Indigenous Se7en - adventures with Maxton Rollerskate #43

In reply to BoxheadTim (Forum Supporter) :

Output shaft seals "should" all be the same, they all used the same driveshaft as far as the transmission end is concerned.

heh. Atkins Rotary shows the same seal from '71-85.  It's a different design from the '90-13 Miata 5 speed seal but I bet they would interchange functionally.  42 years!

edit: It occurred to me that the '86-91 RX-7 and '90-13 Miata seal looks a lot different with its funky oversized dust boot, because starting with the '86 RX-7, independent rear suspension was used, so the seal no longer had to deal with a driveshaft that was constantly plunging.

In reply to BoxheadTim (Forum Supporter) :

Been off the forums for a bunch of years but glad to be back and see that # 43 is out of Barry's storage unit and back on the road!

Chuckling at the picture of your tach with the plastic redline indicator sitting at the bottom of the gauge.  Mine's in exactly the same place on # 16 - it's on my to-do list.

Just finished adding a steering wheel ground last night to fix my horn problem and now I see the picture of yours.  Thanks for sharing, but just a bit too late to save me from the extra work.

In reply to BoxheadTim (Forum Supporter) :

I have a nicely rebuilt master cylinder (either Girling or Lockheed, I can't remember) that came off of a Formula Ford. If it's something that you can use, I'd be happy to donate it to the project.

Lockheed.

Are you wanting to keep the vdo gauges boxheadtim? If so, i have the same tach with the red still attached and some other matching  2 1/16 in my box o used gauges 

In reply to Woody :

Thank you, appreciate it. Unfortunately that master cylinder isn't going to work for the Maxton as the inlet and outlet connectors are in the wrong place.

Dusterbd13-michael (Forum Supporter) said:

Are you wanting to keep the vdo gauges boxheadtim? If so, i have the same tach with the red still attached and some other matching  2 1/16 in my box o used gauges 

Yes, definitely planning to keep the VDO gauges as those are original to the car.

Not yet time to declare victory on the clutch front yet, but after swapping out the clutch slave and the clutch line for new parts from RockAuto, the clutch bled fine and I don't get the "master cylinder slow to return" issue anymore. Haven't driven it yet as I'm planning to change out the gearbox oil in the hope that it's just a little low on 28 year old fluid, and also change the diff oil before I drive it again.

Gah, guess what sort of copper or aluminium drain plug washer size I don't have amongst my assortments? That's right, the M18 one that I need for the transmission. Guess I'll have to wait on Amazon Racing Supplies for that one. Transmission is currently draining and I really don't like the consistency or the colour of the oil that came out. I suspect it'll be much happier with fresh MT-90.

Oh, and I also learned that if the gearbox ever has to come out, I get to pull both gearbox and engine together. Rear crossmember/gearbox mount is welded in and there is not enough space to move the engine forward to just drop the trans. Which I probably couldn't do anyway because I doubt I can get at the upper bellhousing bolts with the gearbox still in the car.

In reply to BoxheadTim (Forum Supporter) :

Designer must have spent too much time with MGBs, Spridgets, Lotus Elan, Seven.etc. There are a few others as well where the gearbox won't exit prior to the engine.

In reply to TurnerX19 :

Agreed, some of the inspiration from old Brit metal has been taken a little too far.

Well, the stuff that came out of the gearbox didn't look too hot:

While poking around underneath it again, I also noticed that the OMP appears to be leaking somewhat. I guess that goes on to the to-do list also:

In reply to BoxheadTim (Forum Supporter) :

Have you watched the old Motorweek episodes where they built one?

https://www.youtube.com/watch?v=xpba3LT7q9U

In reply to Woody :

Yep, watched it multiple times already. That's almost 50% of the Maxton videos on YouTube, but I intend to change that a bit .

I remember seeing the Motorweek blooper reel at the end of that year. Craig and Pat had just finished gluing in the carpet, said, "And we're all done!", stood up and passed out from inhaling the vapors. It was priceless. I wish I could find that video.

In reply to Woody :

That would be a great find. I recall them mentioning that they were getting a little baked while glueing down the carpet, but I don't think they put the blooper reel on YouTube.

Finally got the Maxton back together, at least to the extent that made it drivable. The diff oil that came out of the rear axle definitely did not look any better than the one that came out of the gearbox, just a different colour. So after changing out those fluids, it was time to take it out for a spin. Well, right after I ziptie'd the oil cooler lines up a bit to stop the steering shaft from munching away at them.

Good news, the clutch issues are fixed. It looks like the rebuilt clutch slave cylinder was leaking a tad and between that and a clutch hose that had seen better days - probably about twenty years ago - it was overdue for retirement. The gearbox is still a tad stiff and I'm not sure the synchros are in that great a shape, but as usual, Redline magic fluid - in this case MT-90 - seems to do the trick with the much improved shift.

The test drive - which was maybe about 15-20 miles, if that - highlighted a few additional issues, though.

• The rear axle likes to bunny hop on rougher surfaces. I know, we're dealing with early 80s technology here, but I think this can be improved.
• The carb does not like to supply fuel in sharp corners. The route included some of my favourite local hairpins and pretty much every time, I had to wait until the car was straight before getting on it, otherwise it displayed definitive signs of fuel starvation. Also, the fueling isn't set up well below 3500 rpm. Between 3500 and 6000 the engine goes nuts, below that it's about as responsive as I am early on a Sunday morning.
  The PO said he rebuilt the carb and I'm hoping that he didn't replace some of the RB specific parts with standard parts. RB supplied these carbs with a modified emulsion tube to correct fuelling at the lower end. Although TBH it feels like it may need a bit more rather than less fuel at the lower end. Either way I have to pop the carb open anyway to replace the top gasket as mentioned in another thread. As it is I'm not risking running it during an Auto-X or track event, at least until I have a spare 13B.
• I had one scary moment when I thought I had almost lost the brakes. The pedal almost went to the floor before retardation happened. Pumped the pedal a couple of times and it came back for the rest of the drive. Not sure if I blew something or if the soft lines are also playing one-way valves like the clutch line may have done. Guess I better find out what those hoses are from and replace them.
• The oil temp gauge has a bad contact, so it works about a third of the time. The fuel gauge appears to be pegged at full all the time. Let's hope I can fix that without having to drop the tank (which would also require me to drop the rear axle).
• I think the exhaust may be leaking a bit
• Got to find a way to stop the passenger side harness from rattling. That drove me nuts.

So all in all, still within the resurrection phase, but I'm making progress. And the test drive showed again what I already knew - rotaries work a lot better when you beat on them. It idled much better when I came back from the test drive.

Car looks good.  The color is great. 

Make sure the float level is high enough. This can cause both symptoms you describe. Those emulsion tubes need to be emersed exactly the right amount, and corner starvation is classic float level.

Brake pedal issue could be pad knock back.  Symptom matches what you describe.  So maybe check front wheel bearings?  I get that issue on track after a series of esses even with tight wheel bearings.

TurnerX19 said:

Make sure the float level is high enough. This can cause both symptoms you describe. Those emulsion tubes need to be emersed exactly the right amount, and corner starvation is classic float level.

Thanks, I'll definitely look into that. The PO rebuilt the carb and I don't know how deep he went, but I could see that affect the float level.

sevenracer said:

Brake pedal issue could be pad knock back.  Symptom matches what you describe.  So maybe check front wheel bearings?  I get that issue on track after a series of esses even with tight wheel bearings.

Front wheel bearings are on my todo list, so I'll check for that. The odd thing is that it happened on what was the straightest, mildest part of the drive.

Either way the rubber brake hoses are 28 years old so it's probably time to change them.

Just an FYI, if they used rear shocks from the RX-7, Fox-body shocks will fit with some trimming of the lower eyelet.  KYB AGXs are relatively cheap and have 8 ways to get the wrong damping 

With 175lb springs, 4 feels too stiff.  I guess they are like toasters that go to 11 but turn bread into charcoal at 3.