Stub axle to upright re-assembly

[Mark Gregory]

Are there any special techniques to re-assembling the stub axle to the front upright?

Is it normal to use Loctite on the tapered faces or are they assembled dry?

What is the torque on the retaining nut?

Any advice gratefully received.

Thanks, Mark

Stupid spelling mistake corrected!

 

Edited by - Mark Gregory on 5 Jul 2004 23:02:54

[Joe 90]

Tapers must be clean and unmarked, no dents etc. As they act on a wedge principle, they shouldn't be loctited and I actually suggest a bit of copperslip so that you can get then apart again. The nuts should be nylocs, so I do them up by feel.

 

SEP field working, not spotted in 101,600 miles. Some photos on webshots, updated 10 June

[Mark Gregory]

Oliver

Thanks for your suggestions. Both tapers look pretty good - no damage. I think I'll wipe both surfaces with an oily rag before re-assembly. Any ideas on torque for the Nyloc nut or just tight plus a bit for good measure? When I pressed the stub axle out it went with a satisfying BANG!

Thanks, Mark

[Paul Richards]

Suggest you use a NEW nylock nut on reassembly and if you have cycle wings, it will normally be a half nut to ensure nylock works. I'm not aware of recommended torque setting, but would have thought around 65 lbs ft would be about right.

 

Paul Richards

Joint AO - L.A.D.S. (Lancashire and District Sevens)

Growing old is compulsory - Growing up is optional

[Tyrone]

Mark,

Extracted from the build manual for new upright assembly:

 

Attach the steering tie rod (2) to Vertical link (1) using bolt (16) and spring washer (21) pass the bolt through the tie rod, the tie rod spacer shim (17) and into the vertical link.

Pass the tapered end of stub axle (3) through the vertical link and the tie rod then secure using plain washer (20) and nyloc nut (12).

 

Torque: Bolt (16) to 25lb ft (34NM)

Nut (12) to 60lb ft (81NM)

 

Hope it helps.

Brian

[Mark Gregory]

Paul

I'm afraid I'll have to use the same Nyloc for the time being until I can get hold of some new ones to the correct size. Now added to list for next Caterham order.

 

Brian

Thanks for the torque settings. Are the torque settings for the brake caliper bolts the same as bolt (16)? It's the same size thread.

 

Thanks, Mark

[pete east]

Mark - A little tip I learned long ago for getting taper components e.g Stub axles track rod ends etc apart was to use two hammers either side of the component in which the taper component sits. Many years ago I spent nearly a day trying separate some taper joints using hired taper joint wedges/hired rocker type joint separator etc without any success, Finally took the offending articles to a garage hoping they had a suitable press. The old guy just got two ball pein hammers and lightly tapped the components simultaneously at each side. The taper joints that I had spent nearly all day trying to separate just flew apart.(Something to do with the effect of the shock wave within the component) so now I use this method every time and it works a treat ,but be sure to keep the securing nut on the end of the stub axle to retain it or it will fire itself across the garage, and may end up with thread damage where it hits the deck.

[Sheds Moderator]

Mark, Re torques a general engineering principle is that bolts of same sizes going into same materials should be tightened to the same or similar torques. The upright is steel (IIRC) so an identical torque is appropriate. The components are suspension in any case so they don't get hot or vibrate. Consequently "tight enough that they don't shake loose" is the best policy and this leaves a lot of scope either side.

[elie boone]

Pete, the trick with the 2 hammers works good but a 20ton press is even better 😬

[Rust Red Seven]

Yep i use the hammer technique as well and it has never failed me yet. Leave the nut on as they do launch themselves across the garage also if you miss the hammer does not BuXXXx up the thread.

 

Rust Red

[Mark Gregory]

Pete

Thanks for the 'hammers' technique. I've seen a similar method used to remove track rod ends from steering arms, holding one large (lump) hammer at the back of the joint then hit the opposite side of the joint with another hammer.

 

BOSS

Yes, I've used the same torque on the caliper bolts. Just hope they don't fall out in the middle of the race at Croix 😳

 

Elie

20 ton press!! All I can say is: you've got a big one!

 

RR7

There's always a risk of unintentional damage when using hammers, that's why I prefer the control of a hydraulic press, but you cannot always get the parts onto a press.

 

Many thanks for all replies. Car is back together now & raring to go - shame the driver is half asleep.....

Mark

[pete east]

Ellie - If available the 20 ton press must be very usefull, but I have in the past had a joint damaged by a press where the taper joint was set so hard all the press did was deform the threaded section of the joint against which the press was bearing. Fortunately it was only a track rod end so not expensive, but it came out of the press still joined together with the track rod, but banana shaped! The car was a reliant scimitar.

[elie boone]

First of all a 20ton press is not that big.

 

Pete, When you apply pressure always considerate what you are doing and even sometimes it still needs a tap from the hammer to get things apart.