Hewland MK 8/9 problems

[79royale]

I recently purchased my first Formula Ford on ebay. Its a 79 royale rp 26. When I went to pick up the car, I unfortunately found out the clutch wasn't working. I've now replaced the master cylinder, slave cylinder, and throw out assemby. While apart I notice that the clutch shaft has quite a bit of play in it and the oil seal looks bad. Most recently, I noticed that the differential section of the gear box is dry of oil with a lot of metal shavings on the plug. The gear cluster portion of the box has only 3/4 of an inch of oil in the bottom with metal shavings on the plug. The car had been sitting for a year and a half. So I'm feeling kind of screwed. I'm guessing I have to take apart the whole transmission and replace all bearings and seals. I would appeciate any words of wisdom regarding this situation. I hope to make drivers school next spring.

Thanks, Dave Loken

[eaglefordracer]

All may not be lost. Do you have the clutch working now? What was the root cause for the clutch not working? Did you remove the pressure plate and inspect the clutch disk and pressure plate face? Is there overheating or bluing? What type of "chips" did you find on the plugs? It is not unusual to find some fine filings on the plugs...it's the problem with dog rings wearing.

Given your concern, it might be prudent to pull the side cover, I think drivers left (?) will allow you to remove the ring and pinion.

Loose shaft may not be the end, it might be loose because when not installed, there's not much holding it in place, ergo the spline and needle bearing in the clutch and crank respectively.

Now, going to the rear of the gear box, with the cluster out, give the output shaft a good strong handshake, if it's loose, now you'll be talking about a rebuild on the gear box.

You could always just pull the box and send it to Taylor, or others, and have it rebuilt.

[Modo]

Fix the clutch and try, you can weld or braze to reinforce the throwout fork on the lever on the outside or get a hydraulic slave cylinder, u may have a slave cylinder then check for leaks and sounds like an adjustment problem.........also be aware that there may be the nessesity of using an extension bobbin to hit the clutch fingers correctly....must do a careful measurement from the clutch fingers to the throwout bearing in its retracted position....................put a quart and a half of hypoid 80-xx oil and head towards your nearest university parking lot on a sunday (or whatever).........yes the clutch input shaft is wiggly...not a problem it is a slip couple.......also they always have metal bits in there......hopefully not too big!!

Have fun,
Mike O

[JHaydon]

If you haven't driven the car with the gearbox dry, then it may not be cause for any concern at all. The metal shavings may just be bits of dog ring material. That happens.

EagleFord is correct about the left sideplate and the play in the input shaft being normal. The play is deliberate to allow for slight misalignment in the clutch disc. In fact, if you're not careful, you can wiggle the input shaft far enough to stretch out the oil seal. (Another reason never to use that shaft as a handle when picking up the gearbox! )

I'd say the magnets in the plugs have done their job -- keeping the inevitable metal particles from getting into the bearings and between the gears (hopefully).

[James Hakewill]

You can download the Mk9 Manual here - the manual says 1 3/4 - 2 pints max.
http://www.hewland-engineering.com/drawings/mk8-9.pdf

Regarding the oil level - for years, I would measure how much oil came out, then put the same about back in (plus a little for spillage). Then someone told me that you can make a little dipstick to go into the plug on the left hand side of the casing - see the attachment. Duh.

When the car is sitting, the oil in the diff casing will usually drain into the gearbox part, cos it's lower.

If the box was run with too little oil, you will probably find that the gear ratios are a lurid blue color - which is bad and expensive. I had a bright blue ratio somewhere, but couldn't find it to take a picture. Little chips (silver on the magnetic plugs, gold in the oil) is normal I think -- at least for my driving anyway.

My mk9 gearbox (out of the car at present) has about 1/4" total movement up-down on the input shaft.

As for the clutch - as you mentioned that you replaced the slave cylinder, I'm assuming that you have the type where the slave cylinder is mounted on the bellhousing, and has a pushrod which pushes on an arm. The lever is attached to a cross-shaft which goes through the casing and has a fork which operates the clutch.

There's also a type with an annular slave cylinder inside the bellhousing.

I'll assume that there a no bits of clutch disk dropping out of the bottom of the bellhousing..

So.. when you press the pedal..

1. Is there any pedal pressure?
- does the pressure increase then decrease?
.. some clutches need a pedal stop - if you go too far it goes over-center and re-engages
- hopefully the bobbin is still in place between the fork/throw-out assembly and the clutch cover - easy to forget when reassembling..

2. Does the pushrod move? Straight away? Is there more than 1/8-1/4" vertical play in the rod?

3. Does the arm move? - the arms are prone to break..

4. Does the cross-shaft move?
- the arm can be attached to the cross shaft with splines.. which can get mashed up..

5. How far does the clutch arm move?

Anyway - unless all the internals of the box are blue, you're probably OK..

James

[JHaydon]

One more note on the clutch -- While you have the gearbox off, check the tightness of the bolts that hold the slave cylinder bracket to the transmission and LOCK THEM in place. They are impossible to tighten once the gearbox is installed, and looseness there translates into more lost motion at the clutch.

[79royale]

Thanks everyone for your input.

The throwout lever had stripped on the throwout fork, so I replaced the throwout fork with a new one where the forks are welded all the way around the shaft. I ordered a new lever since the grooves were stripped out, which is on its way. I got some stronger spring clips that hold the throwout bearing to the forks. The bobbin and throwout bearing were in good shape so I kept those. The slave cylinder had a pretty bad leak, in addition it would not hold pressure so I ordered both a new slave cylinder and a master cylinder. Probably keep the old master ad fix with a rebuild kit and keep as a spare.

I didn't take the clutch assembly apart while I had the tranny off. I have the tranny back on now so I think I'll get my hydraulic system together and see if the clutch will disengage. I didn't see any blueing in the differential gears just peeping with a flashlight through the plug. I haven't had the cluster out yet, but I'll take it out and check the output shaft to see if it is loose. Also, I will probably take off the side cover as see whats going on in there, at least to give me confidence in those parts.

The shavings on the plugs were really fine, so I guess that sounds pretty normal. Hopefully it wasn't driven without oil in it and it just leaked out or something. I'm feeling better about my situation, at least I know what to look for. Thanks again!

[Jonathan Hirst]

.. it just leaked out or something.

A very likely scenario if the car was stored over a long period of time. Look into a means of sealing the gear selector bushing.

Good luck with checking over the rest of the car and welcome to FFord.

Jonathan

[DOC]

79,

You have not indicated what sort of clutch you have. If you are using a stock Ford clutch, you should be fine. If you have a "racing" clutch, though, it probably has overly strong springs for a FF. Even the softest "buff" springs are a bit much for a conventional clutch arm. Annular slave is the only reliable solution unless you go "back" to an OEM Ford clutch.

DOC

[Bill Kincaid]

Actually, I've used an external slave cylinder with an F3 clutch for many years. The trick is that the actuating arm needs to be heavy duty- the stock ones bend and break. Neil Porter carries the good ones.

[James Hakewill]

One more note on the clutch -- While you have the gearbox off, check the tightness of the bolts that hold the slave cylinder bracket to the transmission and LOCK THEM in place. They are impossible to tighten once the gearbox is installed, and looseness there translates into more lost motion at the clutch.

And uh, Bill - one also needs to remember to actually install the slave cylinder before attaching the gearbox..

My old Royale has helicoils in the holes -- much easier!

James