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MG Midget and Sprite Technical - 1500 clutch?
|I am have owned a 1275 midget for 43 years so I know that drivetrain and the clutch release bearing and ribcase transmission issues well.|
I am working on a 1500. The clutch has gradually reached the point where when the pedal is all the way to the floor, it remains partially engaged. Hydraulics were replaced last year and there are no signs of leaks at either the master or the slave cylinder.
I assume that the clutch disk, pressure plate, release bearing are worn and need replacement. It is not good to have the gears grinding.
If anyone can advise how long the 1500 clutch usually lasts and if there is anything special about engine/transmission removal that needs to be observed, I would appreciate it. Is it practical to remove the engine only? The 1275 with ribcase is best removed as a unit. Are there any levers or pivots in the Triumph setup that are subject to premature wear and that may require replacement?
Also, I have read about the famous thrust washer issues with the 1500 engine. Is it best to replace thrust washers and bearings while the engine is out as a preventive measure, even though the engine is running well? The engine feels very strong and is not used in severe speed or load conditions.
Any suggestions would be greatly appreciated.
I guess like any wearing part it depends on how and where the car is driven!
If the driver "rides" the clutch or it's used in lots of stop/start traffic it'll wear out quicker.
You can remove the engine on it's own, but the triumph engine has lots of bellhousing nuts and bolts, some of which are a bugger to get at in situ.
The other thing worth checking/replacing is the pivot pin on the righthand side at the end of the clutch arm. The interference rings that hold this pin in place can wear and the pin can fall out! Which results in lots of free play and can give a dragging clutch.
I guess it makes sense to replace the thrust washers and possibly the bottom end bearings if the car has done lots of miles whilst the lump is out.
But overall the 1500 set up is far more robust than the infamous, archaic A-series carbon thrust.
|SR Smith 1|
|Wear in the clutch disc (friction plate) normally results in the biting point getting higher and higher, eventually resulting in slip.|
What you are describing is more likely to be hydraulic, or a fault in the release mechanism.
|Dave O'Neill 2|
you've put >>Hydraulics were replaced last year and there are no signs of leaks at either the master or the slave cylinder.<<
if by that you mean the clutch fluid was changed and seals were found to be sound, if the flexi-hose wasn't replaced what about its condition, could it be collapsing and/or deteriorated inside
wear on slave pin or connection?
that's me out of ideas
|A agree with Dave; a worn clutch plate or pressure-plate would result is slip. It's unlikely that the clutch thrust bearing would wear sufficiently to cause your problem unless it hasn't been replaced in a long, long while and, anyway, it would be noisy if breaking up. |
What about the position of the slave cylinder itself? Check that the pinch bolt is present and that it is the right size (if replaced with one that is too narrow it won't fill the indent), and check that the indent on the side of the cylinder is lined up with the pinch bolt and that the cylinder hasn't pushed itself backwards out of its housing.
I removed my 1500 engine separately and, though some fastenings are difficult to get at, it didn't take long. I had the car on axle stands so I could easily get underneath it - makes a massive difference to access.
I had trouble with my 1500 getting the clutch to clear and after doing the hydraulics found that the clutch pedal pivot bush was badly worn. You have to take the pedal box off to access it. The shaft was also worn ( its just a big shouldered bolt )and it had been moving in the pedal box too. The eye in the clutch pedal that connects to the clevis on the master cylinder also had wear and had to be welded up and redrilled.
After all this was done the biting point on the clutch was about 1" higher, and the brake pedal feel inproved too
|P J Vass|
|Nige the 1500 doesn't have a flexi hose, it's a plastic pipe end-to-end.|
|Thank you for the comments and suggestions. |
Both the master cylinder and the slave were replaced last year when they started leaking fluid. The biting point was the same after the hydraulic overhaul, pedal low but functional. I loosened the pinch bolt yesterday and the slave is positioned as forward as it will go.
I will check the pedal pivot as this went early on my 1971. In 1974, it was possible to buy a new pedal arm at the British Leyland dealership. The trick has been putting a slight amount of grease on the clevis pin and wear is almost completely eliminated. There is no noticeable elongation on the 1974 replacement pedal arm after 250,000 miles or so.
It would be great to avoid an engine-out repair on the 1500. With the 1275 ribcase setup, the clutch biting point would get lower and lower with release bearing/clutch disk wear. When it hit bottom, I would insert a longer pushrod from an Austin 1300 and this would buy me 10,000 miles or so of additional clutch life. I am now running a Datsun 5 speed with its mishmash clutch configuration so I am out of the carbon release bearing business.
|David, thanks, I keep forgetting the differences on a 1500|
|Glenn, It still sounds backwards to me for a worn clutch disc to be the problem. As the disc wears, the point where the throw out bearing meets the pressure plate will move towards the rear of the car and make the bite point of the pedal higher not lower. With a carbon bearing, wear would make the pedal bite lower, but I don't know 1500s to know if it is carbon.|
Besides checking the pivot points, I would check the total throw of the slave, I would check the end play of the crankshaft, and I would look for a bent fork or for a bend in some other part of the system. Crank end play is easy to check with the engine in the car.
|C R Huff|
|Thank you Charley. It had not occurred to me to check crankshaft end play. This could be an issue with the weak 1500 bottom end.|
The 1500 apparently uses a roller release bearing, not the infamous carbon pad. I think it must be wear in the linkage, starting with the pedal and probably at every mechanical point in the system. In the end, it will probably be an engine-out proposition.
This thread was discussed between 13/08/2014 and 15/08/2014
This thread is from the archive. The Live MG Midget and Sprite Technical BBS is active now.