MTFCA Forum

Is anyone out there running the "jack rabbit" clutch discs ?
And if so how well does it work?
Thanks in advance.

You asked this same question recently.
My answer is the same.

Watts & th400's are 2 totally different animals.

Hi Roger,
I have run all four types of clutch Jackrabbit, Turbo 400, Watts & stock. With the exception of me screwing up a stock clutch I have been happy
with all of them. If you have a Auxiliary transmission I feel the freer neutral of the aftermarket clutches is advantageous. But I know many that
do not agree. Common thought is that if you slip the aftermarket clutches they burn up & the stock clutch will not. I'm currently going through
a stack of Ford discs hoping to find enough good useable ones to put together a full set for a engine I'm working on. It appears to me if you slip
any clutch it will burn up. I have 15 years on a jackrabbit with no issue. 3+ years on a Turbo 400 That I blew up a low drum on & when I rebuilt
the trans the clutch was in great shape & went back in that engine & is waiting a new speedster to put it in. I have a Watts in the speedster as
of just over a year I like it very much. My thought is that the clutch lugs are more important than anything. If the lugs are not smooth & square
no clutch will have a free neutral all the time. The watts seems to be more forgiving of poor lugs but not being made anymore. 1925-27 lugs
seem to be the best with new shoes & new drums are in order if a good smooth lug is not achievable. If the lugs are smoothed up they must be
square or they will break the large discs no matter if the jackrabbit, Turbo 400 or the stock clutch is used. The Watts can be dressed to fit a
unsquared lug. I suppose the others could be also I have not tried that. At some point discretion becomes the better part of valor and you just
buy new parts.
Craig.

The Jack Rabbit is a modified Turbo 400 disc, by cutting away some of the disc fingers to fit the clutch drum.

For all practical purpose the Jack Rabbit and Turbo 400 are the same game. (Except you can't use a Turbo disc as supplied by auto parts stores without cutting away some of the disc fingers.). So the name is the same if the part is made to fit the Ford clutch drum.


The better discs are the gray color High Performance waffle groove discs, they cost more than the regular grades of Turbo 400 discs made by many companies. Have used these type discs for years, and no issues. But be sure to measure thickness of worn Ford large discs to sandwich the small turbo disc to get the proper stack height. I try to use large discs in the same thickness range.

My 1924 cut-off touring came to me with a new Jackrabbit clutch, it has given me good service for ten years and counting. I found the driving style is a little different, you can't just dump the clutch like you can with the stock Ford all steel plates, you have to ease it into high just a bit. My car also came with a new 1925 short brake drum with provisions for lug shoes like the '26-'27 drums have.

I seem to be a little lost on the clutch name issue The one on the top is a Watts. the one in the middle I made from new Turbo 400 clutches. the one on the bottom was what I received when I
ordered a Jack-rabbit clutch from one of the venders. When did the Turbo 400 clutch start being called a Jack-rabbit? And it appears the
bottom one is not made from a Turbo 400 as there is only 6 teeth instead of 12?
Craig.

speedytinc wrote: ↑

Fri Mar 01, 2024 3:35 pm

You asked this same question recently.
My answer is the same.

Watts & th400's are 2 totally different animals.

John, I asked a similar question recently but don't know if this guy did.