A differenbt sere 2A clutch adjustment issue

[StX_Rovers]

HI,

I am having a perplexing problem with the clutch adjustment on our 67 2A diesel 109. The car is receiving a frame over rebuild (I hesitate to call it a restoration). The car has a new bulkhead from Ike Goss to replace the bent and rusted original. Clutch worked fine before the car came apart. The car sat for some time between work and building a house. Now, the house is done, need to mover Rover. The clutch would not disengage,a nd as it had to move just started it in low range and reverse and backed out of old space. I am thinking rust from our humid warm salty environment. Then, when try to go up our hill, it will move but then starts slipping. Towed it up with my wife's 88 and put it in the shop at our new place.

Pulled the tranny, and find that the hub of the driven disk is stuck in the ring that holds the round piece that the throwout mechanism bears against. I knock it out with a chunk of wood, clean up the surfaces and put it back together. Now I do what I should have done in the beginning which is check all the adjustment. When the slave cylinder pushrod is correct (using the measurement from the upper reference nut to the bracket technique) along with the pedal height and freeplay, I can push the clutch pedal down and the clutch eventually disengages. I am checking by turning the parking brake with the transmission in gear and driveshafts disconnected. When I push the pedal all the way down to the floor the clutch binds again. All I can figure is that the hub is contacting the center of the pressure plate even with all the adjustment correct. I call RN and order a new pressure plate. The piece in the middle is loose and it should not be so figure replace it. Get it back together. I also order a new slave cylinder push rod, fork end and pin, lever and spehrical bush. Put it together after painting all the bits. I checked the hub of the driven disk no burs sticking out as far as I could tell, if nothing else it is slightly reduced in diameter from where it contacted the pressure plate. Get the linkage together today, go to check it, same problem. It is as if there is too much volume of fluid being moved by the master cylinder. I am contemplating three approaches. One is order a new driven disk, even though the linings on this one have low mileage,. Expensive, time consuming, might not fix it. Second is to install a stop on the floor similar to the throttle pedal. I have done this on our 70 RR when I installed the Soft lock clutch to limit pedal travel.Third is to pull the disk and have a machine shop turn the hub down. I think i have another driven disk somewhere (still unpacking which means finding it.....) so I could try substituting it and see if the problem goes away.

Anyone have any thoughts or similar experiences?

Best regards, Dave

[ArlowCT]

Is the driven disk in the wrong way around?

[Les Parker]

Dave,

Do you have the Genuine Drive Plate and Proline Clutch cover? Sometimes the hub will not fit through the centre of the Clutch Cover.

:confused:

[StX_Rovers]

Dave,

Do you have the Genuine Drive Plate and Proline Clutch cover? Sometimes the hub will not fit through the centre of the Clutch Cover.

:confused:

Hi Les,

It is a genuine drive plate and a Pro Line pressure plate as it seems the Genuine pressure plates are NLA. Io ordered teh replacement pressure plate due to the damage to the center piece on the pressure plate that was installed. However, the pressure plate that was initially damaged by the driven plate is a genuine one so I think the clearance should have been okay. Not sure how the problem happened initially as the engine transmission combination was installed into the new frame without disassembling and it is the driveline that was in the car before the original frame broke in half, got repaired, then the relay ripped out of the cross-member. I am pulling it back out this evening and checking things again. I found a good drive plate that seems to have a smaller diameter hub that has plenty of lining left in the old stash of parts. Could the driven disk I have in the vehicle be for a Series 3, which has a pressure plate without the ring therefore might have a larger hub? Even then it is unclear why it worked before and not now but if the initial adjustment with the new bulkhead was off maybe it got pressed farther than ever before and I was just lucky before????

Arlow, the driven disk is the correct way around, I made sure of that. Thanks for the suggestion as it is always worth being reminded to check the simple stuff first.

[Les Parker]

David,

I would check the height and width of the rear facing part of the plate, both Genuine and your orginal, there seems to be a variance on the stock we've been getting. All works fine on a Series III, some troubles on Ser II/IIa.
Let us know your findings.

[StX_Rovers]

David,

I would check the height and width of the rear facing part of the plate, both Genuine and your orginal, there seems to be a variance on the stock we've been getting. All works fine on a Series III, some troubles on Ser II/IIa.
Let us know your findings.

Hi Les,

You mean the piece the throwout mechanism bears against? I will take some measurements and also try some photos. I will also measure the two driven disks I have.

The original pressure plate is a genuine. The replacement I just got is a Pro-Line. All driven disks are genuine. I also have one other genuine pressure plate. Both genuine pressure plates are Borg and Beck make. I will have to check on the driven disks for make.

Thanks.

Best, Dave

[StX_Rovers]

Hi Les,

I did some measurements last night after pulling the transmission back out. The Genuine pressure plate and the Pro-Line replacement are almost identical in terms of height. The distance from the triangular shaped piece on the face the throwout mechanism contacts might be 1/16" closer on the Pro Line. The id of the retainer piece on the inside of the triangular piece is 1-5/8" on both pieces. The genuine one is damaged from when it got jammed together onto the driven disk.

As far as I can tell it appears that the driven disk is the culprit. The driven disk that was in the car, and had been for some time, the hub has an outside diameter of 1-5/8". A driven disk that I had on the shelf, that this one replaced when I rebuilt the engine years ago, teh hub is 1-1/2" outside diameter. The face of the hub is also 1/8" farther away (more clearance) than the one that was in the car most recently, and had been working. Both driven disks are Borg and Beck and were genuine parts sourced through RN years ago. There is a number on the center of the larger diameter hub that is 53005. The number on the center section of the driven disk with the smaller diameter hub is 47810. I think the 53005 one must be for a Ser 3 and the 47810 is for a Ser 2A. This might explain an occasional problem I had where occasionally the clutch would act like it was not releasing fully. I learned to push the clutch down leaving the transmission in gear and rev the engine. This would pop it free. I attributed it to rust on either the splines or the flywheel or perhaps slight contamination as it was intermittent. I think I have been just lucky on the pedal adjustment over the years but now that everything is spot on the little bit of clearance I had is gone. I believe that the small diameter driven disks will work for both ser 3 and 2A but not the other way around. This is potentially a problem as the same driven disk is listed for both a 2a and 3. Give me a call if you like.

Bottom line, the problem appears to be the driven disk, not the pressure plate. My current plan is to put the old driven disk and maybe find a machine shop and turn down the other one. The large diameter one is nice as it has the grooves in the linings to shed dust etc.

Best regards, Dave

Some pictures:

First is a pic of the two driven disks. The next two are diameter measurements. The 4th is the two plates hub to hub aligned with an input shaft. You can see where the one on the right is larger and the marks where it was in the piece on the pressure plate.

[Les Parker]

Dave,

Good to talk with you today. Let me know how all this pans out, I've spoken with Inventory folks and we'll make the necessary changes.

Best,

[NC_Mule]

This might explain an occasional problem I had where occasionally the clutch would act like it was not releasing fully. I learned to push the clutch down leaving the transmission in gear and rev the engine. This would pop it free. I attributed it to rust on either the splines or the flywheel or perhaps slight contamination as it was intermittent. I think I have been just lucky on the pedal adjustment over the years but now that everything is spot on the little bit of clearance I had is gone.

Funny I have the same problem, pops up every so often. Was thinking may be I needed to adjust my clutch but it sounds like I should leave it as is.

[StX_Rovers]

This might explain an occasional problem I had where occasionally the clutch would act like it was not releasing fully. I learned to push the clutch down leaving the transmission in gear and rev the engine. This would pop it free. I attributed it to rust on either the splines or the flywheel or perhaps slight contamination as it was intermittent. I think I have been just lucky on the pedal adjustment over the years but now that everything is spot on the little bit of clearance I had is gone.

Funny I have the same problem, pops up every so often. Was thinking may be I needed to adjust my clutch but it sounds like I should leave it as is.

Hi Mule,

Try consciously pushing the clutch down the minimum amount you need for it to disengage and see if that fixes the problem. If you then push the clutch down farther and the problem comes back you probably have a Ser 3 driven disk. Is your vehicle a 2A? If it is a 3 then the problem might be different. I put in the driven disk that I removed when I rebuilt the engine (it has plenty of lining left, just replaced it as part of the rebuild) and it now feels fine. I can push the pedal to the floor and the transmission turns freely turning the parking brake by hand with the box in gear and the driveshafts disconnected. The seatbox is out so easy to do from above. You could disconnect the rear driveshaft, put the transfer in 4 high and the main box in any gear, have a helper push down the clutch pedal while you try to turn the parking brake. When it releases, have the helper continue to push the clutch pedal down. If it then binds before the pedal gets to the floor then you likely have the same issue. If it never releases fully you have a different issue.

Best regards, Dave

[StX_Rovers]

Dave,

Good to talk with you today. Let me know how all this pans out, I've spoken with Inventory folks and we'll make the necessary changes.

Best,

Hi Les,

Likewise. I put it back together last night and tested it by turning the parking brake drum by hand. With the old disk that I replaced when rebuilding the engine a few years ago it works fine. Now the clutch releases and stays released with the pedal all the way to the floor. Fortunately the old disk has plenty of lining. I cleaned it with some scotch brite, xylene, and light sandpaper and it should work great. Now have to finish putting the rest of the car together.......

Best, Dave

[NC_Mule]

Yup it's a 2A. When the problem pops up again I'll experiment with the minimum amount of travel idea. Hate you had to pull the tranny so many times but glad you fixed the problem and even more excited you posted your findings. Thanks in advance for saving me a bunch of extra work when I go to change my clutch.....hope it's not anytime soon.
pb