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Newer Auto Swap?
https://www.slantsix.org/forum/viewtopic.php?t=22896		 Page 1 of 1
Author:  stuggin [ Wed Apr 25, 2007 11:26 pm ]
Post subject:  Newer Auto Swap?
Hey y'all,
So i was searching through the forums but i can't seem to find an answer so here it goes:
I was wondering if there was a transmission swap that i could do from my A904 ('62 vintage) to a later automatic transmission that will:
- have part throttle kickdown and
- net me better fuel economy (and maybe make a little less engine noise) ie lower RPM's
From what i have come up with the lockup A904's would have both these features, but how hard would this be to retrofit to my system (pushbutton)? I understand the Imperial conversion is the way to go?
Also, I don't like the idea of flipping a switch for the electronic lockup on and off (as i know that i will forget to do it on a regular basis), is there anyway that i can get around that?
Thanks,
Allen
Author:  Charrlie_S [ Thu Apr 26, 2007 4:50 am ]
Post subject: 
The 62 engine has a small pilot hole in the end of the crank. The lock up converters have a large pilot "nub". They will not fit. I don't think you can get a custom built lockup converter, with the small pilot. You could call some converter builders to check.
Author:  SlantSixDan [ Thu Apr 26, 2007 8:00 am ]
Post subject:  Re: Newer Auto Swap?
You'd have to do a fair amount of custom work (and spend a fair amount of money) to make a lockup 904 (or any '66-up 904, for that matter) fit and work in your '62. There's the pushbutton conversion to worry about (expensive and a long wait for turnaround), you'll need a new driveshaft, some floor mods for clearance, a custom torque converter (which I'm not sure can be made with lockup!) to adapt your small-pilot pre-'67 crank to the large-input '68-up transmission. It seems to me there are much less difficult, less costly, and less invasive means of achieving what you want. Pat Blais ( tflitepatty@verizon.net ) has been working on a quality-engineered way of adding part-throttle downshift to the '60-'65 Torqueflites. I haven't checked progress in awhile, but last time I asked in on it, the mods had all been figured out and it was just a matter of machining some valve body parts. This has been done before, on a one-off basis, by adding some external fluid feed pipes to the valve body. As for lower RPMs on the highway, the easiest and least-invasive way to achieve that is with a taller-ratio rear axle assembly. Many of the early cars came equipped with 3.23s or 3.55s; a 2.76 unit is perfectly well suited to these lightweight early A-bodies as long as your engine isn't sick and tired, and since 2.76 came as standard equipment starting in '68, that is the most commonly available ratio on the used-rear-axle market. But you may not even need to swap the rear axle assembly. Depending on what the present ratio is (probably 3.23, but might be 2.93 in a late-production '62), you may be able to achieve the RPM drop you seek simply by going to larger wheels and tires, which will give additional benefits in ride and handling. What size wheels and tires have you got now?

A locking torque converter will drop the highway RPMs only slightly (about 5%), but if you plough ahead with the lockup trans changeover, you won't have to worry about electrics. The lockup is controlled hydromechanically on all but the last couple years' slant-6 truck transmissions.
Author:  stuggin [ Thu Apr 26, 2007 11:41 am ]
Post subject: 
Erm well off the top of my head i think the tires are 80mm sidewall and the wheels are the 13" stock ones. I want to upgrade to some custom 17's though when i do the disc brakes. If my wheel/tire combination increases in diameter I'm probably going to have to get my speedo re-calibrated, right?
I know that a higher ratio rearend will do the trick but the thing is most of my driving is in the city and i like the performance that the little 170's giving me right now, so i'm reluctant to change the rearend if just for the occasional roadtrip.
Thanks,
Allen
Author:  SlantSixDan [ Thu Apr 26, 2007 12:03 pm ]
Post subject: 
Quote:
Erm well off the top of my head i think the tires are 80mm sidewall and the wheels are the 13" stock ones.
P205/70R14s on 14" wheels will help a lot
Quote:
I want to upgrade to some custom 17's
Yo-yo-ghetto-yo. Image
Quote:
If my wheel/tire combination increases in diameter I'm probably going to have to get my speedo re-calibrated, right?
Yep...you'd need a different speedometer drive pinion.
Quote:
I know that a higher ratio rearend will do the trick but the thing is most of my driving is in the city and i like the performance that the little 170's giving me right now
Ahhhh...a 170. OK, thought we were talking about a 225. Yeah, I would say 3.23s with a 170. But a locking torque converter still isn't going to give you a big reduction in engine RPMs on the highway.
Author:  slantvaliant [ Thu Apr 26, 2007 3:11 pm ]
Post subject: 
Quote:
... i think the tires are 80mm sidewall and the wheels are the 13" stock ones. ...
.

Perhaps you mean 80-series (aspect ratio), as in 185/80R13? That would be a sidewall height 80% of the section width.
Reading Tire Size
Author:  stuggin [ Thu Apr 26, 2007 5:11 pm ]
Post subject: 
Quote:
Perhaps you mean 80-series (aspect ratio)
Bingo, yeah definitely meant that.
Quote:
Yo-yo-ghetto-yo.
Different strokes for different folks, Dan. Besides its not like I'm gonna put hydraulics on it and gold-plated A-arms or anything like that. The ones i got in mind are gonna look slammin.

-Allen
Author:  dakight [ Thu Apr 26, 2007 6:09 pm ]
Post subject: 
17s aren't so bad. Not my cup o' tea but not totally outlandish either. I'm going to 15s because there is simply a wider choice of tires and wheels at a manageable cost than any other size.
Author:  Romeo Furio [ Fri Apr 27, 2007 6:08 am ]
Post subject:  newer auto swap
Hughes Transmissions built me a small pilot locking converter for a 904.
Stalls around 18 to 2200 rpm (depends on how much HP is in front of it).The converter hydraulically locks with no trans internal mods.
The trans had a low gear set and front pump installed from a later model with the larger input shaft. The price of the converter was 300 bucks 8 years ago. Still working great.I just called them up and told them what the plan was. The converter was shipped with in a week.
Author:  stuggin [ Sun Apr 29, 2007 11:54 am ]
Post subject: 
Author:  Doc [ Mon Apr 30, 2007 1:33 pm ]
Post subject: 
I wonder if a 66 VB casting will also work?
1966 was the first year for the single pump, machanical linkage, slide-in rear yoke 904.
DD
Author:  Doc [ Mon Apr 30, 2007 1:36 pm ]
Post subject: 
Quote:
I wonder if a 66 VB casting will also work? (it looks like that year was intentially pass-over) :?:
1966 was the first year for the single pump, machanical linkage, slide-in rear yoke 904.
DD
Author:  stuggin [ Mon Apr 30, 2007 5:38 pm ]
Post subject: 
Lookin' into it as we speak, just sent Pat another email.
Author:  stuggin [ Wed May 02, 2007 2:48 pm ]
Post subject: 
Pat says:
"The 1966 and early 1967 valve bodies do not have the hydraulic feed passage necessary to ad on the part-throttle accessory; late 1967 is when Chrysler changed the valve bodies to accommodate the accessory. The attached picture shows the feed hole in the upper casting after the cover plate is removed; it’s the small hole slightly above and to your left slightly from the smaller spring sticking out."

Image

-Allen
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