Gearbox: Tremec TKO-500


This subject has been a good learning experience. I obviously knew about gear and final drive ratio's and their effect on shaft spinning speeds, but I didn't account for how wheel size was so important in achieving the predicted speed of the car with respect to the gear and final drive parameters.

Also, the term "foot-pounds of torque" caught me completely off guard. But it's not too much of a mystery now and I know enough to be able to talk about these subjects for a couple of minutes each... And that's good enough for me! 

My Car's Theoretical Speed Calculations


In reality, I'll only get about 160mph

Clutch: Ram Clutch 88794HDT

Clutch Slave Unit: MDL MD-910-1002 Hydraulic External Slave T5/TKO LF Series Type 2

Diff': BTR Hydrotrack speed-sensitive limited-slip differential (Ratio 3:07.1)

Gearbox Installation: Unpacked the Gearbox and was quite surprised how compact it was. Four bolts and literally 'job-dun.' (not quite..!)

I decided to fit the gearbox to the engine first. This to see how and where the clutch slave cylinder had to go and how much room I had to fit the fixing plate. As I have to drill the bell housing for the fixing bracket it seems the best and least risky approach. 

I cut away the cardboard box leaving the gearbox perched nicely in the support packaging. Offered the 26 spline output shaft to the engine using a couple of trolley jacks and a flat board to line it up.



Pushed the gearbox in as far as I could, gave it a wiggle, and all was well...

Gearbox Mounting Plate: The gearbox was nicely positioned in the tunnel and I temporarily supported it with a plywood mounting template. I used the 1/4 inch steel plate from the engine transit frame to manufacture the proper one. I just needed to cut it to size and drill six holes in it. Not too concerned about drive-line angles at this stage but I will get this sorted before I tighten everything up.

Comment: Most gearbox mounting plates I'm seen on blogs are attached to the underside of the chassis support frame... I'm not comfortable with this configuration as all the weight and stresses are on the four fixing bolts. I intend to put mine on the top of the two fixing brackets, therefore having all the weight supported by the plate and therefore having no stress being placed on the retaining bolts.  

Measured up and cut the plate using my 9-inch angle grinder (man-cave tool or what..!!!) then dressed it and tweaked the fitting with a hand file.

Issue: Perfect fit, however, when trial fitting the plate, the weld fillets on the chassis (where the supporting brackets are welded onto the frame) were causing the plate to not sit flush, so I trimmed the underside edges to ensure a snug mating of the horizontal surfaces.

Marked up for the holes by lowering the gearbox (with the gearbox mount now attached) until the two bolts were touching the plate. Then I marked-up these and the positions for the four plate securing holes and drilled them for a perfect fit. I've used M12's for the four fixing bolts and the two mount bolts were 3/8th... (Job's a good'un)


Clutch Slave Cylinder

All fitted