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 Posted: 10-03-2007 02:06 pm
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frank12873
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Am hoping to get some input from the board on a clutch or transmission issue.

Memorial Day weekend, coming home from a 100-mile jaunt in my JH, I came upon a traffic back-up going down a hill. I shifted the transmission (a 4-speed) into neutral (noting an unusual but subdued "clunk" as I did), and then, while coasting down the hill with the clutch in, could not get the transmission to go back into any gear. Clutch pedal felt normal. I couldnt even "bump-shift" into a gear by goosing the throttle and moving the shift lever into gear with the clutch out.

I ended up stopping the car at the side of the road. The shift lever and clutch pedal felt normal and, with the engine off, went into each gear.  After the traffic dissipated, I started the car in 1st gear and drove it the 5 miles home in 1st gear. She got me home!

I was hoping the problem was my clutch cable had stretched so much that pushing the pedal in wouldn't disengage the clutch. No such luck; I finally adjusted the cable this weekend (it needed it), and still can't go into any gear with the engine running.

Should I be able to bump shift this transmission? Is there something different about it that makes it normal that it won't bump shift? I've never had a manual transmission that wouldn't bump shift.

Could all the transmission syncros have gone out at once? If I was able to drive the car home in 1st gear (with no unusual transmission noises), isn't it likely the transmission is OK?

I realize my next step is to drop the transmission and check the clutch. Someone told me it sounded as if one or more clutch disc springs broke, and have jammed and locked up the clutch. Possible? Needing only a new clutch would be the best scenerio at this point I think.

Any comments or guidance would be greatly appreciated. 

 

 

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 Posted: 10-03-2007 04:36 pm
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Greg Fletcher
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You should be able to shift without the clutch if the transmission is otherwise ok. Your comments make me think the problem lies in the transmission rather than the engagement of the clutch. That clunk you heard does not bode well. Was this 4 speed rebuilt? If the gear clusters on the layshafts are not staked correctly and the nuts not torqued (always use Loctite on these) properly at reassembly (I've always found this challenging myself), they have a tendency to come apart. When that happens, bad things follow.

The syncos are normally not a problem on the 4 speed. Typically, the teeth on the gears simply wear down before that and it starts popping out of various gears on deceleration.

I have seen high mileage units fail where they will not go into several gears, but those always show significant problems long before that happens.

I know this sounds lame, but it's probably worth checking the shift lever to see if it's actually engaged correctly. I once had the bolts loosen up and the lever started slipping up and out of position.

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 Posted: 10-03-2007 05:50 pm
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Judson Manning
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The clutch fork may have 'clunked' off its pivot inside the bellhousing.  The t/o bearing spring and clutch cable may be holding it in place, but without the fulcrum you arent' getting adequate engagement. 

Easily (temporarily) fixed w/o removing the transmission, but a permanent fix requires bending the little ears to hold more tension.

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 Posted: 10-03-2007 10:48 pm
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frank12873
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Thanks Greg and Judson for the replies.

Greg, the transmission has not been rebuilt during my 4+ years of ownership. The car only had 40K on the odo when I bought it, so I doubt the transmission has been rebuilt. Also, I've never had a problem with the transmission jumping out of any gear. I will check the shift lever as you suggest.

Judson, I will get a mechanics mirror and have a look inside the bellhousing at the clutch fork. Someone posted a good picture in another clutch-related thread recently of how it's supposed to be positioned.

Thanks again, guys!

 

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 Posted: 10-28-2007 03:09 pm
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Steve Jarvis
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Let me know what you find when you drop your transmission. I've had a similar problem with stopping at a light and not being able to get back into gear. Seems to resolve itself if I stop and start the motor. I thought the clutch plate was not releasing and stuck on the flywheel, for some reason, which continued to spin the transmission.

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 Posted: 10-29-2007 12:27 pm
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jcdean
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I agree with Steve.  This was my exact symptom when my clutch stuck to the flywheel.  It was solved by being towed a short distance with the tran in 3rd, engine off, for a short distance.  Another pop was heard and all was well.

Joey

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 Posted: 12-26-2007 12:26 am
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frank12873
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OK, fellas, my problem appears to have been (note the past tense) another iteration of "The Mysterious Sticking Clutch".

After purchasing a couple more jackstands this holiday weekend, along with a full-size floor jack so I could raise the car high enough to get underneath it semi- comfortably, I used a mirror and "feel" to determine that the clutch fork was indeed where it was supposed to be on its pivot.

I had pretty much decided to call in the local British Classic Car mechanic who made 12873 roadworthy over 4 years ago, thus depleting the "Judson Fund" that I have managed to accumulate over the years towards a performance engine rebuild.

I figured I'd at least run the engine before I headed into the house, since it hadn't been run in a while. Started it, got in the car, tried first gear, no go, second, no go, first again, CLUNK, it went in! Unbelievable! I shifted the transmission into all the gears for about five minutes, then took it off the jackstands and drove the car for the first time since early September! Shifted as if nothing had ever happened. The oddest thing. 

Steve and Joey, I'm sorry that the "resolution" of my problem doesn't help you diagnose or resolve your similar issues. I also realize that my problem can (will?) recur, but I'm thankful to have a drivable car again, at least for the time being.

Happy Holidays to All!

 

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