TH400, 125K on it, behind a 454. Never had a problem shifting/slipping at all until this week. Now after towing a trailer into the mountains it's slipping. Probably the obvious answer that I fried it. Didn't really go up any huge hills and it was only an hour and 15 min trip.
Symptoms now are slippage pretty bad in 1st and 2nd. Put it to the floor engine sounds fine but not picking up speed anywhere near as fast as I should. Seems to shift kinda hard also.
So my questions:
First, is there anything simple I can check? I checked the fluid already and it didn't smell burnt and was at the right level. Should I get a gauge and check the line pressure? If so what kind of gauge(what size end) will thread to the port on the tranny? Do I also need a vacuum gauge to check the modulator? If so what should it read? Is it worth dropping the pan and changing the filter? It had a tranny service about 2k ago with a filter change. No metal shavings in the pan then.
If I'm just totally screwed here, any recommendations on replacement? Suck it up and go to the dealer? Will they warranty it if I put it in(yes I've replaced engines/trannies before and have the equipment to do it). Am I better off finding a good shop and just having them rebuild it? If so anyone know any good shops in the albany ny area?
Thanks in advance, Ed