trans swap
 

I have been talking to a guy who has a 61 Cat convert. and would like to put a turbo 400 in it in place of the slim Jim. Any one here have any suggestions as to how to go about it and costs involved, This is an original 61 engine. :confused:

It's been discussed here a number of times, I would suggest doing a search - that said, the biggest problems are adapting the transmission to the engine (requires an adapter plate, available from Wilcap or Bendtsens) and using some sledgehammer therapy on the transmission tunnel to make space for the larger TH 400 transmission.

Stu is correct on the prior threads. However, I have personally put 400 thms in 2 61 Catalinas and have never had to touch the floorboards with a hammer or anything else.
Not sure why others apparantley have to beat their floors to make them fit and i do not.

The real problem is the adaptor. When I swapped the trans in, I also used a later engine and did not need to use an adaptor. There is little room getting the some of the bellhousing bolts. I can only imagine there being that much less room having to use an adaptor.
In my opinion, if anyone is going to go throught the time and cost to swap in a later trans and buy an adaptor, I would not use a 400thm, I would use a 700r4. You will reap the benefit of the lower first gear, similar to what the stock trans has, plus, you will have the 4th gear overdrive for better mileage and hiway cruising. On top of that, if you use the lock up converter, it drops the rpms down another 200-300 which, effectively acts as a 5th forward gear. It is hard to argue with the vitues of having '2' more forward gears and the very wide spread of gears on top of that.
Oh, the 61s that I did put the 400thms in, I later swapped them for 700r4s. :)

You could also locate a '65-'66 389 block and swap al your '61 389 parts on it if you wanted the original look. It would save you the adaptor costs and give you more room for the bellhousing bolts and let yo use the later starter as well.
Both of my 61 Catalinas have later engines with 700r4s now.

Those adapters mentioned from Wilcap and Bentsens are in the $700-800 range. A cheaper alternative would be to get this style plate from Butler performance for about $300 or have your own made from this drawing.

http://www.jbp-pontiac.com/products/...otorPlates.htm

High Bill I am the one looking to change my trans
Over to the 400. What I was wanting to know is
About the adapter will I need to change the fly
Wheel and also is the adapter plate just for
The sake of the starter?

The bolt pattern is the same, so yes the only reason for the adapter is to hold the starter. You may need a flexplate as well for the differant bolt pattern for the torque converter it may be differant than the slim jim set up. Someone else will have to chime in and verify that.

You will need a flexplate as the slim Jim style is a style all it's own.
Also, no torque convertor on the slim Jim, so you will need one of those too.

Even for a automatic?

Yes. The slim jim "flexplate" is actually very similar to a manual transmission flywheel in appearance. I've seen others refer to this as a "taurus member adapter". It won't accept a TH400 torque convertor. You'll need a TH400 flexplate with the proper crank register diameter. I can snap a picture of what you will find in there if you want.

Also, another place to check on the starter mount is with Brad at Fabcraft Metalworks. I believe they sell and adaptor of somesort.

Thank you I would like to see a pick of it.
is there any were I can get all the parts I need?
are do I have to peace it togeather?
I know what the adapter plate is going for
but I want to know were do I go to
price the trans and the other parts?
thanks also Im knew to this web site
how do you post a profile pic?
Boy seem's like alot to switch out
the trans. I have had my slim jim rebuilt and still having
Problems out of it ready to try somthing els I need all
the help I can get thanks guy's.

Go back to #4 post and click the link to Butler performance for the adapter, they will have the flexplate you need if you plan on buying that adapter.

I would check you local trans shops like where you got your other one rebuilt if you want them, doing another one for you, they should be able to have something for you that has a warranty.

To add a profile pic go to usercp towards the top of this screen and click on the avatar button and upload a pic from your computer.

Here's a lengthy discussion that you should read through from the 62-65 Tech section:

http://forums.maxperformanceinc.com/...light=dampener

Photo 1 is of the flywheel only for the slim jim and photo two shows the flywheel and the spring dampened plate that slips over the splines on the trans and bolts to the flywheel.

thank you for the pic's do i have to do any thing with the drive train?

Thought the torque converter action (fluid coupling to couple the engine to trans) was done in the small coupling internal to transmission? I think GM called it the accelerotor.:attention

if I wanted to go with a 400 trans out of a nother older pontiac what years would
be best to find a 400 trans that would do the job?

It is, it behind the oil pump and the coupling does the job of the older dual coupling's two couplings- all in eight inch diameter. The small fluid coupling is also the only trans with a fluid coupling and a third element. That element is called ( by Hydramatic Division ) the torque multiplier. The term accelerotor is a Oldsmobile term for the same part.
It's a name game, just like on the dual coupling 4 speed, Hydramatic division who designed it calls the trans Controlled Coupling Hydramatic, Olds calls the same trans Jetaway, Pontiac calls it Strato Flight and later Super Hydramatic, and Cadillac calls it 315 Hydramatic.
For Roto hydro, both divisions call it that name along with it's maker Hydramatic Division.

Years is not really a problem, but what you need is the long tailshaft T-400 which is used on the full size cars.

D.