Anyone Here Swapped Auto Trans to 3 Speed?

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doc540

doc540

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I'm looking into converting my '61 Lancer from A904 to factory three speed floor shifter system. (starting to look for parts)

Is there an existing link on such a conversion or has anyone here done it?

Thanks
 
Here's to hoping that your existing crank has the pilot bushing already installed!!!...
 
The back end of the crankshaft needs a pilot bearing for manual transmissions. The tip of the 'snout' on the manual transmission fits into that bearing. I assume that is to help locate and support the front of the transmission so that there is no movement during clutch engagement. Sometimes crankshafts in engines that were destined for an automatic transmission had a hole where a pilot bearing could be placed. In that case, you can easily put one in. However, sometimes, on cars with automatics, the back of the crankshaft is flat and will need to be machined for pilot bearing installation. Hopefully that is not the case for you, because that would require crankshaft removal. Your crank could also already have a pilot bearing in it. When I converted my factory 340 automatic Barracuda to a 4-speed, the crank already had a pilot bearing in it; so yours may already have one in it. Then you will have the fun of taking out the Automatic tranny brake pedal and putting in the manual transmission pedals (brake and clutch). you will need to cut a hole in the floor, and you will need to install clutch linkage, bell housing and clutch. It is a lot of work, but if you are a descent shade tree mechanic, you can do it.
 
harrisonm said:
The back end of the crankshaft needs a pilot bearing for manual transmissions. The tip of the 'snout' on the manual transmission fits into that bearing. I assume that is to help locate and support the front of the transmission so that there is no movement during clutch engagement. Sometimes crankshafts in engines that were destined for an automatic transmission had a hole where a pilot bearing could be placed. In that case, you can easily put one in. However, sometimes, on cars with automatics, the back of the crankshaft is flat and will need to be machined for pilot bearing installation. Hopefully that is not the case for you, because that would require crankshaft removal. Your crank could also already have a pilot bearing in it. When I converted my factory 340 automatic Barracuda to a 4-speed, the crank already had a pilot bearing in it; so yours may already have one in it. Then you will have the fun of taking out the Automatic tranny brake pedal and putting in the manual transmission pedals (brake and clutch). you will need to cut a hole in the floor, and you will need to install clutch linkage, bell housing and clutch. It is a lot of work, but if you are a descent shade tree mechanic, you can do it.
Click to expand...

Well my friend, you are partially right, the pilot for manually shifted transmissions is not a bearing, it is a brass bushing that the front snout fits in on the back of the crank! Most every crank I've seen is drilled for machining in the rear, but not all of them are reamed for the pilot bushing! Of course, nowadays, there's a way around that! 2 options here....either get a brass bushing and have the outer diameter turned down to slightly over the size of the unreamed hole and put it in the freezer for a bit before tapping it in, or they make a pilot bearing that fits into the torque converter snout recess in the crank and negates the need for the bushing! Trouble with the bearing route is that I do t believe it is made for the 66 and earlier crank recess for the torque converter snout, which is smaller than that of 67 and later small blocks!!

Pic with no bushing installed!
 

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Aww man! Sucks to live in Beaumont,Texas.
904s are about as simple as it gets. If your local shop can't handle it, I gotta wonder what else they can't handle.

In this case, I just don't see the swap as being viable. I read between the lines and take it that you may not have the skills to want to dig into it yourself, but I tell you what; there are several of us here that have plenty of experience with this gem. And if you can throw pictures at us I'm pretty sure we (as a team with you doing the wrenching) can get that 904 humming down the road the way it should. Besides, what do you have to lose,cuz as it stands;that 904 gonna be an expensive doorstop.
 
AJ/FormS said:
Aww man! Sucks to live in Beaumont,Texas.
904s are about as simple as it gets. If your local shop can't handle it, I gotta wonder what else they can't handle.

In this case, I just don't see the swap as being viable. I read between the lines and take it that you may not have the skills to want to dig into it yourself, but I tell you what; there are several of us here that have plenty of experience with this gem. And if you can throw pictures at us I'm pretty sure we (as a team with you doing the wrenching) can get that 904 humming down the road the way it should. Besides, what do you have to lose,cuz as it stands;that 904 gonna be an expensive doorstop.
Click to expand...

Thanks

Top shop in the area said they had plenty of experience with early 904's. Everyone else in town recommended them.

They rebuilt it, and during the test drive it rolled the sprag.

They rebuilt it again, changed out the converter, and put in a sprag kit (all on their dime).

Rolled the sprag again within 30 miles.

Now I'm plum fed up with the overall state of affairs.:banghead:
 
Me and my big mouth! :(
Their dime? OK, I take back what I said. Maybe they're the good guys.
In nearly 40 years,I've never seen a street 904 do that.
From what rpm was the neutral drop done, and what's in front of it, and just how hard does it hook? lol.
Any pics of the carnage?
 
AJ/FormS said:
Me and my big mouth! :(
Their dime? OK, I take back what I said. Maybe they're the good guys.
In nearly 40 years,I've never seen a street 904 do that.
From what rpm was the neutral drop done, and what's in front of it, and just how hard does it hook? lol.
Any pics of the carnage?
Click to expand...

Neutral drop was done at low rpm after letting the engine warm and idle drop.

.030 Slant 225 with Sig Erson cam, Clifford intake and headers, Holley 390.

Drive it like a granny.

20151128_131908_zpshabmgdli.jpg
 
I can see your problem from here. It's the MSD. I heard they're good for over 1000hp! heehee

Getting back to "rolling a sprag". I fail to understand how that is possible in a 904. Oh wait, is that a 904 with a rear pump? Sorry, I've never had one of those apart. I have one in my shed somewhere, but it's buried, so I cannot take a look right now to see how it's built back there, compared to the later bolt-in sprags.The non-rear pumps have the sprague cam bolted in with 7 little bolts.The parts are very robust for the job they need to do.IIRC tho, the pump is on the back-side of the case, in the extension housing, so the sprague area should be the same or similar. ok I'm off to Google
Yup that's right;pump is on the back.
Sprague failure, in your case, should be impossible.
 
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