S1 1.5 Diff.

[genneton4]

Hi, could anyone on the forum tell me if my car has a LSD or not please. I can't find the answer 100%. I wish to drain and replace the oil as it is a little 'whiney'.
Chassis is 1E344623 - it's a yank S1.5 coupe.

Thanks

Keith

[Gfhug]

Keith, any little tags on the bolts of the diff? See here for help: http://forum.etypeuk.com/viewtopic.php? ... sd#p112890

Also, there’s a way to check if it is LSD, and I’ll be corrected if wrong but raise the back of the car off the ground and rotate one of the wheels. If I’m correct the other wheel rotates the opposite direction if LSD. Waiting for someone like Steve (mgcjag) or Christopher Storey to give me the thumbs up or shoot me down
Or Tom W as below

Also I think all S1 and 1.5 UK or USA had LSD

Geoff

[Tom W]

With the rear wheels in the air, rotate one wheel. If the other wheel rotates freely the opposite direction then it’s an open diff. If both wheels rotate easily the same way, and the propshaft turns, then it’s a LSD. You can confirm by putting the car in gear. With an open diff, you’ll still be able to turn one wheel freely and the other goes in the opposite direction. With an LSD the wheels will be difficult or impossible to turn. Obviously the handbrake needs to be off for all this.

[genneton4]

Thanks.
I will try this when I next get the car on stilts !
Keith

[genneton4]

All sorted thanks. There is a tag that says PL. Also, when I rotate a wheel, the other wheel rotates the same way and the propshaft turns.

Also, there is a breather 'chimney'. Am I right in thinking this also confirms a LSD unit ?

What oil, should I use ? The manual just says hypoid. What sort of hypoid ?

Am I right in thinking that I can't use an additive or a thicker oil to quieten the whineing - because it is a LSD ???

Thanks again.

Keith

[Gfhug]

I believe the breather chimney is on all diffs, certainly was on my original S2 non LSD diff. Oil see this topic:
viewtopic.php?f=3&t=17596

Geoff

[christopher storey]

As far as oil is concerned, any Hypoid EP90 oil will be suitable. I believe that Esso used to do a multigrade EP90/140 which might be slightly heavier when hot which may help with noise

PS Millers Oils do Classic EP Oils in both GL5 and earlier GL4 specifications, the latter in both EP90 and EP140 grades . Others will know better than me, but I believe that the GL5 is suitable for the most extreme loadings

[abowie]

You need an oil with the LSD additive.

I use https://www.repco.com.au/en/oils-fluids ... p/A9458805

[rswaffie]

Hi
When Alan Slawson rebuilt my diff back to 3.07 spec, he supplied a couple of litres of castrol z90 oil for it, along with this info on the invoice:
Warning Note – Castrol ‘Axle Z90’ limited slip oil or quality equivalent oil to be used for the LSD unit.
Synthetic or semi-synthetic oils do not work in these units and MUST not be used

[christopher storey]

You need an oil with the LSD additive.

It's interesting that you say this , Andrew, because there is absolutely no mention of it in the workshop manual , or for that matter on the data plates. The list of manufacturers in the manual is extensive , and all mention EP and /or Hypoid, but none AFAIK mention any additive either at page A18 or H5 .

[chrisfell]

"Synthetic or semi-synthetic oils do not work in these units and MUST not be used"

Hmmmmm!

Mine has had 75W90 fully synthetic oil in the axle (with the appropriate friction modifier added) for many years and many tens of thousands of miles. Why should I have not been using it? What disaster will befall my axle? How long will it be before this catastrophy occurs?

[44DHR]

Sorry to be late to the party, but a few comments in response.
With regard to what is the correct oil and service recommendations, you need to look to the actual manufacturers recommendations. Jaguar did not make the Powr-Lok differential and hence a little history is required.
The Powr-Lok was developed in the 1950s by the American Dana Corporation under patents from the Thornton Axle Company. It was manufactured under licence by GKN Salisbury Transmission Limited for European use. This is from the Service Manual from the Spicer Axle Division of the Dana Corporation in Fort Wayne Indiana. Please note the “Important” paragraph below :-



You could use a SAE 90 oil in a Powr-Lok differential, but the limited slip clutch and friction plates would not be working effectively and there would be a high degree of risk of damage to them without a suitable oil either already containing a suitable friction modifier, such as this Castrol oil, or adding said item to standard SAE 90 oil - such as below :-



As regards the original questions, both the non Limited Slip and LSD differentials have breathers. The action of the Powr-Lok differential is to effectively lock both sides of the output shafts, hence why when the car is jacked up, both wheels will rotate in the same direction. It is when the car turns a corner or one output shaft moves differently to the other that the clutch plates need to operate and without the correct friction in the oil they are not effective and can give rise to chatter. This is especially true when a axle is rebuilt and the various clutch and friction plates need to “bed in”. Regarding the axle noises, this would not be a result of the LSD components and much more likely to be originating from incorrect meshing of the drive gear and pinion, or from bearings on the differential or pinion shafts developing play. No oil additive is really going to sort those sort of issues, other than inspecting the axle to track the actual cause.
I trust this assists.
Regards,
Dave

[christopher storey]

Jaguar never recommended standard 90 gear oil . The recommendation was for EP oils which of course have a totally different shear strength to cope with the pressures between teeth of a hypoid type drive . You can still buy standard 90 gear oils for classics but they are suitable only for cars much earlier than ours. I think the important bit in the page you have reproduced is that the oil should conform to GL5 spec