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For an upcoming Harley powered MG M-Type replica car project, I picked up an '06 Miata 5 speed with 20k miles on it. It was from a burn salvage and has just a bit of melt here and there.
Edit: Sorry forgot to ask this, but is the driveshaft yoke the same for all Miata transmissions? The reason I ask is that for my project car, I will need a yoke and a few inches of the driveshaft tube still attached to the yoke u-joint to fit an '06 5-spped below. I have my MGB banjo rearend rear driveshaft u-joint and part of the driveshaft so all I will need is to have a driveshaft made from the front yoke parts and mate up with the rear end u-joint flange parts. If all are the same, it widen up my search a BUNCH for a broken driveshaft yoke to fit my '06 5-speed below. Thanks!
So here's my question. Below you will see two switches, the one of the top shift shaft and the one below mounted vertically without any melted wire ends.
I want to be sure of the purpose of those two switches. The top one "seems" to be closed when in neutral. The ohm meter goes open when in any gear other than neutral. Is this some type of a neutral safe start without the clutch switch?
The other one I'm guessing since it's closed when only in reverse, that this is the backup light switch. Is that correct?
The other teardrop yellowish cover had what looked like a plug housing on the end, but when I took it out, it's only an O-ring sealed plug. Is this where a VSS was inserted? Since the plug on the cover was solid plastic and slightly melted, I ground it off smooth for looks etc. Since I will be using a GPS speedo sensor, it's really not an issue what goes there, but just curious about it's use.
It has a shifter of sorts still with it. The rubber seal around the top has been melted a bit, so it will get replaced along with the tail shaft yoke seal.
Does the Miata shifter slide over this stub shaft and set screw to it? Does anyone have a picture they can share of this area? I "may" have to make a bent back shift lever because of the placement within my upcoming project car. Since it's going to be a MG M-Type replica of sorts only with the Harley motor out front, there could be some logistic issues with the placement lengthwise within the car frame and seating area. It may work out great as is, but just thinking ahead in case.
Picture this with a Harley motor out front...
Any help will be greatly appreciated.
Keep well and have a great weekend.
Dan
Last edited by Dan Lockwood; 03-21-2020 at 02:17 PM.
NA/NB Miata shifters are two piece, rubber damped. I may be wrong but I think you are looking at the inner steel shaft, the outer rubber and threaded shaft for the **** melted away.
As for your other switch questions, I'd get a multimeter and shift the transmission around while checking for continuity on the switches. The neutral switch on the 6 speeds are pieces of **** and fail on their own, the backup light switch fails and leaks transmission oil from the wires. Those look like they got warm. Not only would this identify which is which, but it would make sure they are working and don't need replaced.
NA/NB Miata shifters are two piece, rubber damped. I may be wrong but I think you are looking at the inner steel shaft, the outer rubber and threaded shaft for the **** melted away.
As for your other switch questions, I'd get a multimeter and shift the transmission around while checking for continuity on the switches. The neutral switch on the 6 speeds are pieces of **** and fail on their own, the backup light switch fails and leaks transmission oil from the wires. Those look like they got warm. Not only would this identify which is which, but it would make sure they are working and don't need replaced.
Thanks.
The switch that appears to be a neutral safety switch, does go closed when in neutral only. Any gear opens the switch. Can you start Miatas in neutral without the clutch being pushed in?
The other vertical upside down switch only goes closed in reverse, so I'm assuming that IS my reverse backup light switch.
I asked this in my edit of my first post, but it may have been missed. Can you tell me if all later gen Miatas use the same driveshaft yoke? That is will the yoke from a 5-speed MT fit the spline of a 6-speed MT, or possibly a 6-speed AT? As I mentioned in my first post, I need the front yoke and a short section of the driveshaft tube to be used in making a new driveshaft to mate up with my MGB banjo rear differential. If all yokes are interchangeable, that opens up my search quite a bit.
The neutral switch is only used to cancel cruise control on older miatas. NB used the neutral switch to control when to idle. None of them used them as the starter interlock, that was a separate switch on the floor. NC still have a clutch switch and a neutral switch, so I assume they are similar. NC might finally not pass all starter current through the interlock switch like all NA and NB, it probably lets the ECU know when it's safe to start.
I do not know about the yokes, but I do know NC require a different driveshaft if you want to swap 5 speed to 6. That isn't the case with NA or NB miata. I would bet the outputs are all the same and all the difference is in the length but I am just guessing. Either way, all miata driveshafts are disposable and have typically non-serviceable u-joints. If your plan is getting a miata driveshaft and cutting it up you are going to need a good driveshaft shop.
That is very enlightening, thanks for the information.
I've dealt with Denny's Driveshaft company in the past when I had my driveshaft made up for my 1940 ****** couple. It had 654hp with a blown '57 392 Hemi. I'll do some checking around for a shaft, but maybe getting directly in touch with a company like Denny's would be the best solution.
I've been dealing with David at Shaft Masters about making up a driveshaft for my next Harley powered car running through an '06 Miata 5-speed and running an early MGB banjo rearend assembly.
He sent me a drawing of the yoke that they use on the '05 and earlier. I measured me output shaft and bushing. When compared to the drawing, they matched. So the early style front yokes are the same spline and diameter as the later 5-speeds.
He also said that they stock the rear U-joint flange that matches my MGB pinion flange. I'm sure that you all pretty much know who makes what for different years and models, but for those who don't know, here's their website link.
03-21-2020, 01:16 PM
'06 5 Speed Help Please
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