One corner of the modified XK120 bellhousing. The boss extends through the bellhousing shell and is welded on both sides.
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RE: The Driven Man (TDM) TreMac 5-spd XK120 conversion kit installation progress. As I mentioned, my mechanic was unable to fit the bolts sent by TDM into my bell housing using the holes in TDM adaptor plate. TDM owner claimed that my mechanic was basically incompetent. He said he sent a TDM Xk120 adaptor plate to is father who had an XK120 bell housing off the car and he was able to put screwdrivers through all of the holes. NOT the proper way to test the fit in my opinion. The proper way would have been to send an adaptor plate AND all the bolts to see the bolts fit. Using the adaptor they sent me, only 2-bolts actually lined up. The other 4-bolts were off just a âsmidginâ, So, the only option my mechanic has, is to bore out the 4-holes so the bolts will line up. Upon reading a couple other T-5 threads on Jag-Lovers, someone mentioned that XK120 cars had 3-versions of bell housings and therefore, so the TDM adaptor plate is not a âone-size-fits-allâ. I just checked with my repair shop and my car will be ready on Monday (I an on a short trip to California), all the mechanic has to do is finish notching and cutting operations so my T-5 rear mounts fit properly. I really hope the TDM T-5 will operate smoothly and there will be no âshudderâ in first and reverse gear like I read about in another Jag-Lovers thread. I will post again when I drive my car next week.
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That makes ever so much more sense than an adapter plate between the bell housing and the engine, and also, you can remove the transmission from the bell housing without having to disassemble the entire car.
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The additional 5/8â(16mm) distance with the adaptor plate on a 140 or 150 is of no consequence, yes it moves the transmission rearward a bit but actually for me the shift lever is in a more desirable position. The transmission is removable from the bell housing with the adaptor plate and it is not necessary to shorten the input shaft. One can either machine down the nose of the input shaft to accommodate the original Jaguar spigot bushing or as Mike did machine a custom bushing to accommodate the T5âs original dimension. I chose the adaptor plate route because I did not want to permanently modify any original parts of the car even though obviously Iâm not a diehard purist.
xk120dude the T5 conversion done properly will absolutely transform the car for driving in todays traffic conditions, having a smooth shifting all synchro gearbox with a much needed overdrive (0.73 in my case) makes it so much more enjoyable without losing the carâs unique vintage character.
If Iâm the Mike referenced, I used an off the shelf Olite bronze bushing from McMaster Carr. ID was the same as the T5 and the OD matched the bore in the end of the Jaguar crankshaft.
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There may be many Michaelâs, but youâre always first in our hearts! 
Youâre the Mike! Good to know, do you have a part number? (No hurry on that)
Not anymore. Itâs been a few years. Mic the spigot on the end of the input shaft, mic the OD of the Jag pilot bushing, find a standard bushing that accomodates that OD and ID. It was pretty simple.
(big eyeroll) I am not a role model!
I have a T5 in my sixties Mustang, and it is indeed a very nice, smooth gearbox. My main gripe is that the overdrive is too long for UK motorways, which have a legal limit of 70mph. 70 in the Mustang (3.50:1 CRP ratio) is only just around 1800rpm, which is too low for a petrol engine for a sustained period in my opinion. Ideally Iâd cruise at around 2500 upwards - itâs not a diesel! My T5 has the optional shorter overdriven 5th gear which is more acceptable.
That said, my XK140 has a Moss 'box with overdrive, and the non-overdrive (3.54:1) CRP ratio. This, to my mind, is perfect - cruising at 70-80 between 2750 - 3250rpm. My car is a DHC, which I consider to be a grand tourer rather than a sportscar. OK, 1st to 2nd and back down again is a challenge, but thatâs fine with me.
I buy Oilite bar from my metal stockholder and turn it up myself.
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