wonele67

Alright, I'm about ready pull my hair out here!
I have a '67 Mustang, have a Mcleod 1300 series Hydraulic TOB set up. The car came with it when I bought it. The only thing I did was change from a Lakewood Bellhousing to a T5 Bell, the bearing ate itself last year.
Contacted McLeod and they had to make me up a new one. A week ago I heard some strange noises, thought to be TOB.
Pulled the trans. TOB looked great. Contacted McLeod and they had me re-do my measurements. They felt I needed a shorter piston in the bearing.
Got it, installed it, it's WORSE.. no noise, but it's grabbing AT THE FLOOR.. and not disengaging didn't make it 1 mile from the house ..

WHAT am I missing? I adjusted the clutch pedal rod as much as I dare... what else???
I need help here..
I'm thinking of throwing the towel in on the Hydraulic and going to a cable clutch... very disgusted.

racer_dave

so all this started after changing the bellhousing... what was the difference in height between the two? I run the Howe version of there on my racecars and they are trouble free. With it all assembled measure the distance from the clutch fingers to the base of the trans where the TOB will set. subtract the TOB thickness fully compressed. What is the difference? I set it on my race car at about .060, just using shims to get it where I want it. If mccleod gave you a different measurement use it.

Make sure it is bled out. It takes a long time. I changed to a 24" long bleed line so I could get it up and mount it on the firewall to make it easier. What size M/C are you using for the clutch? If you went to a short throw sleeve and its not engaging until the pedal is on the floor then you may need a larger bore M/C to move more fluid, or a longer sleeve so it is more stable, or more spacers. But it's all going to start at the measurements.

Make sure when you adjust the pedal rod you aren't accidentally engaging the M/C as that would cause all kind of issues.

wonele67

No, all I meant was I'm using everything the previous owner was using except the bellhousing. McLeod sent me a second piston .200 shorter. After installing it, the clutch was grabbing ON the Floor, at one point I had to shut the car off in order to stop it. Theres no more adjustment left in the pedal.
We used a Vac. Bleeder to bleed the TOB as well. that is not an issue.

racer_dave

again, if everything is the same except the bellhousing, what was the difference in depth between the previous bellhousing and the one you have now? When you do the math how much free play does the TOB have? That free play measurement is the single most important thing and it going to be measured in thousandths of an inch. So if the old bellhousing and the new one were 'close' to the same that's not the same as 'exactly' the same. The pedal travel adjustment isn't the issue, it's that the TOB isn't releasing and you're trying to fix it with the the pedal adjustment.

And I personally don't trust vac bleeders. I use them to get it close and then go to the old fashioned way of pedal bleeding. I do it that way because there is a difference between vacuum and pressure. If the system is going to be under pressure then I bleed that way. Speed bleeders are wonderful if you have to do it on your own.

67mustang302

Like Dave said. You need to double check the clearance setting on the TOB, what is the height difference between the 2 bellhousings, was the new bellhousing aligned, pressure bleeding is the way to go.

barnett468

hello;

if you do not have the old bell housing to measure and you are certain your hydraulics are fine just get a sleeve around 400" longer and you are done providing your clutch does NOT currently engage until you have depressed the pedal at least 3.5 inches. the leverage ratio is around 6:1 so 6 x .400" will raise where the pedal currently engages and disengages by around 2.4" which will be a little more than you need to disengage it therefore you will get some of your adjustment back on your rod.

wonele67

Tossing in the towel. Going to take out the Hydraulic Throw out bearing and put the stock TOB / Fork back in. I am looking into buying a external Slave Cylinder to use with my Hydraulic Master Cylinder.

racer_dave

Well, that's too bad... but you never answered any of the questions we had to help you get it adjusted. We can't help if we don't get any information back...

One of three things is happening

1- the free play isn't enough (the TOB will not release)
2- too much free play on the TOB (will need too much pedal travel to get it to release and it may over extend the TOB)
3- pedal shaft/rod isn't long enough (you run out of pedal travel before the clutch releases)

These are the only three things that can be happening, yet to tell what is going on we need the numbers... or post us some pictures so we can see...

wonele67

Free Play is perfect according to McLeod. The TOB is lightly against the fingers.
The Pedal Shaft/Rod MAY be the issue. What dimensions am I looking for?

barnett468

hi . . forget my previous post . . i forgot you had a hydraulic bearing . . what you say is happpening is impossible unless your pressure plate has a prob because. your commennts suggest your leverage ratio changed when you instlled the new bell housing . . well it does not work that way actually . . either you had the same prob before or you have air in the lines or your clutch pressure plate has developed a prob