Shift help!
 

OK, so it has been a while since I played with one of these things!

Hurst indy shifter with the modified linkage from Unique on a toploader. Center force clutch.

The problem:
Car shifts OK under part throttle. Down shift is always a chore especially 2-1. You can absolutely forget a quick up shifts at full throttle.

Questions:
- proper way to adjust the shifter/linkage
- any thoughts about the nature of the problem

I posted on David Kee thread but never received any sort of response. So I turn to all of you!

Thanks

Rick

Possibly a stick input shaft bearing on the back of the crank or a misaligned input shaft to crankshaft.

Does it grind when you put it in first or reverse while sitting still with the motor running and clutch pushed in?

It could also be a pressure plate problem check to make sure no bolts are backing out of the PP.

I think the problem is just as likely in the bellhousing as behind it.

rdorman,
Are you sure you've got sufficient clutch release? Like Mr Fixit asked, does it go into gear (particularly reverse) from neutral (with foot off clutch) without grinding?
First, if you have to pump it or if pumping the pedal helps the shifting, it may need a serious bleeding.
Second, check the "free" play at the pedal (between fully depressed and the point when the clutch begins to engage and the car starts to move)...should have at least an inch of pedal travel from floorboard to point of engagement. If not, check the linkage adjustments. Make sure slave cylinder is at or near beginning of stroke (topped or bottomed out, whichever yours uses) and check the clutch arm stroke (at the bellhousing) - should have 3/4" or so at the end of the throwout arm.
Good luck.

Thanks guys
 

To answer your questions:

No grinding going into first or reverse when sitting. You can run it through the gears more or less as fast as you want when sitting, clutch in, motor running. But I will double check this. As I think about it, some times you have to 'slap' into reverse. But not so much because of grinding but because of the resistance to dropping into gear. Same goes with first. This is when it is sitting and running. When driving, you push it towards first and just be patient.

No pumping of the pedal is required.

The point where the clutch engages is a good distance from full pedal travel. I need to put in a stop so that I don't depress the pedal so far. You begin to 'feel' the clutch once you depress the pedal about an inch or so.

I hope this helps you guys narrow it down!

Thanks again

Rick

I think that your clutch is not fully disengaging cleanly, or the pilot bearing is dragging the input shaft. If the rear tires were off the ground and the motor was running with the tranny in first gear and the clutch pushed in, I bet your rear tires would start turning.

Sit in neutral with the clutch out, motor running. Push the clutch in and pull the shifter into first, it should be smooth, same thing with reverse. If it is not smooth, than the tranny's input shaft is still turning.

If you do have significant clutch pedal travel after the point of release, you will damage your pressure plate. When or if that happens don't put another centerforce plate in, get a McLeod.

Exact same problem!!
Had Ford Clutch
No change
Toploader rebuilt by David Kee
No change
Rebuilt Tilton Hyd. throwout bearing
No change
"Re-adjusted" shifter linkage
No change
Installed new pilot bearing
No change
If I got my numbers correct, the Centerforce should release at .450 inches travel
A Tilton throwout bearing will BLOW THE SEAL at .700 inches travel
I have a 7/8" Tilton master clyinder which will move the throwout bearing .496 inches
I have to use the entire movement of the master to get the trans to reasonably shift. This is pushing the limits of the system.
For mechanical reasons, I have a hard time keeping the clutch in adjustment. As soon as I lose even 1/8" travel at the master, I begin to have big problems shifting.
I am absolutely positive I am not getting enough travel at the clutch
John W.

Rick,

Since your clutch seems to engage/release fairly high, I would suspect some problem other than the hydraulics.

Did you check the bell housing concentricity? This could cause a tweaked input shaft.

Unfortunately, the alternative is an internal gearbox problem...

see what we can find out
 

I am going to check the travel and bleed the system this weekend. Easy stuff first! I will let you know!

Thanks guys

Unique Cobra Clutch Problem
 

Rick,

I also have a Unique with a 428 FE & toploader and am having fits trying to get the clutch to work properly. It will not go into reverse unless I shut the engine off then it shifts into all gears easily. If I start it in neutral, it won't go into gear, if I start it in gear, the car starts to creep. If I'm driving, it will shift, but it won't go into gear easily especially at high revs. Here's what I've done so far:

From the very first day I started the car in Feb 01, neither myself, So. Auto folks on 15 Apr 02 nor anyone else has been able to adjust my clutch properly. I still can not get the clutch to adjust properly. I have replaced the flywheel, pilot bearing, clutch disk, pressure plate, throw-out bearing, Wilwood ¾” master cylinder, Wagner F-124111 slave cylinder and the silver slave cylinder rod adapter with jam nuts. I have checked to insure the proper fork (DOTZ-7515-A) is installed which it is according to Unique’s assembly guide for a 428 FE. I have installed 0 washers/shims, 2 shims and 3 shims under the fork and it made no difference except to move the fork closer to the slave – it didn’t help the adjustments. I have bleed the system numberous times using 3 different methods: normal peddle pressure method, the let it sit and let the air bubbles rise method and the vacuum method. There are no air bubbles in the system. I have made sure the slave cylinder piston was all the way retracted by opening the bleeder valve and pushing the piston in until it stops at the back of the slave cylinder.

It appears that the slave shaft does not move far enough to disengage the clutch completely and therefore only partially disengages the clutch. When I depress the peddle a half inch, the slave moves a half inch. When I continue to push the peddle all the way to the floor (an additional 1-2 inches), the slave doesn’t move any further. Some folks have told me all it should take to move to disengage the clutch is ½ inch, so why isn’t mine working? When we replaced the flywheel, my mechanic noted that the pilot bearing had some wear which he thought was excessive for only having 3800 miles on it. He thought that maybe the transmission was binding in the pilot bushing. He said besides changing the throw length of the slave by either replacing the master or slave or both with a different size, the only thing left to check is the bell housing alignment. I noticed that the bell housing was stamped “Not a Safety Shield”. Is this the correct bell housing? When I ordered the engine, I was told these engines came with shatter proof bell housings, so maybe I’ve got the wrong housing.

Before I start changing the master and slave cylinders again and aligning the bell housing can anyone answer the following questions for me:
- how far should the fork have to move to fully disengage the clutch? Pioneer/McCleud 3-finger, 12 inch.
- what is the maximum distance the Wagner F-124111 slave cylinder is capable of moving? I was told this is a 7/8 slave, but the bore measures 1 inch.
- Do you have any other suggestions than what was discussed above?

Thanks,

clutch
 

Jer:
Call me, from your discription I think I know the prob
grover

clutch
 

John;

We clevies have to stick together
Think you prob is pretty simple.

Sounds like mismatch of cyl. volumes and stoke capability.

Since you have eliminated all the hard and expensive stuff lets got back to basics.

Assuming you have the numbers right and your clutch releases at .45 in. and your 7/8 mc can only move the clutch .496; thats only .044 leeway. Not near enough. The thermal expansions of hot discs etc will take .050 in out of the system. Your discription of adjustment being sensitive and goes out if the adjustment is moved 1/8 in make sense. If your numbers are right your dragging the clutch. Do the Mr fixit test; jack you rear up, start up, at idle push clutch in and put it it first. I'll bet you a bottle of scotch you hear a thud and the wheels start turning. I bet you have to put a fair amount of e-brake to stop them with the clutch in.
Solution -simple: if your 7/8" mc moves the TO bearing .496 in; then your 7/8 moves .60 cubic in of fluid at 1" stoke. going to a 1.0 dia mc will move 1.0 cu inch or 40% more TO stoke and fully release the clutch. Now doing the math a 1 in mc will move the TO .700 in.
This will clearly release the clutch but will put you too close to exceeding the throw of your TO. Do some carefull measurement and put a pedal stop so the total is only about .65in TO.
movement.

gn

Thats what I've been thinking. I went through these same numbers with the guys at Tilton. Unfortunately they don't make a 15/16 inch master clyinder. It would have been perfect.
I will probably pull the trans so I can actually measure the travel so I don't exceed the limits of the throwout.
I've had clutches let go in traffic before (twice in another car) and its not much fun. Both times though I was able to drive it home by rpm matching.

clutch
 

Don't worry about 15/16.
Use a 1.0 in mc and under your pedal build a stop; on my old race Porsche we had them under the cluthc and gas pedal; just a large headed hex screw with a jam nut. after you measure the throws or find exactly when the linkage was full open just screw the bolt up until it stops the pedal at that exact postion and lock the stop screw down with the jam nut. For the clutch I would stroke the pedal until in released completely then add about 1.0 to 1.5 more pedal travel until I hit the stop. Just measure to insure you still have margin on the .700 in total limit. Once you sort it out, it's simple and idiot proof.
Your experience with internal TO's is why I use external only. Easy to fix, don;t have to remove engine; and the biggy, you don't ruin a disc with fluid.

gn

"When I depress the peddle a half inch, the slave moves a half inch. When I continue to push the peddle all the way to the floor (an additional 1-2 inches), the slave doesn?t move any further."

If you don't have air in the system, or something mechanical broken, how this can happen is beyond my comprehension. In fact, since your clutch is apparently partially releasing, I am even more confused. When you press the pedal beyond the first half-inch (as you described above), how much does the pedal pressure increase?

OK, I bled it.
 

I gave the system a thorough bleeding and the results are, well better. There is no clashing between gears and the travel is good. When depressing the peddle you go about 1/2 inch before you 'feel' the clutch. At the bottom you have 2 or so inch of upward travel before the clutch begins to engage. Shifting is easier but it was not the entire problem.

I knowticed that when going from 2nd to 1st, there is a faint whirling noise that picks up in speed until it finally drops into first.

At this point I am thinking syncros and/or bell housing alignment. The bellhousing is a stock peice but whether or not it came off this engine and whether or not it was checked for center on the crank I do not know.

Any more thoughts with the new info???

Thanks guys

clutch
 

rdorman:

Your discription of things sound normal.

There is mc piston travel before the port is closed and compression starts.
2 in of free play from floor sound sabout right.

You need to "prove" to your self the clutch is releasing; can you push the car by hand with the clutch in and in gear?? Do the test! You must systematically eliminate items before you can identify the real problem.

Whirring sound going into 1 st can be totally normal; the sounds of the sychro's matching shaft speeds can sometimes be heard.

"ONCE" you eliminate potientials, you can this find the real problem.
since you discription of clutch action sound normal; the linkage on a top leader is critial; if its misadjusted or worn you get sloppy shifting. Need a TL expert for that one. Call McKee again; he has a top reputation.

gn

niles
 

I have not tried to push it with the car running in gear. I can say that the car will roll on the slightest of inclines with the car running, in gear and the clutch depressed. Is that good enough?
Thanks
Rick

clutch
 

roll backward or forward?; rolling backward -good; forward can be symtom of dragging clutch. Do it level garage floor with engine off

gn

hey niles
 

It will roll backward or forward in a gear of the opposite direction. As if there is no rolling resistance, you know, just as it would if it is in neutral. I know it will also roll easily on a level surface with the engine off, in gear, clutch in.

It really seems as though the clutch is disengaging!

Keep it coming guys!

Thanks

The clutch needs to FULLY release or you will hot spot the flywheel and pressure plate, while wasting the disk and your time.

Get the rear tires off the ground, sit in car, put in gear, push in clutch. Try to rotate rear tire with your left hand , it should, as you release the clutch it will grab and the tire will stop moving. This is the best one man way to verify clutch release on a cobra.

If it doesn't release, there is a list of things to check that is as long as my arm.