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BoxheadTim
BoxheadTim GRM+ Memberand MegaDork
9/13/20 9:18 a.m.

As mentioned on this forum already, I spent a few days before Labor day weekend bouncing almost halfway across the country - well, at least to the other side of the Mississippi River - and back with this "the 90s want their tow rig back" outfit.

Yes, obviously this photo was taken on the way back, I didn't think there would be much interest in a photo of the empty tow rig. I also got lucky with the weather - going out, it was tipping down between here and about Columbus OH, but bone dry on the way back so I didn't have to put any tents, err, roofs up on the Maxton.

In essence, I did a Tyler Hoover and bought the cheapest Maxton Rollerskate for sale in the US. Well, it was also the only one, so that also makes it the most expensive at that time. Why "indigenous Se7en"? Well, it is clearly inspired by Caterham/Lotus/Westfield type cars, but it's also been fully engineered in the US (well, other than the drivetrain, that is). And as Caterham is fiercely protective of their trademark, cars like this are commonly known as "Se7en"s in the UK.

Anyway, what did I end up buying?

Well, a 28 year old almost kit car that's not been driven much. I bought it from the long term owner (since '96) who had bought it from what we believe is the original owner. It's had very sparing use during the time and was only driven to the odd car show. Actual mileage is unknown as the speedo cable is seized and ate the plastic drive gear at the gearbox end. Based on the PO's estimates, it probably has about 3-4000 miles on it.

The paperwork suggests that it actually has a 12A from 1976, which would make it an RX3 12A, I suspect. Not sure if it has the gearbox and rear axle from that car as well.

As we all know, vehicles that don't get driven get sad, and this one is no exception. A quick test driver before I handed over the cash showed a few issues:

  • Horn, well, doesn't but at least the button pops out on its own
  • Some typical kit car ground issues with some of the gauges showing fantasy readings. Hopefully that's only  ground issue
  • The parking brake is more of a hint or a polite request and actually went on strike after the test drive
  • The clutch felt like it had air in it and needed the pedal pumping a couple of times from time to time to get the gearbox to accept commands.
  • Apparently it was considered a good idea by the company that assembled the car to just throw the battery in the trunk and have 50lbs of lead bounce around there. That's not going to fly on the track or at an Auto-X
  • The car was described as completely original, which is true. Unfortunately this also extended to the tires and fluids other than the engine oil. Yes, the brake fluid looks like something that you could get from a coffee pot at the local truck stop. Ewww.
  • The paint on the frame also seems to have lost its propensity to adhere to the frame. Not exactly a surprise given the heat a rotary generates.
  • One of the front "bumper" stays has delaminated. Fortunately it comes with the car so it's "just" a matter of reglassing it in.

Anyway, it wasn't like I would be able to find another one at the dealer down the road, it was the cheapest one I've seen in a while so on the trailer it went.

BoxheadTim
BoxheadTim GRM+ Memberand MegaDork
9/13/20 9:37 a.m.

I already had an appointment at the DMV to register the car, which I fortunately can do before I need to get it inspected. Put the plate from the 911 on it and got the 911 an Antique plate in the process. That still allows me to drive 911 from Friday mid-day to Monday mid-day and on public holidays, but without the need for an annual inspection.

Anyway, back to the Maxton. First order of the day was to make Monsieur Klaxon (yes, it's got a French horn) toot again. After I finally found the horn (hidden below the coolant expansion tank) and took it off, there was a nice layer of corrosion between the body of the horn itself and the ground connector:

Cleaned that off with some Deoxit, but still the best I could get out of the horn was a 'plop', yet it worked when hooked up directly to the battery. A check with the multimeter suggested that while I had all the volts at the horn contacts, I also had none of the amps. These cars are bit notorious for having bad grounds between the steering column and the body of the car, and they run the full current for the horn through the button and column. Yes, I already have a relay sitting in the pile of spares...

Pulled the steering wheel and horn button off to measure a tad more but with not much success.

Problem was, I couldn't figure out how that dang steering column was grounded in the first place. Some head scratching later and staring at this area of the car wondering why the steering column was shiny and it penny dropped:

See this thing?

Yep, that's a "sliding ground connection" that looks like the assembly crew put it there. Only that it wasn't bent right and didn't touch the column. Some bending later and we haz contact:

With that done and a side mirror suction cupped to the car, off I went to get it inspected. The only problem the local garage found were inoperative brake lights, but fortunately those were just a bad contact at the pressure switch. Unplugging and re-plugging them produced working brakelights and an inspection sticker. Still need to go over those contacts with Deoxit also, but at least the car is now legal.

Yes, needs moar GRM sticker on the windshield.

I also tried to bleed the suspected air out of the clutch, but it ended up feeling like either the master cylinder is bad (slow to come back) or the clutch hose is acting as a partial one-way valve. A quick chat with the PO (who still follows the saga along) points at the hose as the more likely suspect. He had the slave cylinder replaced recently and the mechanic apparently mumbled something about seeing rubber bits floating out of the bleed screw when he bled them. I'm just hoping that this is a stock Mazda hose...

The master cylinders are all Girling - the car has a full Neal race car pedal setup with dual master cylinders for the brakes with a balance bar, and a single master for the clutch. Looks like rebuild kits are still available, plus some of the other Maxton owners have successfully replaced them with compact Wilwood cylinders.

Either way, the clutch worked a lot better after my attempts at bleeding it. The gearbox is still not very cooperative, but I suspect that this may have something to do with the fluid in there being at least 28 years old.

Last night I put it up on the QuickJack (carefully) and tried to pull the wheels off it. That was a saga in itself that may or may not show up on a YouTube video and included the QuickJack flattening itself so far that one side wouldn't come up again. Yes, it was operator error and I fixed it by lifting the front of the car with a jack. Wheels eventually came off so I could inspect the brakes. They all look pretty good, I suspect that the front brake spindles and wheel bearings (Mustang II) would benefit from a regrease, but they look good otherwise. The rear drums are the older non-self adjusting kind so I carefully pulled them off, dribbled some brake cleaner on them to clean up the dust without blowing it all over the shop and set to adjusting them. Both sides needed a click, and adjusting the parking brake cables produced what feels like a working parking brake.

Poking around underneath it suggests that it's all pretty clean, but there is an oil leak either from the gearbox or the engine. I need to clean up the gearbox and check if I can see where it's coming from. I have to change the gearbox oil anyway, so that's not a big deal.

Oh, and it fits pretty well on a QuickJack 5000:

Seriously, what a vehicle. You are winning at life.

Trent (Generally supportive dude)
Trent (Generally supportive dude) PowerDork
9/13/20 10:43 a.m.

Four spoke revolutions are some of the best wheels ever made!

vwcorvette (Forum Supporter)
vwcorvette (Forum Supporter) GRM+ Memberand UltraDork
9/13/20 11:31 a.m.

Looks great in that colour too!

mr2s2000elise
mr2s2000elise SuperDork
9/13/20 11:36 a.m.

Congrats! 
 

hope it treats you better than the s2000

einy (Forum Supporter)
einy (Forum Supporter) Dork
9/13/20 12:53 p.m.

I have always loved the look of the Maxton Rollerskate .... super happy to see this on the forum!

Pete. (l33t FS)
Pete. (l33t FS) GRM+ Memberand MegaDork
9/13/20 2:16 p.m.

I am now curious about what is going on with the rear brakes.  If it's RX-7 running gear, the kind that self adjust ('81-85) have the clicky star wheel thing.  The non self adjusting type ('79-80) have two cams and locknuts that you access from the back side of the backing plate.

 

On the other hand, I'm also wondering about the Mustang II setup up front.  This is getting more and more interesting smiley

GoLucky
GoLucky Reader
9/13/20 4:19 p.m.

Beautiful 

BoxheadTim (Forum Supporter)
BoxheadTim (Forum Supporter) GRM+ Memberand MegaDork
9/13/20 8:12 p.m.
Pete. (l33t FS) said:

I am now curious about what is going on with the rear brakes.  If it's RX-7 running gear, the kind that self adjust ('81-85) have the clicky star wheel thing.  The non self adjusting type ('79-80) have two cams and locknuts that you access from the back side of the backing plate.

Err <fx: shuffles feet> that would be me adjusting the 81-85 self adjusting brakes. Everything on this car is a bit stiff from lack of use and the adjusters were backed off a bit too far and/or hadn't self adjusted. Giving them a click each and tweaking the simplistic handbrake cable just about gives the rear brakes enough purchase to hold the car while still allowing the wheels to turn.

 

On the other hand, I'm also wondering about the Mustang II setup up front.  This is getting more and more interesting smiley

Maxton only used the uprights with the OEM Mustang II brakes and mounted them to some nicely fabricated A-arms. I'll snap a photo or two the next time I'm poking around the area.

Do you by any chance happen to know if the "up to 1980" clutch slave cylinder is mechanically different (like different throw or something like that) from the 81-85 cylinder?

I'm still figuring out what the mishmash of parts is and given that the slave cylinder was recently touched I'm trying to figure out if they put the correct slave on. I have to have a closer look at the transmission to try and figure out if that's a 76 smooth case transmission or if someone just stuck a '76 engine in front of a 81+ gearbox and rear axle.

TurnerX19
TurnerX19 SuperDork
9/13/20 9:37 p.m.

Having lots of experience with all brands of hydraulics for racing cars, I would advise sticking with the Girling master cylinders. They are the most reliable, and are readily available in all sizes from Pegasus. So are rebuild kits if the bores have no pitting, which I consider unlikely do to age and your comment about the fluid.

Professor_Brap (Forum Supporter)
Professor_Brap (Forum Supporter) GRM+ Memberand SuperDork
9/14/20 7:34 a.m.

Is there photos? If so they arnt showing up on my end. 

BoxheadTim (Forum Supporter)
BoxheadTim (Forum Supporter) GRM+ Memberand MegaDork
9/14/20 9:32 a.m.

In reply to Professor_Brap (Forum Supporter) :

Yes, there are self-hosted photos and they should be showing up. What browser and OS are you using?

BoxheadTim (Forum Supporter)
BoxheadTim (Forum Supporter) GRM+ Memberand MegaDork
9/14/20 9:42 a.m.

In reply to TurnerX19 :

Thanks, didn't realist they were still available. That would of course be the easy button as ISTR someone mentioning that the Wilwood cylinders would have to be "adjusted" somewhat.

Pete. (l33t FS)
Pete. (l33t FS) GRM+ Memberand MegaDork
9/14/20 10:04 a.m.

In reply to BoxheadTim (Forum Supporter) :

Editing is hard on tablet so no quotes.

 

Trans is easy, if it is a smoothcase it is not a '76.  Smoothcase started with RX-7 production.  Where is the shifter?  If it is on an extension like a Miata it is '81-85.  If the shifter goes into the case itself, it is '78-80.

All RX-7 smoothcase clutch hydraulics are interchangeable.  The only real differences are, '78-80 had 10x1.25 thread pitch on all the hydraulics, '81-up are 10x1.0. (This is true for the whole car, not just the clutch) 13B cars had a restrictor valve in the master cylinder.  '83-85 12A had a funky shaped slave cyinder so one could access the bleeder screw with the top mount oil cooler in the way.

There is something odd with SOME FC slaves/forks where I had to shorten a pushrod by about 5mm but I could not tell you what combination of parts did that.

BoxheadTim (Forum Supporter)
BoxheadTim (Forum Supporter) GRM+ Memberand MegaDork
9/14/20 1:06 p.m.

In reply to Pete. (l33t FS) :

Thanks, I'll try to snap some pictures tonight.

From memory, the shifter and the speedo cable are going into an extension housing that is bolted to the rear of the main transmission.

Pete. (l33t FS)
Pete. (l33t FS) GRM+ Memberand MegaDork
9/14/20 1:15 p.m.

In reply to BoxheadTim (Forum Supporter) :

Sounds like you have a '78-80 trans if it is a smoothcase.

There was a VIN split in March of 1980, where they changed transmission designs.  If you have one of the later type transmissions, you can swap that tailhousing onto any '81-up smoothcase, including pickup and NA/NB/NC Miata.  Before that, the shift fingers and forks were secured with bolts, not roll pins. The remote shifter units have the main shift rod on a different location, so the shift fingers have to change.

I used to HAVE one of those.

Professor_Brap (Forum Supporter)
Professor_Brap (Forum Supporter) GRM+ Memberand SuperDork
9/14/20 1:43 p.m.
BoxheadTim (Forum Supporter) said:

In reply to Professor_Brap (Forum Supporter) :

Yes, there are self-hosted photos and they should be showing up. What browser and OS are you using?

Chrome on a phone. 

BoxheadTim (Forum Supporter)
BoxheadTim (Forum Supporter) GRM+ Memberand MegaDork
9/14/20 2:01 p.m.

In reply to Professor_Brap (Forum Supporter) :

Hmm, that's odd. I just tried Chrome on my brand new Android phone and it's showing the photos fine.

Hammeringman
Hammeringman New Reader
9/14/20 2:25 p.m.

I'm having the same issue with pictures. I'm using Firefox on win 10. Love the car. Great story behind it.

 

BoxheadTim (Forum Supporter)
BoxheadTim (Forum Supporter) GRM+ Memberand MegaDork
9/14/20 8:07 p.m.

OK, crawled under the Maxton again to take some photos, hunt for some leaks and do some cleaning. But first, I had to go and get some proper SAE tools. I only had a small set - basically one set of deep 3/8" sockets and a couple of wrenches, and didn't have some of the sizes I needed for the Maxton. Enter an Hammer Store coupon - get 20% off if you buy three ICON hand tools:

OK, onto photos of the transmission - I tried to capture the tail housing as best as I can as I need to identify what I have so I can get a new output shaft seal. The one on the transmission appears to be mostly responsible for oiling the underside of the fibreglass:

Photo of the shifter turret:

And yes, it's a smoothcase transmission:

While I was under there I also noticed some ugliness-in-waiting:

Yep, this doesn't look too good:

Looks like I should be able to fix it with a couple of dorifto-spec cable ties, but the fundamental issue appears to be that the lines are just a tad too short and I can't lift them up high enough to completely get out of the way. I suspect that the best way to deal with this is to make some braided hoses that just a touch longer.

It was also hard to overlook that we had an electrical egg spurt working on the car at some point. Like, really?

Last but not least, the PO told me that the car had always had this "special" pin in the hinge, but I suspect I really should find the correct hinge pin instead.

Pete. (l33t FS)
Pete. (l33t FS) GRM+ Memberand MegaDork
9/14/20 8:45 p.m.

That may actually be one of the late 80 units.  My friend's '79 looked a lot more skeletonized.

 

So yes, anything that bolts to a 1st gen will work, clutch actuation wise.  They all had the same form factors and the same diameter pistons.  Your main concern is going to be the thread pitch for the clutch hose.

ebelements
ebelements Reader
9/15/20 2:18 p.m.

I've never heard of these! What a delightful mix of so many recognizable roadsters. Just pretty.

Were these always rotary, or, like Caterhams/Se7en kits, kind of an "anything goes" sort of thing?

BoxheadTim (Forum Supporter)
BoxheadTim (Forum Supporter) GRM+ Memberand MegaDork
9/15/20 3:37 p.m.

In reply to ebelements :

They were designed to accept an RX7 drivetrain. I suspect that trying to fit something else might be problematic and not really possible without major surgery to the bodywork. There isn't much ground clearance as is, so if you were to fit a piston engine that's not a flat four or flat six - which likely wouldn't fit without modifying the space frame - you'd pretty much end up with the engine sticking through the hood so you can keep the transmission centerline where it is.

BoxheadTim (Forum Supporter)
BoxheadTim (Forum Supporter) GRM+ Memberand MegaDork
9/15/20 3:40 p.m.

In reply to Pete. (l33t FS) :

Time to get my thread gauge out then if I can find it so I can figure out the thread pitch for the hydraulics and don't end up having to remake some lines. Fortunately it looks like one can still get braided clutch lines for both generations of thread pitch.

I still have to figure out where the transmission came from so I can order the correct output shaft seal, though. Don't want the garage or the car coated in fresh Redline MT-90.

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