Leaf Springs - centre bolt

[stevep]

Hi all,

I have pulled apart one of the leaf springs & cleaning them in preparation for a paint & lube. But the centre bolt is nearly rusted through - are they a generic part, that can be bought at the local suspension place or do I have to get a land rover part?

It's a 1958 SWB 2 litre & the front springs are 7 leaf not 9 leaf like most. Which doesn't seem to make much sense when I look up the part numbers for what is available these days.

appreciate any help & comments
Regards
Steve

[VK3UTE]

G'Day Steve.

I replaced mine with a standard Umbrako cap screw, worked perfect

Unbrako Fasteners (http://www.unbrako.com.au/)

Cheers Simon

[JDNSW]

Any spring works should be able to supply a centrebolt. Measure the head diameter (check this against the socket for it in the axle - mine had been fitted with the wrong size!) and the shank diameter and length, remembering it will be a simple measurement in inches.

Unbrako cap screws are not wholly suitable for three reasons - the end beyond the nut should be peened over - impossible with these, the head is almost certainly the wrong size, and the very hard bolt is more likely to break.

John

[Lotz-A-Landies]

...
It's a 1958 SWB 2 litre & the front springs are 7 leaf not 9 leaf like most. Which doesn't seem to make much sense when I look up the part numbers for what is available these days. ...
Hi Steve

You are correct about S1 and SIII springs, but I have it in my mind that there was something confusing about the early SII vehicles, particularly in relation to presence of capstan winches which may account for the issue of 7 Vs 9 leaves.

The other possibility is that someone has made up a replacement spring pack using Australian spec steel stock, which is thicker than the UK OEM spec for Land Rover. Using thicker stock you need less leaves to achieve the same rate.

Your third option is that a previous owner has removed several leaves to soften the ride. Check if the overlap between leaves is consistent, if there are big and small spaces then you'll find 2 leaves have been removed.

https://www.aulro.com/afvb/images/imported/2015/01/984.jpg

[stevep]

Thanks for the info Diana, I figured out from the parts book that a 2L did have only 7 leaves - part no. 238208 as opposed to 2.25 - 242863. I'll have a look at the dimensions for the rear springs because they definately have taken two leaves out of them, you can still see the wear marks & uneven gaps along the underside.

regards
Steve

[numpty]

Any spring works should be able to supply a centrebolt. Measure the head diameter (check this against the socket for it in the axle - mine had been fitted with the wrong size!) and the shank diameter and length, remembering it will be a simple measurement in inches.

Unbrako cap screws are not wholly suitable for three reasons - the end beyond the nut should be peened over - impossible with these, the head is almost certainly the wrong size, and the very hard bolt is more likely to break.

John

I must admit, I have used "socket headed cap screws" :angel: in the past with no issues. I recall turning the head down slightly (on an 8mm bolt?) to fit.

Excuse my ignorance John, but why do the threaded ends need peening over? This to me, would make them dificult to remove, if and when the need arose to do so. I appreciate that if major surgery was to be done on spring packs, that the centre bolt would be replaced.

Perry

[JDNSW]

I must admit, I have used "socket headed cap screws" :angel: in the past with no issues. I recall turning the head down slightly (on an 8mm bolt?) to fit.

Excuse my ignorance John, but why do the threaded ends need peening over? This to me, would make them dificult to remove, if and when the need arose to do so. I appreciate that if major surgery was to be done on spring packs, that the centre bolt would be replaced.

Perry

It is a foolproof method of ensuring that it does not come undone when you least want it undone. It also ensures that there is no exposed thread. To undo it, all you need is to grind or file it off - and as you say, it should be replaced anyway if you take it out. Alternatives would be to use a nyloc nut (less secure and likely to be damaged) or a drilled bolt with a cotter pin and castellated nut, just as secure, but likely to be damaged. Remember this is sticking out the hole in the spring plate and gets every rock you hit. It is doubtful if a spring washer is sufficiently secure, same with loktite, and both are likely to have protruding thread that you have to cut off anyway because of damage.

John

[stevep]

Excuse my ignorance, but what does the centre bolt do when the u-bolts are done up? except the round head fits into the axle housing and helps locate it.

I just thought its there to help keep the springs together while you are fitting them to the axle.

regards
Steve

[chazza]

The correct grade of Loctite won't let go if properly installed - I will bet something precious and personal on it :D

The centre-bolt stops the axle from slipping backwards, which the U-bolts don't seem to be able to do on their own. A car with a broken centre-bolt will crab when driven,

cheers Charlie

[JDNSW]

Excuse my ignorance, but what does the centre bolt do when the u-bolts are done up? except the round head fits into the axle housing and helps locate it.

I just thought its there to help keep the springs together while you are fitting them to the axle.

regards
Steve

That is the theory, but the practice is a little different. The centrebolt is the positive location for the axle as well as keeping all the leaves in position. But you are right in that the U-bolts should be tight enough to prevent any movement and to ensure that there is only minimal load on the centrebolt.

John