filter. This means first removing the filter in service on your car, installing a new one, performing the flush on this new filter then discarding this filter and replacing it with a new one again. The HSF will push what the filter has trapped back into circulation if the filter is restrictive enough to open the bypass. And it does not take much to push that tiny filter into bypass. Whatever they charge you at the dealership to swap a new filter for the HSF will be worth it.
^^^^
Yep everyone is entitled to do as they wish BUT IMO, smarter, depending on miles driven, to take advantage of GM FREE service year one. As the GM procedure specifies the FLUSH is done BEFORE the filter is removed. Then that early wear-in debris is removed, flushed into the filter housing and when the ~8 oz of fluid in the housing and filter are removed - debris is removed!
Yep, you are correct if waiting until the required change at 7500 miles, the filter could be clogged and the two filter approach you outlined is recommended. BUT like all mechanical wear-in the bulk occurs in the first 1000 miles or so. As I did with my 2020 C8 Z51 I'll have my E-Ray GM free service year one, this coming January when my OLM will show my engine oil must be changed. Like my 2020 C8 will have ~3000 miles. IMO if you have over ~1500 miles smart to do. This is why.
A key reason I will use the Free service year one is:
There were a number of posts where with relatively few miles folks go a DCT CEL. When the dealer told GM Service the CEL Code they were told to perform a FLUSH. NO NEW DCT filter, NO new fluid JUST A FLUSH. In many cases CEL was gone and did not return
I had observed in the 1st ~1000 miles as I crawled into my garage at ~2 mph controlling my easy to see drivers mirror tip to wood door molding to about an inch (so passenger side easily cleared) it was a bit jerky. I attribute that to the multiplate 1st gear clutch wearing in as it was slipping. It has to slip below 4/5 mph OR the engine would stall. After >1000 miles it was smooth. IMO high spots on the multiplate clutch were removed. Good to get that stuff out. FLUSH helps that process.
At year 3 with ~8000 miles I had a new DCT filter with FLUSH FIRST and as required all DCT Fluid replace. The DCT is NOT like an engine, where blowby, cold start caused water etc to go into the oil and create contamination. Once that initial wear is removed the filter should easily deal with minor ongoing wear. BUT if you want to change often your prerogative.
DCT is essentially Two 4 speed standard transmissions, little mechanical wear after the initial ~1000 miles.
The concentric multiplate clutch's do have some wear but Tadge said they should last the life of the car.
