Having Problems with my 4-spd; was hoping someone would have an idea what my problem may be? First, the car is a 69 Mach, 428 SCJ, Everything is new. The only thing not rebuilt was the tranny. The car was recently completed and am just trying to do initial break-in drives, etc.....The shifter is very hard to get into gear when running. When car is off, i can shift lever thru the gears easily. When running, i have to shift into reverse, and in and out of 3rd and 4th, then try shoving it into 1st...sometimes goes, sometimes not??? Clutch new, resurfaced flywheel, all other 4-spd related parts new, factory shifter been rebuilt. Any suggestions? Hoping its somekind of adjustment????
It sounds like your clutch might need an adjustment. Is the clutch pedal at the proper height?
You also indicated the transmission was never rebuilt. Worse case scenario, it can be the synchronizers in the transmission. Often, people will visibly check the teeth on the internal gears and assume everything looks good but you can't visually see the condition of the synchros without pulling the tranny apart. More often than not worn synchros will cause the shifter to pop out of gear, I would first make sure clutch is properly adjusted before doing anything else.
The 69's were know for shifter problems BUT since yours seems to shift fine without the motor running and then has problems once the motor is running I believe that Mike is on the right trail.
Double check you clutch adjustment.
Yes by all means check the clutch adjustment. As the reason you can't get it into gear while the engine is running is the clutch is dragging on the flywheel or the pressure plate causing the input shaft to turn. That is why you have a synchronizer on first gear. It will compensate for the normal friction and allow you to engage first gear, with the engine running. If you have to much drag as you are describing, it can be difficult if not impossible to get into gear. Something is causing the input shaft to turn. Clutch dragging, can be poor adjustment, bent disc, separated lining. broken disc, I've even seen the input shaft worn to the point the disc won't slide freely causing drag. Sorry to be the bearer of bad news.
Here's hoping a good adjustment cures your problem.
JTS 71 Mach1
If all else fails here's something that you can try but you'll need a helper:
With the car not running, disconnect the battery. Jack the car up and remove the driveshaft. Have your helper step on the clutch and put the tranny in gear. Have them hold the clutch pedal down. Now use either the driveshaft (that you just removed) or a spare driveshaft yoke to turn the output shaft of the transmission. It should be relatively easy to turn. Try it in all 4 gears. If the clutch is dragging or the pilot bushing is tight, you'll feel it in all 4 gears. If it's only tight in one gear then you have a tranny problem. Keep in mind it will be slightly harder to turn in 1st versus 4th because of the gear ratios but it should still be fairly easy to turn.
Hopefully it's just a mis-adjusted clutch. Easy fix. I've seen pilot bushings cause problems too however. The pilot bushing presses into the crankshaft. The hole in the pilot bushing that rides against the input shaft of the tranny gets slightly smaller when it's installed. If it wasn't made properly to accommodate this (i.e. Chinese replacement) you'll have problems. You can ball-hone it to fix this but you'll have to pull the tranny. Finally there could be a misalignment problem. The bell-housing aligns with 2 dowel pins pressed into the block. If one or both were missing when the bell-housing was installed, you'll have big problems.
(08-02-2014, 04:21 AM)jrpav Wrote: [ -> ]If all else fails here's something that you can try but you'll need a helper:
With the car not running, disconnect the battery. Jack the car up and remove the driveshaft. Have your helper step on the clutch and put the tranny in gear. Have them hold the clutch pedal down. Now use either the driveshaft (that you just removed) or a spare driveshaft yoke to turn the output shaft of the transmission. It should be relatively easy to turn. Try it in all 4 gears. If the clutch is dragging or the pilot bushing is tight, you'll feel it in all 4 gears. If it's only tight in one gear then you have a tranny problem. Keep in mind it will be slightly harder to turn in 1st versus 4th because of the gear ratios but it should still be fairly easy to turn.
Hopefully it's just a mis-adjusted clutch. Easy fix. I've seen pilot bushings cause problems too however. The pilot bushing presses into the crankshaft. The hole in the pilot bushing that rides against the input shaft of the tranny gets slightly smaller when it's installed. If it wasn't made properly to accommodate this (i.e. Chinese replacement) you'll have problems. You can ball-hone it to fix this but you'll have to pull the tranny. Finally there could be a misalignment problem. The bell-housing aligns with 2 dowel pins pressed into the block. If one or both were missing when the bell-housing was installed, you'll have big problems.
Also several good thoughts on the subject. JTS 71 Mach1
I have a 69 428 cj with the stock shifter and clutch. Had the same problem it turns out it the the input shaft bearing.I would check the clutch set up first and make sure it's working right then I would check the shifter linkage adjustments if that's all good you should take a look at the input shaft bearing play.
(08-04-2014, 07:57 AM)randybob Wrote: [ -> ]I have a 69 428 cj with the stock shifter and clutch. Had the same problem it turns out it the the input shaft bearing.I would check the clutch set up first and make sure it's working right then I would check the shifter linkage adjustments if that's all good you should take a look at the input shaft bearing play.
Excellent advice...let's all keep our fingers crossed it's only a clutch or linkage adjustment.