Auto to manual conversion on 400??

Hi guys,

I've come across a very, very nice 400 GT with carbs for an even nicer price.

It has however an automatic transmission.

I've never owned anything but stick shifts and I really don't like automatic transmissions, especially not the older ones.

So I was wondering what, besides the obvious things like center console and pedal box, would be involved in converting an automatic 400 to a manual tranny? And would I be able to find a manual transmission for it?

Any comments very welcome!

Thanks

Hans

 

Does it have to be a Ferrari tranny?

There was a gentleman here who had started looking into putting a Doug Nash 5 speed in one, and it seemed to be a feasible idea. More fabrication at the front end, but a more durable piece with available parts when you're done.

Let me see if I can find the PM and get his info to you

 

No, doesn't have to be a Ferrari transmission. As long as it is able to withstand the torque of the engine....

I'm not particularly focused on keeping things OEM stock, so yes please, I'd be very interested in this PM.

Thanks!

Hans

 

Hans,
If you get serious I know where you can buy a 5-speed tranny from a 400i. It'll run you $5,500. It isn't mine, I just happen to know someone who is parting one out.

PS - Is the car you're looking at the red one at Checkered Flag?

<EDIT> I just noticed you're overseas, so I doubt that is the car. Sorry.
The tranny is however here in the US.

 

Hmmm, interesting. However, that's a lot of money, especially if I'd factor in the work involved.....

Stilll, very interesting. I'd have to think that one over a bit....

And no, it's a car in Luxemburg, Europe. I'm in The Netherlands, which is only a few hundres miles away...

Thanks!!!

 

I've wondered about doing the same thing. I thought that since a GM TH400 was the stock item, a GM manual might bolt right up. The 5-speed out of a Vette or Z28 should be able to take the power.

However, when I asked someone about the possibility of doing this, he said it was "virtually impossible" because of the torque tube driveline. I'm not sure I believe that because the auto was never designed for a torque tube either, but they've obviously made it work. Another thing is that autos usually have different rear axle ratios than manuals, so that's something else to consider. I don't know if Ferrari used different axle ratios or not.

If you have to use genuine Ferrari parts to make the conversion, you'll probably add enough to the price that you could just buy an original manual car in the first place. If you can do it with less expensive parts, it's probably a worthwhile upgrade. Either way, I'd be interested to know how you get on.

 

If you get all the "other stuff" from the car it can work out.



Just because the 400i uses a GM Turbo 400 don't think it's not different.

Jaguar and Rolls Royce used them in their cars from that period but there were pretty significant differences from the Chevy stuff. At the very least you will need a bellhousing and clutch and flywheel.

If you're going the "Monster Garage" route and don't care about originality you could replace the rear-end and eliminate the torque-tube. Maybe a Jag rear end out of an XJS or Series III sedan might fit (with a little help from the plasma cutter).

I think you have enough to do now but it doesn't hurt to dream.

 

IMO: The change over is WAY TO MUCH effort for the reward. I have a 400i with the TH400 and I HATE AUTOMATICS! My solution is to change the torque converter to a switch-pitch type as used in RR and some American models.

The switch-pitch converter lets you pick from two stall speeds at the flip of a switch. One for torque amplification and the second for that 'tight' feel of a manual trans.

You will need a switch-pitch converter, front pump, and an input shaft. I just bought this complete set of stuff on eBay for $350. Any trans shop can do the conversion.

You will need to figure out how you want to control the switch. Mine will be hooked to my MegaSquirt to be controlled by engine speed and load.

 

Just to play devil's advocate...

What about using, say, a truck or SUV transmission (I'm still thinking GM stuff might be the easiest to adapt) with lower ratios to compensate for the higher automatic rear axle ratio? Aside from shifting like a truck, would it present other problems?

Incidentally, I'm not planning to do a conversion anytime soon. I prefer a manual, but I don't really mind the auto. If I had to pull the motor or tranny for some other reason and there were a relatively economical conversion, I'd do it. I'm just curious if anyone has done it and what approach they took.

 

Anything is possible with enough money.

You might just change out the rear end gearset to get the better ratio.

 

Mark

I see you have a MegaSquirt - does this mean you have replaced the fuel injection and ignition systems? If so, how different does the car feel and do you have any other observations? I'm considering replacing the CIS and ignition systems on my car so your thoughts would be valuable.

Aidan

 

I was thinking the same thing about the difficulties of changing from auto to manual after seeing that beautiful red 400 with the automatic for $23k.

The most killer idea would be to find a wrecked 456 or 550 and take the engine, manual trans and rearend out of that. OK, ok, don't shoot me, but it would still make one fantastic resto-rod

 

Big conversion project to make a 400 take a transaxle. Better to buy a good auto car and a 5 speed wreck and part it out, sell whats left. Probably the cheapest way.

 

I don't know what they would cost to make but last time I inquired about a ring and pinion Maranello Concessionaires wanted $14,000 and that was 10 years ago.

 

Not to sound like Pollyanna, I was thinking that there might be a gearset out there on a dusty shelf from a manual trans rear-end.

 

I'll second that.

 

OK, but it was a good thought by hans. I have this same thought EVERY time I see one of these awesome cars with an automatic transmission for cheap. Its such a pitty

 

Do the 400 series Ferraris have inboard brakes? If not, would you suggest changing the rear axle from the jag or (if possible) just keeping the inboard setup (that will make brake jobs insanely expensive)? If you do this project make sure to post pics!!

 

Has anyone installed a Tremec 5 or 6 speed behind a 400 and converted over to an open driveline? We are preparing to do so.

 

I'm the one who has the WC 5 speed, bellhousing, Factory clutch cable, Hydraulic throwout bearing, Factory pedal box with both pedals and pads, clutch assy and working drawings for the kit. In both SolidWorks and AutoCad formats, during an engine out extensive service, I set about taking dimensions and creating drawings from which a WC 5 speed could be installed. This was an extensive process.

This requires an adapter unit which mounts to the rear of the Offroad WC 5 speed, mating to the unmodified flange of the stock Torque tube. A short shaft is housed in the adapter riding in two sealed bearings, providing power transfer to the stock unmodified shaft.

Drawings are done. Big cylinder of aluminum for housing ready for machining.

I was and am willing to sell all to the right person to take over the project. Remaining is to decide and resolve clutch actuation. Simple cable/lever or hydraulic throwout bearing.

Hard work is done, maching of housing according to drawings, adapter shaft machining and many little things to be done................ Tranny is virtually new, clutch, cable, hyd T/O bearing all new.

If you have the engineering / design background to complete this, make me an offer for all of it.....................

Godspeed!
Dave

 

Anny tranny swap is going to be a very difficult task:

First unlike many other TH400 equipped car the tranny output is not through a yoke: the rear axle (including torque tube) is directly bolted to the gearbox splin-line (so to say). Only solution for a transmission swap is to use a tranny that is exactly the same lenght with the same splin-line. To crown it all this is a tight fit and there is no room for a transmission that is 10cm wider than the TH400. All in all the transmission needs to be small (shorter than the TH400 and not to wide).

Assuming that the whole of this can be undertaken, the transmission stick will then have to be located correctly, which again is not an easy task. Last but not last you would have to find a rear axle from a manual 400 as the gear ratio is different. Once you have paid for the rear axle, the additional cost of the tranny itself is not much...

Given all the time involved in such a project, you'd be better of paying for a 412 manual tranny (unlike the 400i, these have bi-disc clutches).

As suggested before a Variable Pitch biffed-up th400 is the most realistic option. For added performance it can be mated to a late 400i or 412 rear axle that is slightly shorter. A word of caution though: I've had a very bad experience with PAE variable converter (which is the stock converter sold with these VP kits). These ones do not like high rpm and mine was just blown out after 1000 miles. ProTorque has proven satisfactory so far (even if the claimed numbers do not look so appealing).

We do have 4 of these nice cars ( 365 beefed up to 400hp, 400 carb manual, 412 manual and 400i auto): above 40kmh, the auto pushes harder... The transmission was modded by Jakes Performance (this is a ~$1500 tranny). Other than that one could simply use a 2500 converter with added cooling (~$400). For an ultimate option there is Jhon Kilgore super light th400 (~$5500). All these options are plug and play...

 

I have been doing a bit of searching regarding the auto box. There seems to be two main problems in just replacing with another box, and that is the bellhousing and the torque shaft.

the main problems with the box itself is, I think, the lack of a lock up torque converter and too few gears.

I have found that you can get some sorts of lock up converters, and also that you can get a modern version of the overdrive unit, which effectively makes the box a six speed unit, it bolts to the rear.

Have anyone, I guess in USA, got any experience with either? or similar

http://www.theturboforums.com/threads/361363-th400-lockup
https://www.gearvendors.com/hrgm3s.html

 

Hi have a project that’s a is using 400i as base. Resurrecting this thread as would like input help on the conversion auto to manual. Has there been any progress since this thread ?? Anyone got any recent experience ??

Thanks