Internal Slave/Hydro Throw Out Bearing?
 

Engine is out and am toying with going with an internal slave that rides on clutch center...Gets rid of all the screwed up geometry rod to fork, gets rid of the fork etc.

Down side is if it goes bad the trans or motor has to come out...

Thoughts?

Steve H
SPF 1764

https://www.summitracing.com/parts/m...BoCvIAQAvD_BwE

External slaves for me.

Worked on enough internal failures.

Internal has more reasons for failure.

Had a HTOB eat itself twice. Went to an external slave and the clutch was much easier and never failed again. Plus if it did fail, no need to drop the entire trans to fix it.

Get the Mike Forte kit. You'll not regret it.

Hydraulic throw-out bearing on mine. Never a problem. I'm not sure what make / model, but transmission is out right now so I could check.

Edit: I can see no identifying marks on mine. The design looks very much like the McLeod design from what I can see online, but my car was built in 1991 and the HTOB is steel, whereas the new McLeod HTOBs all seem to be made of aluminum.

What mine looks like: https://www.5speeds.com/v12hydraulics.jpg

From McLeod (current product):
https://b4b4c1e06d06f0b8f86a-3c942b7...rge-385-v1.jpg

I have used a McLeod HTOB with 3 years of racing without any problems. Just prior to pulling the engine the year it tasing not working well, but that was due to boiling the fluid out of it and once I held the old fluid and refilled, it worked fine. I am going with a Quarter Master setup this time and like the look of it. The Quarter Master HTOB comes with a stud to replace one of the bolts on the front of the transmission and there is a corresponding cutout on the bracket for the HTOB that fits over the stud and locks it in place so that it does not spin on the shaft during install after you have set the distance from the forks on the pressure plate.

I did notice that during install, while I was underneath the car and wrestling with the transmission that the McLeod had a tendency to spin on the input shaft I was never fully sure if I got it back to the right depth.

No major concern with me, but then again it is a race car and the engine comes out every 2-3 years. Also, with the Mark III you have more room for an external fork than I do with the Mark II.

Jim

I bought a used replica - already built. It has a HTOB. No idea what the make or model is. The car has about 20-25K miles on it. It was completed about 2003.

The only problem I ever had was self inflicted. I flanged the exhaust, and the new plates were close enough to boil the hydraulic fluid. I drained the fluid, rerouted the line, refilled and blead the air. Bleeding the air sucked. The HTOB has no bleed port. I had to loosen the hydraulic line, which included making a wrench.

I have read that there are some details on installation and setup that if done in-correctly causes failures. I also think there were some poor quality HTOB sold at one time (perhaps they're still being sold). These two factors gave them a bad reputation.

I believe there are HTOB sold with a bleeder port. No idea how to determine quality, but I think there are some OEM units sold, which should be reliable.

Bottom line: in theory, arguably in reality, a HTOB is a very clean install that elegantly solves a ton of issues that other designs have. If it fails, it requires disassembly. If it is reliable, you will wear out a clutch before it fails.

So in short all the arguments boils down to one thing, if it is reliable all the arguments against it are mute.

All the arguments why an external slave is better is based on, it is easier to fix, when it fails.

Easier can mean a lot. Money ,Time, Parts, ECT.

If you insist on an internal slave DO NOT get a McLeod one. Had 2 fail. Their o ring arrangement at swivel joints is junk. Tilton is much better.
Went with an external slave after those failures. No problems in 20,000 miles.
There really is no advantage to an internal slave.

HTOBs are extremely sensitive to mis-alignment. I chose to change it out instead of trying a third time to get the alignment fixed. Each trip to the mechanic was a kilobuck. Should have replaced it with the Forte kit on the second try.

Depends on what transmission you're using. My race car uses a stock T56. I use the stock factory hydraulic bearing. It's easily lasted 4 seasons of racing without a hint of failure.

If you have to use an aftermarket part, I'd probably use an external slave.

Thanks fellas
 

Thinking a tilton?

Tiltons are well regarded. I did not use one because I like using a total package (flywheel, clutch, pressure plate and HTOB) from the same manufacturer and Tilton unfortunately does not offer a clutch for a top loader currently.

Htob
 

My car was built in 1998 with a Mc leod bolt on htob. On the top loader it takes the place of the front bearing cover and t.o. bearing slide tube. It had some corrosion on the piston, so I elected to go with external hydraulic slave. Had to find an original nose piece, and Mcleod provided a "modified" pressure plate ( the diaphram fingers were cut back for clearance as the std tob tube was larger diameter than the HTOB TOB set-up was.
That set-up was never good, cutting the fingers looses about 20% of the leverage of the fingers, and the cuts on the fingers leaves a sharp edge that cut into the bearing face and causes the system to "hang-up" So I have decided to see if I can get the HTOB to work and be reliable. Right noe my problem is one of the hose connections ( banjo fittings) leaks. ( this is an older set up with banjos, not swivel fittings.)
More later

Tedl

Comment
 

I am running a TKO600 which i believe is a sibling (or at least a cousin) of the T56?

I have had bad luck with the Mcleod HTOB. Much happier with the reliability of my external package from Forte Parts Connection. The fork had to be modified to fit but it works great. A little stiff but it was stiff with the HTOB too.

John

I HIGHLY recommend the Tilton throw out bearing. Tilton uses a lip seal in their throw out bearings, most others just use an o'ring. The lip seal is infinitely better and much more durable. There is no other choice in my opinion.

6tn: talked to Tilton today, unfortunately they have nothing for a 4spd toploader with the big input shaft. (1 3/8 dia at the splines.
We are lucky to have in our area, a company known as B.A.T. aka British-American-Transfer. A parts supplier geared to the sedan racing crowd. They sell oil coolers, all types of hoses, AN fittings .and other stuff. They are on the web under their BAT name. Erik is the guy to talk to. I used them for all my fluid lines when building BDR's for "Sucoast Cobra".
Anyway I had him make me up two hyd -3 lines with the banjo fittings which solved the leakage at tha point .McLeod wanted $165 for two lines, BAT price $45. I'll see what it looks ilke in the AM.

Dash -3 lines are too small for fast shifts. They can't pass fluid fast enough. We found that out the hard way when Car and Driver destroyed a clutch when they were "testing" our car.

*Edit: It was actually Motor Trend that killed that clutch.

I think I remember that C&D story - many years ago.