Three to Four Speed Trans Swap Questions?

[BrianT]

I bought an A body four speed out of a 69 Dart to put into my Duster. It currently has a 318 with a factory three speed on the floor. I was wondering how many of the original parts can be retained?

The clutch and pressure plate are fairly new and the flywheel was resurfaced by the previous owner. Will the new transmission just slide in place of the three speed?

What about my driveshaft? I will slide underneath later and measure the three speed, but I was hoping that someone would know the lengths of these two transmission. If I need to have the driveshaft shortened, I have a local truck shop that builds reasonably priced driveshafts.

Thanks to any manual experts that could chime in and help? Pics because EVERYONE loves pics.

 

[RustyRatRod]

If you have an A230 3 speed with a similar side cover to the A833, the swap will be pretty easy. You will however, need a four speed bellhousing to match the current flywheel size.

 

[BrianT]

If you have an A230 3 speed with a similar side cover to the A833, the swap will be pretty easy. You will however, need a four speed bellhousing to match the current flywheel size.

So there IS a difference between the three speed and four speed bellhousing? I did not realize that. Thanks

 

[YY1]

You don't need a 4 speed shifter?

 

[RustyRatRod]

So there IS a difference between the three speed and four speed bellhousing? I did not realize that. Thanks

Yes. Trans side bolt patterns are different.

 

[BrianT]

You don't need a 4 speed shifter?

Look at the second pic in the first post.

 

[BrianT]

I have another aluminum bellhousing but I think it was out of a pick up. I'll have to drag it out today and see if I can get some numbers off of it.

 

[Murray]

Some bel housings are dual pattern as 3 and 4sp are different. See what you have. Also the throwout bearing collars may be different sizes, check your bel housing.

 

[Professor Fate]

You didn't say what year your car is, but it has to be '70 or later since it's a Duster... and as such, it should already have the dual-pattern bellhousing. Three speeds never came with the oddball overdrive bellhousing with the oversize retainer bore, so you should be good there, too. EVERYTHING you have will bolt up, with the exception of the driveshaft. The three and '68 and later four speeds use different slip yokes (3 speed has a smaller diameter output shaft with fewer splines than the 4 speed).
Deal with that and you should be good to go. Swap the speedometer drive gear from the 3 to the 4 speed to keep your speedo accurate.

 

[BrianT]

Thanks! I'll check that out later today. I'll still need a yoke for the driveshaft though. According to Brewer's, the A body four speeds take the 30 spline yoke? It looks like they have them in stock.

 

[413]

Here is a 2892482 and it has both bolt patterns To fit 3 and 4 speeds. So you may have a dual pattern bell in the car already.

 

[YY1]

Look at the second pic in the first post.

But you're gonna give me a red X instead of saying "I already have one"?

Thanks.

 

[BrianT]

But you're gonna give me a red X instead of saying "I already have one"?

Thanks.

I deleted it once I replied?

 

[Dan Brewer]

Your Duster has an A230 3speed in there now, it will be the same bell/clutch/flywheel. Change the trans & shifter, you will also need to change the yoke on the driveshaft from 26 spline to 30 spline. Length should be good.

 

[BrianT]

Thanks @Dan Brewer