1986 TH400 w/ 78K - Any precautions or tips?

[sw99]

Only 78K miles on my 86 K30 with the TH400 transmission. Not sure how well the PO maintained so I am looking for suggestions. Drop the pan and refill or ??

 

[The_Eric]

Change the fluid and go. They're a tough unit.

 

[eagle23]

You're probably fine on just the drain and refill. They're tough as nails, but I understand your concern for the age of the fluid.

Maybe consider installing a drain plug (if it doesn't have one) on the pan while it's off for easier future drains? That's strictly optional but can make draining/refilling really easy.

 

[artificialist]

Dropping the pan and replacing the filter is fine. When buying a new pan gasket, use rubber gaskets, never use cork gaskets.

A transmission flush is even better. It is also a great opportunity to replace the Dexron III with Dexron VI.

 

[sw99]

I like the pan drop more than the flush. Transmission shifts pretty nice. Going into reverse is a bit rough. Lots of oil and grease on the under side of the engine and transmission though.

Thanks folks!

 

[RF Overlord]

Just throwing this out there.

I had a 1968 TH400 from a Buick Electra rebuilt and put into my 1968 Skylark Convertible in about 1979. The rebuilder recommended I use Ford Type F and I have ever since. The thing shifts crisply when I treat it gently and snaps my neck when I lean on it.

FWIW, I should have gone with a TH350...the gear ratios are more compatible with the 350-4bbl engine.