Diff Mounting

[swanny]

Have just fitted a set of diff polybushes, front pair went in fine, bit stumped with the rears, they have two washers each, one with a large hole, one small, I presume washer with the large hole goes on first, followed by the two bushes, then the washer with the small hole, then the nut, trouble is the nylock nut doesn't fit fully, have I got something wrong?...

car is a 1967 tr250.

Paul 

[RogerH]

Hi Paul,

              the small one goes on last - Poly/diff/poly/washer with small hole/nut

However it may be a good idea to double up on the washers to squish the poly a little more.

So the washer with the large hole sits on top of the washer with small hole.

Make sure that the washer with big hole does actually go over the pin and not get snagged.

 

Roger

[swanny]

Roger

That would work with the front bushes, they don't have the steel sleeve, the rear ones have the steel tube that goes up the middle, I don't think you can compress the bushes due to this, you are just tightening against this tube, the large washer does not fit over the tube, if I removed the washer with the large hole then I could get a full nut on, I will contact polybushes and see what there thoughts are.

Paul

[RogerH]

Hi Paul,

       the extra washers are just a fiddle that may help with some problems.

If they don't fit then don;t fit them.

 

Roger

[Dave McDonald]

Paul,

I'm puzzled by your reference to 2 bushes and a washer with a large hole.

The rear mounts should comprise a pair of bushes both approx. 40 mm dia, top one parallel sided, bottom one partially parallel sided but with a cone shape at the bottom. These two bushes should be bonded to a steel plate, one above it and one below it, making it one composite unit. The steel plate should have 2 projecting lugs drilled to take 5/16" unf bolts. See Moss catalogue p. 122, item 68, part No 147783Z (I'm not clever enough to attach a link.) That's actually a rubber Elastomeric component but the poly versions that I've used in the past have been similar.

The 2 lugs on the plate bolt under the projecting ears on the diff backplate. There is, as you say, a steel tube up the centre. Under the bottom of the bushes there is a large diameter thick washer, c. 40 mm dia but with a hole drilled to fit over the 3/8" unf diff mounting pin on the chassis. This butts up against the steel inner sleeve. Since that washers' hole is standard 3/8" stud size it shouldn't need an extra thin washer. The Moss catalogue doesn't show another thin washer here.

Sorry to labour it a bit but I hope that's clear.

Dave McD

[swanny]

Dave

if you look at the polybush website, item 34J shows all the pieces included in the diff rear mounting kit, it comes with several parts that fit onto the diff and then fastens to the mountings. It shows a second washer with a larger hole, this is the item that puzzels me?

 

Paul

[tr graham]

Swanny

sounds like you have the earlier type rear mounting ,same as a 4A washer with large hole goes up first then polybush , then diff then polybush then small washer then nyloc nut

regards

graham

[RogerH]

8 minutes ago, tr graham said:

Swanny

sounds like you have the earlier type rear mounting ,same as a 4A washer with large hole goes up first then polybush , then diff then polybush then small washer then nyloc nut

regards

graham

There should be no need for the washer with the 5/8 hole to support the poly bush.

 

If Swanny has the kit for the later TR6 diff back cover but actuaslly has the TR4A cover then he will need a different bush kit.

My TR4A poly bush kit did not have any large washers included.

 

Roger

[swanny]

My diff support bracket is early Tr250,  as per item 3 of the moss rear axle page, but it looks like its the same bushing set up for all tr250/5&6

Paul