I'm re-building a two bearing engine. I removed angular contact bearings and one shim front the front. I've carefully measure the depth of the housing and it's an earlier, deeper one. Woodrow's manual says there should be two shims! Careful measurement shows the bearings won't be pinched on re-assembly. The bearing are in good enough condition to be re-fitted. The lip is also fine.

Any suggestions as to where I can obtain one shim? I've tried all the usual sources to no avail and don't want to go to the expense of buying new bearings.

Location: Bedford

Bodgers' Corner.Get a pair of tin snips and a selection of biscuit or other tins and get snipping. Beer cans make good shims about 4 thou thick.

Location: Somerset

There seems to be confusion between spacers and the very thin shim sometimes used to eliminate movement from used bearing pairs.I presume the enquiry refers to spacers.

Assuming the standard thickness spacer and that both bearings are of the narrowed type, if spacer fitted to the front only the crank would be in near correct location but, despite the clutch push, very unlikely to stay there. The front housing, rear bearing tracks, and gudgeons likely show evidence of movement.

It is not easy to make a very flat spacer. Any springy home made one or assembly of would best be placed to the rear.

The diagram in Woodrow is drawn wrong. Does not depict the wider width of the outer rings of the later stepped angular contact races.

Location: Auckland, NZ

Er, more correct, diagram C in Woodrow does not show the full (as original) width of the inner rings of the later stepped races, larger relative to the reduced outer rings.
if spacers are not available a reconditioner may have a suitable old oil ring rail which could be supplemented with a more easily made thin shim.

(I always acquire these when I can. Handy as spacers for holding work out from the chuck in a lathe.)

Location: Auckland, NZ

I had this problem recently, 2x 30thou shims needed. Finished up making them myself.
I would follow up Ruairidh's offer first.

Location: Bonnie Galloway

Sorry, I suppose I do mean spacers, not shims. According to Woodrow there should be two, each 1/32" (or 30 thou approx). I've only got one.

I've been told that when angular contact bearings were first introduced to replace the existing ones, only one size was available and the kit was provided with the two spacers for the older, deeper housing. The spacers not being necessary for the earlier, less deep housing.

Curiously, the engine number (I don't have it to hand) would indicate it's a '35 according to Purves and therefore a later, shallower housing according to Woodrow. The car's an AAK and therefore a '34 or '35, but there's no guarantee the engine's original.

Sorry for not replying earlier, but no image appeared at the bottom. Was it something I did?

Location: Bedford

Hi Shuttle

Tony's contribution to the Sept posts "Front A/C main bearings" indicates that the crankcases were fitted with shims/spacers as original for some time after intro of a/c races.

Whether or not a very thin shim should be fitted to slightly preload the bearings (and further stress the original frail lip) is a whole different but related topic. I shimmed my car at one stage, but the whole bearing housing and lip had been replaced by a strong machined steel insert!

Location: Auckland, NZ

You're not telling us which a/c bearings you've got - narrow outer race or wide outer race. The next move depends on this.

Location: Bonnie Galloway

I've (apparently) the earlier, deeper housing with the narrower a/c bearings requiring a couple of 1/32 spacers.

Location: Bedford

Shuttle,

you are welcome to phone me on 01419428037 and, if I can help you with this, I will.

Hi Shuttle,

As I said in an email to you-

I think that If your bearings are narrow outer ring angular contacts then they could be approaching 80 years old.

For the cost of a new pair of standard width angular contact bearings you problem will be solved and you won't have to do it again with all the resultant work when the old pair fail after being disturbed as they might well do (providing you are careful fitting the new pair) .

As noted above, if interested you might check the Forum for recent discussions on Crankshaft Bearings.

Tony.

Location: Melbourne, Australia

As Tony suggests, having stripped down the engine and with the ready supply of good (branded) bearings, I would never skimp on the the cost of replacing the mains.

Location: Farnham

Had a good long conversation with Ruairidh. Gave me some very useful information which I'm certain will apply. Thanks.

This isn't my car, but belongs to a museum where I'm an unpaid volunteer one or two days a week. I'm trying my best to maintain standards against budgets and general ignorance, mostly mine as I've never encountered 7s before.

I'm sure I'll be back here sooner than later.

Location: Bedford

When I was seriously running a Seven, much of the satisfaction was from eking many quality miles from discarded parts.

The bearings may be recent modified ones. But even if old, age is of no consequence if the balls and tracks are uniform shiny with no pits or indentations or rust patterns, and the external diameter not seriously worn. Cleaned dry bearings with the thick edge of outer rings abutting and the inners pinched together should have no or barely perceptible shake. Spacing the outer rings with a very very thin shim can restore this although it is a bit haphazard as track wear is not uniform.
I suspect that in their day the a/c races were a cheaper solution; load rating is not increased. Absolutely no clearance, which lessens the harshness, but expensive to obtain with rollers, was achievable/achieved. Significant preload brings a rigidity which seems a dubious goal with such a flexible crank and frail lip.
I gather some have used inexpensive ordinary ball races which would seem to offer radial clearances no worse than standard rollers but there has been no direct response to this on Forum.
Unfortunately, if the external rings have not been clamped, bearings have likely been moving and turning in the crankcase and may be worn undersize (and the crankcase lost the interference fit) although could still be within new tolerance. For new bearing outer dia may be ½ thou under nominal size; years ago, based on info provided by Tony P, the tolerance range was double this.

Location: Auckland, NZ