troubleshooters - need help now!!!

bigchillcar · bigchillcar's Garage

hey gang,
bigchillcar need help now! my '74 with 915 transmission has either a transmission or clutch problem. first, a little background on it's behavior lately. its always been a bit stubborn going into first (crunch) without first going thru second or fifth for a smooth shift. when the car gets hot (around 220 or more) and the transmission fluid as well, i suppose, the 'trick' is less successful and grinds a little getting into first using the aforementioned method...going into reverse is downright noisy (grinnnnnnd). anyway, don't know if this characteristic is related to what happened today or not.

tonight, coming home about half an hour ago, i downshifted into fourth and heard what i thought was a little 'pop' near my feet and the clutch pedal...suddenly the pedal was soft...
when i stopped at the light, i found that the clutch would not engage to shift. i finally had to jam the transmission into second in order to get rolling, run a few lights (late night, light traffic) and get home where i've come immediately to this board! it won't shift into any gear. help! what happened? is it possibly just a cable? could this explain the 'grinding i've been experiencing?

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Early_S_Man · 03-10-2002, 09:05 PM

Actually, you now have problems with BOTH your transaxle and clutch!

Well, first off ... if ever confronted AGAIN with a broken clutch cable, or inoperative clutch ... don't you dare force the shift lever into gear with the engine running! That grinding you heard may end up costing $2500 to fix your 915 transaxle!!! The 'proper' way to drive a vehicle with no clutch is to put the car in first gear with the engine off ... and start the engine! Any shifting will have to be done using a double-clutching technique, and at each necessary stop, the engine should be turned off and started in gear again.

1. The symptoms of grinding when shifting into reverse almost always indicate a dragging clutch, which means your clutch pedal had a negative value of freeplay! That can be from a worn clutch disk, or a partly-broken, stretching clutch cable, or a cracked, failing clutch pedal shaft/lever arm ... or some combination of the three! Continuing to drive with a grinding reverse and first gear was a BIG mistake! The cable has 10-12 strand of wire, and when age, lack of lubrication, etc. cause a couple of strands to break, the remaining strands begin to stretch ... and when about half of the strands are broken ... things go downhill rather rapidly. The last few strands of your clutch cable breaking may have been the pop or snap you heard, or perhaps the end of the clutch pedal lever breaking or cracking.

2. Because of the abuse which you inflicted upon your 915 that caused the grinding ... you car should NOT be driven again, until the gear oil is drained and the magnetic drain plug examined for broken dog teeth from the abused gear synchronizer assembly!

bigchillcar · bigchillcar's Garage

early_s.

ouch...i think i just got spanked and sent to my room without supper!

anyway, thanks for responding. upon reflection, i should have turned it off and started it in gear (think second is easier)...just wasn't thinking at the moment. wish i had known ahead of time that the problem with 1st and reverse was related to a dragging clutch; it was only apparent to me it seemed when the temperature was getting on the warm side and i was thinking along the lines of the fluid itself...jeez.

i hear often that these transmissions are tough; hopefully that will be borne out with only a broken cable. i only jammed it into gear (second) once - hopefully i won't find any teeth in the gear oil and have learned a valuable lesson.

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masraum · 03-11-2002, 12:24 AM

Early S man, when you say,

Quote:

a cracked, failing clutch pedal shaft/lever arm

Is that the pin near the pedal that I've heard about shearing? Or is that something different?

Also to clarify if "Bigchillcar" didn't get the "double clutch" reference. Obviously you can't use the clutch, but you can shift a tranny without the clutch by using the rev matching that is part of double clutching. When up shifting give a tiny bit of tension on the next gear before the revs start to fall and it should drop in when the revs are right. When down shifting you have to blip the throttle to get the revs high enough for the first gear still using a tiny bit of tension against the next gear.

bigchillcar · bigchillcar's Garage

well,
talked to my wrench yesterday who confirmed that my clutch spring broke (i had found a piece of it on the floorboard) and the clutch cable was pulled, frayed and splitting which resulted in the loss of clutch feel. he's replacing the cable today and i gave him pelican's number to call for the spring. tranny fluid fine, but having him replace, adjust valves and change oil...what the hell, it's only money. wish i had the time to learn and do more of the work myself! its been three days without the car...i want my mojo back!

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Jim Sims · 03-13-2002, 08:38 AM

I'd also recommend your wrench check the transmission to body ground strap; remove, clean contact surfaces and reassemble with a good dielectric grease.

Jim

bigchillcar · bigchillcar's Garage

jim,
thanks...what is this meant to do?

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skinnerd · skinnerd's Garage

I've personally gone through a couple of clutch cables, and the first thing you should have noticed was a gradual change in your clutch free play travel as the cable gradually stretched. If you're really "in tune" with your car, this is something that normally tips you off that something is amiss. I always notice this first (the free play in the clutch) when driving someone elses car. Early_S_Man was "right on" with his tips on driving w/o a functioning cable. Mine broke at the beginning of a 1000 mile trip home to see my parents once.... arrived safe and sound using the procedure S_Man outlined with few problems. Good luck. -Doug

Jim Sims · 03-13-2002, 09:46 AM

If the transmission to body ground is poor (the flexible strap provides this ground) the large ground current to the starter finds other routes back to the battery. One of these is through the clutch cable since one of it's ends is located close to the starter on the transmission bell housing. If current travels through the clutch cable you can overheat its wires, ruin their strength and then they start to break. I would especially check the strap if your starter has been running more slowly lately. If the strap contacts are bad you could ruin your new clutch cable in short order. Your mechanic will be under the car fitting the new clutch cable end anyway so its a good time to clean and retighten the strap. Jim

Early_S_Man · 03-13-2002, 09:58 AM

Yes, the pin is ONE of the failures that can occur in the pedal cluster. The lever that the pin holds to the shaft can also crack, especially if the pin backs out on one end ... and the lever flexes on the shaft while only held by one end of the pin! Also, the short lever at the clutch cable clevis end of the shaft can crack or break.

bigchillcar · bigchillcar's Garage

jim,
thanks for the explanation. just got off the phone with wrench and he said would do and also check the throttle cable as well. clutch cable hasn't made it in yet, so still no car...he says he'll order the clutch (helper?) spring and says he can put it in later after i get the car...guess this means i'll be able to drive it without for a little while.

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Jim Sims · 03-13-2002, 12:00 PM

The throttle uses a linkage with rods, bushings, bellcranks, springs, etc.; there is no cable. There is a speedometer cable though, so he may be checking that? Jim

bigchillcar · bigchillcar's Garage

jim,

jeez...i hope so...i know he said 'throttle cable'. maybe he was just fatigued!

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