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Discussion Starter #1
Hi folks,

I've got a '67 duetto with Dunlop brakes.
One of the front calipers is leaking slightly.
Can I buy Ate calipers and bolt them on or is the bolt pattern different?
IAP shows Ate's for '69 on.

Thanks,
-Clark
 

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You'll need to replace everything from the spindles out, it's not a bolt-on replacement. The details are well covered in this thread--1st gen ate brakes--as well as a few others.

Incidentally, there are rebuild kits available for the Dunlops as well as rebuilt units. Alfa Stop in the UK carries them as does Highwood Alfa (also in the UK), as well as others I'm sure.

Thanks,
Alex
 

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Discussion Starter #3
I have a whole front end from a '74 105 series car. I'll just put the spindle and rotors on from that and get new Ate calipers. I'm not worried about keeping the car all original.

Thanks,
-Clark
 

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2L spindles are a bit different from the duetto's. Slightly taller, a bit like addint the GTA knuckle riser. Also, they have all right hand lug nuts, while the duetto had left and rights, Discs are bigger in diameter, and the ATE calipers are larger than the 1600 ATE's.

1600 ATE MC is either 20 mm - manual brakes; or 22 mm for the vacuum boosted ones.

2L rear brakes are the same as early ones, but added a rear brake limit valve.

It's an easy change, but you may need to get the adjustable upper suspension arm to get the geometry right. Don't know if the front cross member was changed for the taller spindles.

Robert
 

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Discussion Starter #5
I'm in luck. My buddy used to look after this duetto for the previous owner and he did put adjustable arms on it.

Thanks for the info!

-Clark
 

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Dunlops

Goldline brakes in Seattle can rebuild your Dunlops. It is less hassle for you. John does a great job and he's very easy to talk to with great advice. I am swapping out my rear axle which is Dunlop based and looks Rube Goldberg-ish but keeping my front Dunlops.

The rear Dunlops are a complicated arrangement compared to ATE's. The fronts aren't. I picked up an ATE axle with supposedly low miles cheap and locally. It won't be cheap if I install it and it doesn't have low miles, but my springs are sagging in the rear just like me so why not swap out the axle now. Rebuilding an original rear axle LSD is expensive and you need a supplier which has all the proper shims to properly set lash in a LSD rear axle, or you bite the bullet and spend 1000 or so for one of the Alfaholics LSD's.

Front spindles are easily available with all the 70's 80's 90's spiders running around, so either way is easy, Goldline or swapping out the front spindles. I'm not sure what it will do with the balance of the original braking system however, that is beyond my knowledge base. I'll let you know.
 

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I am swapping out my rear axle which is Dunlop based and looks Rube Goldberg-ish but keeping my front Dunlops.
Rube Goldberg shakes his head in amazement when he sees the Dunlop rear setup. Somehow, though, they seem to more or less work.

Is it possible to run Dunlops up front and Ates at the back? I thought the MCs were a different size on the two systems. But perhaps I'm mistaken.
 

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Is it possible to run Dunlops up front and Ates at the back? I thought the MCs were a different size on the two systems. But perhaps I'm mistaken.
I don't see why not. Especially if you put an adjustable proportioning valve in the rear brake line, and fooled with the front-rear bias a bit.
 

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I don't have a proportioning valve on the Dunlop based duetto. I did not have one on the early ATE style with a single booster euro car either. The first ones I saw were in 69. You can find them easily enough used.
 

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I don't see why not. Especially if you put an adjustable proportioning valve in the rear brake line, and fooled with the front-rear bias a bit.
That makes sense. I'll be interested to see how this goes.

Thanks,
Alex
 

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The early Alfa proportioning valve is often gummed up or corroded. But Tilton makes adjustable valve that all the racers use. Knob or lever adjustment.

Robert
 

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In my TS I'm putting parts together for I'm using a proportioning valve I bought from Larry at APE. I hope it's not gummed up!

Robert what is the distance between ATE front brakes 67 and ATE front brakes 69 on for the mounting bolts?
 

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In my TS I'm putting parts together for I'm using a proportioning valve I bought from Larry at APE. I hope it's not gummed up!

Robert what is the distance between ATE front brakes 67 and ATE front brakes 69 on for the mounting bolts?
I think the 67 spindles are 1/2 inch closer spacing for the caliper bolts than the 2L (70+). 69 (1750) I think are same as the 2L.

Anybody know for sure?

Robert
 

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The question I'm unclear on is there doesn't seem to be any advantage to small spindle ATE mounts. seems even with Brembo's added the 69 on spindles are still the way to go?

Right?

Thanks,
Wes
 

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Let's see if I can catalog the options:

1. 67 Spindles:
--Brembo Calipers from Milano gives lower unsprung weight
--L and R wheel lugs (is that a good or bad?)
--Smaller brake discs and calipers
--lower height affects suspension geometry (see later comment)

2. 2L spindles
--Larger brakes and calipers gives stronger braking
--All RH lug nuts (easier to find for fancy wheels)
--Taller spindle gives "Knuckle Riser" effect - mostly better camber on strong cornering

BTW - the 2L front has a larger sway bar, 'though aftermarket bars are available too. Mine is a 27 mm Shankle. While it's apart, check for wear on the lower ball joint and steering joints. Replacing the lower A-arm bushings is common, and it's very good to use this same one on the inner upper arm as well. Polyurethane is good for the sway bar bushes and the castor bush, but NOT the upper or lower A-arms!

I also found the idler arm needed rebuilding. If there is play, replace the bushing and possibly reweld the shaft too.

I added zerk (grease gun) fittings on all the ball joints and steering balls, as well as the idler arm.

If you put a stronger sway bar in, consider welding reinforcements at the bolts. Also, if the engine is out, weld in some reinforcement for the steering and idler box, and the suspension cross piece, which can also be seam welded for strength. (Later cars had heavier sheet metal in these areas and were notably stronger. Probably only important for racers). There are threads on these reinforcements.

You can also add a rear sway bar from a later car (67 didn't have one) really easy. Four body bolts, and the two trailing arm bolts they connect to. The Duetto usually does not need anything stiffer in the rear sway bar, 'thou serious TT users fuss a lot with this bar to get perfect balance (after changing everything else).

If you want to replace the rear Dunlop brakes, get an entire 2L rear axle. That gives you a LSD differential as well as the ATE brakes; early 2L LSDs were 4.56, later ones or sedans were 4.10. You have to change the rear u-joint yoke or get a 2L spider driveshaft (sedans had a different length). All rear ATE's are the same. I put in a tilton rear brake limiter instead of the ALfa 2L one, but I ran with none for years too. Be sure to get the special 9 mm shoulder bolts for the u-joint. Check the olive on the TX output shaft for wear (lots of vibration!) and replace the driveshaft bronze bushing if needed. Check the gubio very carefully, and consider getting one of the reinforcements, or get Spruel's super strong replacement for the gubio.

The 2L diff, axles, and drive shaft are all stronger than the Duetto's. And heavier!

Alfaholics can help you change the driveshaft center support for a heavy duty one. There is one bearing here to check too. Be sure to balance the drive shaft.

Your 67 trailing arms are the best ones. They use a small front bushing, which gives better handling; replace f and r with stock trailing arm bushings if needed. Do not use poly bushings in the trailing arms. [Some will disagree with this], but poly at the upper T-bar cones is good, as well as the rear sway bar bushes if you add a 2L rear sway bar.

The Duetto rear usually sits too high, you can shorten the springs as much as one turn. This will give you about the same rear spring stiffness as any of the special kits. The light Duetto really is happy with very light rear springs and shocks.

Choose your poison on the front springs. Or cut one turn off and adjust height with spacers. (That was John Shankle's original trick). Use Koni reds on full soft at the rear, and Koni Yellow at mid setting on the front if you use stiffer front springs, or Reds on mid to stiff if you keep stock fronts.

With all this, you need better tires. I have Panasport 14 by 6 with Yoko A008R's in 205/60-14. With the 4.56 diff, these tires are the same dia as OEM, so the speedo is right on. Big tires makes parking an arm strength test, but they stick like glue.

All this will give you remarkable handling. 1 inch lower, so watch out for the dips or you'll buy a new oil pan and motor mounts. Drives like a slot car! Beats 'Vettes at the autocross with good tires. Cornering limits may be well above your fear level!

**************

OTOH - the original Duetto suspension is really sweet handling. Light, nimble; thrash about all day with little risk. It's a lot of what we love these cars for, and the Duetto is the lightest of the spiders (by more than 500 lbs for some of the S4's), so it's really a blast. The wide grippy tires are the biggest source of losing this nimble feeling.

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A small issue: you have to be an Alfa Jedi to see any of these mods. The only thing visible is the LSD diff center casting.

Good luck. Let us know what you tried.

Robert
 

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Robert;

Thank you. It seems then that there isn't much advantage going with the small spindle front ATE's except being able to use lighter Brembo's, but that doesn't seem like much advantage.

I rebuilt a LSD with new friction discs from Alfaholics and the lash was rechecked so I have a rebuilt 4.56 ready to go. At the time I was looking for new friction discs, Alfaholics recommended using my original 1967 Euro ATE equipped lighter rear axle with their LSD, but I decided to go with what I had purchased, a 70's 4.56 LSD.

George Willet told me the same thing about cutting the springs, but he doesn't "go for" a rear antisway bar.

Thank you
 

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Now just to throw you a wrench ;), you can also get late 1600 spindles that have the same height & geometry as the 2000 ones but have the 3" spacing that allows the use of the Brembos - hard to find in the US though ...
 

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I'll have to see what came with my Montana doulikecars duetto, 3.0" short or 3.5" long. Still learning all the time.
 
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