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MG MGB GT V8 Factory Originals Technical - HTOB again

Hey everyone, as most of you know Dan at D&D built me a stroker Olds 215 to replace the semi stock Old 215 that was in my conversion. I also changed out the stock MGB 4 speed and purchased a T5 World Class from Dan as well, this with the HTOB. My problem is that no mater what we can't get the clutch to totally disengage. The people at the tech support line for the HTOB just keep reading us back the instructions and (Dan is great but) Dan just refers us to the tech support line of the manufacturer of the HTOB. I've read through the archives and tried everything but the clutch will not fully disengage. The shop that I have doing this is getting frustrated leaving me in a bad spot, a car that won't run. Could the HTOB itself be bad? Can anyone here help me to get this HTOB to work properly?
Michael S. Domanowski

If you are using the Mcleod, the only way you can screw up the installation is to fail to provide the proper clearance between the HTOB & the clutch finger during installation, or fail to bleed the bearing & lines.

If this is correct, then I presume the bearing to be faulty. I have used this set up in 3 of my cars & know of many others using the same system with no problems.

E-mail McLeod, addressing the E-mail to Red Roberts & ask for his help. He was on the tech line for years & I believe he is still there, but not on the tech line. He was & still(?) is president of the company
Jim Stuart

Other than a bad HTOB you have one of two possible problems; one is a fault in the hydraulics and the other is incorrect adjustment.

Donít discount doing something stupid as I did. After rebuilding both ends of my system and bleeding through a couple bottles I built a pressure bleeder, but before using it I found I left a fitting loose.

I have seen two approaches to setting the adjustment, but the method that that I think makes the most sense is to measure the distance from the bell-housing surface of the motor to the pressure plate fingers. Next measure the distance from the forward end of the bell-housing and the forward end of the HTOB and adjust the HTOB so it is a tenth of an inch greater than the first measurement. Then you know the gap between the HTOB and the pressure plate is one tenth of an inch before stepping on the clutch. A working HTOB with proper hydraulics will cover the gap and disengage the clutch.
George Champion


Did you replace the pressure plate? Which style/model pressure plate are you using? Which clutch disc?

I used the Tilton HTOB, and I found it to be a pretty fussy installation. The mounting collar that goes on the front of the T5 seemed to be just a little too short for even my old fashioned (Bork and Beck style) pressure plate. In my opinion, they also provided incorrect bleeder hardware, so I had to fire up the lathe and make an adapter. (Whenever I'd loosen the bleeder screw the whole couplng below the bleeder would leak, making it impossible to fully bleed. They had apparently used some kind of swivel coupling where I think they should have used something simpler.)



Curtis

I am having issues with my HTOB as well. My original one had broken, and I sent it back to McCleod/Weber. The repaired it free of charge. With the Ford set-up, it required the threaded colar and a spacer collar to get the proper gap. With both on the new one I cannot get any gap at all, even with the screw in adjuster bottomed out in the HTOB housing.. Any ideas??

Micheal, can you get me the Phone number for them , I lost it and need to talk with Red about this heh He was very helpfull the last time..
Larry Embrey

Larry is correct. The GM T5 does not required any collars. The Ford T5 you must follow instructions and adjust the lengh correctly. Also some Ford T5 had a different input shaft cover that will affect the lengh, but this can be corrected with the screw that comes with the HTOB.
A common mistake is installing the bleeder line on the botton, the bleeder should be the top line.
Bill Guzman

Thanks all for the come back. I will go through all this stuff again today. Dan has also agreed to call my mechanic to see if he can add any insight to our problem and we will also contact Red Roberts at McLeod. Yes, I have the GM T5 so no spacer is required. It is the McLeod HTOB. The Clutch master cylinder is brand-new and a MGB item with the proper diameter and length of stroke. It has been bled correctly several times but we are going to do it again making sure the bleeder line is on top.
Michael S. Domanowski

<<Yes, I have the GM T5 so no spacer is required.>>

Michael, this is not a given. There are number of GM T5 users (myself included) that had to use a spacer between the trans and the HTOB (mine's a Mcleod). I didn't order the spacer from Mcleod, I just went to the local hardware store and picked out some BIG ol' washers that would fit over the trans bearing support. It took 3 of them.
Carl

HRMMM reminds me, I need to uncouple he hoses to make sure the bearing bottoms out, then check adjustment. As it stands, I have NO gap between bearing and pressure plate fingers.

Guess I add one more thing to the laundry list!!!
Larry Embrey

Micheal,
You might check out this problem I have. Essentially not enough travel at the master cylinder. Mine won't completely disengage the cluth to get into reverse but only after the tranny in warmed up (GM T5 with a 10.5 inch chevy cluth an a lightened stock Buick flywheel)I can't get the bearing any closer to the PP fingers without having the bearing touching the finger and then always be spinning. What I found is that my clutch pedal moves the stock master cylinder plunger 3/4 inch and the HTOB moves 3/8 inch. This ratio is indicated on the instructions for the Weber HTOB. However it was also indicated that the the master should move 1 inch, thus moving the HTOB 1/2 inch. I will change the pivot point on the pedal arm to give another 1/4 inch travel or rig the clevis pin farther (higher) from the cluth arm pivot point to bet the increased travel. I haven't heard of others having this problem. There is very minor wear at the clevis pin, about 1/32. So this isn't where I'm missing 1/4 inch of travel. Maybe this will be helpful
Rick

If the clevis pin is worn the pedal arm and push-rod holes probably will be too doubling the loss at each point, and if the pin is worn where both contact it you are doubling it again. With the wear I had on all mine I calculated I was losing 1" at the pedal rubber.
Paul Hunt

You first need to isolate the type of problem. Is it hydraulic, mechanical, or alignment? There should be no softness in the pedal other than the top inch of free play for clearance, otherwise a hydraulic problem exists. Pull the pedal up to see if there is any more travel available, with the pedal box cover off, make sure the pedal arm hits the stop. Make sure the pedal goes all the way to the floor with no obstructions. (carpet) Another possibility is input shaft alignment. Check the bellhousing for runout and parallelism. This can keep the clutch from disengaging.

Jim
Jim Blackwood

Found the pedal worn about 1/4 inch, welded it back to stock specks. Still not fully disengaging the clutch but all dimensional travels are what they should be, Dan at D&D suggests high spots on the new clutch may be the culprit and just needs to be worn off by a 10 mile or so drive. I have some other unrelated problems that need to be addressed before I can finish with this. I'll keep you all informed.
Michael S. Domanowski

This thread was discussed between 10/02/2003 and 24/02/2003

MG MGB GT V8 Factory Originals Technical index

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