Bristol 400 rear axle gears

[Hydroglen]

Geoff,
Thanks.......yes you are correct. In essence there are 2 adjustments. One,
for the bearings using the distance washers that come in different
thicknesses, and the second with the brass shims between the cases. If
either or both are off, then this will affect the CW mesh/lash.
When dismantling it took me some 10 minutes of careful tapping to split the
case and not damage the brass shims. That is what I meant when I said this
is a hard adjustment to make. Hopefully the original shims will do the
trick.
This rear axle seems to have suffered at the hands of some strange people.
Apart from the distance washer already discussed, the main carrier to the
axle itself had 1/2 the studs stripped or broken. I realized this as I was
unbolting it. I will have to drill and tap new threads.
The CW/P are actually in amazingly in good shape.
Thanks
Dorien>

Peter:
I tried to send a picture of the replacement crown wheel carrier and bearings
but it's in the wrong format for this site. If you (or anybody) will send me
a note to wmw79@aol.com, I will try to send you the picture directly. I called
Wayne Mitchell. He has 2 or 3 units on his shelf.
He can be reached at: wtmitchell@att.net**** He has a website:
www.dogrings.com** (He makes parts for Hewland gearboxes)
Bill Watkins

[Hydroglen]

Thanks Bill,
Certainly pictures would be good to have. Perhaps you know the Arnolt that
Bill Mac Farling owns, that he converted with a Chev 289.
He changed the rear axle, (Mercury Monarch) to handle the
horsepower.
Cheers
Dorien Berteletti

Dorien:
The pictures have been sent. I don't know Bill MacFarling but I have seen 3
or 4 Arnolts that were converted to Chevrolet. I almost did it myself after I
cracked a crankshaft, but I came to my senses and bought a new crank. The
suitability of the rear axle was one of the issues. The other was the class (with
Can-Am cars & such) that I would have to run with at the Monterey Historics. It
was only possible to qualify for entry because of some publicity that Wacky
had imported a couple of cars without engines with the intent of installing
Chevys. I asked Michael Arnolt about this and he said that his father had never
followed through on that.
Bill

[Kevin H]

The photos from Bill are attached to this post.

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[Bellerophon]

I have previously written about the rear axle on the Bristol, but will
repeat some of what I have said.
First, all the gears for most of the 2 litre cars were made by ENV Gears of
NW London, these were precision ground gears of a very high standard. However,
ENV went out of business (not certain of the date but think it would be in
the later 50's). Bristol had to then resource, and went to Salisbury for the
rear axles which were not manufactured by the same methods and therefore not
as accurate. The result of this was that Bristol experienced noisy axles, so
much so that they had to take action, so appointed Percy Kemish their racing
engine man to sort out the problem. He told me that it took a while but found
that the problem was a quality one and was cured by better finish in
manufacturing, and a more selective fit. (not easy to get right)

Now the workshop manual gives full instructions on setting up the crown
wheel and pinion, and as they have been run together for some time now should not
cause a problem. One point to note is that the ratio is stamped on the
components, and would be most likely a 3.9 or a 4.22 on the overdrive cars.
However some cars which were used for sporting activities had the later ones fitted.

If some of our members do not have a copy of the workshop manual and intend
to work on the cars, they will save themselves a lot of bother by having the
facts to hand.

My regards,
Bellerophon

[Hydroglen]

My gears are infact stamped ENV 10 x 39. The Pinion and Crown also have the
numbers 2130 handwritten with an indelible marker.
The only damage to the sytem is some slight nicks to the bolt heads securing
the Crown. This would have happened as the pinion slid back as there was no
spacer to hold the bearing/companion flange. The faces are in great shape.
Considering I have toured England, Scotland, Wales, France and a good part
of Eastern Canada, with my 400, I conclude that I am very lucky the pinion
staid in place. It decided to move whilst in the safety of my driveway as I
was leaving for a club event in New England.
Given that you have experience on the subject, there are a couple of points
that you might help me with.

I would be curious to see a picture of the CW bearing caps and their fixed
counterparts. On mine, the castings do not match so as to make a perfect
piece. Infact there is a ledge or notch were the two halves meet. Seems as
if the bearing caps were from a different carrier / casting. Can it be
partly 400 and partly 401? I have sent pictures to the webmaster to
illustrate the point.

Some of the studs that hold the carrier in the rear axle have been crudely
welded on the inside of the case. This caused me much grief as when undoing
the nuts the stud started turning. They could not act as bolts and back
out, because of the welding. Round and around we went.
I had to carefully cut them off with a high speed grinder and now will retap
and repair WITHOUT welding.
Bodges on my car, or has this been seen before?

Regards

Dorien