Stub axle retaining compound question

[TurboFource]

I see  mention of using Loctite 635 as the retaining compound between stub axle and drive flange splines...

If you look at the Loctite Retaining Compound Design Guide https://5.imimg.com/data5/AE/AX/JM/SELLER-2044578/loctite-retaining-compound-638.pdf page 16 chart, 660 Retaining Compound is the only one that mentions splines, it also has a .020" fill capacity and a longer setup time than 638 (635 is not mentioned in this chart), would this be a better choice? (The original owner of TCST used stud and bearing mount which seems to have worked great!)

This is what Loctite says about 635: LOCTITE® 635 is a green, opaque liquid, 1-part, medium viscosity dimethacrylate ester threadlocker with high strength. It is designed for the bonding of cylindrical fitting parts. Typical applications include rotor to shafts in fractional and subfractional horsepower motors. Locks bushings and sleeves in housings on shafts. It augments press fits.

I hope to reassemble these components in the near future and want to use the best solution... thanks for anyone's forthcoming input!

[jbcollier]

Gap filling is not necessary.  If your hub and splines are worn then they will no longer mount, or run, true.  With everything cleaned up, the hub should be a snug fit on the splines.  Always replace worn parts.

Set-up time, however, is critical.  Given the loads involved, the retaining compound supplements the mechanical fit, not replaces it.  If the retaining compound sets before everything is fully seated, IT WILL COME LOOSE.  You want at least 24hrs before the compound fully sets.

Best practice is to drive and vigorously corner after tightening the axle nut and check the torque again.  Repeat at least three times, or, until the nut no longer goes tighter.  Then fold over the local tabs.

[SwiftDB4]

I've used 640. 1 hr. fixture time with 24 hr. full cure. 400 degree temperature limit. As JB says I wouldn't be too concerned with high viscosity/ filling capacity. Some of the green loctites only have temperature limits in the 300 degree range and I found they broke down when I did trackdays.
Loctite # are confusing as they seem to be updating/ changing them periodically.

[TurboFource]

It will be months before I drive the car……should I put this together for the time being without Loctite then do the final assembly/torquing after it is drivable?

[jbcollier]

I would say, "Yes!" to that.

Th rear hubs are a known weak spot.  Doing it as best as possible is a very good idea.  Just don't forget!

[S2Zetec54]

 I recently used 660 to very good effect

In fact it is so good I haven’t bothered to fit the new stub axles I bought yet…..

I spent a long time cleaning the splines I also used Loctite SF7649 Activator 150ml

I don't know how worn they are of course….so am keeping a very close eye on them.

[TurboFource]

Is the hub or the axle usually the issue? It would have been nice if they had designed it to use more of the spline on the the hub leaving only enough unused spline to make sure everything was seated...

[jbcollier]

Both are shite.  They both wear.

[GavinT]

[...] It would have been nice if they had designed it to use more of the spline on the the hub [...]

The Hillman Imp configuration uses all the spline.

Just make a 3/8" ally spacer is what I did (pics below).
This permits regaining the 3/8" of spline engagement, deletes the spacer on the shaft and reduces the rotational leverage potential of the hub.

[jbcollier]

That'll help.

[TurboFource]

Excellent Gavin!
I was looking at this yesterday and thinking the same thing could be done!

[Fotog]

With Gavin's spacer, you'd need longer studs, correct?

Vince

[TurboFource]

Fotog,

Yes. Gavin what did you use?

[Fotog]

In the case of the original Lotus design, or with Gavin's solution, a spacer is used to place the rear tires 3/8 in. further outboard from centerline than if the spacer weren't there.  Any ideas about why they didn't simply design it with the rear bearing carriers located 3/8 in. further outboard than they presently are?  That would result in better engagement of the splined shaft and hub.  I think the parts involved were virtually all Lotus designs (half-shafts, hub carriers, trailing arms..)

Vince

[GavinT]

Yes, longer studs are needed.
The back story to this is that losing a wheel at over 60MPH is the mother of invention.
Luckily I had a pair of Hillman Imp axles & hubs on the shelf as spares.

A Hillman Imp hub is interchangeable with the Lotus hub except for two differences.

1. The Imp hub uses 7/16" UNF studs on a 4" PCD.
(Lotus hub uses 3/8" UNF studs on a 3 3/4" PCD.)

2. The drum centre locating spigot on the Imp hub is larger and therefor needs to be turned down to suit the Europa drum.

The pics show a Hillman Imp hub with the stock Imp 7/16" UNF studs.
The Imp stud holes were welded, the hub refaced and re-drilled to the Lotus PCD.
The ally spacer locates on the drum brake spigot . . and looking at the pic now, I could have made it a little larger in diameter, too . . oops.

The little rings you see around the studs are merely nuts turned down to locate the drum. With the stock Lotus arrangement, there's a plain land on the stud that locates the drum but this is lost when using the spacer.

This was all done before we had the interwebs so I just reused the Imp studs and obtained suitable wheel nuts - I wanted to get the car back on the road.
Plenty of people have adapted longer and larger studs - Land Rover Freelander?
You can also get longer (48mm) Triumph studs these days which suit the stock holes - link below.

https://www.ebay.com.au/itm/222988223478