Engine and Transmission Tech

The McLeod axial slave cylinder/throw-out bearing devices (HTOB) seem to be widely used in V8 conversions. But they are expensive and seem to have reliability problems. Auto manufacturers used similar devices on some of their car/truck models. These tend to be cheap because they were mass produced in the millions, and they were also engineered for reliability; parts like this tend to last well in excess of 100,000 miles. One example was used by Ford in T-5 applications with a variety of engines including modular V8s, 302 and 351 V8s, as well as a variety of V6s. The vehicles included vans, trucks and Thunderbirds. The one exception is Mustangs which always used a cable operated clutch. Anyway, this HTOB is Dorman part number CS37897 and I see that Summit sells it for about $78. It should fit any T-5 application using the standard length Ford T-5 input shaft (94-95 Mustang transmissions are probably excluded). I also found that GM also has HTOBs for a variety of V6 and V8 applications that can be bought for under $100. I would think these are worth checking out…

I agree. Factory parts are hard to beat. My McLeod HTOB has not let me down in 13 years, though. I guess I'm just lucky.

Glad to see you here, Larry. You have much knowledge to contribute. Waaay more than I ever could.

I have been convinced in my own mind that I needed a concentric slave for space constraints; I didn't want to sacrifice foot room due to an external clutch actuator. But, I am having trouble finding a "reasonably priced" option. I looked at the Dorman CS37897 specifications, but it says 1.0313 bore, and i just measured my T5 bearing retainer at 1.437. I can't find a complete Dorman catalogue on line that lists the specs for bore. I'll keep looking, or figure a way to use the TO bearing arm with some Rube Goldberg operating mechanism.
Dennis

I've gotta say, the HTOB is a money maker for me.
When they fail you get all the additional labour to pull the trans.
And as a bonus you get to sell a new clutch to replace the oil soaked one.
Personally I'll take a conventional TOB any day.
Cheers
Fred

I'm with Fred on the slave preference but that being said, the Zetec swap on the Mgexperience board used the Chevy LS1 HTOB with the Ford T5 with AN fittings. The newer Ford with the pivot on the other side can get away with the shorter arm and Nissan slave. The GM Buick V6(H body cable type) is a similar setup for the Buick V6,300 V8 guys.

I agree with Fred. Why put a slave cylinder inside a bellhousing when you can put it on the outside and change it in an hour if you have to?

It is strange that the ID of the Dorman part is 1.03 inches because the standard shaft diameter for a T-5 is 1 and 1/16 inch; 1.06 inches. Perhaps this HTOB is not for a t-5, yet it is listed for 351 V8 applications in an F250. I cannot imagine that this transmission would have a smaller diameter input shaft than a T-5, but who knows. Looking at clutch disks for such vehicles they all seem to fit on a 1 1/6 or 1 1/8 diameter input shaft... Anyway, all of these OEM HTOBs have flanges with bolt holes so they are designed to bolt to the transmission itself and so do not need a sleeve around the input shaft; it is part of the HTOB itself. I looked through the Dorman web site at all of the slave cylinders and there is no clear evidence that any HTOB they make is actually intended for a T-5, but there are several for newer transmissions (Viper, new Mustang, Camaro/GTO).

Larry, T5 was never in the Ford truck. It used Mazda or another brand trans.

I just finished my external hydraulic setup for the T5 in my TR7. Or I should say, I finished Rev 2. I bailed on Rev 1 before making brackets for it ($12 toyota slave cylinder). I'm hoping Rev 2 works, but I'm worried about how stiff the pedal may be. I considered the hydraulic TOB route, but I too prefer a conventional TOB and external actuation. So far, all my upgraded brake parts as well as my clutch master and slave cylinders are from production cars. Cheap and easy to find, if you can remember what you bought! Right now, I'm 1:1 for master and slave cylinder diameters pushing on the mustang clutch fork. On paper, it's perfect for clutch pedal travel and clutch fork travel. Who knows what it will feel like.

Mike, probably will be fine. A lot of the Ford guys use the 3/4" Nissan slave with 3/4" clutch master. Even with the clutch fork shortened 1", The pivot for the cable clutch fork is further away and gives more leverage than the old style, the diaphragm style pressure plate helps too. If someone wants to replicate the same thing with the Buick V6 or 300 V8, Use the cable clutch bellhousing from V6 H body.

Jim, good to hear that it may work. I need to order a hose and try it out.

Of course, I did it the hard way. Who else has 13/16 master and slave cylinders? I annoy myself sometimes.

Mike, Hey whatever works! Your 5.0 looks like it belongs in the TR7!