A904 Torqueflite Questions

[chasetepher]

Hello! I suppose I'm new here but I've been around Mitsu's for ages now. I've got a 90 Mighty Max with a narrow 63 swap, and until a few months ago, a 5 speed D50 transmission. Long story short, the driveshaft took a dump and with it went the bellhousing on the manual. Thankfully I've got an A904 from an 83-86 Max/D50 in the garage that I was waiting to use when we got more serious about racing, but it seems like a sign.<br><br>What I don't have is a torque converter or flexplate. I've read in another thread that the auto trans from the narrow 2.0 was the same as the auto from the narrow 2.6. Does this mean I don't need a 2.0 specific TC/flex plate? Because I can't find anything that shows to be 2.0 specific. IF, this is true, I assume the starter and starter plate are interchangeable too.<br><br>Thanks for any info! Sorry for the novel :/

[chasetepher]

Formatting is hard?


Hello! I suppose I'm new here but I've been around Mitsu's for ages now. I've got a 90 Mighty Max with a narrow 63 swap, and until a few months ago, a 5 speed D50 transmission. Long story short, the driveshaft took a dump and with it went the bellhousing on the manual. Thankfully I've got an A904 from an 83-86 Max/D50 in the garage that I was waiting to use when we got more serious about racing, but it seems like a sign.

What I don't have is a torque converter or flexplate. I've read in another thread that the auto trans from the narrow 2.0 was the same as the auto from the narrow 2.6. Does this mean I don't need a 2.0 specific TC/flex plate? Because I can't find anything that shows to be 2.0 specific. IF, this is true, I assume the starter and starter plate are interchangeable too.

Thanks for any info! Sorry for the novel :/

[geezer101]

I'll say yes, the flex plate should work. The question is - will the TC work as well? If the parts were both sourced from A904 optioned drivetrains then it'll be yes. With a bit of luck the TC from a 2.6 should work well with a turbo'd 2 litre. Next question will be - how does the kickdown on your A904 work? This might be the tricky part to get around. You will need the correct starter motor for that trans combo as well.

[chasetepher]

Thanks, that's good to hear! The kickdown shouldn't be an issue, it's a fully manual valvebody. I do have the correct starter and starter plate as well.

The parts stores have some cheap flexplates and converters, will probably pick one up to confirm it works and at least make it roll.

[pennyman1]

the narrow A904 autos are the same from 79 - 86 on both 2.0 g52b, g63b and g54b 2.6. There are also flexplates on ebay - they are 6 bolt, with a alignment hole for the 86 2.6 auto. some people show an 8 bolt flexplate for our trucks, but they are for the American a904 - our 904s are really an Aisin-warner "baby" 904, licensed from Chrysler.

[geezer101]

The A904 is a half decent auto trans for a 4 cylinder but it won't hold up to pushing big numbers through it. I'd say the A904 will like 200-250 hp but will go into self destruct mode once you reach 350 hp. If you can get your rear ratios right it will launch like a bullet :grin:

[chasetepher]

I was wondering about those 8 bolt flexplates! I figured they were just for 318's and 360's and such. V8 mowters only. I think I might call around for a mild stall on the converter, not sure that anybody offers a "performance" option.

Thanks geezer! This is actually a built transmission, supposed to be good for 800-1000. Probably won't be there anytime soon so I think it should last. I'm thinking it should launch and shift a whole lot better than the five speed! Rear end is an 8.8 with 3.55 so we'll see what that ratio does.

[geezer101]

Part of the issue with the A904 is hp - the other part is torque delivery. If you're running a turbo set up that comes onto boost narrow and fast, it will stress the hell out of it. But seeming you've built one up to the task, pushing 4-500 hp through it should be a walk in the park. :thumbup:

[chasetepher]

Yup, it's a baby turbo right now, but we just want to work out the kinks in the whole truck before we step up the power. It ran an 11.7 many years ago with a five speed and 440hp/550tq, kinda curious how little power I'd need in the auto to beat that lol.

Picking up a flex plate from a parts store tonight, will see if it fits. Haven't ordered a tc yet, was thinking I might give these guys a call. http://www.floridatorqueconverters.com/transmissions-dodge-904.html

[chasetepher]

Parts store flexplate doesn't fit. It's 83-86 2.6 but it didn't even clear the bellhousing. Diameter was 11.75 in so I need something that's not that. Apparently.

[geezer101]

That would've sucked if you'd bolted it all together and tried mating the engine and trans (please tell us you didn't have to go that far...)

[chasetepher]

Thankfully, no! I was already skeptical so I just held it up to the bellhousing, didn't clear at all.

Starting to think that the 2.0 and 2.6 A904 were not the same.

[haruman]

Took me two years to find the flexplate for my baby904 & 2.0 engine. Good luck. :shock:

[chasetepher]

Haha, that's reassuring. Where'd you find one? I may have a lead on a complete setup pulled out of a junkyard.

[haruman]

Haha, that's reassuring. Where'd you find one? I may have a lead on a complete setup pulled out of a junkyard.

Ended up getting one from a member on here, actually.

[chasetepher]

That's pretty much what I figured.

Should be picking up the complete setup in a few weeks so I'll report back then if I get that hot manual valvebody action going.