5 speed or re-build gearbox

[Jen]

Hi Well the noisy gearbox has become the very, very noisy gearbox & the magnetic drain plug is covered in swarf !!!! So dilemma time!.....either replace with a 5 speed or rebuild the all syncro factory 4 speed (Its a matching numbers EJ box). I would welcome any advice or comments especially from long term 5 speed owners. I know there have been other treads on 5 speed conversions but they all seem a little out of date. Mine is a 4.2 series 1 roadster so its a SWB car ruling out some of the options

It I go 5 speed the Elite 5 speed looks the best value but I`m not sure about the .63 overdrive ratio? All comments welcome

thanks

Jen

[PeterCrespin]

Elite will do other fifth gears. 0.75 or similar is the usual I think.

[jag68]

Hi Jen

I installed a Metatronics 5 speed in my '68 ots about 5 years ago. I've done 20k miles since. It's a worthwhile installation if you do a fair amount of high speed driving (60mph plus), otherwise no. First you'll notice kits to do this are quite a bit more expensive that rebuilding a stock 4 speed. Installation is difficult. Certainly if you have had some experience in removing and replacing an E type engine and transmission you won't find it insurmountable but if you lack that it's a bear. You can acquaint yourself with installation at this thread: viewtopic.php?t=5964 Rory - the fellow doing this, is very meticulous in his approach and really does beautiful fabrication. My installation encountered some if not all of the same problems he faced but my solution was more hammer, grinder, and tin snips. I managed to refit the mostly unmodified cover with the original screws.

I don't find the 5 speed to be as nice to use as the stock all syncro box. Throws are shorter and more notchy. The syncros don't work quite as well, and it's a bit noisier at speed and has a bit more vibration - more like a minor buzz at certain rpm in 4th and 5th gear. (I have to concede that I don't use a stock Jaguar clutch, disc or pressure plate, and have an aluminum flywheel (not recommended due to gear rattle at idle - something I don't find to be a problem)) All of these issues are very minor - they don't go beyond being just noticeable and are not irritating. Other manufactures' boxes are undoubtedly different. A friend has one from another manufacturer and he really doesn't like it. Don't know that manufacturer's name - nor does he (can't recall where he got it.)

You know the stock all synco box is really really good.

As to a .63 ratio - that's a big drop from 4th which is straight through. I have a .75 and run with a 3.72 differential out of an S Type and find it all quite workable. I think that with a normal diff ratio like 3:31 or 3:54 a .63 is too high. You'll find part throttle acceleration trying, and will have to get out of the gear frequently if there is traffic or hills.

[abowie]

You know the stock all synco box is really really good.

And it is. I'd keep it.

[christopher storey]

So would I. The EJ box has far and away the best ratios of all the E boxes, with 2nd and 3rd being particularly useful with a 3.07 axle , and the change quality of a properly fettled one is beyond criticism being light and positive. The later KE/KJ/KJS boxes have wider ratios on which 2nd is considerably lower ( as is 3rd ) and therefore not as useful for overtaking , and this applies to most of the 5 speed sets which I have seen

[Heuer]

I have a T5 and it is superb having covered 45,000 miles with it. Shifts are fast and I can't beat the synchro. On the downside it does have an inherent weakness which meant the it has been out of the car twice. Both times it was a failure of the clip holding the speedometer worm in place which meant it moved backwards and the speedo stopped. Which is a good thing because that small clip not only holds the speedo worm in place it also holds 5th gear on the main shaft as well. Had I not had the lack of speedometer I would have continued driving with the catastrophic failure of the gearbox likely at any time. First time they machined a deeper groove for the clip, second time I got them to TIG weld the worm in place. The latter option means the box can never be economically serviced in the future but it is the lesser of the two evils. My box was supplied and repaired by Watjag and the second repair was done by Elite. This failure cannot happen with the Medatronics JT5 because Paul C is smart enough to understand the speedo drive needs to not work against the retaining clip, so he reversed it.

New production by Elite may have solved this problem but worth checking. My 5th gear is a 0.8 ratio. The Jaguar box is good but the current replacement synchro rings are prone to rapid wear (not hardened correctly) and they only lasted 5,000 miles on my restored box, hence I opted for a 5 speed.

[288gto]

That's interesting information about the T5, thanks.

Jen,
If it is any help and depending on which route you decide to go down, I have a very good 4 speed all syncro box from a roadster that is available should you need it now I have decided to go the 5 speed route.

Simon

[RogerM]

I fitted an E Type Fabrications 5 speed gearbox to my series 2 when the original gearbox gave up and am absolutely thrilled with it. Gear changes are very slick, fitting was easy with no modifications required to the structure, lever is in the same position, improved mpg, lovely cruising.

[jag68]

That's an interesting statement about the syncro rings on the stock 4 speed David. Aren't they brass?

[Heuer]

Yes they are brass but the originals were made of a different and harder ratio of zinc/copper and possibly used an additive. The current repro items seem to be made of any brass to hand, hence their reduced longevity. I don't suppose anyone has bothered to test what the original synchroniser ring content was or found the Jaguar specification.

[christopher storey]

David : I doubt whether the original rings were brass. Phosphor bronze was almost universally used for this type of wearing part up to the 1980s

[steve3.8]

It's not only the material they are made from but the way they are made , original baulk rings were sintered [ ie pressed bronze powder then furnaced ] and made to an exact material content , i doubt the current replacements are , they may be even cast items . Sintered rings are also porous , taking in oil . cast items will not .

[Heuer]

"Synchronizing rings are made of metal and can be provided with anti-wear coatings called a friction lining. Common metals for synchronizer rings are brass and steel. The linings typically consist of molybdenum, iron, bronze or carbon. The synchronizing rings are produced either by massive forming (common forging) or sheet metal shaping. The latter involves the stamping of the blank out of a sheet metal strip and the subsequent machining with follow-on composite tools or transfer tools. A friction lining usually consists of thermally splashed molybdenum. Alternatively, iron or bronze sinter friction layers can be used. Carbon-coated synchronizer rings are particularly wear resistant and offer very good friction behavior. Due to their higher price, these are reserved for high-performance transmissions"

[christopher storey]

What is the source of this quotation, David, please ? The vast majority of synchromesh baulk rings are made from phosphor bronze, as a search of the standard automotive text books and indeed of suppliers easily reveals

[steve3.8]

Christopher i think David's info is relevant to modern syncro rings , some made from sheet steel with a sintered bonded lining , The T5 has a 3 part snycro , steel -friction material -steel , working like a wet plate auto gearbox it gives a smoother faster gear change , with more surface area than a single piece syncro it slows the gears rotation quicker .

I did notice at the NEC on Friday that Jeremy Welch had Jaguar 4.2 syncro rings in his display cabinet , looking at his website they quote as being made in the UK , so maybe a quick phone call by someone will reveal how and what they are made from ?

http://www.bighealey.co.uk/category/cat ... ar/gearbox

[christopher storey]

Steve : thank you, that is interesting . I wonder when the change in materials came about - it certainly would explain why the modern replacements for the Jaguar all-synchro box do not seem to last

[Heuer]

Christopher

http://en.wikipedia.org/wiki/Manual_transmission
http://www.bighealey.co.uk/category/cat ... ar/gearbox
http://www.burtonpower.com/brass-synchr ... 2e521.html

[jag68]

Here's a video by Paul Cangialosi on how syncros operate. It deals with US transmissions primarily but shows brass syncros and the modern three piece syncro rings. Not entirely helpful to the current discussion of what material is used but it's useful to know.

[MatthiasS]

I had the same Problem and renewed al bearings and synchro rings. The slave shaft needed a new layshaft which was ? 48 and had to recondition the end of the main shaft with some bushing in oversize.
the total costs were about ?500 including the reconditioning of the main shaft (?200)
Now i am happy with my gearbox again :-)
There is nearly no Special Tools needed exept extracting one needle bearing from the 4rth gear.
The 2"1/16 wrench was a bit of a hassle to get here in Germany but finally i found one on an Oldtimer Fair at home.

took 1 day dismantling and cleaning and painting the box and 1 day to reassemble everything

Best Regards Matthias