Looks like I'm gonna do a tranny swap. The 904 automatic in my '73 Valiant is starting to have trouble switching into second gear. Not a huge surprise... I estimate this tranny probably has well over 300K miles on it and I have no idea how previous owners treated it.

The good news is, I have two other 904's in my garage. I believe that both are from '72 cars and probably have much less mileage on them. I was planning on replacing my leaky rear main seal anyways, so might as well kill two birds.

Both spare trannies have been sitting for several years, so here's my question: What should I do to prepare for a swap? I've never done one before. Can anyone give me a quick checklist of things I should do before throwing one of these on my car? I assume I should remove the pan and check it over and change fluid... but I don't really know what to look for in there. Are there items that I should replace? Not looking to do a rebuild or anything...

Thanks for your advice!

-Matt

before changing the trans,try adjusting the kickdown (second gear band) per the correct year service manual. there might be another 100,000 trouble- free miles in the trans you already have in the car.

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V8?? We don't need no stink'n V8!!

Hey Bigslant6fan, thanks for the advice. I'll definitely look into it because either way I'll be probably be stuck with this trans for another month or so.

But, I'd still like to prepare for a swap because this is mostly only happening when the tranny is all warmed up which is leading me to believe something inside is gummed up. Fluids are right where they should be.

Thanks!

-Matt

With the age an mileage of the trans I wouldn't be surprised if the pump were getting worn and there was internal leakage. I'd pressure test it to confirm.

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Joshua

Hey Joshua, thanks. I'll check my service manual and see if I can find instructions on that.

I might not have been clear in my original post. I'm not really looking for advice on pinpointing the problem in my current transmission (although I'm certainly not opposed to it)... I'm more interested in hearing what you guys would check on a tranny that's been sitting for a while. The one I will probably put in my car has been sitting almost a decade!!

What are the most important things to look at? I plan on taking off the pan and making sure things look clean. I'll replace the filter. Is there anything else I should do to spruce it up before it goes on the car?

THANKS!!

-Matt

Just make sure you don't get dirt in the cooler lines and with fresh fluid and filter it should be fine. Oh and do a new front pump seal for sure and eyeball the front pump bushing while the seal is out.

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Joshua

Thanks Joshua, really appreciate the advice!!!