Talk Morgan Forums Morgan Sports Cars Maintenance & Servicing Gearstick turret on MX5 gearbox

Having racked up 57k miles over the past 14 years in my Plus 4, I thought it time to check the oil level in the gearstick turret. This is one of the first fitted with the Mazda MX5 (type N7S) box. For those who may be unaware, it should contain something like180ml of gear oil which is separate from the main gear box oil itself.
After removing the gear knob and rolling back the tunnel leather, the gearstick clamping plate is easily accessible, held by three bolts.
Removing the bolts, the lever is easily pulled out. Although my idea was to suction the old oil out, I managed little more than about 25mm.
I have now refilled with recommended gear oil (Morris FS 75w90) until it fully covered the mechanism (about an inch below the top. That took about 180 ml.
Cleaning up the ball part in the clamping plate, I noticed that there was a small split in the rubber bellows. So, if anyone proposes doing this job, it may be worth getting a spare bellows in advance as they are only around a tenner.
I very much doubt that this task is done during dealer routine servicing unless the customer specifically asks.

Changed the dust cover today.
For anyone contemplating, having removed the gearstick, it is easiest to cut the old one away with a stanley knife. Then give the ball a good wipe over. The hole in the new dust cover looked impossibly small but after applying a smear of silicon grease to the shaft, it slipped on surprisingly easily.
Also replaced the nylon cup on the bottom of the shaft, which came with it. All done for £8.83 from Amazon and less than half hour work.

Thanks Doug, helpful as always

So, if I've understood correctly despite only extracting 25ml it still took 180ml to refill, and as the total capacity is 180ml the 25ml you were able remove was more or less the only oil left in there after 57,000 miles?

That would make it a total loss lubrication system, all be it a very slow one

I also found this guide that supports your words.

https://www.midstatemiata.net/yahoo...nance/aug_2020_nc_turrent_oil_grease.pdf

This guy had a completely empty turret at 156,000 miles, taking 230cc of GL4 to fill it back up!

Dave, Although what I withdrew was a measured value with a syringe, there was probably still a small amount in there that was inaccessible. So I merely sucked out all that I could get to. It so happened that I had a part empty bottle of gearbox oil from my last oil change that had something less than 200 ml according to the scale imprinted on the bottle. So in pouring all that in, it filled it to about an inch below the top, well covering the moving parts. With the gearstick re inserted, the ball part would now be receiving lube as well.
So, yes, there was very little in there and I guess it gradually drains down into the main gearbox over a period of time.
However, the point where the end of the gearstick with the nylon cup drives the selector shafts was still oily, but was unlikely to stay that way forever!
Thankfully, it’s such a quick easy job to do…gearknob off, roll back tunnel leather and just 3 x 10mm bolts. In future, I will only recheck it every 25k when I do a gearbox oil change.

(The link you provided is for the MX5 which has a second top rubber boot and centre console dismantling. Thankfully, Morgan is much less sophisticated. The only thing I would add is that as the gaiter that was split is rubber, and I would avoid using any type of mineral oil based grease for the top of the ball which may cause the rubber to perish..I used a smear of silicon grease.)

Thanks Doug

Does it more or less look the same as this Mk3 (NC) MX5 in there on your Duratec Plus 4



The reason I ask is I'm considering fitting the G-Racing short shifter shown in the video, but I'm trying to work out if it'll fit Monty?

In this second video from the same guy he seems to really rate it



If it fits, I can see it working well in conjunction with my lightweight flywheel project

https://www.gracingshifters.com/

Dave, I would advise taking some measurements first!
Although it’s a short shift, the stick is obviously longer. The effects of this could be:
Fouling your hand when operating the fly off handbrake,
The higher turret: the Miata tunnel is a bit higher and has a secondary convex rubber boot. The morgan secondary “boot” is of course part of the tunnel leather trim and is concave; it sits well down towards the gearbox. So would the higher turret foul the leather and push it up so as to interfere with stick movement or at the very least look a bit ugly.
One final observation, they have done away with the nylon cup that sits on the tiny ball at the bottom end. Looks like they have instead, increased the diameter on the metal ball, so it’ll be metal on metal…all the more reason to make sure it’s lubed.

Completely different gearbox, but I fitted a quick shift to my Type 9. I found that, due to the Morgan gear lever being much shorter than a standard one, it was near on impossible to select the correct gear. The 'gate' was so tight that there seemed only millimetres between gears. I persevered for a week, but changed back to a standard shift.

Indeed Doug,

The challenge has not escaped me, although looking at this nice low image I think I can make it work



My approach was to ask the manufacturer for a drawing giving me the measurements & throw, ultimately this will allow me to mock up a dummy in CAD (Cardboard Aided Design).

I anticipate another one of my Blue Peter masterpieces on the horizon

Dave



NB: There is a bush at the bottom, it's clearly shown in this video.