T9 gearbox conversion

[alaric]

Hi all,

I’ve managed to spend some time out with the car over the last few days - sad actually, it’s been -7 outside, and I’ve been sat in the garage surrounded by heaters…

Referring back to earlier posts: After some thought, I re-measured the height of the clutch pressure pad, but with the clutch plate fitted this time. It was not having the clutch plate fitted that was the problem. The measurement now comes out at ~99mm, which is spot on what it should be.

So it was my mistake - I wanted to clear that up, as now that I’ve been able to spend some time at it, I’ve managed to get the gearbox fitted and test the clutch operation - needed three hands, a foot and the pedal box from the car, but it definately works. So the kit, at the moment, looks great. I’ve measured the prop shaft length based on the distance between the engine mount and the output spline, and it matches that for the standard 4 speed prop shaft. Also, the gear lever is within a few mm of the original position.

The gear selection is really nice. I’ve cranked the engine on the bench with the starter motor, and all the gears are really sweet. The selection feels very precise.

This evening I’ve put helical inserts into the starter motor threads on the bell housing, and spent an eternity carefully filing the speedo gear to accept the speedo cable drive and altering the clamp arrangement, but it’s finally together.

Next job is to offer the whole assembly up to the chassis, and work out where to attack with the angle grinder.

The most difficult part of this conversion has been getting concrete information about how to procede. I guess that’s par for the course with these cars though, and maybe it’ll make it all the more satisfying once the car’s on the road.

All the best.

Sean.

[tower_of_strength]

I’m sorry it’s six months or so late, but just wanted to add my two penny worth to this thread;
Regarding the gearbox types, the Type 9 (5 speed) was developed from the Type N (4 speed)
there are two types of 'box, heavy duty (long input shaft) and std (short input shaft) the heavy duty type was fitted to diesel sierra and Granada/scorpio’s and P100s, V6 Capri, sierra and Granada/scorpio2.3/ 2.8 engines (inc 4x4s)
the standard 'box was fitted to Sierra, Granada and Capri 4 cylinder cars.

The Transit had a wierd set up, with the long (heavy duty) input shaft and the selector on the side of the cast iron part of the gearbox.
the input shafts (memory fails me on numbers) have the same number of splines as the type N 4 speed (2litre and2.3/ 2.8 petrol, 2.4 and 1.8 diesel) and the spigot bearings are also the same.

My findings are that the ratios are all over the place, but the diesel gear set in the 1.8 turbo diesel Sierra are, from memory, the closest set ones. A good source of info on this would be Autodata/Glasses technical data manuals from the late 80’s if any one has a set.

The clutch diameter and depths of pressure plate will vary from engine to engine, but the 4cylinder petrol ones are the same (capri, sierra and granada), the V6 one is larger diameter, the transit larger still.

The bellhousing from any 5speed petrol 4cylinder car will fit the twincam, however they are designed for a cable clutch.

after market concentric hydraulic release bearing conversions are available from the rally/performance outlets, as are various alloy belhousings (original MK1 Escort RS 2000 would be Ideal!!

2.4/2.9 and twin cam Sierra/Granada/Scorpios had the MT75 type Gearbox as per the Spyder Zetec conversion.

with regards to changing the input shaft from long to short, the output shaft also needs to be changed as they are matched pairs (from memory)

In my opinion,for what its worth, the std duty Type 9, in good condition or properly reconditioned will handle all of the torque and power that a Twin Cam can throw at it. In my distant youth I ran a 170 bhp Pinto through a 1.8 cvh sierra gearbox for 40,000 miles with no problems, bear in mind that this was a 2nd hand gearbox, in a Capri and I thought I was Nigel Mansell (only 23 at the time so give me a break!!)

I’m going to try and create a “budget” 5 speed conversion, with both the twin cam and Zetec or Duratec engine for the Elan and Plus two in the not too distant future and if there is sufficient interest, I’ll keep you all posted of my progress.
My aim is to modify my plus 2 so that I have an unleaded tolerant, useable,daily driver, bearing in mind the actual value of the car concerned (?3-4500), without destroying its classic/period feel and outward appearance.

How did the Voight conversion work out finally? Sadly its beyond my budget (Just aquired a ready made family) and my Enginuity gland has just kicked off

regards

Mark

[alaric]

Hi

The Voigts conversion turned out to be ok on my car. I haven’t finished the restoration yet so have not driven it on the road. However, I have run the engine with the box, tested the clutch, and gone up and down the gears. From what I’ve read, the box is really easy to rebuild, so I can’t see there being an issue with it. The conversion wasn’t really designed for fitting to a 5 speed Elan, that was the main problem. I now know of two other +2 owners that have fitted the box having seen mine in the garage. One is having hassle getting the speedo drive to work. The other has just placed the order so is awaiting delivery. I think the speedo issue is actually because the drive wheel Alan supplies is intended for the 4 speed box coupling. I spent a lot of time carefully filing mine to get it to fit, so I think it’ll work ok.

I’m happy with my Voigts box.

You mentioned a Duratec engine. That’s not the 6 cylinder Mazda one that I have in my Mondeo I take it. If it is, that’d be a fantastic conversion. And I have a donor car which even has the same concentric clutch actuator as in the Voigts box.

Sean.

[tower_of_strength]

Hi sean,

the V6 in a mondeo is actually a ford engine ( almost half a Vanquish V12!!), The old Probe used Mazda engines,
The Duratec is the current alloy block chain driven cam engine as found in Mondeos etc, I have one in my company car and its a super engine, just lacking the "coming on the cam " surge you get with the standard twincam. As a rally car building friend of mine has informed me that the Duratec is only marginaly lighter than the zetec, he recons it wont be worth the effort. I’ll just have to see whats lurking at my local breakers yard (they are my inlaws tenants so they are pretty tame and helpfull).
What ever I eventually do to the car will be reversible as I dont want to change its fundamental nature and may get the originality bug later!!

Regards

Mark

[GrUmPyBoDgEr]

Hi,
the thread seems to have diversified a bit & has reached a point in the discussion where I think my earlier investigations may be of some interest.
with ref. to MT 75 G/boxes; I believe that most British derivatives, that is right hand drive, have the mounting for the starter motor on the left hand side. This would get very badly in the way of any sensible exhaust manifold.
According to Wiggy at Spyder, left hand drive variants have the starter motor on the right hand side as per normal RHD Elans. One or two variants also have a hydraulic concentric clutch actuation as standard. This info’ also from the Spyder “Oracle”.
Having built a Zetec into an Elan, I have also had a look at the newer 4 Cyl. Duratec. No measurements or weights but subjectively it looks a bigger lump than the Zetec.
One thing that put me off was the reversed (European LHD) cylinder head configuration that puts the exhaust manifold where the carbs (or fuel injectors ) should normally be. That would mean on RHD Elans, the exhaust manifold would have to be woven around the steering column.
Just thought I’d sort of mention it.
Are there any more Christmas cards in the shops?
John

[tower_of_strength]

good point about the duratec John, i’d forgotten that it was back to front!!

Mark

[lotusanglia1965]

Surely can’t be any worse than twin cam exhaust on a lhd car?
I’m putting in the 1600 zetec(focus) engine,it too is reversed,but the gains outweigh the extra exhaust hassle.just bought bellhousing to mate it to alan voigts’ five speed conversion.should be running next week…
or not!
Martin

[alaric]

Well, it’s a year since I started this thread on the T9 box that I’m trying to fit to my +2. Over that year the body has been restored, but is due to go back for some correctional work over Christmas. Before it goes I’m trying to fit the engine and gearbox to the car - the idea being that if there’s some fettling to do I could get it tidied up while the car’s there.

So I tried to fit the engine this afternoon. It’s a tight fit - manouevering to the nearest mm - it’s my first time, working on my own, so I’ve been taking my time.

Here’s a piccy of the T9 box:

The problem is the thing sticking out of the top. It’s a spring loaded plunger that keeps the box in gear. It fouls on the underside of the body, and I can’t get the engine and gearbox past a certain point; I need to get the gearbox tail into the tunnel of the chassis, but then the front of the sump is sitting on the steering rack, and I can’t get it any further.

Has anyone else had this problem with a T9 fit? What’s the solution? Do I have to cut a slot in the body? I’ve never heard of this if I do have to.

Thanks in advance for your help.

Sean.

[Foxie]

Sean,

This was one of the problems I encountered when I did the prototype installation in my Spyder chassied Plus Two.

When you are pulling /replacing the engine + gearbox as a unit, the selector detent spring unit fouls the bulkhead.

I got around this by fitting/replacing with the detent unit removed. It can be removed /replaced with the gearbox (almost) in position with a sawn-off 19mm ratchet ring spanner. The usual gynacological skills of a good Lotus mechanic are very useful for this job.

Sean Murray

[alaric]

Sean, thanks for that. Very helpful! As you know trying to fit the engine is tricky until you’ve got some practice, so that’s useful.

So, it sounds like you’ve got the same large detent spring assembly. I’ve found pictures on the web of the same model of t9 as the one I have - it’s the later one. I’ve attached the pics. As you can see these pics show a small dome on the top plate instead of the relatively huge spring assembly that I’ve got. Has the dome been removed on purpose - my assembly looks like it’s been welded on there as a afterthought. Would a non modified top plate fit?

Once the box is in place, and I refit the detent spring assembly, won’t it foul the underside of the body? If not then great.

Thanks again.

Sean.

[tower_of_strength]

John,

I have an MT75 bolted to my Twincam, it fits in the chassis just fine( a bit of tickling with the grinder is needed around the top near the body/chassis mount points on the trans tunnel. I made my own gearbox cross member that takes the lotus/ford standard 4 speed mount, The out put flange needs to changed for a transit one, I’ve made my own gear stick/shift mechanism using a rose joint and a simple swivel bush.

The gearbox to use is not from LHD cars, this is bull dust, the gear box you need is from the Ford Scorpio, 1995 on models (the one with the bugeyed sulky look)any of the 4 cylinder ones will fit, it has a concentric slave arangement and the starter on the drivers side. the fly wheel/clutch needs changing to a fiesta XR2 Flywheel (MK1 crossflow jobbie) if you can find one, or burtons do a crossflow/T/C flywheel with a ringear to suit a pre engaged starter motor.I’m going to try a capri flywheel and clutch to see if that fits (?58 complete clutch cant be bad!!!) and use the scorpio starter motor. I’ll post a link to some pictures of the box and its fitting in the chassis, (its too much like hard work to reduce them for posting on here):
the Scorpio gearbox:
i125.photobucket.com/albums/p42/ … 0199-1.jpg

engine/box in chassis:
i125.photobucket.com/albums/p42/ … 000200.jpg

Gear Shift:
i125.photobucket.com/albums/p42/ … 000324.jpg

hope this is of interest
regards

Mark

[Foxie]

Sean,

The cover with the “blister” is new to me. I think the original Alan Voights cover and detent unit was different to the original T9. It might be no harm contacting Alan for the latest.

It’s been three years since I fitted my T9, but looking at your photo, there seems to be a detent spring adjuster bolt on top of the “spud” If I remember correctly, I may have cut this off and brazed on a shorter fixed cap to minimise the height of the “spud”

But I haven’t had to disturb it since… Great set up, especially with a 3.55 diff.

Sean Murray

[alaric]

Sean,

That’s interesting. I wonder if this is not an issue for the baby elan, which I believe is the car that Alan targeted his conversion kit at. My spud, which is an excellent technical term for it, certainly does have what looks like an adjustment bolt on it. I think a call to Alan is in order, just to find out why. If there’s no particular reason for it then I think I’ll look for a replacement standard top plate.

Thanks again.

[tower_of_strength]

the bump as you call it on the T9 top cover is standard ford fare, its the gearbox breather!! theres a small hole in it. The arrangement on the Voight box is possiblya replacement for the reverse gear locking plate, this normally sits just below where Voight has put the gear shift on the standard box.

Mark

[alaric]

Thanks Mark, that makes sense. I haven’t had a chance to try the engine fit again just yet - can’t see any reason why it won’t go in now - just need to determine whether the plunger needs to be modified.

Sean.

[tower_of_strength]

I tried a type 9 in the chassis(body off) attatched to the bottom end, pics available but they are big files!! The selector tube along the top of the box prevents it from being raised up level, because of this(possibly) the speedo drive housing on the box fouled the reinforcing webs inside the chassis. Obviously removing the selector tube as per worzels conversion and the Voight box aleviate this issue.
At the time I had an MT75 to hand and apart from the starter on the wrong side it seemed the easier conversion (since found the right front casing for correct starter position!.
I do like the Type 9 as a gearbox, I’ve driven many in specials etc over the years and it seems more in keeping with the Elan than the later MT75. I feel the need to locate an oxy kit and another type 9!!!

Regards

Mark