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Oh please let me know what you decide to do with the exhaust. Mine could be a bit more 'sporty sound wise. Sounds like you have the installation well in order.
Quentin
I’m pretty sure I’m leaving the catalytic converters in place, although there is no requirement here in Iowa. I have my appointment Wednesday and will keep you posted.
I’m pretty sure I’m leaving the catalytic converters in place, although there is no requirement here in Iowa. I have my appointment Wednesday and will keep you posted.
Mine still has the cats. Also has quad tailpipes. Will post a pic after I pick it up from the garage.
Hello Jeff,
The shipping for my Getrag 265 conversion kit was approximately $750.00. The Tremec is a bit heavier so may affect shipping cost.
I’d love to hear how your project goes. It will absolutely transform your 72 XJ-12! I highly recommend Simply Performance.
Regards,
Pete
Southeast Iowa
DIY is not hard to do. A Chevy bell housing will work if you make a simple adaptor. You don’t need careful measurements. The bolt holes are all oversized because their only function is clamping. Transfer the alignment holes carefully But be aware that different transmissions have different lengths of pilot shafts.
The other issue is the depth to set the clutch throw out bearing. Measure to be sure.
It takes me a morning to create this adaptor. With a band saw I can cut out the plate in a few minutes. Using a saber saw it takes me a 1/2 hour.
Finding a good used transmission typically they cost me $1000. Yes used is fine. The car isn’t brand new. ( though I always buy a new clutch and throw out bearing.
I would suggest caution if going the Tremec 5spd route.
I have an '88 V12 5spd that was originally done using a Tremec T5 world class by the previous owner.
One garage did the conversion and then a second garage had another go at it after issues were encountered.
Three weeks into my ownership the clutch throwout bearing failed prematurely at 6,000 miles.
My mechanic took it apart and found excessive clutch plate wear, but no obvious reason for bearing failure.
Going the tremec route required machining of the bearing to make it fit; not sure if that was a factor or not. Also the output shaft brass bushing was difficult to source I understand.
Rather than replace the clutch and hope for the best, I opted to go with a conversion kit offered by Simply Performance in UK, which uses all off-the shelf components (Getrag was the brand used in the 5spd XJS's). They offered a Getrag 265 5spd conversion kit (~$CAD 4k incl. used gearbox). Luckily I managed to find one locally that was NOS.
I understand that they have officially stopped offering the Getrag conversion kit as used Jaguar-specific gearboxes are increasingly hard to find. However, they are working on doing a kit for the more modern Tremec TKX, which I understand will be available later this year. Ben Thomson at Simply performance was helpful in responding to my questions (ben@simplyperformance..com) Shipping costs from UK may be high!
I am sure there are owners that have made the Tremec T5 work for them, but that was not my experience.
In spite of the anguish and $ bleed, I have to say a 5spd V12 is a thing to behold. I am not sure I would even be an XJS owner if the only option was the 3spd auto (Oh no!, I have just offended 99.86% of forum members!).
Good luck!
Quentin
Clutch plate wear and throw out bearing failure is due to a misadjusted throw out (T.O.) bearing.
The throw out bearing was never designed to be in constant contact with the pressure plate. Yours was not only in constant contact but also permanently depressed slightly causing the rapid clutch wear.
Those internal throw out bearings must be pre-set to the proper clearance ( I use .012 ) the adjustment is done by rotating the T.O. Bearing in or out. You find that measurement by measuring the depth of the pressure plate. Then the surface of the T.O. Bearing.
Clearly your first mechanic wasn’t aware of that.
I’ll grant you that is not the typical way to adjust a hydraulic T.O. Bearing. Although we racers do that normally.
It is also possible on certain Clutch master cylinders to misadjust the depth of the rod activating the cylinder in an attempt to make the clutch pedal even with the brake pedal. Again effectively slightly depressing the clutch.
It takes a deft touch to feel the required “slop” to make sure that is not happing. You cannot feel only .022 of an inch with your foot. That needs to be felt with an extremely sensitive finger.
06-04-2023 | 01:29 PM
