Anyone had much experience with different size rollers ? Ordering via the chassis number the rollers are 32 mm ,but 36 mm rollers are avalible ,the reason I ask is I’ve some drive axle drums and shoes that I fitted new together and the drum is bearly worn and the shoes have 10 mm in the middle to the rivits however the rollers are right up on the cam in adjusted running position ,the s cam dosent appear to have worn spots .
Whats it on?
I would say you have wrong shoes or drum, 4mm larger diameter roller wont really compensate for the problem you have.
Wont matter if you ordered by chassis number or not as you wont know whats gone on before you got in there.
This won’t be strictly relevant but it will give an idea.
Going back into the mists of time and AECs, the C spring brake used three different sizes of cam rollers for when the drum had been ground out. Once 5/32"" had been taken out of a new drum the cam roller diameter increased by 1/4". A pair of incorrect rollers fitted should be obvious either the drum will not go on or the cam will be on the point of going over centre. What is not so easy to see is when someone has ftted one incorrect roller in one shoe and the right one in the other shoe. I had the shoes off an AEC only last week.
Going back not quite so far DAF used to profile the linings to the drum diameter.
The rollers are 32 mm fitted new by me when I did the drums and shoes they’ve done 100,000ks on the drive axle ,as above 10mm left on shoe centres perhaps 15 mm when new ,drum Hardley worn ,but the rollers are very high on the cam ,all seems a bit odd ,there’s only one drum listed for this axle .shoes are 8 inch quick fits .