5 Speed Gearbox Clutch Slave cyinder pushrod displacement

[mark030358]

Hi guys,
So engine and 5 speed Lotus box back in the car just a few bits to finish before she gets fired up. However, I'm not sure about how much adjudstment I had to make on the pushrod. So I pushed the actuating arm fully rearwards so the release bearing hits the clutch and adjusted the pushrod arm, leaving a few thou clearance. However to get this adjustment the pushrod its almost at its limit, so is this correct?????

Please see photos...

thanks
Mark

[Steve Brooks]

Hello Mark, found this in the workshop manual. Might help.Steve

[mark030358]

Hi,
Actually I kind of knew the answer before I posted. So here is what the answer actually is for my application, along with som photos to explain.

The release bearing carrier and elease bearing are 100% correct so that leaves the clutch assembly. I bought a new 5 speed Helix friction plate and pressure plate. The problem is I think this unit is too short by around 6 to 10 mm. I have a spare gearbox lever arm and pushrod and did a couple of test on the bench with a bit of paper and a ruler (see pictures).

I fixed the clutch arm pivot point (in almost) the correct postion. Marked a reference line for the pushrod, then adjusted the pushrod nut to maximum adjustment and marked the lever arm finger position (where the half moon fits). Re-adjusted the pushrod nut to where I believe is a normal adjusted position, maintaining the pushrod on the same datum line and again marked the lever arm finger position.

A 9.25mm changed in carrier bearing position causes a 15mm movement at the other end of the arm, see pictures.

So as my clutch/flywheel assembly has been balanced I need to make a new carrier for the thrust bearing then all will be sweet. An alternative is moving the pivot point forward but I'm not happy with this.

One final point, I rang the supplier and asked if anyone else had complained, then answer was yes, one guy had complained, WTF!!!!. So my engine has to come out again to fix the problem

It should be noted that the clutch did disengage at maximum adjustment, but required a lot of pedal pressure and the feel was terrible and as it wears wont get any better and may run out of adjustment completly.

SO MAKE SURE YOU ASK BEFORE YOU BUY A 5 SPEED PRSSURE PLATE... DOES IT WORK!!!

[john.p.clegg]

viewtopic.php?t=36013&p=246446

John

[promotor]

The release bearing carrier and elease bearing are 100% correct so that leaves the clutch assembly. !

Have you got a photo of the bearing and carrier you have fitted?

[mark030358]

No sorry I haven’t, but it is the five speed one.

I remember in some old post someone put up a picture of a carrier that was much thicker, off an RS Escort I think.

If anyone has one and could measure it up that would be great.

Thanks
Mark

[promotor]

No sorry I haven’t, but it is the five speed one.

I remember in some old post someone put up a picture of a carrier that was much thicker, off an RS Escort I think.

If anyone has one and could measure it up that would be great.

Thanks
Mark

I thought the 5 speed had to have the thicker carrier - plus the round nose bearing - to suit the flat-fingered (ie no thrust pad) clutch that the 5 speed uses as the clutch unit is shallower when the thrust pad isn't present.
RS1600 used a flat fingered clutch without thrust pad, a deeper carrier and a round nose bearing as far as I'm aware.

[promotor]

Thicker carrier :

https://www.ebay.co.uk/itm/170922926354

[mark030358]

Thicker carrier :

https://www.ebay.co.uk/itm/170922926354

I pinged that guy earlier asking him to measure the bore and O/D, not had a reply yet. As an aside Kelveden make thier own 5 speed carriers, so will ring and ask them to make me a special. Around 12mm thicker I think to be on the safe side.

cheers
Mark

[promotor]

Thicker carrier :

https://www.ebay.co.uk/itm/170922926354

I pinged that guy earlier asking him to measure the bore and O/D, not had a reply yet. As an aside Kelveden make thier own 5 speed carriers, so will ring and ask them to make me a special. Around 12mm thicker I think to be on the safe side.

cheers
Mark

Is the Lotus 5 speed nose on the gearbox where the thrust bearing carrier sits a different O/D to the 4 speed?

[mark030358]

Thicker carrier :

https://www.ebay.co.uk/itm/170922926354

I pinged that guy earlier asking him to measure the bore and O/D, not had a reply yet. As an aside Kelveden make thier own 5 speed carriers, so will ring and ask them to make me a special. Around 12mm thicker I think to be on the safe side.

cheers
Mark

Is the Lotus 5 speed nose on the gearbox where the thrust bearing carrier sits a different O/D to the 4 speed?

Yep, so need the dimensions to see if it can be machined.
Cheers

[2cams70]

I think you are putting the cart well before the horse by considering making a taller release bearing carrier before having split the engine and gearbox for detailed clutch inspection first.
Q1. Have you 100% eliminated clutch hydraulics as the cause?
Q2. What components have been changed from when you took it apart originally? I assume it was working correctly before.
Q3. Did you correctly install the "U" shaped release bearing carrier pivot ring?

[mark030358]

I think you are putting the cart well before the horse by considering making a taller release bearing carrier before having split the engine and gearbox for detailed clutch inspection first.
Q1. Have you 100% eliminated clutch hydraulics as the cause?
Q2. What components have been changed from when you took it apart originally? I assume it was working correctly before.
Q3. Did you correctly install the "U" shaped release bearing carrier pivot ring?

Hi,
Its a new installation of a five speed box, so nothing tomcompare with. Evertyhing is fine hydraulic wise, bearing and carrier. Only difference is the clutch. Its just that the aftermarket ones are a different thickness (shorter), thus my excess travel.

cheers
Mark

[2cams70]

Only difference is the clutch. Its just that the aftermarket ones are a different thickness (shorter), thus my excess travel

Although possible it is unlikely. There's quite a number of different pressure plates, release bearings, release bearing carrier combinations possible and it's quite easy to get it wrong. What bellhousing has been used? Ford (if it's Ford based) had a few different depth bellhousings depending on the car it was installed in.

They've been around quite a while now and I'd be surprised if Helix got key dimensions wrong. Once you have it apart further dimensions can be measured.

[mark030358]

Only difference is the clutch. Its just that the aftermarket ones are a different thickness (shorter), thus my excess travel

Although possible it is unlikely. There's quite a number of different pressure plates, release bearings, release bearing carrier combinations possible and it's quite easy to get it wrong. What bellhousing has been used? Ford (if it's Ford based) had a few different depth bellhousings depending on the car it was installed in.

They've been around quite a while now and I'd be surprised if Helix got key dimensions wrong. Once you have it apart further dimensions can be measured.

Hi,
It’s the Lotus bell housing specific to the application. As I said, a few mm at the top is amplified at the pushrod end. Maybe lots of small issues have come together to give me a problem. When I pull the engine I;ll remove the bell housing and fit it to a spare 5 speed box I have and do some proper measurements.

Thanks and `I appreciate the comments all very welcome.