Spitfire Spitfire Clutch Help

[John Kuzman]

Working on a 1972 Spitfire with a later 1500 engine and gearbox (single rail). The clutch makes a metallic noise while idling in neutral. The noise increases with engine RPM. I can stop the noise by applying slight pressure to the clutch pedal. The noise sounds like the release bearing is bouncing/knicking against the pressure plate.

Is the release bearing supposed to ride on the pressure plate? If yes, what keeps it there, the little spring in the slave cylinder? If no, then what holds the release lever back away from the pressure plate? Thanks.

John

 

[startech47]

Crankshaft thrust bearing???

 

[DrEntropy]

Tranny input shaft bearing.

JMHO.

:smirk:

 

[71MKIV]

I had a metallic noise that filled those symptoms right before the whole clutch plate came apart.

Sounds like a little exploratory surgery is in order.

 

[Andrew Mace]

The alternative is to let it "blow" and deal with the damage after...and that's really NOT a good alternative. Been there, done that...almost ruined a nice alloy bellhousing and could have ruined much more (right leg, etc., etc.)! :eeek:

Pulling the gearbox really isn't all that major a job.

 

[John Kuzman]

I agree that pulling the gearbox is the prudent thing to do. That is what will happen. I am still confused on whether, under normal operating conditions, the slave cylinder spring is supposed to push the release lever far enough forward such that the release bearing rides on the pressure plate. if not, then what keeps the release lever retracted when you let off the clutch?

 

[TR3driver]

John, I'm by no means an expert on Spitfires. But on the TR4A-6, the spring in the slave is supposed to keep the release bearing riding on the pressure plate (and turning). The bearing is a special free-turning bearing so it will spin easily under light pressure. If the bearing becomes too stiff (because it's failing); or if the wrong bearing is fitted, the result is similar to what you've described : noise that quits with light pressure on the pedal.

I'm <span style="font-weight: bold">guessing</span> the Spitfire design is similar.

 

[John Kuzman]

Thanks Randall. Since I have the gearbox tunnel out, and the seats come out rather easily, I am just going to pull the gearbox out through the passenger compartment this weekend. I did this years ago on an earlier model Spitfire and it went rather smoothly. I am betting on a problem with the release bearing or the release lever is loose from the pivot pin or even possibly bent.

John

 

[HerronScott]

We did this several times with my wife's old Spitfire due to clutch issues including once on the side of the road. First clutch failure was due to age. The second was due to poor quality and a cracked presssure plate.

Scott

 

[John Kuzman]

Re: Spitfire Clutch Help - Update

Pulled the gearbox. I am surprised the clutch worked at all! The collar/sleeve of the front cover is sheared off! See Item #5 of the Moss catalog:

Item #5

What is worse is that the previous owner of the engine/gearbox paid a "professional" to go over the engine and install a new clutch. The piece of the sleeve is nowhere to be found.

I guess my options are to either find another gearbox or somehow replace the front cover on this one. How difficult of a job is it to tear far enough into the gearbox to change the front cover, Item #5.

Thanks.

John

 

[70herald]

Re: Spitfire Clutch Help - Update

The collar bit should be part of the bellhousing, not the gear box. I thought is was cast as one piece but apparently not. Never really looked at it to closely!
In any case, if the gear box works properly, and the gears look like they are in good shape all you need is a different bellhousing and you are ready to go.

 

[71MKIV]

Re: Spitfire Clutch Help - Update

John,

PM sent

 

[John Kuzman]

Re: Spitfire Clutch Help - Update

Steve -

PM sent. The "front cover", as it is refered to in both the Moss catalog and Haynes, appears to be pressed into the bellhousing. I am now shopping for a good 1500 bellhousing rather than trying to locate the front cover.

John

 

[billspit]

Re: Spitfire Clutch Help - Update

Shouldn't be too hard to find one. Shipping may be a pit painfull though.

 

[John Kuzman]

Re: Spitfire Clutch Help - Update

Success! I sourced another bellhousing locally. Thanks to all who rendered assistance.

John