T5 Clutch fork....

[thesameguy]

Here's how the master cylinder stays full:



I'm not 100% confident in this. One thing I didn't account for is the size of the nipple on the reservoir. It's of course 5/16" so there is no "easy" way to connect that to a system based on AN fittings. If someone made an AN -4 or -6 to 5/16" hose barb elbow or 45 degree...well, then there would be. I couldn't find such a thing. So it's an AN -6 elbow and 3/8" hose and Oetiker clamps. I think it will be fine... it's 1/16" and nice squishy hose.

It makes for a nice install, although tightening the nut on the elbow is a little... um... tight. But it works.



Next/last is the brackets for the transmission end.

[thesameguy]

After a few false starts, I made this goofy thing:



It goes here:



The whole zip tie thing is temporary - I will pick up some actual hose clips ..... at some point. A company called NotcHead makes exactly the right thing... I'm just not prepared to fork over $10 in shipping on a $20 part right this second.

I will probably fix up some mounts for the hoses at some point, but its good enough for testing right now.



Bleeding the clutch was a snap - I used a syringe with a long length of hose on it and the other end connected to the bleeder valve, then gently pushed 100cc of brake fluid through the bleeder and back up into the reservoir. This reverse bleed takes air the way air wants to go - up - and worked immediately.

'Everything seems to work great...

https://youtu.be/Wq0FP0oOtVw

Clutch effort is a bit heavy, to be honest, but it's a pretty short throw and I don't think it will be an issue. If I do end up finding it fatiguing, I think moving to a non-compact master cylinder may be an option with the space I've got. Since I wasn't sure how that was gonna look initially I didn't want to take the chance, but since all these aftermarket master cylinders use the same spacing a change down the road should be minimal trouble.

I literally have no idea what's next at this point. Probably would be well served by a nut & bolt check since I've been pretty haphazard with "tightening" thus far.

[john keefe]

When's it on the road? A TON of work, and great documentation with the pics. Not being a smart-ass at all, but aside from the satisfaction of accomplishing it, was it worth it to get away from the cable linkage?

BTW, your vid looks like a decades old, stock Hollywood clip used for hospital IC scenes, with the mechanical respirator moving up and down. Would seem more realistic, though, if you had the bellows sound effects, maybe also a beeping pulse monitor in the background.

Was wondering how you'd keep that reservoir stable. Have you air-tested it live with wheels moving while up on jacks? Quick engagement? I'm guessing there's enough throw left to your pedal stop to compensate for clutch/tang wear (i.e., your full-clutch point occurs well before you hit the pedal stop).

One way around a heavy clutch, is to only use it for take-up in 1st. First, though, you gotta' be a cheap bastard like me who loathes spending $$$ or time on clutches... All the more reason for my appreciation of your results.

I learned from my cousin to up- and down-shift, double-clutch, heel-and-toe, etc. w/o the clutch. He did a lot of road and drag racing, actually ended up being Captain for Novato Police and started the whole "Beat the Cops" Night races up at Sears Point to curtail the street racing. Had a very cool '56 tubbed and caged Bel Aire that turned mid-low 9's, painted and lettered all old school police black and white. He got on me early about listening to the revs change, and feeling the shifter to know when the transmission was ready to fall into gear. That's back when all his other hot rod buddies were betting each other who could slam-clutch-shift quickest, and scattering clutches, flywheels, and gears all over the road. One of them almost blew off a foot, before they all wised up to scatter shields. You miss sometimes and cringe at the grinding, usually when I'm trying to demonstrate it to someone else. Go figure.

But, that's one way to make a T5 last, it does save a lot of worry and $$$ on at least one item, and it really makes you a LOT more involved in the actual driving. Not ideal for drag racing, but the only thing you're really babying is waiting a touch longer for the right revs; if it's geared properly, you're usually dropping into the best TQ range anyway.

[thesameguy]

I think I'm probably a couple weeks from getting on the road. This whole thing has taken so long I've lost track of the details of the project. I think the only "major" things left to do are put oil in the gearbox, bleed the brakes, and reinstall the upper intake manifold. But I'm fairly confident I'm forgetting things, so I'll probably need to go through the whole thing, look at everything I touched, and be sure it's right. (I'm assuming I set up the diff right, too...)

One thing I really like about HTOBs is that they are self-adjusting. The pressure plate fingers are what compress the slave cylinder, the throwout bearing is always in light contact with them. As long as you keep fluid up (and you aren't outside the mechanical limits of the slave cylinder) no adjustment is ever necessary and pedal travel is always the same. It's a great technology (and I'm pretty sure Saab pioneered it )

I never had problems with the cable & the David Godfrey manual adjuster, but I did save a few ounces (the fork weighs a TON!) and eliminated a maintenance point so I'm happy there. And, the fact I was able to eradicate an NLA part or two (the cable and the fork) is an added bonus.

The experiment and the documentation is well worth it... I know (hope?) I will use all this info again, as this is the recipe for my Saab-motor-in-an-XR4Ti project I wanna tackle, maybe later this year. And having searched for days or weeks for other people who'd done something similar only to have no info and no pictures... hopefully this helps the next T5'd XR4Ti who needs a clutch fork.

I'm not *too* worried about the pedal feel. Everything will be different in the drive I'm sure, but it doesn't seem *impossibly* heavy. It's not light like a modern car, but I don't think it's heavier than my Alfa Romeo clutches and they have a very long throw. It might be a problem if I had an intense commute, but I don't. I *think* it'll be fine.

[thesameguy]

I'm reviving this thread, as I'm becoming less satisfied with the clutch feel on the car. It's absolutely fine for driving, but I think it might be too heavy for traffic. I found some documentation from MDL:

Here are the volume displacement requirements for the Tilton bearing assembly:
Travel = Volume (cu/in)
0.4” = 0.483
0.45” = 0.543
0.5” = 0.604

With my .82" master and 1.1" stroke, I'm moving about .57 cu in of fluid, thus moving the HTOB about .55" at full pedal stroke.

My two options to decrease pedal effort are to move the master cylinder higher on the pedal or decrease the diameter of the master... decreasing the volume might require increasing the stroke.

It's somewhat difficult to change the lever on the pedal as there isn't a huge amount of space between where it is and the actual pivot/mount. It's very easy to decrease the diameter of the master.... a couple nuts and a couple screws (and $100). A .750" master puts me at .48 ... a loss of .17" of movement at the slave. I don't know what the means in practice, maybe nothing! The next option would be going to a Wilwood master, which add the cost of some copper tube and a couple tube nuts.

Not sure how motivated I am, but before I forget all this I figured I'd write it down.

[thesameguy]

Hey y'all ...

Been a minute, but I wanted to update this thread....

The irrelevant part is that it was crazy hot lot year, and it's been crazy wet this winter, and the XR is a lot worse off for it. I think I may be reaching the point where it's not going to be a streetable car anymore. Most of the exterior rubber is beyond shot - windows, sunroof, everything has leaked. Admittedly, the rain this year has been extreme, but I think the damage may be done. I think '23 is the last year for this car. I'll either dedicate it to track use, or sell/scrap it. It's killing me, but I don't know what else to do.

But, I don't like to leave projects incomplete so....

After a lot of miles, I came to the conclusion the clutch was just no good. The pedal effort was starting to be a problem, and the clutch travel was so short that traffic was borderline unbearable. I yanked the Tilton .810" master cylinder and replaced it with a Wilwood .750" master cylinder:



The Wilwood has an integrated reservoir, which is very poorly located... but workable. How often are you in a clutch reservoir anyway? The other annoyance with this MC is that the outlet is on top, facing the firewall, so now I have a goofy clutch line:



I do not like that it goes up at all, because bleeding is worse, but the smaller bore and extra 1/4" of travel makes a difference. I don't have many miles on it, but clutch effort is substantially less, and it's much easier to modulate. I cannot find an SAE-style master with more travel, so this damn well better work out.

Fortunately, both the Tilton and Wilwood ARE SAE-style, so it's basically plug & play. The flange is the same, the thread on the pushrod is the same. It was a one hour operation swapping them and making a new hydraulic line.

Thread-related, the motor mounts in the car was awful. Simply unbearable vibration. My SPG has solid motor mounts:



and was less annoying to drive! I don't have an explanation, but it made me even more irked at the whole motor mount thing. Maybe what I got shipped were solid rubber mounts or maybe they were old stock and dried out, IDK. I jumped on rockauto, bought a pair of DEA hydraulic mounts for a T-bird, and bolted them in. While doing so, I tapped the new mount for an M10-1.5 thread and used 10.9 bolts instead of the 8.8 studs. I realize the studs are safer, but 8.8 hardware on motor mounts gives me the willies... so 10.9 bolts and threadlock. I'll check back on them in a few hundred miles and make sure they're still tight.



In case anyone cares, those bolts are M10-1.5 x 70mm with an extra thick fender washer. This yields about 12mm of engagement in the motor mount, which is maximum. Any longer starts digging into the rubber of the mount. The old studs did not have this much engagement, for whatever that's worth. I'll tell you, installing mounts without that top stud is cake! Maybe worth the price of admission!

No more cabin vibration, better clutch feel... we'll see how 2023 goes.