thetodd717 Posted September 9, 2009 Share Posted September 9, 2009 Greetings! I am relatively new in all of this and trying to learn everything I can about my truck. I noticed that the clutch pedal has no free play at all and will need adjusting. When I put the truck in gear, the truck sometimes will not move at all or will move very slowly forward. The truck is a 1968 Mack CF600 fire truck. The service manual claims the original clucth was a Dana Spicer AS-1400 series. Looking at the diagram and reading about the adjustments seems easy enough, but what I see in the manual doesnt seem to match what is in the truck. I believe the second department to own the truck replaced the clutch with a ceramic one, but I do not have any paperwork on it. Looking into the bell housing, I cant seem to identify where the adjusting mechanism is. If anyone has any ideas or tips what I should be looking for in there, I would really really appreciate it. I have only had the truck for a few weeks and I really want to get out and drive and enjoy it before I put it in storage. Thanks! Quote Link to comment https://www.bigmacktrucks.com/topic/10594-clutch-adjustment-help/ Share on other sites More sharing options...
fjh Posted September 9, 2009 Share Posted September 9, 2009 Some where on the clutch face you will find other a lock tab held in by a 3/8th bolt or a winder held in with 2- 3/8 bolts depends on how old the clutch is! You may have to have somone wind the engine over a bit to actualy see the bolt/s in question. Quote Link to comment https://www.bigmacktrucks.com/topic/10594-clutch-adjustment-help/#findComment-40162 Share on other sites More sharing options...
thetodd717 Posted September 14, 2009 Author Share Posted September 14, 2009 Some where on the clutch face you will find other a lock tab held in by a 3/8th bolt or a winder held in with 2- 3/8 bolts depends on how old the clutch is! You may have to have somone wind the engine over a bit to actualy see the bolt/s in question.Thanks for the help! Hopefully I can find some time to get out there and play with it now! Quote Link to comment https://www.bigmacktrucks.com/topic/10594-clutch-adjustment-help/#findComment-40338 Share on other sites More sharing options...
HK Trucking Posted September 14, 2009 Share Posted September 14, 2009 Thanks for the help! Hopefully I can find some time to get out there and play with it now!Don't forget to jam a board against the clutch pedal to keep it depressed while you're trying to adjust. The adjusting ring won't turn unless the clutch is released.I've always used a breaker bar with the proper size socket (1-7/16)applied to the harmonic balancer retaining bolt to turn the crankshaft enough to get the adjuster at the bottom. Just make sure the engine stop control is pulled out before rotating the crankshaft.To give more free pedal, turn the adjuster clockwise. After turning the adjuster a few notches, unblock the clutch pedal and check the free travel. Usually I set it at 1-1/2 to 2 inches.When it's properly adjusted, put the lockstrap back in the adjuster and tighten the retaining bolt (old type) or make sure the quick adjust has popped out into the locked position (newer quick adjust type. Quote "If You Can't Shift It Smoothly, You Shouldn't Be Driving It" Link to comment https://www.bigmacktrucks.com/topic/10594-clutch-adjustment-help/#findComment-40340 Share on other sites More sharing options...
fjh Posted September 14, 2009 Share Posted September 14, 2009 Don't forget to jam a board against the clutch pedal to keep it depressed while you're trying to adjust. The adjusting ring won't turn unless the clutch is released.I've always used a breaker bar with the proper size socket (1-7/16)applied to the harmonic balancer retaining bolt to turn the crankshaft enough to get the adjuster at the bottom. Just make sure the engine stop control is pulled out before rotating the crankshaft.To give more free pedal, turn the adjuster clockwise. After turning the adjuster a few notches, unblock the clutch pedal and check the free travel. Usually I set it at 1-1/2 to 2 inches.When it's properly adjusted, put the lockstrap back in the adjuster and tighten the retaining bolt (old type) or make sure the quick adjust has popped out into the locked position (newer quick adjust type.Make sure that the clutch brake is working right before you start adjusting or youll endup doing it twice. Quote Link to comment https://www.bigmacktrucks.com/topic/10594-clutch-adjustment-help/#findComment-40365 Share on other sites More sharing options...
HK Trucking Posted September 15, 2009 Share Posted September 15, 2009 Make sure that the clutch brake is working right before you start adjusting or youll endup doing it twice.Absolutely!Since he didn't mention a problem with the clutch brake, I didn't go into that. Quote "If You Can't Shift It Smoothly, You Shouldn't Be Driving It" Link to comment https://www.bigmacktrucks.com/topic/10594-clutch-adjustment-help/#findComment-40405 Share on other sites More sharing options...
thetodd717 Posted September 18, 2009 Author Share Posted September 18, 2009 Thanks all for your helpful insight and advice! I finally found some time and a good buddy to come over and we got the truck up and running again! Everything seems to be holding, so hopefully we are in the clear. Thanks again!! -Todd- Quote Link to comment https://www.bigmacktrucks.com/topic/10594-clutch-adjustment-help/#findComment-40555 Share on other sites More sharing options...
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