QuestionQUESTION: Jim- I have a '78 spit (parts car) and a 74' spit restoration project. My transmission does not work in the "74 so i am replacing it with the '78 transmission and driveshaft. My first question is will that work. They look to be identical but I do not have them side by side. My second and more pressing question is how do i get the driveshaft and the transmission separated in my 78'. I have removed all of the bolts on the driveshaft and it will not come apart. I am afraid i will damage it if i start knocking it around. Thanks for all of your help.
Ross
ANSWER: Ross,
If no one has tinkered with the cars previously, the '74 should have a 3 rail transmission (10 spline input shaft) and the '78 should be a single rail (20 spline).
Either transmission will work with the 1500 engine, but since the transmissions are different lengths, the driveshafts are different. So, you'll need to keep track of which driveshaft came with which transmission, and install them as a "set".
Also, since the number of input shaft splines is different... the clutch disc is different. Again... if the clutch in the '78 looks ok it can be reused... Spitfire transmissions are easier to get at than most other cars, so it's annoying but a fairly quick process to remove/replace the transmission.
As to removing the trans in the '78... As installed there's just a bit of pressure between the driveshaft and trans tail flange. I typically use a flat blade screwdriver (junk... or something with a lifetime warranty like Craftsman) and gently pry between the trans flange and the driveshaft flange. Once you can get them started it's easy to pry them apart.
If you don't find the single rail ('78) and 3 rail ('74) then most likely you'll find 2 examples of the same transmission.
Cheers,
Jim
---------- FOLLOW-UP ----------
QUESTION: Jim- thanks for all of the help. It worked just like you said. Both the transmissions look the same as do the clutch plates. Is there a way to tell if the clutch plates are different? Also, before I put the other transmission into the '74, what should I look for to make sure it works like it should? On the replacement transmission I can go through all of the gears without trouble and it looks like it works fine. The clutch release does not move freely though and that concerns me because the one on the transmission I took off moves just with my hand. Thoughts?
Thanks again.
Ross
AnswerRoss,
First question. Count the splines (ridges) in the center of the clutch disc. And measure the diameter. If both are the same, the discs should be interchangeable.
If the throwout bearing sleeve isn't moving freely it's time to pull the clutch fork out and clean the sleeve carrier and regrease with a light grease, like lithium grease. Otherwise you're looking at other problems down the road.
BTW, what is the spline count? 10 or 20?
Cheers,
Jim
