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WC T5 problem

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WC T5 problem

Post by DrJ on Wed Sep 09, 2015 8:07 am

So to review I swapped my Muncie 4-spped with a used WC T5 last Winter. That all included a new pilot bushing, flywheel, LUK clutch, bell housing, clutch slave, hydraulics and master and...the T5. I had it inspected by a reputable transmission shop prior to install, checked out OK. Fabricated the adaptors and transverse mount to compensate for the 18 degree clocked issue, 3 quarts of Dextron IV and it was done. Drove great this season and I have about 400 miles on her. THEN Labor day the wife and I go for a 200 mile cruise. On the way home I suddenly sensed that the last shift sequence was stiffer. Then I came to a light in neutral and could not get it into any gear, no grinding, just would position the aftermarket Hurst to where a gear should be and would hit a solid stop. Long story I did finally get it in a gear and with great difficulty could manage the few shifts home. At stop lights I would grab second and sit with the clutch in until we got a green.

So the clutch seems to work, I could sit stopped in second without stalling the motor. I see no fluid leaks. Back in the garage, engine off, clutch in, I can feel some partial engagement into 1-5 but then I hit resistance.

Two unknowns and probably unrelated: Since putting her in service I occasionally hear and feel a clunk when beginning a roll in 1st or reverse from a dead stop. It is occurring somewhere behind my seating position and is only occasional. 2nd while on that trip we did 70MPH for a long stretch and I could feel a rhythmic vibration in the seat of my pants. Part of the T5 swap included having two inches cut from the driveshaft, new heavy duty universals fitted and a rebalancing. Kind of felt like the balance was off a bit.

So the plan Sunday is to pull the Hurst off the top and see what I can see. If the Hurst internals look good the I guess I'm pulling the transmission. If I do, is this something I can dissemble and inspect myself or an I sending it back to the shop? I am thinking any manual transmission is simpler than an automatic but I dunt know what I dunt know.

Any help?

DrJ

Posts : 131
Join date : 2014-06-19

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T5 OK

Post by DrJ on Sun Sep 27, 2015 8:24 am

It was a real head scratcher for me. One minute it's shifting fine, the next moment not one gear available and more curiously reverse was crunching. Labor Day was the hottest day of the year and when the shifting issue began we were in a long stretch of slow moving traffic with lots of red lights. The Novak slave I installed had no heat shield on it, something that bothered me when I installed it due to it being located 2 inches above the exhaust. One of those things that I was going to get to but didn't. Did the hydraulic fluid boil leading to a fading effect leading to a incomplete clutch release? A week later I sat in her, engine off. I could shift into all gears cold so I drained the system and refilled it with DOT 4, bleed it and no joy. With it up on jack stands the problem was the same. It was while I was under it bleeding it that I noticed that the travel of the clutch fork appeared lacking. It measured out at only 1/2". Now the release bearing of a 10.5" LUK clutch requires 1/2" of travel to fully release the clutch. The clutch fork is a 2:1 ratio so I need 1" at the slave/fork interface and I have half of that. Hmm. Bleeding the new Wilwood master was never easy and as a rookie I overlooked the "bench bleeding" notation in the directions. The pedal did have about 2" of free play travel before any real resistance developed. In review I settled on a 3/4" Wilwood master mounted to a reverse mount Wilwood pedal assembly, the master is in the cockpit, under the dash. Rather than pulling the brake/clutch pedal cluster back out of the car I removed the hydraulic line from the slave and repositioned it in the engine compartment higher than the level of the master and secured it in a cup of hydraulic fluid. Bleed until the bubbles subsided and reconnected it. This yielded an improvement of 1/4", 3/4" total but short of the 1" goal. Another week of thinking. The pedal has a 6:1 ratio. The pedal arm below the pivot is 12", the portion above the pivot 2" where a adjustable clevis attaches to the master pushrod. The master has a 1.1" stroke (the 3/4" slave is good for 2"). To get 1" of travel at the master the pedal needs 6" of travel. A quick measurement shows a little under 5" due to an adjustable stop I installed on the firewall. I remove the stop and it improved to 6", the fork now travels 1" and I drove her down the road shifting effortlessly into all 5 gears. Sure glad I didn't pull the tranny.

Now I will tell you that 6" of pedal travel is a lot and I may not need all of it. I will probably reinstall the stop and gradually reduce the pedal travel to see what happens. As an alternative for 60 bucks I could but a 7/8" bore Wilwood master. The increased volume should result in less pedal travel required at the cost of a slightly stiffer pedal.





DrJ

Posts : 131
Join date : 2014-06-19

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