I'll soon be converting my X300 XJR from auto to manual box. I already have all the components, but I have a couple questions about the gearbox and flywheel:

a. I've heard that the 3.6L XJS flywheel is considered an "upgrade" from the original dual-mass flywheel used in the manual X300 cars, but I don't know why, nor do I know whether it should be a direct fit. Does anyone have more details on this?

b. Searching for information on the Getrag 290 also yields results for the HM290, New Venture NV3500, GM 5LM60, and something referred to as the "G290/5" that was apparently used in the Alpina B10 BMW. Is the Getrag 290 used by Jaguar actually one of these variants? I know that some of them are for 4WD applications. What are the differences between them otherwise? I'd like to know so that I can order the appropriate rebuild kit when the time comes.

--Colin

 

Mine is a converted manual too, so here are my two cents.

Don't know about the 3.6 XJS flywheel. As the XJR6 has a 4.0 Supercharged engine, I would go with the original configuration and not think of any "upgrade" at this stage. There are many other ways to upgrade car performance; get the "Andy Bracket", try the 3.58 differential...... Do some research and you'll have a good idea how to get the best bang for your investment. Your priority now is to get the car running as per the manual configuration, as you would not want having to investigate what might have gone wrong if you can't start the engine or have any running problem.

The Getrag 290 manual gearbox is also used on BMW and across other makes. I thought of finding a rebuilt kit for the gearbox too, but having consulted our friend down south, previous owner of AL NZ's XJR6 who owns a Jaguar workshop in New Zealand, the advice was these gearboxes are very durable and rarely need a rebuild.

My advice is to concentrate on a direct fit approach, and find all the right parts to avoid future re-visits that might cost you an arm and a leg. Replace all radiator heater hoses (and the radiator as well, as the manual version is different get it if still available) and the old one is nearing end of life anyway), engine belts, replace the oil plug seal front and rear while you have the gearbox out, make sure you have the right bolts for holding the manual flywheel in place (Classic Jaguar Parts) still have them, replace the engine mounts, gearbox mount, propeller shaft coupler, find a new clutch kit even the used one still have some life left, find the X40 clutch master cylinder (X300 original no longer available), buy a new slave clutch cylinder (don't use any rebuild kit), replace the supercharger oil or better still rebuild the supercharger, find and install engine oil cooler kit and new O-rings (from X40) so you prevent future leak and prolong the life of you engine oil.

And, contact Andy ("XJREngneer" on this forum) to get you an engine ECU with the manual configuration for the peace of mind. Conversion without the ECU remap might end up with frequent stalling of the engine at standstill.

Let us know how you get on with the conversion

 

Hello, I'm usually in the series 1 &II xj6 forums. I have an xjc project car I am contemplating either an xj12 or xj66 powerplant for, and have found a good looking and running donor 96 xjr. I'll want to convert to Getrag 290 and see they were fitted to Chevy Silverados in that era. I'm in Northern California and can find one of these boxes pretty easily right now.

Question for those that have done it: will this fit and/or what is the optimum 5 speed setup and availability in N America? BMW boxes? I am also in the UK quite a bit and can pick up parts there as needed.

Thanks in advance!

 

The US is paradise for automobile conversions. Have no idea how wild one can go in the US, but my advice would be to strike a balance between thrust, economy and comfort unless race is what you have in mind. Differential ratio will be your focus I would think.

 

Hi Oliver,
I am intrigued that you say the Getrag 290 manual gearbox was used in the Chevy Silverado. I've never heard that before, though that doesn't mean it isn't true. However, I think there may some confusion here. The automatic transmission used in the XJR6 was the GM Hydramatic 4L80E. This was used extensively in many GM products. It seems very likely that this gearbox was fitted to the Silverado, amongst many other GM vehicles.

The Getrag 290 was used in all manual Jaguar vehicles sold between 1990MY and 1997MY (XJ40, XJS, X300). I think that a manual transmission was std spec on all 3.2L XJ40s and X300s, so there should be plenty of them still in UK scrapyards. If you travel to the UK regularly, I think this would be your best option. The XJR6 has a different flywheel and clutch cover to the naturally aspirated cars. these parts are no longer available from Jaguar, so all DIY conversions use the parts from natural aspirated cars. So far, nobody has reported any failures. I would recommend that you fit a new friction plate, which is common to all manual cars, to maximise your clamp load. The engine to gearbox adaptor plate is also different for the manual transmission, so you will need this as well.

The engine ECU will be expecting to receive a signal from the transmission ECU, that will no longer be present, after your conversion. The engine ECU will go into a default mode, retarding the ignition timing by 5 degrees. I suggest that you either fit one of my revised crank sensor brackets to offset this effect, or have me reprogramme your ECU as a manual specification. Please email me directly for more details (andystodart@metronet.co.uk)

 

https://www.drivetrain.com/manual-tr...0-overhaul-kit

90's stick shift Silverados run a G290 variant, but did some research since posting and as you say Andy there are issues that will probably make it easier to ship a UK tranny (and pedal box) than trying to get the Jag ECU to talk to a different transmission. Probably some useful parts interchange angles with what's available in the US though.

My plan if I go ahead is to drive the xjr for a few months to trouble shoot and tune up (and while I have the XJC on the rotiserrie) until it's time to do the Frankenstein merger between the two. It would make sense to do the manual conversion in the XJR first to make sure everything works before opening a new can of worms with the transplant...

 

The Getrag transmissions where used in Plymouth or Dodges under a different transmission name ( New Venture ) that can be a local source of parts and advice

290 version I don't know about if the same used , but some day for M' Lady Penelope .

Nv3500 ? as the name

I'm wondering if Dodge or Chevy or even Jeep clutch pedal brackets or hardware can be used to make it easier to do the conversion ?

https://www.drivetrain.com/manual-tr...s-illustration

https://en.wikipedia.org/wiki/New_Ve...0_transmission

 

Does anyone know the gear ratios for the Getrag 290?

 

1 - 3.55
2 - 2.04
3 - 1.40
4 - 1.00
5 - 0.76
R - 3.55

as installed in the 4.0 XJS.

 

Nice! Thank you, I couldn't find that anywhere

 

This book hasn't help me fix anything yet, but it is full of info and diagrams.