Bowden tube length

[carmangary]

Hi. Why is the bowden tube for 72 and later transmission longer than the earlier ones. Is there something different about the frame or transmission that makes the tube need to be longer?

I have a 1972 frame and a 1971 transaxle. I don't know if I should use a 71 bowden tube or a 72 bowden tube!! I have both and they look nearly the same except that the 72 is about 3/4" longer and the thing that slides up and down the tube is shorter than the one for the 71 tube. Also, what is the thing that slides up and down the tube for anyway?

Thanks,
Gary

[PJMS]

I assume you are talking about the clutch cable flexible guide tube. If so, then keep the the guide tube with the cable it was used for. In other words, assuming you have not replaced the clutch cable on the 72 chassis, use the 72 guide. Both cable and flexible guides were changed for the 72 model year. I am not sure that the rubber tube is supposed to slide.

[carmangary]

As far as I can tell there is nothing special about the chasis. It looks the same as the 69 chasis I replaced it with. So again, why a difference in length of the bowden tubes? Is there a change in the bracket that mounts to the transaxle? Does anyone know the difference?

[Marc]

I think if you'll take a good look at the two pans you'll see a subtle difference in the length of the clutch tube that protrudes out of the back of the tunnel. There are three bowden tube lengths and six different cables, and the changeover dates for the cables and tubes do not always correspond (another factor in cable selection is the length of the release arm on the cross-shaft and the length of the "hook" on the pedal - both got longer as years passed). Why did they go back & forth in the `70s? I dunno, possibly in an attempt to unify the Type I and II bowden tube lengths and/or to work better with the more compliant `73-up trans mounts. The rubber sheath is there to protect the tube and the trans case from chafing where they rub together - it was pretty stationary on OEM Bowden tubes, on the cheap-ass replacement ones available today you need to position it and secure it with tape or Ty-raps.

Bowden tubes:

311 721 361...-`71 T1, -`67 T2, & T3 and some `74 T1 (From 1x42398011 to 1x42663259) 13-1/8", long at bracket

211 721 361D (or A)...`72-early`74 (thru 1x42398010) T1 and `68-`79 T2 14-1/4"

111 721 361E...late`74 (From 1x42663260) -up T1 13-1/4", short at bracket


Cables:

111 721 335 thru 1960 and 1962 - 1963½ (ch#5 261 829)
111 721 335A 1961 only 2250mm
113 721 335 1963½ (ch# 5 261 830) - 1966
113 721 335A 1967 - 1971 2260mm
111 721 335C 1972 - 1974 (to 1x42663259) 2281mm
111 721 335E 1974 (from 1x42663260) - 1979 2268mm


113 721 335 was 2258mm (virtually the same as the 113 721 335A) and
111 721 335 was the same length as the 111 721 335E so those part numbers aren't stocked much anymore.
The earlier cables had a shorter shank on the eye at the front so when substituting a late cable in an early chassis you need to watch out for interference with the front of the clutch tube.

[Guest]

Thanks for the detailed explanation. Sounds like in my case (72 frame and 71 tranny) I should just try some different combinations and go with what works best.