Step by Step how-to: Auto to manual conversion

[Reaper-Zed]

Ruffly, How much would it cost to do a 5 speed manual conversion??? we talking about 1k? I understand it depends what parts you get and all that, but im thinking a decent 5 speeed nothing to trashed maybe re-cond. with all the rest being new parts as you recommend??? From what I can tell you can pick up a box for about 400ish in good cond. 300 if your lucky. how much does the other parts cost ruffly?

[BobsYourUncle]

I'll ask this here because it's about this conversion...

 

The auto box has two hard lines that go to the radiator to cool the transmission fluid, and one that goes up to the to the manifold near the carbs. Is this third line for vacuum? I take it the manual box doesn't need this, so I'll need to block off the point on the manifold where this connected, is that right?

 

While I'm at it, the manual gearbox doesn't require the two lines to the radiator, does it?

[Zeddophile]

I'll ask this here because it's about this conversion...

 

The auto box has two hard lines that go to the radiator to cool the transmission fluid, and one that goes up to the to the manifold near the carbs. Is this third line for vacuum? I take it the manual box doesn't need this, so I'll need to block off the point on the manifold where this connected, is that right?

 

While I'm at it, the manual gearbox doesn't require the two lines to the radiator, does it?

 

Correct on both counts, to the best of my memory.  Definitely don't need the two auto cooler lines, but only have a vague recollection of a vacuum hose needing blocking off.

[Zedman240®]

Best option to limit any chances of a vacuum leak, grab a brake booster inlet manifold hose connection from a manual car and replace that with the auto one with the smaller pipe coming off it. If you don't seal it right, you could have a  vac leak from there. Or just get an oxy torch and fold and weld it shut.

[Six_Shooter]

Or just simply get a vacuum cap....

 

I've been using vacuum caps for years with no issues. I have even, at times when I didn't have a vacuum cap available, used a short piece of vacuum hose, and the inserted a snug fitting screw or bolt, to block off the hose. Some cars I have driven this way for years without issue.

 

You can simply remmove the two cooler lines that go to the rad, the manual has no fluid cooling provions in stock form.

[BobsYourUncle]

Great, thanks for the feedback everyone.

[BobsYourUncle]

Right, finally got some more time to work on the car, and straight away I've got another question...

 

How do you remove the flex/drive plate? I can't figure out how to brace it to stop it turning. Tried a big bolt through one of the torque converter bolt holes, but that just warped/cracked the flex plate. How do you brace it?

[Zedman240®]

Theres a couple of ways but both are a bonus with an extra pair of hands. One way I do it is with a large flat blade screwdriver poked through the starter hole in backing plate on its side so the blade of the screwdriver is in the teeth of the ring gear while the screwdriver shaft is supported by the back plate. Another way is with a small pinch bar levered against the dowel pin on the block and the pinch bar blade in the teeth of the ring gear. 

[Six_Shooter]

Easiest to use an impact gun and socket, when available.

 

If you have to do it by hand, get a second set of hands, they will be needed.

 

Re-install one of the bellhousing to engine bolts, and using a large flat head screwdriver or small to medium sized prybar, brace the screwdriver or pry bar against the bolt with the end pushed into the teeth of the flex plate.

 

You will have to do this again, when torquing the flywheel, as well.

 

There are also tool made for doing this that grab into the teeth of the flexplate/flywheel, with a handle on it.

[BobsYourUncle]

Re-install one of the bellhousing to engine bolts

 

Embarrassed to say I didn't think of that 

 

In the end I braced it with a metal bush from my old brake pedal, it was just the right size to sit between the teeth on the flex plate and the little dowel pin on the block. Did the same thing to bolt on the flywheel.

 

Although I have to take the flywheel now, I didn't think it through and kept the round flat plate that was used like a washer for the flex plate, and now the bolts foul on the clutch pressure plate

[BobsYourUncle]

The last page or so of this thread is just me asking questions, but I guess that's what it's for. I've loosely bolted up the clutch, but I want to check - at the moment there's a gap between the clutch and the flywheel where the bolts are - that is, I can see the bolt thread between the clutch and the flywheel. I assume as I tighten these bolts to the required torque, this gap is meant to go away as the the clutch is squeezed onto the flywheel?

[Zedman240®]

The clutch and flywheel can only bolt on when all the dowel pins match on both. They can only fit one way. Make sure all the dowel pins on the flywheel match with the clutch before you tighten them all the way to the correct torque..

[BobsYourUncle]

Thanks yes the dowel pins are lined up correctly.

[Zedman240®]

In that case, as you tighten the bolts, the spring of the clutch plate makes it a bit harder as you do it up; as long as the clutch housing isn't bending as you tighten the bolts up..

[Funkysandwich]

2 notes here about 280zx boxes, if you use one: 1, The bellhousing bolts need to be longer (Ie: get manual 280zx bellhousing bolts).  2, The transmission tunnel hole needs to be trimmed between 10 and 50 mm at the front edge. 

 

Can anyone elaborate more on this? Trimmed how? Is that all the way around the edge?

[C.A.R.]

It doesn't need to be done on a 2+2, James.

[BobsYourUncle]

It doesn't need to be done on a 2+2, James.

 

I had to do it on my 74 2+2... I'll take a pic tonight if I remember. You only need to trim the front (towards engine) edge.

 

edit: as promised...

 

[peter t]

Hey Mate if you want any help give us a shout.

Peter. 0412 236599

[drzoidberg]

hey guys

 

im halfway through a manual conversion on a 280zx, using a bluebird 5spd box, im short a flywheel and clutch.

 

Any tips on what flywheels fit, im thinking a 280zx one may be pricey and hard to find?

 

cheers

[dat2kman]

Not a L18 or a L16,

Any others will bolt on, the clutch plate diameter will be 225 mm for the zeds, but some were 200 mm diam.(l20b)

Have a hunt around some wrecking yards, will prob need a light skim, screw in a gearbox mount bolt into back of engine, use big screwdriver to jam against ring gear, then use breaker bar with a bit of extension tube for levetage, they will be tight.

You could reuse the bolts, not recommended, but for regular road usage, should be fine.

If you require new, either Nissan parts, or ARP, i have a set of new ARP flywheel bolts avail, much stronger.

Hey while at it, have a look around forums etc about info on taking a few kg of weight out the backside, will help engine rev up quicker, a little!

 

[wildy55]

Hi guys

Doing the convo this weekend coming and have everything...apart from the gearbox spigot bush that's mentioned in the sticky. I have a 280ZX flywheel, clutch and box, but do I need the bush, too?

If so, does anyone have one to sell and post asap? If not, has anyone the dimensions so I can get one turned down? Is it brass?

Cheers

Martin

[Zedman240®]

I have one here but I need to use it, I can give you dimensions and part #

Part # is 32202-B950A

Dimensions are

ID: 16mm

OD: 20.7mm

Length: 17.4mm

 

Hope that helps! and yes, it is brass.

[reverendzed]

If I remember they are available from Repco and Nissan.

Rev.

[wildy55]

Cheers fellas!

When I go to Repco  and as the guy who's half the age of my car for this (cue blank stares), do I ask for a 240Z bush or 280ZX? I'm thinking 280...

[benny]

its the same wildy though i would get onto nissan before you try elsewhere just give them the part number!!