I suspect this has been discussed in numerous threads, but here is my query.

I have a 60 MK2 with Moss OD tranny. I just replaced the shift lever bushings and did post a question as if possible to remove the entire top housing while in the car. Answer was yes but I elected not to do so.

New bushings installed and shifting a lot more positive and I can live with it. So............

Non synchro first gear aside, is there really any advance to the later Jag box v the Moss in terms of

-part availability
-longevity
-gear ratios
-cost of repairs
-ease of repairs
-etc.

If a really good deal on a Jag box was available other than the synchro first, would it be worth the swap if the Moss box was working ok?

Would love a 5-speed but the cost! Also I have heard that the Tremec 5-speeds have problems. A neighbor had his 5 speed removed from an e-type and fixed drivability by lowering the rear axle ratio.

I owned two Healey 3000 over the years and really did not think the non synchro first was a significant drawback.

Thanks
jjsandsms
-

 

since we are ruling out the advantage of a synchronized first gear... what is the attraction of the five speed?

IMO, unless the fifth gear creates lower RPMs per MPH, and it may not, and one is concerned with engine longevity, i can't see the advantage. unless one's racing, and in that case closer ratios between all gears would be advantageous.

so i'm not convinced "more is better" holds true in this case. my guess is that automobile marketing departments demand it because they are convinced (and rightly so) that their clientele (male in general) takes their cue from the racing fraternity and that the car will sell better if so equipped.

race cars have them because there is a REAL ADVANTAGE to keeping the engine in an RPM range (usually a very narrow band in comparison to street cars) that offers its greatest HP, so it makes sense to have numerous gears. and where an excessive amount of shifting within the course of a race is of no concern. ...hardly true of the cars driven in everyday conditions on public roads.

 

My only attraction to a five speed is modern technology (although not in of itself a real plus in some cases), and hopefully maintenance free. As time goes on parts for Jag and Moss units and the overdrive are going to get harder to track down if one has a serious issue. Which could force one to do some sort of upgrade. The five speed attraction is also only strong if 5th gear is indeed an overdrive ratio, similar to the OD units on the Moss and Jag.

I have a BMW 2800CS (E9) that had a stock 4-speed ZF tranny. I sourced a Getrag 5-speed with 5th as a true OD ratio. The first 4 gears in each tranny had essentially the same gearing. So before the swap on the open road, the car was crying out for a 5th gear!

Lets say my Moss dies, so what options would I have, try and find parts to fix, another Moss, the newer Jag, ???

Thanks
jjsandsms

 

'Back in the day', I covered 80,000 miles or so in all kinds of conditions with the Moss box and my father covered a similar distance with it. We didn't have a problem. Just remember that you push it towards second before engaging first or reverse. For other gears, make the slightest hesitation in neutral. My box has a bit of a notch in neutral (going from second to third) that I hope I've resolved by some careful grinding of the selector finger and the slots it goes in. If I had to replace it, I'd consider 3 options: another Moss box with OD, the Jaguar 4 synch with OD, or the Toyota W58. A swap to a different box costs time, money and effort - I'd not do it without both a good reason and confidence that the replacement is significantly better. I'm not convinced by most of the 5-speeds on offer. The Toyota W58 is very good, but as rare as hen's teeth these days. Some offer the W59 or W57, but the ratios don't really suit.

If it's not working as nicely as it might, it can be worthwhile trying different lubricants. Don't let a mechanic put hypoid gear oil in it. It doesn't work nicely and isn't good for the gearbox. The original lubricant was 30 grade engine oil. A modern alternative would be a manual transmission fluid such as Castrol FE (Ford and M-B specs). In the day, on the advice of a lubricants man, I tried an old type (Ford ATF spec similar to Castorl TQF) automatic transmission fluid and it worked very well. I've mentioned Castrol products only because they're easy to look up and find. The Fuchs company also have an informative website. Glyn is an oil expert and will correct any errors I've made here and have better suggestions.

 

The Moss box is not fussy. Any SAE 30 engine oil with or without OD will do.
Jaguar box I would put an SAE GL4 75W-90 gear oil in it with or without OD. On no account use a GL5 in this box. You will damage the synchro cones.

After all these years the squabble between the 2 boxes still continues. Some love the vintage howl out of the Moss 1st gear & it's lower ratio.

My take: The Moss box is utterly agricultural. The Jaguar gear box is civilised with synchromesh on all gears, has better ratios and is the one to go for with or without OD. There are 2 versions of the OD. The long tail, (generally used with the Moss box) & the compact. Either is fine & they are the same ratio 0.77 to 1. The OD pump pressure feeds the Jaguar transmission. The compact was always fitted with the Jaguar GB never the Moss.

So no contest in my eyes. The Jaguar GB with compact OD. If you don't want to develop unusually large calf muscles in the left leg fit the 9.5" diaphragm clutch. Avoid the 10" clutch plate with spring pressure plate at all costs.

At sale time the 3.8 litre Mk2 or S Type in equal condition with Jaguar box & OD adds value. Considered the cream of the crop.

 

Glyn, My suggestion to try other lubricants was based on my experience (a long time ago) with ATF, which seemed at the time to improve the action of the synchromesh and that of Morgan owners. Morgans used the Moss box with smaller engines than ours and require more cog swapping. They are convinced that modern MTFs improve the change over SAE30. Of course, it could be placebo (I'm not joking).

 

They will improve the change but shorten the life of the gearbox significantly. It is an ancient artifact from the past. Even Potassium Borate wont hold it together when you start messing with the viscometrics. Jaguar engines are not shy on torque production. Moss Synchro design is one of it's greatest weaknesses IMHO.

 

Keep engine & gear oils well away from one another. Contamination either way will cause severe air entrainment & foaming.

 

I also really like the tranny whine in 1sr gear, but not such as fan of its ratio, especially with the 4.55 rear axle ratio in the car!

The whine reminds me of a couple of panel tracks my father had in the 50's used in a small plumbing business. I remember the sound and the fact 1st gear was called a creeper and really was not needed to start out on level ground.

I need to think about changing the rear axle ratio. Car was originally a early 1960 2.4l and now has a 3.8L 9.1 compression ratio engine. But still has original tranny and rear end. So as it drives now, it is pretty quick in stop light races.

jjsandsms

 

You will ultimately break the back axle. It was only designed by Salisbury to take the torque of the 2.4 ~ Not a 3.8 - 9 to 1.

 

Yes I am afraid of that.
Somewhere I read that the very early MK2 2.4's had a different rear axle carrier. That one could not use a ring and pinion from a later diff. So is that true, and what are my option here. I really don't want to change then entire carrier. I understand a 3.77 ratio should be the one to look for?

Thanks
jjsandsms

 

You will have to change the whole rear axle & make your mind up about gearboxes before choosing an axle ratio. I'm running a 3.77:1 with Jaguar Sync 4 & OD on my S Type & find it the perfect combo ~ the same would apply with Moss + OD. If you end up going Auto most use 3.54:1. The same would apply with Moss or Jag without OD.

 

So I am hearing that I cannot just change the ring and pinion? That I need an entire rear carrier??

Ok 3.77 seem to be the right one to get then. An Auto is NOT in the cards. I have a soccer mom van with an auto tranny, boring. Besides shifting the Moss is a constant adventure and pleasant experience. Occasionally I find my self using words that I thought I would never use again when shifting!

Thanks
jjsandsms

 

Yes correct!

EDIT: I should also state that this is on a standard 185/(79/80 aspect ratio) X 15 rolling circumference tyre.

 

Changing the whole axle is easier. The only difficulty is that 3.54 and 3.77 axles don't appear for sale so frequently and are rather more expensive than the shorter (numerically larger) ratios. I once tried a non-OD 240 with, most likely, a 4.27 axle and the engine seemed very busy with a lot of noise. The racers often used 4.09 axles on 3.8 cars, but they wouldn't worry so much about damage or noise. I don't think your present axle should come to any harm unless you really thrash it. The ideal ratio is a matter of personal opinion. I've a feeling that Jaguar's original choices might have been aimed at squeezing the maximum top speed from the cars plus motorways were few and far between in 1959. Many prefer 3.54 even with OD and the later and heavier XJ cars eventually went to 3.31 with the 4.2 engine and 3.54 with the 3.4 litre.

 

Yes it's very personal but also very important. Every 2.4 in our club that has been up engined has suffered axle failure and Dana don't make beefed up crown wheel & pinions for the smaller diff case. Yes they are enthusiastic drivers which is why they upped engine capacity in the first place. There are plenty of 3.54 and 3.77 axles lying around SA but the freight would kill it.

 

Great info, so to be clear to this new owner

Even if I find a 3.77 or 3.54 ring and pinion, It cannot be put in my current diff carrier? Yes/No?

So am I forced to change the entire rear axle?? Yes/No?

Thanks and sorry for my confusion.

jjsandsms

 

This an extract from the manual which shows which chassis numbers had the 3HA diff and which the 4HA, this might help but without looking you won't know for sure what you have.

 

Q1 ~ No
Q2 ~ Yes

And unfortunately there is a lot more to a diff than the casing.

 

Thanks so my research continues and a search begins.

Jjsandsms