Diff indentification and parts sourcing

[pleask]

I have a '92 Caterham with the Kent 1700 motor. As you know I only got it a few weeks ago, and I have just had my hoist installed so I had to lift something up, just for the heck of it!

Could you kindly identify what the diff (Crown and pinion) is that I have (see pic). As well, where can I get a new one, what car(s) were they common to and so on in case I need one.

As you may recall, I have a nasty "Clunk" on starting up in first. Many suggested I get new "A" frame bushings that have just arrived and will be installed soon'ish. But as the car was up on the hoist I put it in to 4th gear and moved the rear wheels back and forth lightly. I for sure heard/felt/sensed metal "slop/clunk" sound coming from with in the crown and pinion pot, hence my question above. So I fear this may be the problem and not the bushings. As well, I just want to know ;)
Thanks all, Pat

PS: I have posted a pic of the diff, I hope you can see it I'm new to this forum and how it works.

[moosetestbestanden]

I have the bible at home. It may (or may not) have information about what live axle's were put in the car back in the 90s. I'll give it a look after work.

In the meantime, istr that they used a Leyland live axle called 'Ital' for a long time. A google found much, pics and so forth.

Similarly, a quick search on BC revealed this. It's the 1st line in the IPs post that shows a '92 Ital live axle'. Of course, that may or may not mean yours is. And this, which says the same about another '92.

Welcome to the wonderful world of Caterhams. :-D

Edit: A rebuild may be easier than sourcing another. The fellers Over There also change the Ital for a Ford. Don't know much more about either as I have De Dion rear suspension. HTH.

[GWise]

They came with cortina, sierra and ital axles. I cant confirm when they used which (nor can caterham, I would guess). I think they all look pretty similar too, so you'll probably need to do some research or ask someone how to distinguish.

What is the "crown and pinion pot"? You do realize that the a frame bushing that has been discussed is right beneath the crown and pinion, right?

[pleask]

Yes, no problem with the "A" frame bushing location thanks for ensuring that! Hopefully someone on this list will know how to identify the diff I have. I guess I'll have to install the bushings first and hope to "heck" that is my clunk.. but history has shown me the easiest fix does not normally go my way! I may wait till winter to pull the pot. I'll keep you posted, again thanks, Pat

[moosetestbestanden]

The Bible (Chris Rees' book The Magnificent 7) isn't precisely clear but there's some info there. They were making some Vauxhall powered cars at that time as well as more basic Crossflow powered cars. From what I can gather it's probably an Ital live axle.

[pleask]

Thanks for looking Chris, I assume that The Magnificent 7 is the book I should be looking to buy?
Pat

[pleask]

Chris.. I just looked up this book on eBay and there are several versions available. which one do I want? (Anyone got one for sale?) I'm looking more for a tech manual than a history on the car.

[escondidoron]

You might be able to tell a bit more about which axle that you have by the bolt circle. IIRC, the Ital rear axle has a 3.75" bolt circle, like a Triumph - and my S2. The Ford axle has a 4.25" BCD. So if your bolt circle isn't 4.25" the axle is definitely not a stock Ford unit.

I'm looking more for a tech manual than a history on the car.

I have this book ..... and several others. I think that you also might want to consider this one:


Lotus Seven: Preparation, Restoration and Maintenance, by Tony Weale.

It's out of print. And it's not cheap.
They come up on ebay periodically as well as Amazon, albeit possibly at a bit more cost.

That's how I sourced mine. It has proven to be worth every penny. Loads of pictures and info on the cars, both technical data and service how-to's. First published in '91, it primarily covers cars from Series 2 Lotus through ~'90 Caterhams.

[pleask]

Thanks, just a couple of clarification questions please. When you talk about the bolt circle, if I took a coffee can that is say 4.25" in dia and placed it over the bolts holding the crown and pinion in place is that correct?

I've not seen the use of the "~" used before, does this mean all 1990 Caterhams? (Mine is a '92).
Thanks, Pat

[escondidoron]

Thanks, just a couple of clarification questions please. When you talk about the bolt circle, if I took a coffee can that is say 4.25" in dia and placed it over the bolts holding the crown and pinion in place is that correct?

The bolt circle is the notional circle determined by the positions of the bolts. The center of every bolt lies on the circumference of the bolt circle. For a 4-bolt wheel, this measurement is merely the distance between the center of two diametrically opposite bolts. See picture below:

I've not seen the use of the "~" used before, does this mean all 1990 Caterhams? (Mine is a '92).

The use of a tilde is meant in the mathematical sense where it is used to denote "is similar to" or in this case "approximately".

[pleask]

Duh... okay sorry I did not know you were talking about the bolt pattern of the wheels, my brain was thinking of the diff bolt pattern.

I have the book you suggested on order!
Pat

[pleask]

Sorry it took so long.. I have four wheel studs in my wheels, and the distance cnt - cnt is 3.75" Does this tell you (and me) what I may have for a diff then? Thanks, Pat