Clunk: Time for New C/V Joints?

[Rosebud]

I've been chasing a sound in the front end of 'Rosebud' for a couple of months now. Upon acceleration and deceleration I get a "clunk" that I can hear and feel. I've replaced the ball joints, front wheel bearings and tie-rod bushings. The steering rack is tight and there's no play in the steering wheel. The engine steadies and motor mounts are firm. I'm thinking the only other possibility is the C/V joints. There seems to me to be a ton of play in the drivetrain (see video https://youtu.be/on620fXoKGc, although I'm not getting the typical clicking sound when making a hard, low speed tight turn that's normally associated with worn joints. Any ideas?

If it is the joints, should I suspect the inboard pots or the outboard joints? Thanks!

[MiniDave]

You should be able to feel the play in either, grab the axle in the center and twist while first holding the pot joints, then the disc or drum, if there's excessive play you should be able to feel it.

[Willie_B]

I have had that twice. Both times it was the passenger side outer bushing in the steering rack. If you have a passenger they can feel it with their feet on the floor/firewall right where the rack mounts.

http://www.somerfordmini.co.uk/eshop/index.php?main_page=product_info&cPath=193&products_id=5769

See Spanks entry on these.

https://www.minimania.com/msgThread/107885/1/1/Steering_rack_repair

https://www.minimania.com/msgThread/117623/1/1/Steering_Rack_Bushing_Replacement

[Rosebud]

You should be able to feel the play in either, grab the axle in the center and twist while first holding the pot joints, then the disc or drum, if there's excessive play you should be able to feel it.

That's a great idea to determine inboard vs. outboard CV joints play. However, a forum member viewed my video and said that the transmission and C/V joint play looks normal, although the "clunk" sounds exactly like the sound produced by turning the wheels when jacked (see video). My other guess would be ball joints (new and correctly shimmed)[/size], sloppy steering rack (the rods ends have no play and is firmly attached to the bulkhead[/size]. Motor mounts and engine steadies all good[/size].

[jedduh01]

I posted to your other posts too... Ill try to get a wheel up on one of my cars setups to compare the 'differential lash you're seeing.

For your case:   
When you do the wheel movement  (rolling ) forward backward.. does the other side wheel do the same opposing movement instantly = or a 'moment' before the slack is taken up  and the other wheel reacts... Should be an 'opposite reaction to your input action.

[Rosebud]

After 6 months of scratching my head, I finally found the source of my "clunk." I initially described it as sounding and feeling like a broken motor mount and/or slack engine steady. I checked my motor mounts and engine steadies and gave the valve cover a cursory tug and everything seemed solid.


I jacked the front wheels off the ground and was concerned with the slack in what seemed to be the diff and/or pot joints—rotating the wheels by hand seemed to produce the same clunk sound. My mechanic and several forum members looked at my video and thought the play was within normal limits. Several members thought it might be that my steering rack was giving out. For good measure I replaced my ball joints, tie rod bushings, track rod ends, and front wheel bearings. The clunk remained. I was about to order a new steering rack.


I adjusted my valves the other day, and while rocking the car back and forth to cycle the valve train, I noticed the motor was moving way too much. Although the top engine steady was plenty tight, I could see the weld that fastens the clutch master cylinder support and also terminates the engine steady at the bulkhead had broken and was pulling away from the bulkhead as I rocked the car.


Lengthening the engine steady so that it is tight against the bulkhead solved the problem. Clunk gone. I'll keep an eye on it, but I think we're good.

[MPlayle]

The better thing to do is get the bracket re-welded to the cross-member.

The "clunk" was most likely the floor pan flexing at the rear mount of the subframe for that side.  When the engine rocks, those tails push/pull on their mounts to the floor pan and can also create cracks in the floors.

[MiniDave]

/\  4.gif

[tmsmini]

This an option as well:

[MiniDave]

Where do you get one of those?

That would be a challenge to install, you'll need two people unless you welded the nuts to the bulkhead on the inside...

[tmsmini]

7 Enterprises sells them. Actually if you mount it with the dogbone in place and mark the drilling locations, then remove everything to drill, it is not too bad. Definitely easier to tighten nuts with a helper. I believe it is an S-racer item.
Terry

[Rosebud]

Wow! That's just what I needed! In the photo, it looks like the clutch master cylinder tray is bolted down onto the bulkhead. Much stronger than my installition. Mine's welded to the vertical part of the bulkhead. Not exactly a good place to anchor an engine steady.

[tmsmini]

I think that is just for display purposes. The "tray" should slip over studs and there should be gaskets and a possible a metal spacer underneath.
Unless I am misunderstanding.

[MiniDave]

A left hand drive car will look like this....

[tmsmini]

Yes, left hand drive no master cylinders, but maybe heater hoses pass through.

http://www.somerfordmini.co.uk/eshop/index.php?main_page=page&id=27

So on the Innocenti that you are converting LHD/RHD, which side does it have studs on?

Link to 7 Ent item:
https://www.7ent.com/products/dogbone-mount-repair-bracket-for075.html

[MPlayle]

The studs are actually part of the pedal box coming up from underneath.  If a RHD car, the black plate shown in tmsmini's picture will be over the studs and underneath the master cylinders.  If a LHD car, then bolts go through instead of the pedal box studs.

The factory original lower bracket for the clutch line (holds the connection of metal line from the master to the flex line from the slave) and engine steady is welded to the vertical surface of the cross member - where the aftermarket bracket in tmsmini's picture is.

[tmsmini]

I forgot the studs are part of the pedal box. Old age creeping in...

[jeff10049]

you can also just add bolts to the stock bracket.