5 speed conversion

very interesting Dave...and i might be very interested...let's talk...PM me your number or call me at the number below.

thanks,

brett, 705-435-1990

 

Good luck guys. I hope this happens.

 

Dave
Did I understand that this is a 4 wheel drive tranny or does 4wd mean something else? If so, what happens to the front wheel drive outputs?
Ken

 

If I understand correctly, he is using the 4wd tranny because it has a tailshaft with a four bolt flange instead of a standard spline type tailshaft into which a driveshaft yoke would slip. Normally that four bolt flange would accomodate the transfer case that would then drive the front wheels. Instead of bolting up a transfer case, he plans to bolt it directly to the existing torque tube (or use an adapter and bolt it up).

 

I have seen several posts indicating that the turbo 400 tranny bolts to an adapter plate on the back of the engine. A couple of posts state that the tranny bell housing (integrated) is the standard GM bell housing. Is it the chevy bolt pattern, or what everyone refers to as the BOP, meaning Buick, Olds, Pontiac pattern?

Thanks for any help.

Lynn

 

Here is a page from the parts manual for the 400 Automatic, showing the TH400 used in that model. (The complete manual is downloadable here: http://www.400register.com/manuals/400-manuals.asp ) Below it is a photo of a TCI TH350 for the Chevy V8.
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So, it appears the chevy bolt pattern. I guess I could have figured that part out from Dave's original post where he said "Tranny mounts to a chevy bellhousing"

There are so many different bellhousings out there. Lots of aftermarket steel ones as well, such as Lakewood.

Lynn

 

Our cars use the Chevrolet bell housing pattern for sure.
Ferrari has already done the hard work to get the front of a Chev pattern trans to fit, it is the adaptation to the enclosed driveshaft that presents the challenge, along with clutch and gearchange operation.
I'd would be very pleased to see this project come to fruition.

 

being that the Ferrari uses the standard chevy bolt pattern (unlike the Jaguars which used TH400 also) then even better then a T5, is a Tremec TKO transmission, is possible as well, which will allow moving location of the shifter should that be needed
but for adapting to a TQ tube, the T56 came in such configuration, though it is a larger and heavier transmission, the benefit is a 6th speed also

 

So, has any one checked out the possibility of not using the enclosed driveshaft? I understand it acts as a torque tube, but that can be accomplished other ways.

 

This thread has come up a few times before, and since we are talking about automatics, what is the opinion here about buying a converted automatic? Would you buy one? I've owned my 400ia for eight years and love it. I can't lie, there are times when I wish it had better pick up, that it always seems like I'm starting in second gear but once it get in the power band it a great drive. Most of us covet the 5speed manual over the automatic but I think this is a great cruiser and well suited for an automatic 99 percent of the time i just wish it had more gears. This brings me to my real question, instead of converting to a manual how about installing a modern 6 speed auto with a lower 1st gear and a higher final o/d, ie the TCI6x auto? Would you buy one if available? What effect would this have on the value of the car? What effect would a automatic to manual conversion have on the value of the car? Would a change like these make the car vertually unsaleable?

 

I would consider more low & mid ratios a plus, even if it were a different autobox.
Four speed auto boxes will generally have the same ratios as we already have plus an overdrive which isn't needed. Any auto trans with more than 4 gears is going to have computer control to adapt.
Nice idea but not very practical.

 

The reason I suggested the TCI6X (although somewhat costly, approx $6000 for full kit plus install) is that the gear ratios are 1st 2.97 2nd 2.23 3rd 1.57 4th 1.18 5th 1.00 and 6th .75. This would give about a 20% lower 1st gear and more mid range gears to help keep the car in its power band. It also has a standard GM bolt pattern and a tail that could be addapted to the original torque tube. You could have the car still look original if so desire. I toy with this idea a little more than a manual conversion due to the complexities of adding a clutch system to a automatic car. The cost is not what keeps me from doing the conversion but rather the battle within on keeping the car original or "improving" the cars drivability.

 

Have you guys looked into an older GM 700R4. That would be 3 speed plus overdrive, non computer controlled

 

The problem is the first three gears are the same ratios as the three speed and there would be no off the line improvement in acceleration. If you could get the 4.30 gear end gears from a manual transmission car it would be a great set up.