automatic to manual conversion problems
 

well while I am swapping a FC engine in (NA), I am changing my car to a manual.

Anyway, fast foward a bit to when I dropped the engine in. I chose to bolt the engine to the transmission out side the car and drop them both in in one shot. I bolted up the engine to the engine mount (using the RB mounting adapter) Then I went to go mount the transmission, I made sure I had the transmission manual tans mounts, crossmember and rear mount.

Now to the problem. The crossmember is attached to the transmission, but the holes for the mounts are a like a half foot behind the crossmember!!!

AND... I dont see even if the crossmember was right where is should be, how the hell the mounts attach!

The bolt isn't even long enough to make it through the crossmember! I must have messed somthing up here.... but what???

What transmission are you using? Ive heard that you might need to swap out the tail sections of the tranny from a 12A tranny if youre using a 13B tranny.

~T.J.

this is a 12a tranny, I'm not sure of the year tho.

I do know its from 81-85.

The automatic cars have the bolt holes for the corssmember in a different place.

I still need to figure out why the bolts fro the mounts aren't long enough to make it THROUGH the crossmember.


youre kidding me right???

well I just found the thread that that came from....



new holes? sturdy mount? I've never fabbed anything in my life. I know people out there have done this, what is the best solution?

I really need help on this one, I havnt ever done something like THIS before or even know how to go about it.

I would assume that maybe something along these lines might work. Something that would let you use the stock holes to mount the mount (haha), but "move" the stock holes forward. This is a fairly simple idea, but I dont know if it would actually work. One hole woud have to be threaded for the crossmember bolt to bolt into though.

~T.J.

https://www.rx7club.com/forum/attach...postid=1432314

Serzy made something like that, and it was really flexible. I think I'd rather try to drill through the floor and use some big flat washers or something.

that looks easy enough

but when I think about it, it would never be as sturdy as the stock mounts..... I guess I dont really have a choice unless there are other options out there?

If I were to make something like what RMD posted does anybody have the exact length I would have to make the holes apart?

I dont see how you could accurately get that measurement. I mean the mount would have to be perfectly level, etc.

I am quite nervous about drilling into the floor, it could be done quite easily, but geting it the right hight and stuff, that would be interesting.

Could anymody post some pics of their mounts for their transmission? Perhaps if I knew where the manual mounts were supposed to be, it might be easier to place them

You could make a cardboard templete first. That might work. Heres another picture showing what I was talking about in use. Please excuse the lack of effort in detail ;).

~T.J.

https://www.rx7club.com/forum/attach...postid=1432381

Ask your friends and neighbors if they own a welder. Mix in a couple peices of angle iron with a chop saw and you'll be set.

Are you using a 12a tranny on a 13b motor? I don't think that's going to work... Aren't the input shaft splines different from the 12a to 13b?
I asked mazdatrix about this a few years back, they had a good laugh.

is your car a 84/85???if it is.... you need to extend the mount 4".... on the 84/85 cars the trannys are longer so the chassis are different, also the driveshafts are shorter on the automatic models..... if you want we could trade driveshafts, i need a spare!!! i have done this conversion many times(its hell!) so if you need any help feel free to ask!!!P/S have you changed the pedal assembly yet??? aaaaaaagggggghhhhhhh

I now have the GSL-SE 13b tranny bolted to a 12a.

matt

yah, SOMEONE82 is right 13b trannys are the same spline size unless its a turbo tranny ....the 86 and up trannys have the shifter moved back 3" farther though ....

Ok, you got the engine and trans mounted in the car. A 13B with RB mount adapter and a 12A trans? You should be able to put a jack under the trans mount and just jack it up until the crossmember is snug against the bottom of the car. Make sure it's fairly well centered by measuring the tailshaft to chassis tunnel on both sides. Now just mark the chassis through the holes in the crossmember and drill... Get some nuts, bolts (after you measure what length you'll need), and large area washers from the hardware store and you're done. Of course you could tack weld the nuts and washers to the floor inside but you'll be fighting with pedals, hydraulics, and a different drive shaft soon enough...

PS, there's wiring under the carpet between the tunnel and the drivers seat for the stereos with amps under the storage boxes.

Yes that is my exact setup and NOW that sounds like the best idea yet.

The only problem is that I think the transmission will be too far up. I'd probably need to put a spacer in there.

The next problem is this. I have the mounts and crossmembers for both the manual and automatic transmissions.

Are the bolt holes on the manual cars for the crossmember pegged?

The bolts for the manual transmission mounts and crossmember dont make it all the way through the corssmember as if it were to meet with a tapped peg or some thing.

To clarify this..... as I've probably confused the hell out of everyone, the auto crossmember has the mounting bolts going through the corssmember.

Could someone take a few pics or something to show me how to properly mount the manual crossmember?

bump

Well, Im kinda confused with your terminology, but I will take a whack at describing how the manual tranny for a 12A bolts to the car.

You have a transmission mount. Its a piece of rubber that goes between the crossmember and the transmission. One side has two lobes for bolts, and the other side has studs. You use the lobes and bolt it to the transmission, and then the studs go down through the crossmember. There are nuts on the end of the studs to hold the crossmember to the tranny/mount. Then, on either side of the crossmember, there are two bolts that go up through the holes in the crossmember into the body of the car.

Does that help you at all?

~T.J.

you've clarified it some, bit the bolts that bolt the crossmember to the car.... they are not long enough to go all the way through the crossmember itself.

The bolt holes in the crossmember have some rubber cussion in there whereas the automatic crossmember is just all metal.

So where the crossmember meets the car, is there something like a peg or something with a bolt hole that slides into the crossmember?

That would be my only guess as to why the bolts dont go all the way through the corssmember.

Hey T.J., How the hell do you just throw together those 3D images (I'm assuming CAD)?! That makes me mad :p:... I try to make things like that in CAD, but they turn out like crap, and don't look like anything other than line drawings of non-existant objects.... lol

oh well.... I stil make a mean Video in Premiere ;)

Jeff