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I have put a Ford Motorsport T5 transmission into my S Type in place of the original automatic. That was partly because when I bought the car it was a rolling shell and the automatic has been disassembled and was in several boxes, including a cracked bellhousing. I didn't know if I even had all the pieces, and at the time for the price of the gaskets, seals and frictions I could buy a brand new manual transmission. It seemed like an obvious course of action. I adapted the rear mount to fit the T5 and had a driveshaft made.
It was never quite right, and above 65 mph the car had quite a bit of vibration. Eventually, I did some research into driveline design and found the rules for U joint angles. Apparently I had broken all of them! According to a Dana calculator my torsional vibration levels were about 6 times the allowable levels.
Originally, I was going to adapt a Series III XJ6 drivashaft and make a 2 piece shaft to have proper angles across all the U joints. However, the way the floor is designed in the S Type, combined with the muffler placement made it virtually impossible to mount a centre bearing in a good place. The next best thing was a one piece shaft with CV joints at each end. The angles at the differential were suited to the XJ40/X300 style rubber Jurid coupling, and a Rzeppa style joint would take the greater angle well at the transmission end.
The Jurid coupling also needs a centering pin in the end of the driveshaft, and fortunately Jaguar has already done the work for us. The first few thousand XJ40's in 1987 had old style differential internals and used a seperate piece for the centering pin. Later XJ40's have the pin as integral to the pinion gear, so a retrofit would require a differential overhaul. I happened to have these retrofit pieces on the shelf from an XJ40 differential I had taken apart to use the ring and pinion in an XJS differential rebuild. The parts are also available as a kit, part number JLM1587. The only changed needed is the flange diameter on the S Type is smaller than in the later Series III and on cars, so the pinion seal needs to be changed to a later style. You can use an XJ40 seal, or a Land Rover seal is the same and cheaper. Land Rover part number AAU3381.
The rubber couplings come in many different bolt circles and thicknesses, the Jaguar is 96mm bolt circle, and early XJ40's are 30mm thick and later XJ40/X300/X308 are 35mm thick. Doesn't matter what you use, just account for the thickness when getting a shaft made. SGP in Germany is the OEM maker, I have heard of trouble with aftermarket couplings, so I avoided them. The Land Rover Discovery uses the same size coupling and they are more common in the junkyards for me, so I took the end of the LR driveshaft. It has a nice bronze bushing for the centering pin too.
At the other end of the shaft, I needed a Ford yoke with the proper spline to go into the transmission. I used one from a Crown Victoria, simply because I was given one for free. I cut the ears for the U joint off, then used the "bell" from an X Type differential. I machined out the center of the bell to 0.002" smaller than the OD of the Ford shaft and heat shrunk them together. The plunging Rzeppa joint is from a Ford Escape driveshaft, it is the same diameter as the X Type joint, so fit the bell just fine. I had a local driveline company make up a shaft that joined the tripod end for the Jurid from the Land Rover and the Rzeppa joint from the Escape. Aside from the unexpected necessity of changing the diff seal, it all fit together nicely and the car is noticeably smoother at highway speed now.
Next, I need to get the wheels balanced again, as whoever did them last time didn't have much of a clue what they were doing. Most wheels have between 6-7 oz of weight, all in the wrong positions. My quest for a car that doesn't shake on the highway continues...
Interesting story ~ thanks. Are you running wire wheels? If so you need to clamp the outer surface of the hub as a spinner does. Using an internal cone will ensure hopeless balancing with excessive weight.
Wrong ~ Figure 2 below!
If you are feeling wealthy you can get this beautiful kit from MWS UK but the Smoothride articles get the job done at a fraction of the price.
Last edited by Glyn M Ruck; Sep 20, 2020 at 06:37 PM.
Thanks Jagboi, That really seems like a lot of work, despite being very inexpensive. You don't mention pedals and shifter mech. Did you already have those too?
And Thanks Yet Again Glyn. Its like you are in my head this week (not sure how I feel about that). I have been pondering having my wheels checked for balance and true and also having a spare made up. I had new tires put on my wires at a local shop who assured me they knew how to do it. So far its been OK, but I never had a spare set up. My car has the original Duplop 6-40 15 Nylon laying in the trunk. Its never been used (no I wont. Dont even think that). I have some spare wheels but havent got to that yet. If I had those cones... I could, dare I say, rule the world ... or at least not have to depend on that same shop. I hadnt occurred to me that I could just have my own set to loan to whatever shop.
Yes, I have wire wheels. Most tire shops have never seen them, so getting a balance won't be easy. I'm sure they did method B, I have huge amounts of weight.
The pedal boxes are the same for automatic and manual cars, the automatic simply has a large pad that bolts to both arms. I changed that out for the smaller manual pads and bolted in the clutch master cylinder. I made an adapter plate between a manual bellhousing and the transmission, so the clutch mechanism is all Jaguar. The shifter is a Mustang arm, turned 180 degrees, as the shift lever comes up rearward for where it needs to be. I used an aftermarker Mustang knob that has the 5 speed pattern, but looks the same as the all syncro knob, although a bit bigger. It's a very nice shifting transmission.
I shall look into the cones. That's probably a next year job, as I will be putting the car away for winter storage this week. At the moment I'm thinking I'm probably better off removing all the weights and leave it!
Making a custom driveshaft.
... or at least not have to depend on that same shop. I hadnt occurred to me that I could just have my own set to loan to whatever shop.
