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TR4/4A OD Speedo cable length?

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RJS

RJS

Jedi Warrior
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Sorry if this has already been asked and answered. My speedo cable failed at the end of last season. Any definitive word on the correct length for a 1966 TR4A IRS with Overdrive?

According to the catalogs from the Big Three, you get widely different answers:

  • According to Big One: TR4 with OD got 96” and TR4A with OD got 63”
  • According to Big Two: TR4 and TR4A 66” for std gearbox and 96” for OD
  • According to big Three: TR4 with OD got 96” and TR4A with OD got 78”

The current cable is 63"and routes along the driver's (left) side of the battery, then behind the fly wheel bell it crosses over the top of the tranny and connects to angle drive on the right side of the tranny. If the correct cable is 96" then I think it is supposed to route in front of the battery and then down the left side of the tranny

Any help appreciated.

Bob
 
The 4A introduced the use of the angle drive, which allows the same length cable to be used with and without OD. The 96" cable is for earlier cars with OD, where the cable has to make a big loop to the side in order to come up to the fitting on the OD tail housing.

According to my factory parts book, the original cable for a 4A with OD (and for LHS without OD) would be P/N 504948, which I believe is the 63" cable you have. A factory supercession listing shows 504948 replaced by GSD114, which I believe is 66".

Apparently the closest that TRF has to offer is GSD169, which I believe is 69" (6" longer than stock), which I'm guessing means they don't have a supplier for the 63". However, several other vendors (including BPNW) have the GSD114 listed, which would be only 3" longer. (Whether that's what they really sell or not is a different question. Some suppliers make part substitutions without telling the customer.)

Sorry, can't help with routing. But I would try to stick with the original routing as much as possible, allowing for smooth transitions to accommodate the extra length.
 
I routed my cable straight ahead on the right side of the gearbox, then up on the engine side of the firewall, crosses behind the engine over the bell housing and then through the dash. Cable from TRF, sorry I don't have length or remember the source that came up with that routing.
 
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