3000m Rear Suspension/Hubs and Bushes

[Erich Stahler]

Does this hub carrier look normal or does it look like it's been been altered in any way?



I am also wondering if the wrong poly-bushes have been fitted, note the gap between the top wishbone bushes and the ally hub carrier casting, there are two types of bushes supplied by sperflex, those fitted (for the later M's) and the top hat variety (earlier M series)
I think the previous owner might have fitted the later ones as they are cheaper! That's my theory anyway.

Can the spaces be packed out with washers?

Edited by Erich Stahler on Saturday 4th June 17:42

[djc100]

There should be washers between the bushes and rear upright/hub carrier. Adjust washer thickness to centralise.
Hub carrier looks normal except mine only has 6 stud holes not 10.

David

[Erich Stahler]

djc100 said:

There should be washers between the bushes and rear upright/hub carrier. Adjust washer thickness to centralise.
Hub carrier looks normal except mine only has 6 stud holes not 10.

David

Excellent, so I don't have to buy a complete new set of bushes.

The extra holes are from some home made hubs that the last guy had made, they used an adapter plate. Hopefully the extra holes wont undermine the integrity of the castings.

[Slow M]

Bushes look wrong, as there's usually more of a rubber/urethane shoulder on each side of the wishbone end.

Also, the hub carrier has been drilled to accept a different hub. If going back to the original style Triumph version (6 hole flange), make sure the ID has not been increased.

BH

[Erich Stahler]

Slow M said:

Bushes look wrong, as there's usually more of a rubber/urethane shoulder on each side of the wishbone end.

Also, the hub carrier has been drilled to accept a different hub. If going back to the original style Triumph version (6 hole flange), make sure the ID has not been increased.

BH

I am using the Quaife Sierra style hubs.

[Adrian@]

I would agree with the need to recreate the register that is the internal diameter of the alloy casting, and the front face has been machined too (reducing track) when you revert to OE style bearings...IMHO IF you are using Spax shocks with Spax top collets they will clash with the chassis under full compression and crank the spring, already the shock looks like it is leaning and needs packer washers to correct.
Adrian@

[kabaman]

Just out of interest...What stops the pivot bars from spinning in the aluminium casting and wearing it? The pre-Ms had pinch bolts but the Ms don't seem to?

Also how do you get the wishbone and upright apart and re-assembled? Do you have to press the rod in with the upright inbwteen the wishbone bushes?

It all looks a lot stronger than the pre-M but dificult to assemble.

N

[Adrian@]

kabaman said:

Just out of interest...What stops the pivot bars from spinning in the aluminium casting and wearing it? The pre-Ms had pinch bolts but the Ms don't seem to?

Also how do you get the wishbone and upright apart and re-assembled? Do you have to press the rod in with the upright inbwteen the wishbone bushes?

It all looks a lot stronger than the pre-M but difficult to assemble.

N

That pinch bolt has most likely broken more Pre-M uprights than an thing else....doing one up too tight shears the alloy casting at that point! As you say you capture the wishbone within the upright and this is why it is important to centrally space the alloy casting when you use poly bushes (rubber have no shoulders and can be drawn through to take up the varying width of the casting and or varying size of the wishbone), once you have spun the nyloc onto end of the bar and added another nut you can spin the opposite nyloc on with little issue, my thoughts are that the pinch bolts are a throw back to not having nyloc nuts to hand and designing in a fail safe that the miss match of steel and alloy cures by corrosion.
Adrian@

Edited by Adrian@ on Monday 6th June 07:54

[Erich Stahler]

Adrian@ said:

I would agree with the need to recreate the register that is the internal diameter of the alloy casting, and the front face has been machined too (reducing track) when you revert to OE style bearings...IMHO IF you are using Spax shocks with Spax top collets they will clash with the chassis under full compression and crank the spring, already the shock looks like it is leaning and needs packer washers to correct.
Adrian@

The picture below shows the depth of the casting from the hub mounting face to the back of the casting is 95mm, is that less than standard? The id is 90mm.

By the way, the hub bits shown in the picture are not what i'm using, (previous owners attempt), if necessary I might use the steel register ring to bring the track back to standard if it turns out that my castings have been faced off.

[Adrian@]

Hi Peter, Just information for the thread (as we spoke) 101mm'
Adrian@

[Erich Stahler]

An update on the hubs, the id of the hub carriers is standard, as in its the correct register for both the original hubs and the new Quaiffe units, the only difference is they are about 4-5 mm shorter each side than standard, but I can compensate by playing with offsets and spacers so I don see any reason why I shouldn't use the original castings.

How would the original hubs have been attached to the carriers, with allen bolts, hex heads or threaded studs as on the TR6?

[Slow M]

Threaded studs.
As memory tells it, they are coarse into the Aluminium, and fine thread on the outside.

B.

[Erich Stahler]

Slow M said:

Threaded studs.
As memory tells it, they are coarse into the Aluminium, and fine thread on the outside.

B.

is there any reason why I cant use allen bolts rather than studs?

[heightswitch]

Erich Stahler said:

is there any reason why I cant use allen bolts rather than studs?

None at all but consider that if you are fitting anything to Alloy you run a higher risk of thread failure by pulling against the thread as opposed to installing a threaded stud which allows you to pull up on the face without exerting a tensile load on the threads within the alloy casting.

If installed carefully this shouldn't pose too much of a risk but a twin threaded stud from an engineering point of view is a better fix.

if I was going to all the expense of installing quiffy hubs then the last thing I would be doing is installing them in those particular uprights!!

N.

[Erich Stahler]

heightswitch said:

None at all but consider that if you are fitting anything to Alloy you run a higher risk of thread failure by pulling against the thread as opposed to installing a threaded stud which allows you to pull up on the face without exerting a tensile load on the threads within the alloy casting.

If installed carefully this shouldn't pose too much of a risk but a twin threaded stud from an engineering point of view is a better fix.

if I was going to all the expense of installing quiffy hubs then the last thing I would be doing is installing them in those particular uprights!!

N.

What's wrong with those particular uprights, do you think the extra holes would significantly undermine the strength of the castings?

[Slow M]

http://forum.britishv8.org/file.php?13,file=4356

They're reputed to flex a little, then break. Those instances, supposedly, are caused by the application of high (accelerative) loads. Closing in the casting holes strengthens them. You can go further, and support the top from either side. See Zappa's reinforced rear upright, here, for an additional option.

B

[heightswitch]

Erich Stahler said:

What's wrong with those particular uprights, do you think the extra holes would significantly undermine the strength of the castings?

Do you know their history Eric?
How old are they?
How many kerbs have they bounced off
were they second hand to start with?
What has been machined off the mating faces?........

You seem to be trying to create a strong rear end with very nice qaiffe hubs to take power , then compromising all your work by installing said hubs into an unknown entity!

All my last post says is " I " wouldn't use them. You may be entirely happy with them.

N.

[Erich Stahler]

Slow M said:

http://forum.britishv8.org/file.php?13,file=4356

They're reputed to flex a little, then break. Those instances, supposedly, are caused by the application of high (accelerative) loads. Closing in the casting holes strengthens them. You can go further, and support the top from either side. See Zappa's reinforced rear upright, here, for an additional option.

B

SlowM, I take it this what you mean by closing the casting holes?


On the Zappa car he has even reinforced the upper wishbone pickups.


HeightSwitch, I entirely agree with your comments......

I don't know the history, how old they are, how many kerbs they have bounced off etc.

The only choices I have are:

1.Replace these carriers with another second hand set of unknown history
2.Beef these up as suggested
3.Get a bespoke pair CNC'd up from a billet of aircraft grade aluminium

My intention to start of with a moderate amount of power, probably less than 250 bhp to begin with, and develop the car and my track skills. I thought it would be worth going for the quaiffe hubs to remove a known weak point in the drive train.

What would your suggestion be?

Edited by Erich Stahler on Wednesday 15th June 10:02

Edited by Erich Stahler on Wednesday 15th June 10:05

Edited by Erich Stahler on Wednesday 15th June 10:06

[TVR_owner]

Erich Stahler said:

SlowM, I take it this what you mean by closing the casting holes?


On the Zappa car he has even reinforced the upper wishbone pickups.


HeightSwitch, I entirely agree with your comments......

I don't know the history, how old they are, how many kerbs they have bounced off etc.

The only choices I have are:

1.Replace these carriers with another second hand set of unknown history
2.Beef these up as suggested
3.Get a bespoke pair CNC'd up from a billet of aircraft grade aluminium

My intention to start of with a moderate amount of power, probably less than 250 bhp to begin with, and develop the car and my track skills. I thought it would be worth going for the quaiffe hubs to remove a known weak point in the drive train.

What would your suggestion be?

Edited by Erich Stahler on Wednesday 15th June 10:02

Edited by Erich Stahler on Wednesday 15th June 10:05

Edited by Erich Stahler on Wednesday 15th June 10:06

Buy a quality un-used set from the guy with the M Series PH ad.

[Geoff38]

Hi TVR_owner , you'll mean these ones.... http://www.pistonheads.com/sales/2658455.htm

the seller is very good but has been hard to get hold of in the past.

Cheers
Geoff