Is my "Bowden Cable" sticking?
08-06-2020, 12:00 PM
#1
Racer
Thread Starter
Is my "Bowden Cable" sticking?
Hi all,
Just completed an intake refresh and trans fluid change and car is running great, bar intermittent no upshift. Not related to kickdown, not gear-specific, and the fluid level is correct as per WSM. The only consistency is that it seems to happen after having been at a high pedal angle, the car then holds the current gear and after a random period passes, something happens and suddenly normal service is resumed.
I am wondering whether my bowden cable is getting jammed, but when I actuate it by hand on a cold engine it seems ok. Would the acid test be to disconnect it and see if the condition keeps happening?
Thanks in advance.
Just completed an intake refresh and trans fluid change and car is running great, bar intermittent no upshift. Not related to kickdown, not gear-specific, and the fluid level is correct as per WSM. The only consistency is that it seems to happen after having been at a high pedal angle, the car then holds the current gear and after a random period passes, something happens and suddenly normal service is resumed.
I am wondering whether my bowden cable is getting jammed, but when I actuate it by hand on a cold engine it seems ok. Would the acid test be to disconnect it and see if the condition keeps happening?
Thanks in advance.
08-06-2020, 02:49 PM
#2
Chronic Tool Dropper
Lifetime Rennlist
Member
Lifetime Rennlist
Member
The throttle-valve cable (not really a bowden cable) has a flex casing section at the front, a hard section in the middle over the torque tube, then another flex casing section at the back to connect at the gearbox on the right side. The connection at the gearbox end has the cable loop to go down to a fitting on the right side, a plastic connection with o-ring seal for the casing. The core connects with a metal end that loops around a hooked arm on a mini bellcrank inside the casing. At the front, the cable connects to the "throttle quadrant" on the left side of the intake manifold.
Since you worked on the intake end last, it's likely that the problem is at that end. During the intake refresh, it's easy to add an extra bend in the casing when you are putting things back, especially fuel rails and the air cleaner housing.. Carefully trace the cable routing to make sure it's not partially wrapped around or pinched by the rest of the intake and throttle linkage bits under the air cleaner housing. Look hard at the actual cable casing end and the cable itself where they pass through the throttle quadrant bracket, making sure they are straight and square to the bracket with no hard bends. Follow through two gentle opposing bends in the casing to where it lines up coaxially to the end of the hard section just above the bellhousing to the left (passenger side on your RHD UK car) of center just aft of the firewall face. Make sure the cable casing has no kinks in it as you inspect.
At the rear, it's faintly possible that the loop on the end of the cable is no longer hooked on the little arm in the transmission any more. Very Unlikely really, but possible. Look there last. You can disengage the cable at the front, then remove the rear connection and set the cable on the arm again. It's a lot easier with two people, so that a person at the front can maintain appropriate tension on the cable core as the housing is refitted at the gearbox end.
Since you worked on the intake end last, it's likely that the problem is at that end. During the intake refresh, it's easy to add an extra bend in the casing when you are putting things back, especially fuel rails and the air cleaner housing.. Carefully trace the cable routing to make sure it's not partially wrapped around or pinched by the rest of the intake and throttle linkage bits under the air cleaner housing. Look hard at the actual cable casing end and the cable itself where they pass through the throttle quadrant bracket, making sure they are straight and square to the bracket with no hard bends. Follow through two gentle opposing bends in the casing to where it lines up coaxially to the end of the hard section just above the bellhousing to the left (passenger side on your RHD UK car) of center just aft of the firewall face. Make sure the cable casing has no kinks in it as you inspect.
At the rear, it's faintly possible that the loop on the end of the cable is no longer hooked on the little arm in the transmission any more. Very Unlikely really, but possible. Look there last. You can disengage the cable at the front, then remove the rear connection and set the cable on the arm again. It's a lot easier with two people, so that a person at the front can maintain appropriate tension on the cable core as the housing is refitted at the gearbox end.
