XJS V12 Manual Conversion & ITB's & Maybe TWR Rep

XJS V12 Manual Conversion & ITB's & Maybe TWR Rep

Author
Discussion

HeWhoDaresRoy

371 posts

172 months

Friday 29th May
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I've got the Getrag from a 3.6 in my v12, along with the 3.54 diff from a 3.6. The gearbox seems to handle the torque fine, but if I was doing it from fresh, I'd be tempted to find a 6-speed.

lukeharding

1,403 posts

45 months

Friday 29th May
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HeWhoDaresRoy said:
I've got the Getrag from a 3.6 in my v12, along with the 3.54 diff from a 3.6. The gearbox seems to handle the torque fine, but if I was doing it from fresh, I'd be tempted to find a 6-speed.
See this is funny, I've got the two Getrag units in two of my V12s (both similar but reverse in different places), and if I was building an XJ or another XJ-S I'd be tempted to try and four speed (if it was an early XJ-S or an S1/S2 XJ), just because I like that box in the e-type S3. It would be nice to find a nice, sharp four or five speed as both the standard ones can be a bit long. There is a very modified 4.2 XJ S3 using a Nissan gearbox that is apparently pretty good.

A four speed appeals for that period correctness and being a B-road car, but as more of a tourer a five speed can be very welcome.

RobXjcoupe

2,111 posts

47 months

Friday 29th May
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Just reading about what torque these gearbox’s can take. Getrag from the xj’s is apparently a stronger box than the t5 but the getrag is rated at the same max torque as a Land Rover LT77. I thought the t5 was the stronger gearbox for torque. Not sure about manual gearbox bell housing though to fit a jag v12.
I have a Jaguar version of the 5 speed LT77 on my 4.2 straight 6. Much lighter gear change than the t5 on my TVR which is fitted to basically a 300ft/lb engine. Would an LT77 simply bolt to a v12 manual bell housing without an adapter plate? Nice Jaguar gearchange then, 5th gear is the same ratio as if an overdrive is fitted to the Jaguar 4 speed

alabbasi

1,120 posts

43 months

Friday 29th May
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The Getrag 265 is a pretty stout box. It's used in several BMW's and a retrofit to the E24 M6 and E28 M5 as the Getrag 280 that was standard in those cars is so weak by comparison. It was also used by AMG and put behind large v8's in the 80's, when they were an independent company.

RobXjcoupe

2,111 posts

47 months

Friday 29th May
quotequote all
alabbasi said:
The Getrag 265 is a pretty stout box. It's used in several BMW's and a retrofit to the E24 M6 and E28 M5 as the Getrag 280 that was standard in those cars is so weak by comparison. It was also used by AMG and put behind large v8's in the 80's, when they were an independent company.
I thought the number used in different getrag gearbox’s related to its max torque?

craigjm

10,784 posts

156 months

Friday 29th May
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RobXjcoupe said:
alabbasi said:
The Getrag 265 is a pretty stout box. It's used in several BMW's and a retrofit to the E24 M6 and E28 M5 as the Getrag 280 that was standard in those cars is so weak by comparison. It was also used by AMG and put behind large v8's in the 80's, when they were an independent company.
I thought the number used in different getrag gearbox’s related to its max torque?
It does

RobXjcoupe

2,111 posts

47 months

Friday 29th May
quotequote all
craigjm said:
RobXjcoupe said:
alabbasi said:
The Getrag 265 is a pretty stout box. It's used in several BMW's and a retrofit to the E24 M6 and E28 M5 as the Getrag 280 that was standard in those cars is so weak by comparison. It was also used by AMG and put behind large v8's in the 80's, when they were an independent company.
I thought the number used in different getrag gearbox’s related to its max torque?
It does
So a Land Rover r380 is a possibility then when used with the hot climate external oil cooler. Probably the same gearbox as the Jaguar xjs 3.6 manual but with the oil cooler facility

alabbasi

1,120 posts

43 months

Saturday 30th May
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RobXjcoupe said:
I thought the number used in different getrag gearbox’s related to its max torque?
Maybe, but the 265 holds up better than the 280. The 2nd 280 in my m635 will tell you the same

urquattroGus

Original Poster:

1,264 posts

146 months

Saturday 30th May
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I thought the Getrag used in the simply performance converted car felt pretty good to me.


craigjm

10,784 posts

156 months

Saturday 30th May
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urquattroGus said:
I thought the Getrag used in the simply performance converted car felt pretty good to me.
Yeah it does. That’s the 265

DP33

183 posts

82 months

Tuesday 2nd June
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alabbasi said:
The Getrag 265 is a pretty stout box. It's used in several BMW's and a retrofit to the E24 M6 and E28 M5 as the Getrag 280 that was standard in those cars is so weak by comparison. It was also used by AMG and put behind large v8's in the 80's, when they were an independent company.
Every day's a school day here on Pistonheads! Makes sense and all very Germanic, but why would the 265 be stronger than the 280? Now that doesn't feel quite so logical...

craigjm

10,784 posts

156 months

Tuesday 2nd June
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DP33 said:
alabbasi said:
The Getrag 265 is a pretty stout box. It's used in several BMW's and a retrofit to the E24 M6 and E28 M5 as the Getrag 280 that was standard in those cars is so weak by comparison. It was also used by AMG and put behind large v8's in the 80's, when they were an independent company.
Every day's a school day here on Pistonheads! Makes sense and all very Germanic, but why would the 265 be stronger than the 280? Now that doesn't feel quite so logical...
Stronger is the wrong word. Robust would be a better description. The 265 takes a lot of punishment and shrugs it’s off. The 280 is a lot less forgiving

alabbasi

1,120 posts

43 months

Wednesday 3rd June
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DP33 said:
Every day's a school day here on Pistonheads! Makes sense and all very Germanic, but why would the 265 be stronger than the 280? Now that doesn't feel quite so logical...
I'm going to guess that it was designed to be a stronger transmission but it did not work out that way. When I bought my E24 M635csi, 2nd gear was completely non functional. I replaced it with another 280 which has weak syncro's in 3rd. I asked around the M crowd (which I'm not part of as I'm more a Mercedes Benz guy) and was told time and again that the 280 has known issues, and what people do when theirs fail is retrofit a 265. 265's are becoming very hard to find these days in the US because these guys are now hoarding them.

DP33

183 posts

82 months

Wednesday 3rd June
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craigjm said:
DP33 said:
alabbasi said:
The Getrag 265 is a pretty stout box. It's used in several BMW's and a retrofit to the E24 M6 and E28 M5 as the Getrag 280 that was standard in those cars is so weak by comparison. It was also used by AMG and put behind large v8's in the 80's, when they were an independent company.
Every day's a school day here on Pistonheads! Makes sense and all very Germanic, but why would the 265 be stronger than the 280? Now that doesn't feel quite so logical...
Stronger is the wrong word. Robust would be a better description. The 265 takes a lot of punishment and shrugs it’s off. The 280 is a lot less forgiving
Would be interested to know what the 265 is "lifed" at - mine has done 90k miles and it still feels really sweet - 2nd from properly cold (hard icy winter morning after a week of no use) can be knuckly but that apart it swaps quickly, cleanly and really doesn't feel like a 30-plus year old 'box. Before I bought the car I'd read the reviews and was expecting it to be crap, but the reality has been so much better. I'd go as far as to say I'm not convinced that everyone who has castigated the manual XJ-S has actually driven one because I can't reconcile their driving impressions with mine...

alabbasi

1,120 posts

43 months

Wednesday 3rd June
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I owned a manual XJ-SC for a while. Bought as a non runner and got it running. It was a nice drive. Very different to the automatic. The shifter bushings were completely shot so shifting was super sloppy but as I was not interested in keeping it, I sold it on as a project. it left it's home in Texas in December and made its way to Amsterdam. Someone must really rust free XJ-SC's with manual gearbox there.

lukeharding

1,403 posts

45 months

Thursday 4th June
quotequote all
DP33 said:
craigjm said:
DP33 said:
alabbasi said:
The Getrag 265 is a pretty stout box. It's used in several BMW's and a retrofit to the E24 M6 and E28 M5 as the Getrag 280 that was standard in those cars is so weak by comparison. It was also used by AMG and put behind large v8's in the 80's, when they were an independent company.
Every day's a school day here on Pistonheads! Makes sense and all very Germanic, but why would the 265 be stronger than the 280? Now that doesn't feel quite so logical...
Stronger is the wrong word. Robust would be a better description. The 265 takes a lot of punishment and shrugs it’s off. The 280 is a lot less forgiving
Would be interested to know what the 265 is "lifed" at - mine has done 90k miles and it still feels really sweet - 2nd from properly cold (hard icy winter morning after a week of no use) can be knuckly but that apart it swaps quickly, cleanly and really doesn't feel like a 30-plus year old 'box. Before I bought the car I'd read the reviews and was expecting it to be crap, but the reality has been so much better. I'd go as far as to say I'm not convinced that everyone who has castigated the manual XJ-S has actually driven one because I can't reconcile their driving impressions with mine...
On its own its reasonably easy to say the 265 isn't an amazing gearbox in terms of shift action, with a long throw and a somewhat sloppy action compared to some. That said, what it does for an XJ-S is quite a transformation and turns the car into something very different with a lot more driver involvement. You've just got to get used to driving with a gearbox like that rather than an MX5 style gearbox I think, and that can be something people struggle with.

V12 Migaloo

518 posts

102 months

Thursday 4th June
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I've heard of some using a W57/58 gearbox from the Toyota Supras… this gives a MX5 style change and are relatively tough so I understand...

craigjm

10,784 posts

156 months

Thursday 4th June
quotequote all
V12 Migaloo said:
I've heard of some using a W57/58 gearbox from the Toyota Supras… this gives a MX5 style change and are relatively tough so I understand...
Yes but the boxes and conversion kits are not so readily available which is why Getrag and Tremec are the main ones

RobXjcoupe

2,111 posts

47 months

Thursday 4th June
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About 15 years ago, I was a member of the Essex region jec. There was another member with a bright red v12 xjc with the later 6.0 engine fitted and a manual getrag gearbox conversion. I remember chatting thinking nice conversion but he admitted he was on the second gearbox and it was weak for the engine and should of gone with the tremec conversion instead. I can’t remember what specific getrag box he was using though.


Edited by RobXjcoupe on Thursday 4th June 23:02

OTT532

5 posts

3 months

Sunday 7th June
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I am just about to convert my V12 XJS from 3 speed auto to 5 speed Getrag 265. I was very fortunate to find a NOS box with a special DJB bellhousing and a new Rob Beere flywheel. This enables the conversion without using any conversion kit. I was ready to buy a conversion kit using an old recycled gearbox with who knows what mileage on it until I stumbled over this new one. I am using Tom Lenthall in Wokingham to do the work. It should be finished in a couple of weeks I will post a review once finished.