Engine mounts should have RH & LH stamped on them

 

This truck is full of surprises, turns out it's an FMX tranny not a C4. I pulled the tranny today (and it took forever!), once we got it in the shop I started following the Haynes automatic transmission book for tear down, and many things seemed different. I got to point of pulling off the pan and comparing it with the rebuild kit I got, and well..nothing matches. After doing a google search on the tag, it appears to be an FMX. Crap.

So at this point, I'm thinking of picking up a used c4 from the junkyard or craigslist, and rebuilding that, instead of rebuilding the FMX. Is there any great reason to keep & rebuild a totally shot FMX transmission?

 

The FMX is a unique beast, no doubt, but it isn't something you would want to scrap or throw away.

It would be about the middle between a C4 and a C6 in terms of strength. The downside is getting parts for an FMX. Regular rebuild kits are easy, but hard parts can be a chore.

Either way, I am sure Broader Performance can hook you up with a kit and have you motoring away in no time.

Broader Performance Home Page

Josh

 

Thanks for the link. It's my understanding that the FMX is not a good transmission for a beginner to rebuild, so I called two shops and both quoted me $900-$1800 depending on what was worn, with the caveat that certain 'hard parts' are almost impossible to find. The rebuild price is out of my current budget, and it may be months before I could afford it.

My local salvage yard, which has treated me well on previous projects, quoted me a price of $300 for a C6 with all the parts I need (torque converter, driveshaft) and a 3 month warranty. He may be able to find a FMX, but doesn't know of any available now.

I think I'd prefer to get a C4 or FMX over a C6, as I'm worried about the parasitic losses of a C6, and I don't do any towing, but all the places I talked to were emphatic about getting a C6 over any other option.

I'd like to get the truck back on the road asap and as cheap as possible (acap?), and have a good daily driver (better mileage is more important that towing ability) without going through a lot of modifications to get it there.

With all that in mind, what would you suggest?

 

Well, you have people trying to rip you off, no doubt about that. You can get a coupletely rebuilt FMX including shipping from Texas for $700 from Broader Performance.

A standard rebuild (seals, gaskets, clutches, pump and misc) should only be $400 give or take, and that includes labor. Doesn't matter if it's a C4, C6 or FMX.

As for the whole C6 versus C4. It is an old wive's tale that a C6 causes that much more losses in power. There are several racers that have gone from a standard C6 to a built, full roller C4 and noticed NO additional speed or decrease in ET.

Besides the fact the C6 is bomb proof stock. No need for fancy clutches or shift kits.

I would never re-use a torque convertor BTW. Who knows what kind of garbage could be in there and they are impossible to clean without a complete tear down.

Shouldn't need a different driveshaft between the C6 and FMX either. And even then, you would only need the intermediate "short" shaft and not the whole 2 piece driveshaft.

Josh

Josh

Josh