Propshaft problem

[Tiger]

Help again please !
Getting a loud bang when first lifting the clutch appears to be coming from the joint  in between the seats.
Looking in the inspection hole the joint seems badly out of line.
What is the purpose of the long nose which points down ?
Is it to set the orientation of the joint ?
See picture.
Regards
             Tim                

[Robert Leigh]

The link pointing down from the joint is to provide location on the chassis for the front of the torque tube which encloses the pinion shaft, effectively giving the axle assembly three point location. The spring pins at the outer ends of the axle cannot on their own stop the casing from turning. Your bang probably comes from the locating ball on the end of the chassis mounted pivot. This is on the chassis cross member at the front of the rear spring mountings. It can all be seen very well from underneath when the back of the car is raised. Use ramps or axle stands for safety. Both the upper and lower joints on the link are adjustable to eliminate any bangs from them if they are loose. I think you have my phone number if you need to discuss things.

[Reckless Rat]

The "long nose" (or short nose on an earlier car) that points down is mounted onto the chassis cross-member by a ball joint or in later models by a silentbloc bush. The bottom ball joint is adjustable and is usually the source of the knocking noise when taking up the drive. You can loosen the locknut and tighten the bottom seating nut, but if there's no available movement you can shim it inside with a washer. The top ball joint is also adjustable by rotating the castellated ring clockwise (after removing the lock bolt if it's there, and assuming there's still some thread left to do it!)

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[Howard Wright]

Hi Tim

The above replies are all spot on, however the ball on the end of the torque tube is often worn and most commonly at a slant, hence the orientation of your torque tube bracket.

Later Rubys had a bracket with a single axis joint and silent block bush on the chassis which prevents this. These can be retro fitted but you need to make up different chassis brackets.

The wear on the ball can be taken up by tightening the big castellated nut, however the wear is often more than can be taken up.  An answer is to turn or mill off the face of the bracket and possibly the end of the castellated nut so that it can be tighten up more.  Alternatively a shim may be installed, I believe David Stepney on the ‘What have you done’ thread has just reported doing this.

Wear in either the chassis mount or torque tube ball can result in a big thump and judder, especially when reversing.

Cheers

Howard

[Reckless Rat]

I forgot to mention the possibility also of loose rivets fastening the torque tube ball mount to the cross-member. They can and do work loose (probably why the one in the photo has been replaced with bolts & castellated nuts. Same applies to the one on the front crossmember for the radius arms.

[Tiger]

Many thanks Gents for the quick replies.
I am going to have another look at the joint this afternoon and will report back.
Nice to hear from you Robert

[Tiger]

I have adjusted the top large joint so now has no play(backed off a little for movement)
Made two tapered washers set at the chassis mounting to bring the joint in line.
All attempts to release the bottom ball have failed so not sure if this will improve matters ?
Trial run Saturday
Fingers crossed!

[David Stepney]

I removed the cap nut on the lower joint on my RP with a 42mm 3/4 in drive socket and ratchet. It was quite tight to move but then came off quite easily. The thin locknut came too! I thought at first that it was missing, until I washed the cap nut, whereupon the locknut fell off. having been stuck on by years of oily crud,

[Tiger]

When the cap was off did the joint need further attention?

[David Stepney]

As it happens, Tiger, it didn't. All the play in my mounting was in the top mounting. I am not familiar with the later Ruby joint, but mine has a lower cup to fit the ball on the chassis, a spacer and the cap nut and locknut. I greased mine and then fitted the lower cup, spacer and then adjusted it so that it was free to move without play. I am perhaps fortunate inasmuch as the ball is still tightly riveted to the chassis.