Is there a conversion to fit a Tremec (or similar) 5 or 6 speed manual transmission behind an AJ16 supercharged 6?

I'm thinking way ahead to a future project retrofitting the AJ16 into a much older Jag (MkII), so I expect to do some modifications for fitment. In other words, I'm not concerned about fitting it into the XJR.

From what I've been reading there was a rare, UK-only factory option. The Getrag 290 might fit, but I'm not sure how well it would hold up to the supercharged version, or parts availability in the US. Tremec has lots of options and parts availability but I can't find details about Jag compatibility, starters, flywheel, etc.

Thoughts?

 

No off-the-shelf conversion kit. Not enough demand to justify, I reckon.

Don't take mine as the final word by any means, but.....

I'm pretty sure the XJR manual trans cars used the Getrag 290.....as did all the "X300" cars with a manual trans. Although only about 200 XJRs had a manual there were a fair number of normally aspirated cars so fitted. But, yeah, you'd have to pay overseas shipping to get all that stuff.

I'm also pretty sure that the Getrag 290 is a kissin' cousin to the New Venture 3500 trans....which is common in the USA. If I'm correct the repair parts would hopefully be easy to find....at least the one that are not Jaguar-specific

Hopefully someone else will chime in.

Cheers
DD

 

Doug is right. There were 268 factory built manual XJR cars built (102 RHD + 266 LHD), so it is quite capable of handling the torque. The flywheel and clutch cover were uprated for the XJR, but owners use the lower rated parts from the naturally aspirated cars when the perform DIY auto to manual conversions.

 

There are companies that do supply kits.
In NZ here there is Conversion Components. They do all sorts of cars, but I am not sure whether they offer X300 - email them and ask.
They have been doing this for at least 20 yrs and export all over the world.

Conversion Components

 

Thanks for the input. Can anyone verify the NV3500 option? Those are common and fairly cheap here.

 

As far as I know the NV3500 that was used by GM and Dodge trucks has the bellhousing and transmission case cast as one piece. You would need an adapter plate to bolt them onto an AJ16. If you are taking this route, it's the same amount of work as adapting a Tremec T56 or any other trans from Camaro/Mustang world.

Jeep NV3550 has a bellhousing that bolts on. I don't know whether the bellhousing from the Jaguar version of Getrag 290 will bolt on to Jeep NV3550. Also, the Jeep version is rigged for a transfer case. You may need a tailhousing from a 2WD version of NV3500 and quite possibly internals from 2WD version of NV3500 or at least a shaft.

I am interested in a manual trans option for XJR6 as well. I'd be interested to know if anyone has looked into this in more detail. I know an outfit that can produce a small batch of bellhousings. If it all bolts together I might order a bellhousing from Europe and try to put together a group buy. They would probably run in the $600 range, and we would need to make at least 10 or 20.

 

I actually have a manual XJR in the US; according to second-hand info from the previous owner, the owner before him found parts from a wrecked Aston Martin DB7 (which in turn is based on the Jag XJS chassis and used a destroked AJ16 in its early supercharged version) and used that as the source for his swap. I can't confirm this, but going underneath the car it's definitely a Getrag 290 as shown by a stamping on the case. I doubt there are many DB7s lying around in junkyards waiting to be scavenged, but it's worth a try.

 

Good thoughts. However, my thought in mentioning the 3500 was only to (possibly, hopefully) address the original concern of USA parts availability for the Getrag 290. If I'm correct about the family relationship I wouldn't be surprised if at least consumable items were the same---bearings, bushings, seals, gaskets, synchro rings, and the like.

Cheers
DD

 

I just realized that the Jaguar version of Getrag 290 has the bellhousing and front transmission case cast as one piece. it looks like the only inexpensive option would be:

- a custom bellhousing for AJ16 and the Jeep variant of NV3550 front case
- use a front case from Jeep version of Getrag 290
- use a tailhousing and internals from a 2WD version of Getrag 290 (GM or Dodge pickup truck)

It can probably be done, but I am wondering if building an adapter plate for Tremec or a custom bellhousing is a more cost-effective route. I am also curious as to the shipping costs from the UK. It may be cheaper to simply ship the trans from the UK via a slow boat.

 

A lot of items interchange between Getrag 290 (as fitted to US vehicles) and later NV-branded versions like NV3500. I suspect that finding wear items like synchro rings and bearings will be a non-issue. There were a few versions of NV-branded Getrags over the years, so you would have to carefully find the parts that cross-reference.

 

Looks like the easiest way would be to get a close-ratio (RPO M50) Chevy variant of NV3500, otherwise known as Getrag 290. Advance adapters can probably make a plate for bolting this trans to AJ6/AJ16. They would need to make a small run of these to justify the engineering effort.

I will need help from somebody with access to manual trans X300. We will need measurements, shifter to front of bellhousing and etc.

 

Damn, I had my clutch done at Samuels last year and you could've measured it then. I'll probably go back there some point soon to get that squeal taken care of so if you want to coordinate we can try that.

 

I will gladly pay Ellston for doing the measurements next time your car is in the shop.

 

Go look on some Australian sites for the bellhousing/adapter plates.

For some reason, all manner of these things seems to be an Australian
thing.

One site had multiple possiblities for Jaguar 6 cylinder engines and
various transmissions.

They might be expensive, but certainly cheaper than custom made
one off solutions.

 

So far I found Dellow, they seem to be offering bellhousings for earlier XK6 engines, they mention 2.4, 3.8 and 4.2 Liter displacements. AFAIK the AJ6/AJ16 bellhousing bolt pattern is different from XK6.

 

Thanks for the updates! I know there are several places that make adapters, and could do a custom one, but cost might not make it worth while. Then again, with so much access to CNC, water jet, etc machines and computer programs like CAD, it might be possible to develop one and have a one-off made more easily.

 

I need to go to my storage and dig up my spare AJ16 engine and trans. I need to cannibalize an air pump anyway I seem to rmemeber that there is a kind of an 'adapter' in stock AJ6 configuration. Said adapter pate bolts on to the rear of the block, then transmission bolts on to it. I suspect that AJ16 has it too. With CNC shops on every corner it can't be all that hard to make a different kind of adapter plate that would allow you to bolt on a transmission with a different bellhousing pattern. If that's the case, I will just need to find a transmission that will work. I looked at Chevy/GM NV3500 bellhousing pattern and the starter seems to be on the right side, where it may (or may not) interfere with the exhaust.

I am also contemplating a totally different route that may be viable: modify the ZF 4HP24 bellhosing and mate it to a manual transmission via an adapter plate. The downside of this approach is that it rules out integral bellhousing Getrag 290/NV35XX transmissions that are cheap and plentiful. The upside is that you can probably use T-5, T-56, TKO, which means that you have plenty of strong transmission options that can take the power of modified supercharged cars.